University of Ghana http://ugspace.ug.edu.gh UNIVERSITY OF GHANA COLLEGE OF BASIC AND APPLIED SCIENCES DEVELOPMENT OF IMPROVED SOLAR FISH DRYING PROCESS AND QUALITY EVALUATION OF DRIED ANCHOVIES (Engraulis encrasicolus) BY EMMANUEL ADOKWEI SAKA [10397049] A THESIS SUBMITTED TO THE SCHOOL OF GRADUATE STUDIES IN PARTIAL FULFILLMENT OF THE REQUIREMENT FOR THE AWARD OF MPHIL FOOD SCIENCE DEGREE JULY, 2015 University of Ghana http://ugspace.ug.edu.gh DECLARATION This is to certify that this thesis is the result of research undertaken by Emmanuel Adokwei Saka towards the award of the Master of Philosophy in Food Science in the Department of Nutrition and Food Science, University of Ghana. …………………………………… ……………………………….. Emmanuel Adowkei Saka Date (Student) ………………………………………… …………………………….. Prof. Esther Sakyi-Dawson Date (Principal supervisor) ………………………………………… ……………………………….. Prof. F. K. Saalia Date (Co-Supervisor) i University of Ghana http://ugspace.ug.edu.gh ABSTRACT Open sun drying (OSD) has been a fish processing method for ages. In Ghana women form a large number of processors. Post-harvest losses still prevail in the trade due to poor fish handling, processing and storage which results in poor quality of dried fish. Solar drying has been introduced to improve on quality of OSD dried fish. A survey of open sun drying practices (OSD) at Kasoa (Central Region) and Tema (Greater Accra Region) showed poor hygiene practices and low value of products. The current study assessed prevailing OSD fish drying methods in Accra and Central region and tested the effect of a new method using a solar dryer on the final quality of anchovies. Fresh anchovies were dried by a new drying method using for a Hohenheim solar tunnel dryer (STD) in Greater Accra, and the quality of dried anchovies using STD was compared with OSD dried anchovies at two different locations at Kasoa (DAK-A and DAK-B). The study showed a shorter drying time for the STD method (7-8 hours; 9:0am and 3:30pm) on a sunny rainless and cloudless day, compared with OSD (1-3 days). The moisture values were 14.16 ± 0.03%, 13.22 ± 0.06% and 11.84 ± 0.08 % for DAK-A, DAK-B and STD. Samples DAK-A, DAK-B and STD had protein values of 62.17 ± 0.16%, 70.01 ± 0.28 % and 74.83 ± 0.45% respectively. Fat content was 4.25 ± 0.15%, 4.12 ± 0.01% and 4.00± 0.10% for DAK-A, DAK-B and STD respectively. Total ash values for DAK-A, DAK-B and STD were 11.11 ± .08%, 12.02 ± 0.06% and 9.57 ± 0.04 %. The FFA values for DAK-A, DAK-B and STD were 61.47%, 57.03% and 39.19% respectively, all above standard limit of (0.5% -1.5% oleic acid). Peroxide values were 55.47 meq 02/kg, 3.25meq 02/kg, and 4.29 meq 02/kg for DAK-A, DAK-B and STD respectively Histamine levels which were within acceptable limits were ii University of Ghana http://ugspace.ug.edu.gh 22.2 ppm,( DAK-A,) 13.02 ppm(DAK-B) and 18.55 ppm (STD). The (aW) varied from DAK-A (0.64%,), to 0.51% (STD). STD was darker than DAK-A and DAK-B. In terms of sensory preference, Sample DAK-A was the most preferred followed by DAK-B and STD in terms of the overall acceptability of the samples. In conclusion, an improved processing method for a solar tunnel dryer can improve most of the quality indices, however due to higher temperatures of STD one cannot achieve similar quality as exists in the OSD method. . iii University of Ghana http://ugspace.ug.edu.gh ACKNOWLEDGMENT I will first extol the name of the Lord Jesus Christ, and the God of our world, my Redeemer and Risen Lord and Master. The I Am that I Am, who saved me, gave me wisdom, strength and favour to finish off this project. To God my Father be all the glory. I am also indebted to the CSIR-Food Research Institute/ European Union project led by Dr. Lawrence Abbey (Principal Investigator and external supervisor) through whose project I had the chance to take up the M. Phil. course. Sincere thanks also to Prof. Esther Sakyi-Dawson (Principal Supervisor), and Prof. F. K. Saalia (Co- supervisor) for their wisdom and patience in helping me. My gratitude extends also to Mr. David Kumador, University of Ghana for his help with the survey. Others are Dr. Frederick Teye (Head Engineering Unit of CSIR- Food Research Institute), Dr. Charles Tortoe (Head of Food Processing and Engineering; CSIR-Food Research Institute), Mrs. Charlotte Oduro-Yeboah (Root and Tuber Development Unit; CSIR-Food Research Institute), Mr. R. Kavi (Liberian; CSIR-Food Research Institute). I also recognise the technical help of my friend Mr. Isaac Nyarko (of blessed memory), auntie Joyce of the FRI Test kitchen, Mr. Solomon Dowuona, Ms. Edna Mireku, Ms. Jemima Ofori, Mr. Desmond Mensah, Mr. Luke Anak, Mr. Victor Lyncher (National service personnel) all of the Food Processing and Engineering Division of CSIR- Food Research Institute who bent their back to make this study a success. I am very grateful Joel, Ms. Yvonne, Bernard of Kasoa Nyanyano Central Region, John and Joseph. I am also grateful to the fish processors at Tema Canoe beach and the Kasoa Nyanyano. My thanks also goes to my dear siblings; Abraham, Gina, Vera. Lastly I thank all my friends who stood by me in prayer. iv University of Ghana http://ugspace.ug.edu.gh DEDICATION I dedicate this thesis to the Lord Jesus Christ my Love, Redeemer, Father and King. v University of Ghana http://ugspace.ug.edu.gh TABLE OF CONTENTS DECLARATION ................................................................................................................. i ABSTRACT ........................................................................................................................ ii ACKNOWLEDGMENT.................................................................................................... iv DEDICATION .....................................................................................................................v 1.0 INTRODUCTION .....................................................................................................1 1.1 Background .......................................................................................................... 1 1.2 Rationale of Study ................................................................................................ 5 1.3 Objective of the study .......................................................................................... 6 1.3.1 Specific Objectives:.............................................................................................. 6 2.0 LITERATURE REVIEW ..........................................................................................7 2.1 Anchovies ............................................................................................................. 7 2.1.1 Anchovies production in Ghana ................................................................ 8 2.2 Fish Quality and Preservation ............................................................................ 10 2.3 Mechanism of fish spoilage................................................................................ 11 2.4 Methods of preservation of fish ........................................................................ 14 2.4.1 Fish drying and importance of solar drying ................................................. 20 2.7 Types and uses of solar dryers ........................................................................... 21 2.7.1 Dryer design and parameters ....................................................................... 25 2.8 Quality of solar dried fish................................................................................... 28 3.0 MATERIALS AND METHODS .............................................................................32 3.1 Assessment of current fish handling practices at the artisanal levels in Ghana . 32 3.1.2 Sample Size .................................................................................................. 32 3.1.3 Study Locations: .......................................................................................... 32 vi University of Ghana http://ugspace.ug.edu.gh 3.1.4 Data Collection ............................................................................................ 33 3.2 Design of the solar tunnel dryer ................................................................... 33 3.2.1 Operation of the Solar Tunnel Dryer. .......................................................... 34 3.3 Development of process for producing high quality solar dried fish (anchovies) using a solar tunnel dryer ................................................................................... 34 3.4 Materials ............................................................................................................. 35 3.4.1 Reference Samples ....................................................................................... 35 3.4.2 Experimental sample (STD) ........................................................................ 38 3.5 Chemical analysis on solar and open sun dried anchovies. ................................ 39 3.5.1 Proximate Analysis on fish .......................................................................... 39 Moisture content .................................................................................................. 39 Ash content ........................................................................................................... 39 Fat content ............................................................................................................. 40 Percentage crude protein ....................................................................................... 40 3.5.1 Fish spoilage analysis ......................................................................................... 40 3.5.2.1 Free Fatty Acid Analysis (FFA) .............................................................. 40 3.5.2.2 Peroxide Value (PV) ............................................................................... 41 3.5.2.3 Histamine Analysis ................................................................................. 41 3.6 Physical analysis .......................................................................................... 42 3.6.1 Colour Determination .............................................................................. 42 3.6.2 Water Activity (AW). ............................................................................... 43 3.7 Sensory evaluation of dried anchovies ........................................................ 43 3.7.1 Samples and Sample preparation ............................................................ 43 3.7.2 Method; ................................................................................................... 43 3.7.3 Analysis of results ........................................................................................ 44 vii University of Ghana http://ugspace.ug.edu.gh 3.1 RESULTS AND DISCUSSIONS ............................................................................48 4.1 Survey on open air-drying of fish and quality of dried anchovies ..................... 48 4.1.1 Socio-Demographics .................................................................................... 49 4.1.3 Knowledge about Unit Operations for Open Sun Drying Process .............. 57 4.1.4 Knowledge about Harmful Substances in Fish Processing. ......................... 58 4.1.5 Knowledge about Sanitation ........................................................................ 59 4.1.6 Assessment of Knowledge about fish storage ............................................. 60 4.2 Determination of solar tunnel dryer conditions over a three day period ..... 63 4.3 Development of the process for the production of solar dried anchovies using a solar tunnel dryer ............................................................................................... 65 4.3.1 Process development .................................................................................... 65 4.4 Quality of traditional open sun and solar dried anchovies ................................. 67 4.4.1 Proximate analysis ....................................................................................... 67 4.4.1.1 Moisture: ................................................................................................. 68 4.4.1.2 Protein: .................................................................................................... 69 4.4.1.3 Fat: ........................................................................................................... 69 4.4.1.4 Ash: ......................................................................................................... 70 4.4.2 Fish spoilage properties ............................................................................... 70 4.4.2.1 Free fatty acid content: ............................................................................ 71 4.4.2.2 Peroxide Value (PV): .............................................................................. 72 4.4.2.3 Histamine Value ...................................................................................... 73 4.4.3 Physical properties ....................................................................................... 74 4.4.3.1 Water Activity ......................................................................................... 74 4.4.3.2 Colour ...................................................................................................... 75 4.5 Sensory quality of dried anchovies. ............................................................. 77 viii University of Ghana http://ugspace.ug.edu.gh 4.5.1 Results for consumer acceptability of traditional sun dried and solar tunnel dried anchovies in tomato sauce .................................................................. 77 4.5.1.1 Appearance .............................................................................................. 79 4.5.1.2 Colour: ..................................................................................................... 79 4.5.1.3 Texture (Springiness): ............................................................................. 79 4.5.1.4 Texture (Hardness): ................................................................................. 79 4.5.1.5 Taste: ....................................................................................................... 80 4.5.1.6 Mouthfeel: ............................................................................................... 80 4.5.1.7 Smell: ...................................................................................................... 80 4.5.1.8 Aftertaste: ................................................................................................ 81 4.5.1.9 Overall Acceptability: ............................................................................. 81 4.5.2 Friedman test ................................................................................................ 82 5.0 CONCLUSIONS AND RECOMMENDATIONS ..................................................83 5.1 Conclusions ........................................................................................................ 83 5.2 Recommendations .............................................................................................. 85 REFERENCES ..................................................................................................................86 APPENDICES ...................................................................................................................96 A. Preparation of solar dried anchovies in tomato sauce ........................................ 96 B. Sample survey questionnaire .............................................................................. 98 C. 1. Hoheiheim solar tunnel dryer stationed at CSIR-Food Research Institute (FRI) Shiashi Accra Ghana. ............................................................................. 107 D. Solar tunnel dried anchovies (7hrs) .................................................................. 109 E. Solar tunnel dried anchovies in tomato sauce .................................................. 109 F. Sample questionnaire ....................................................................................... 110 G. ANOVA results on dried anchovies ................................................................. 113 ix University of Ghana http://ugspace.ug.edu.gh LIST OF FIGURES Figure 1. The Ghanaian anchovies……..…………………………………………………..8 Figure 2. The four phases of fish spoilage……………………………………………….13 Figure 3. Water activity versus moisture content plot for different types of food……….16 Figure 4. A sketch of the Hoheiheim tunnel type dryer ………………………………....27 Figure 5. Flow chart of traditional open sun drying of anchovies in Ghana……..………..36 Figure 6. Flow chart of for drying of anchovies using a solar tunnel dryer……………….37 Figure 7. Flow chat for preparation of dried anchovies for cooking…………………......45 Figure 8. Flow chat for preparation of mixed vegetables for tomato sauce…………......46 Figure 9. Flow chat for preparation of OSD/STD anchovies in tomato sauce...…………47 Figure 10. Drying fish on polythene at Kasoa...……………………………………...….56 Figure 11. Drying fish on bare ground in Tema...………………………………………...56 Figure 12. Packaged dried anchovies at Kasoa………………………………………......61 Figure 13. Final 12 hours drying of anchovies at Kasoa...………………………………...61 Figure 14. Dried anchovies stored in wooden store houses in Kasoa……………...……...62 Figure 15. Fish stored outside in Tema.……………......…………………………….......62 Figure 16. Dried fish on pallets in Tema………………………………...………….........62 Figure 17. A three days solar insolation reading for a solar tunnel dryer……………..…63 x University of Ghana http://ugspace.ug.edu.gh Figure 18. Temperature sensor readings for a three days trial of the unloaded solar tunnel dryer compared with ambient temperature (oC) ……….……………………...…………64 Figure 19. Sample of DAK-A………………………………..…………………...………67 Figure 20. Sample of DAK-B……………………………………………………...……67 Figure 21. FFA content of three dried anchovies samples (DAK-A, DAK-B and STD)……………………………………………………………………………………71 Figure 22. PV content of three dried anchovies samples (DAK-A, DAK-B and STD).…..72 Figure 23. Histamine values for three dried anchovies samples (DAK-A, DAK-B and STD)……………………………………………………………………………………...73 Figure 24. Water activity (aW) values for (DAK-A, DAK-B and STD)…………...……74 Figure 25. L* (whiteness) measurement for DAK-A, DAK-B, FA-J and STD…….….....76 xi University of Ghana http://ugspace.ug.edu.gh LIST OF TABLES Table 1. Seasonal changes is key quality attributes in anchovies landed in Ghana..............9 Table 2. Hazard audit for dried fish production…..………………………………………12 Table 3. Minimum values of water activity for microbial growth…………………..…....17 Table 4. Advantages and disadvantages of different types of solar dryers…….................23 Table 5. Sample prices of solar dryers…………………………………………………..24 Table 6. Fish drying processes and effect on water activity………...….………………....30 Table 7. Summary of demographic information of respondents interviewed…….……...50 Table 8. Summary of years of experience of processors at landing site………….……...51 Table 9. Summary of fish most appropriate fish preservation method.……….………..…51 Table 10. Summary of why processors use open sun drying methods….………………...52 Table 11. Summary about the cheapest method of fish processing..………………..……53 Table 12. Summary on the cheapest source of fuel used by processors ……………..…..53 Table 13. Summary of reasons why processors dry on bare ground ……...……..….………………………………………………………………………….55 Table 14. Summary of how processors acquired skills in open sun dry fish …………….57 Table 15. Information about use of harmful methods during storage of dried anchovies…. …………………………..………………………………………………………………58 Table 16. Summary of processor’s knowledge about best storage practices……………..60 Table 17. Proximate values for open sun and solar dried anchovies…………………....68 Table 18. . Mean Scores for consumer acceptability of traditional sun dried and solar tunnel dried anchovies in tomato sauce……………………………………………….….….......78 Table 19. Summary of rank sums on anchovies in tomato sauce sensory evaluation test....82 xii University of Ghana http://ugspace.ug.edu.gh LIST OF ABBREVIATONS PG; liquid petroleum gas AIT; Asian Institute of Technology BHA; butylated hydroxyl anisol CC; convection cabinet solar dryer CSIR; Council for Scientific and Industrial Research Ghana DAK; Dried Anchovies from Kasoa DC; direct current DM; multi-rack dome solar dryer FA-J; Fresh anchovies landed at Jamestown Accra Ghana FAO; Food and Agriculture Organisation of the United Nations FFA; Free fatty acid GTZ; German Technical Co-operation HQSTDA; High Quality Solar Tunnel Dried anchovies MoFA; Ministry of Food and Agriculture Ghana OR; open rack solar dryer OSD; open sun drying PUFA; poly-unsaturated fatty acid xiii University of Ghana http://ugspace.ug.edu.gh PV; peroxide value SAF; Saturated fat STD; Solar tunnel dried anchovies TBHQ; Tertiary Butyl hydroquinone xiv University of Ghana http://ugspace.ug.edu.gh 1.0 INTRODUCTION 1.1 Background Fish and its products are now a key food commodity for man’s future survival, hence the spate of extensive research in that sector (Beveridge et al., 2013). It is one of the world’s most important sources of animal protein preferred by most people (Immaculate et al., 2013). Due to the added non fish based nutrient it has which are all vital for human health and growth (Centre of Excellence Science Seafood Health, 2011). Aside protein fish has nutrients such as omega-3 long chain polyunsaturated fatty acids (n-3 LC-PUFAs), iodine, calcium, vitamin D, zinc and iron (McManus and Newton, 2011). Studies have shown that eating marine n-3 LC-PUFAs, fish, seafood or fish oils helps develop ones cognitive abilities and reduces the risk of chronic conditions such as coronary heart disease, as well as some cancers, diabetes, rheumatoid arthritis, dementia and Alzheimer’s disease (McManus and Newton, 2011). The fishing business is a vital socio-economic factor in the lives of people, providing employment, food for humans, feed for animals, industrial material and products for export (Delgado et al., 2003). In 2010, an estimated 128 million tonnes out of 148 million tonnes of fish (US$ 17.5 billion) was consumed as food fish globally (FAO, 2012). It is believed that 4.3 billion people depend on fish; which represents 15 percent of their animal protein intake (FAO, 2012). It is estimated that about 800 million of the world’s population are chronically malnourished, this Figure has been predicted to increase by two billion, reaching a total of 9.6 billion with increase in the human population (FAO, 2014). Asia and Sub-Saharan Africa, which are heavily dependent on fish are among the continents that are food insecure 1 University of Ghana http://ugspace.ug.edu.gh (Beveridge et al., 2013). Increase in fish consumption in developing countries has been influenced largely by population and income increases, whereas in the developed world, dietary preference, health, convenience, income, age and taste have been factors that increased demand for fish (Taylor et al., 2007) In 2014, FAO statistics revealed an increase in global fish production, with annual average fish supply rates reaching 3.2%, above population growth rate of 1.6% (FAO, 2014). A different observation was made by the FAO in 2015, in which case Africa saw a reduction in pelagic fish supply, from 4,013,775.31 tonnes to 3,561,781.11, while demersals fish species increased from 1,462,175.19 to 2,220,555.18 tonnes (FAO, 2015). It was also reported pelagic fish supply decreased from 2,713,613.28 tonnes to 2,179,616.26 tonnes. Statistics for Ghana within the West African sub-region showed a decrease in supply of all fish species in the same year under review, with pelagic fishes supply increasing from 507,634.00 to 508,425.00 tonnes, and demersals reducing from 63,819.79 to 38,049.50 tonnes. The observed reduction in demersal fish is a call for sustainable use of the wild fish resource and adoption of other methods such as aquaculture as a stop gap measure and ensure food security within that sector. Aquaculture has come on stream to ease demand pressure on captured fish (Beveridge et al., 2013), with China being credited as the leading country to adopt the technology (FAO, 2014). The average expansion rate of aquaculture globally according to FAO (2014) was 6.2 % for 2000-2012 a little lower than 9.5% 1990- 2000. Africa which had the fasted growth rate within the period recorded 11.7%, followed by the Latin America and Caribbean, both 10%. Aquaculture growth rate for China slowed within the year under review to average of 5.5%, in 2000-2012 (12.7 %, 1990-2000). Intensification of aquaculture will therefore increase availability of fish to the world, with Africa having 2 University of Ghana http://ugspace.ug.edu.gh greater gain. Ghana adopted aquaculture because of the many dams, dug out wells and rivers nationwide, and the success stories other African countries such as Kenya, South Africa, Cote d’Ivoire and Burkina Faso (Bank of Ghana, 2008). Ministry of fisheries (2008) recorded a total production 3, 257 tonnes, in cultured fishes and culture-based fisheries out of which small scale producers recorded 1.5 tonnes/ha/yr. The major demersal fishes in the nations waters have for some time now being; Lujanidae (snappers), serraniadae (groupers) and polynemidae (threadfins), and some commercially important pelagic species such as round sardinella, flat sardinella, skipjack, yellow fin, bumper, chub mackerel and anchovies (Band of Ghana, 2008) Ghana’s fish business which is largely artisanal and almost 100% dominated by women processors and marketers contribute 4.5 % of Ghana’s GDP (i.e. US$ 186 million) from the export of fish and fish products (Ministry of Fisheries Ghana, 2008). Over 80 percent of fish landings in Ghana are from the Atlantic Ocean, the rest is from freshwater sources e.g. the rivers and lakes (FAO, 1992). Fish processing and preservation is a function of location and major source of energy. In Ghana fish based on the specie is either smoked, fried or open sun dried for quality improvement and preservation. The small pelagic anchovies (Engraulis encrasicolus) is among fishes locally open sun or smoke dried. Post-harvest handling and processing of fish remains a challenge in Ghana, because Ghana’s fisheries is largely artisanal. Practices such as poor handling and inadequate 3 University of Ghana http://ugspace.ug.edu.gh infrastructure including weak cold chains are among the identified causes of losses in the fish sector (Ministry of Fisheries, 2008: Kuwonu et al., 2011). Davies and Davies (2009) attributed an estimated losses of about 10% (w/w) of the world fish caught to poor handling, processing, storage and distribution. Fish contains up to 80% water (Bala and Mondol, 2001), which makes it an ideal food material for spoilage Reza et al., (2006). The main agents of the spoilage are bacteria and autolytic processes which are initiated after the death of the fish, or during processing and sometimes storage, Anihouvi et al., (2012). Insects such as blowflies and beetle have been identified as vectors of bacteria in fish, as well as agent of physical damage to fish. To meet the UN Millennium Development Goals to eradicate hunger and poverty, it is essential to reduce post-harvest losses, including losses in the fisheries sector (Abbey, 2015). In addressing fish post-harvest losses several preservation methods have been tried with varying results. These include modified atmosphere preservation (Hovd et al., 2007), application of radiation base pre-treatment of fish for storage (Mbark et al., 2008), hot air- microwave heating (Duan et al., 2011), fermentation (Gram et al., 2002; Koffi-Nevry and Koussémon, 2012), salting, low temperature drying (Ando et al., 1999), high temperature drying; such as smoking (Chukwu, 2009; Aba and Ifannyi, 2013; Gordon and Owusu-Adjei 2011), open air drying and solar drying (Jain and Pathare, 2007; Kwenin et al., 2013). Due to the negative effect of cold storage on key quality parameters such as texture and some biochemical, anchovies has for some time now been traditionally open sun or smoke dried (Abbey, 1998). And since these processes are normally carried out by artisans who 4 University of Ghana http://ugspace.ug.edu.gh lack the skills for best practice the end products of their operations is are usually of low standards and this affects the value. The quality of a dried fish, example its flavor and texture cannot be over-emphasized (Zulema et al., 2002). 1.2 Rationale of Study Open air drying is an inexpensive and environmentally friendly method of fish processing. The main challenge with the method however is loss as a result of poor quality finished product since the process is largely carried out under unhygienic conditions. Solar drying is an improvement on the open sun drying method which yields better quality dried fish. The following research questions were formulated to generate ideas to improve the open air drying process at the artisanal level to produce high quality dried anchovies: i. Who are the players of the open sun dried anchovies and what are the perceptions, cultures, handling and quality challenges? ii. How have intervention attempts helped to add on to the standard of operations? iii. What drying regime can a solar tunnel dryer provide for the drying of fish? iv. What effect would an improved drying process developed for a solar tunnel dryer have on the production of High Quality Solar Tunnel Dried Anchovies (HQSTDA)? 5 University of Ghana http://ugspace.ug.edu.gh 1.3 Objective of the study The main objective of this study is to test the effect of an improved fish drying process using a solar tunnel dryer on the quality of dried fish, i.e. anchovies (Engraulis encrasicolus). 1.3.1 Specific Objectives: i. To find out the current status of open air fish drying operations in Ghana and the effects on quality of fish produced. ii. To investigate the drying parameters within a solar tunnel dryer (STD) iii. To develop a drying process for obtaining high quality solar dried fish (anchovies) when using a solar tunnel dryer. iv. To test the effect of a new method of drying anchovies using a solar tunnel dryer of the quality. 6 University of Ghana http://ugspace.ug.edu.gh 2.0 LITERATURE REVIEW 2.1 Anchovies The European Anchovies (Engraulis encrasicolus) are southern, fish species, with special preference for warmer waters rather than the boreal waters (Alheit et al., 2012). The sensitivity of the fish to water temperature accounted for the near extinction of the fish in the 90’s for the North and Baltic Seas, the fish reappeared after 40 years (Alheit et al., 2012). Anchovies have a slim body, with a dark back used to evade birds of prey, they have a silver belly, which is analogous to the surface of the water when observed from above (Pons-Sánchez-Cascado et al., 2006). These small salt loving fishes, were mostly hunted inshore of the Black Sea, and can also be found in the water of the Marmara, Mediterranean and East Atlantic (Turhan et al., 2001). The anchovy fish landings represent about 20-25% of the total annual fish among all the pelagic clupeoid caught globally (Alheit et al., 2012). These fish species, which are very mobile and short lived (average 3- 7 years), have preference for short plankton-based foods, with some even feeding directly on planktons (Alheit et al., 2012). Among 25 nations, Turkey ranks first, production of anchovies (Turhan et al., 2001). In 2009 alone, anchovies accounted for 61.1% of marine fish production and 53.7% of total marine catch in Turkey (Uran and Gokoglu, 2014). Because the fish lend easily to salting, marinating, canning and as well as processing in oil etc. it is has found many applications in several industrial also (Uran and Gokoglu, 2014). In Turkey anchovies is used in local meals, as fried anchovies, anchovies in soups, pickled anchovies, anchovies rice, and anchovies in olive oil etc. (Uran and Gokoglu, 2014). In Europe anchovies occupies a niche market in the fish trade among salted and cured 7 University of Ghana http://ugspace.ug.edu.gh European fish products like the Atlantic herring (Clupea harengus), Sprats (Sprattus sprattus), sardine (Sardina pilchardus) (Czerner and Yeannes, 2013). Salted and ripened anchovies can be found on the world markets, with Argentina being the first to produce salted and ripened anchovies, they rank among the ten most important export products to international destinations such as Spain, Peru, United States, Italy and Morocco (Czerner and Yeannes, 2013). 2.1.1 Anchovies production in Ghana Ghana’s anchovies, Engraulis encrasicolus in the Engraulidae family has been ranked high among marine fish species Koranteng (1993). The fish as depicted in Figure 1., is known by other names Syn. Anchoata guineensis (local names; Amobi; Abobi; Amoni), it is genetically similar to the European species and can grow up to a maximum 15cm long (Abbey, 1998). Due to volumes of landing and the small size of Ghana’s anchovies, they are usually preserved by sun or smoke-drying (FAO, 1992). They occur in large schools, mostly on the sandy bottoms in shallow waters, and in other cases offshore in deep waters (Abbey, 1998). Figure 1. The Ghanaian anchovies. Source: Abbey (1998). 8 University of Ghana http://ugspace.ug.edu.gh Anchovies is harvested all year round, the fishes are caught with poli nets, purse seines, beach seines, and sometimes trawl nets (Abbey, 1998). In 1993 it accounted for 25% of all marine fish landings in Ghana (Koranteng, 1993). In 1987 alone Ghana recorded almost 88, 000 tonnes of anchovies landings (Koranteng, 1993). The Greater Accra, Central region and Volta regions mostly record large catches, the peak season is August, September and October (Abbey, 1998). Research has shown evidence of seasonal variation in the quality of fresh anchovies for different times in the year in Ghana, this can be seen on Table 1. Table 1. Seasonal changes in key quality attributes in anchovies landed in Ghana (1992- 1993). MONTH LENGTH WEIGHT Moisture Protein Fat Ash Enzymatic (cm) (g) (%) (N x 6.25) (%) (%) activity March 5-7 2.3 78.4 15.5 2.9 2.9 Very little April 6-7 2.3 78.7 14.8 3.2 3.1 Little May 6-8 2.6 77.9 14.9 3.2 3.1 Little June 6-9 2.7 75.8 15.9 4.3 3.0 Active July 6-9 2.7 73.9 16.4 6.5 2.9 Active August 6-10.3 3.2 70.5 17.5 8.6 2.7 Active September 6-11.2 3.9 70.9 17.9 8.3 2.6 Little October 6-10.1 2.6 71.9 17.3 7.3 2.6 Very little November 6-9 2.3 73.7 16.5 6.7 2.9 None (Abbey, 1998). 9 University of Ghana http://ugspace.ug.edu.gh 2.2 Fish Quality and Preservation Fish is a very perishable food commodity which spoils within 12-20 hours, depending on the species and method of capture (Immaculate et al., 2012). Spoilage can occur along various levels of the value chain, due to both the pre and post-harvest influences. The species, habitat, climate and level of pollution of the habitat influence the quality of the fresh fish. Poor handling, processing and packaging of fish remains a major factors affecting the quality of fish, which leads to losses (Prakash et al., 2011). It is estimated that one-fourth of global food supply and 30% of the world’s fish landed is lost through microbial contamination alone (Ghaly et al., 2010). There have been cases of fish contamination with red halophilic bacteria as a result of the use of solar salts (Prasad and Seenanyya, 2014). Histamine level in fish is another quality index for spoilage in fish. These monoamines according to önal (2007) are biogenic amines formed when products such as fish in storage or under process is going bad under the action of the bacteria with histidine decarboxylase enzymes. Typical examples are the Enterobacteriaceae and Enterococcus family, these are mostly found in the gills, gut cavity, or added accidentally through poor handling. This is why icing of fish is suggested (Abbey, 1998). Histamine levels above 40-100 mg and higher has been reported to cause severe food poisoning which can lead to ill health and death, a maximum levels of between 50-100 mg/kg has been suggested (önal, 2007). CODEX (2007) set limits of 10 mg/ kg as indicator of decomposition and 20mg/kg as indicator of poor handling. Ghana’s fish sector which is largely artisanal has also faced issues of poor quality of fish. Fresh fish is not well handled, processed or stored, resulting in poor quality fish of reduced shelf life and market value. 10 University of Ghana http://ugspace.ug.edu.gh Proper fish processing must be ensured as fishing is done to reduce huge losses estimated between 30%-40% on the market (Subarkah et al., 2013). Instances of the use of harmful chemicals preservatives for fish such as DDT have been reported by Bala and Mondol (2001). While physical, chemical and organoleptic analysis are used to assess the quality of smoked, cured or dried fish, in more recent times, large fish industries adhere to HACCP to ensure good standard fish processing (Bremner, 2002). Table 2 shows examples of the hazard audit processes for the manufacture of dried fish. 2.3 Mechanism of fish spoilage Food spoilage is the deterioration in the quality of food due to bacterial and poor storage causes over time, which make the food unpleasant or unsafe for eating, (Bateman et al., 2006). Fish spoilage hence refers to the stage where it is no longer fit for human or animal consumption, due to physical, chemical and or biological i.e. microbial or enzyme mediated factors (Bremner, 2002). Ghaly et al., (2010) identified four phases in fish spoilage as shown in Figure 2. Within the first six days, chemical changes occur, this is followed by bacterial deterioration. Bremner, (2002) also shared some hazard audit for dried fish as shown in table 2. 11 University of Ghana http://ugspace.ug.edu.gh Table 2. Hazard audit for dried fish production Hazard analysis Potential risk CCP Prevention, control and critical operation monitoring measures Fish landing Microbial growth Time-temperature Use clean ice, ice fish as soon as control (CCP2) possible, store at temperature between 1-5OC Washing Bacteria and Hygiene (CCP2) Use clean water chemical contamination Salting Microbial growth, Time-temperature Use clean water Drying Microbial growth, Time-temperature Reduce AW to 0.91 within 48hr. maggot control (CCP2) Ensure insect-free environment infestation Storage Microbial growth, Humidity, hygiene, Humidity < 65%, insect-free insect infestation temperature- environment, temperature temperature < 10OC control (Bremner, 2002). 12 University of Ghana http://ugspace.ug.edu.gh Figure 2. The four phases of fish spoilage. (Ghaly et al., 2010) Beetles and fly larvae have also been linked to physical spoilage in fish (Bremner, 2002). Studies by Owaga et al., (2009) identified the blowflies (Chrysomyra spp. and Wohlfartia spp.), the storage beetles such as De Geer (Dermestes maculatus, Dermestes ater, Dermestes frischii) and their larvae as major insects that attack fish. The extent of insect infestation of fish depends on the length of time of storage, the salt content and the climatic conditions prevailing (Owaga et al., 2009). Bremner (2002) suggested the use of enclosed dryers, salting, insecticides and good housekeeping such as disposal of offal as methods to minimize fly breeding. They also mentioned the negative effect of use of chemicals such as fuel oil, kerosene and insecticides on fish. Better handling, effective packaging and storage can be means of eliminating the use of chemical to preserve or store fish. Spoilage also occurs through oxidation of fish lipids leading to rancidity. Practices such as smoking or direct sun drying have been noted to accelerate the phenomenon of rancidity in fish. In some fish processing, 13 University of Ghana http://ugspace.ug.edu.gh the process of discolouration caused by Maillard type reduction reaction of endogenous sugars is desirable (Bremner, 2002). Fish is decolourised during processing as a result of the slow drying rate, high humidity especially during rainy days in the open sun dried fish (Owaga et al., 2009). Ghaly et al., (2010), gave a Summary of chemical, tissue and enzymatic changes in chilled or frozen fishes. Anchovies deteriorates due to active intrinsic enzymes which remain after death leading to undesirable changes in flavour, texture and other quality characteristics (Abbey, 1998). Fish texture is a very significant quality parameter for producers, processors and fish consumers (Hyldig and Nielsen, 2001). The spoilage of the local anchovies is increased due to poor handling, i.e. not gutted due to their smallness, and not stored on ice in spite of the high ambient temperature, these conditions accelerates the viscera releasing bacteria and enzymes which invade the flesh (Abbey, 1998). 2.4 Methods of preservation of fish Fish can be preserved by controlling the intrinsic and extrinsic factors responsible for spoilage. Physical methods such as regulating the water activity (aW) temperature, and chemical methods such as addition of natural or synthetic preservatives have been recorded. Studies have has also tested the use of chemicals as main preservatives or pre- treatment aids for drying of fish. Owaga et al., (2009) recorded a higher L* after washing dagaa samples with 100 ppm chlorinated water which was better than using 3% NaCl or tap water. Ghaly et al., (2010) used a combination of Ethylene diamine tetra acetic Acid (EDTA) (1 mM) –Tertiary Butyl hydroquinone (TBHQ )(0.02%), ascorbic acid and cold 14 University of Ghana http://ugspace.ug.edu.gh storage at 5oC in darkness as a good storage method for fish and fish products in addition to control of water activity, enzyme inactivation, antimicrobial and anti-oxidative techniques. The success of such a method however requires adequate knowledge about the role of the proximate composition, environmental condition, initial microbial load, type and nature of bacteria and their interaction in order to optimize the shelf-life. Water activity of foods which is the equilibrium relative humidity of the surrounding humid air of a food material (Jangam et al., 2010) is an important food safety and quality indicator that impacts the texture, flavor and smell of foods. Figure 3 shows a typical water activity curve for different types of food. Lower water activity makes a products more shelf stable as major spoilage microorganisms are inhibited. Too low water activity however can negatively impact on the texture of some dried foods. 15 University of Ghana http://ugspace.ug.edu.gh Figure 3. Water activity versus moisture content plot for different types of food (Jangam et al., 2010). Salt (NaCl) has been used over the years in curing and preservation of fish and meat, due to its ability to improve water holding capacity of proteins (Kituu et al., 2009). Dry salting and brining have been used in protecting fish from toxins of microbes such as Clostridium sp., when free water is bound by the salt making it unavailable to the bacteria especially at saturated levels of water activity 0.75 (Bremner, 2002). A study by Kituu et al., (2009), gave the maximum permissible limit of salting of fish to be 5%, a level which makes it suitable for human consumption. The effect of water activity on some major microbes is shown in Table 3. Table 3. Minimum values of water activity for microbial growth Microorganism aW Bacteria 0.91 Yeast 0.85 Moulds 0.80 Halophilic bacteria 0.75 Xerophilic bacteria 0.65 Osmophilic bacteria 0.60 (Bremner, 2002). 16 University of Ghana http://ugspace.ug.edu.gh Other methods of fish preservation are modified atmosphere preservation by Hovda et al., (2007) who showed that farmed Atlantic cod (Gadus morhu) can stay on the shelfs under Modified Air Packaging (MAP) and a temperature of 0oC for up to 11 days, if any gas combination of CO2:N2 and CO2:O2 is used. Mbarki et al., (2008), also proved efficacy of gamma irradiation against fish moulds. The study prescribed lower doses of irradiation for fish, to ensure effective reduction in microbial load, improvement of the biochemical and textural quality of fish and extension of shelf life, since higher doses increase the oxidation rate in some fishes, e.g. Bonito (Sarda sarda). Fish storage using sorbate and irradiation has also shown positive signs of extending shelf life for a period between 6 days to one month for squid, a cheaper and a more effective method than vacuum packaging (Bremner, 2002). Duan et al., (2011) have also indicated that hot air drying followed by microwaving of tilapia reduces drying time and moisture content of tilapia, while incease in temperature increased the rate of dehydration, and increase in microwave power together with the temperature of hot air increased shrinkage ratio and rehydration ration of the fish. The recovery rate showed an inverse relationship with increase in microwave power and hot air temperature. They concluded that initial hot air temperature and a lower microwave power was the most suitable for obtaining the best quality in dried tilapia. Chukwu, (2009) suggested electric oven drying of tilapia was a good method for producing quality dried fish with lower lipid value and high vitamin A as extended shelf life of dried fish. Ida et al., (2013) also smoke dried tilapia (Oreochromis niloticus). They indicated that the best quality smoke dried fish in terms of nutrients and organoleptic properties was obtained using drying parameters of 60OC for 15hours and 70OC for 10hours in a drum kiln dryer. A review of fish smoking operations in Western Region of Ghana by Gordon and Owusu- 17 University of Ghana http://ugspace.ug.edu.gh Adjei (2011) showed that the business was the largest in the fish processing sector, and demand for smoked fishes from the area extends beyond Ghana to Togo, Benin and Nigeria. Others such as Jain and Pathare, (2007) revealed that open sun drying of prawns and chelwa fish (Indian minor carp) occurs only during the falling rate period. Abbey (1998) and Ando et al., (1999) studied low temperature preservation of fish. Abbey established that local anchovies can best stored on ice for a maximum of two days, after which chemical, biochemical and microbial spoilage may start. Ando et al., also advised bleeding of fish for cold storage, because reduction in the fish blood delayed softening of the muscle of yellow horse mackerel. The efficiency of fish preservation by cold storage depends on the temperature range of the particular microorganism, i.e. whether psychrophilic, mesophilic, thermophilic etc. The mesophile such E. coli, with an optimum temperature range of 41oC will not thrive in cold storage temperature such as 3oC; although at that temperature psychrophiles like Pseudomonas will survive (Bremner, 2002). Ghaly et al., (2010) gave the storage life of different type and processed forms of fish. Although cold storage is good it negatively affects the texture of some fishes like the small pelagic fishes (Hyldig and Nielsen, 2001). Anchovies for example are greatly affected by cold storage (Abbey, 1998). Cold or chilled storage impacts on fish muscles, no general agreement however exists to explain the exact mechanisms involved in the texture- changes observed during the ice storage of fish (Hyldig and Nielsen, 2001). Fish drying results in different textures of fish; from wood-hard as in the case of bonito of Japan to the lightly smoked salmond which has a good market acceptance in developed countries (Bremner 2002). Uran and Gokoglu, (2014) who studied the effect of cooking methods on the quality 18 University of Ghana http://ugspace.ug.edu.gh of anchovies, revealed that although cooking sought to make fish and meat more edible and digestible could lead to some undesirable modifications, which affects the proximate and fatty acid composition, peroxide value, colour, texture and sensory properties. They observed that the concentration of some minerals were lowered by cooking. The temperature of cooking however did not affect the quality characteristics of anchovies. Panelists showed preference for the fried samples which rather were higher in fat content that raised the energy value of the fish making the samples not ideal health wise. The frying also increased the saturated fat (SAF) and poly-unsaturated fatty acid (PUFA) of the fish. Although both grilled and baked anchovies were healthier, the baked anchovies was more recommended because of its harder texture, low PUFA and the low acceptability of the grilled. The findings of Uran and Gokoglu (2014) may not be very informative since there may have been some initial changes in the fish before processing. The study design showed that the fish was not transported on ice from the point of purchase to the point of the preparation of the samples. Studies by Abbey (1998) and (Owaga et. at., 2009) kept fish meant for experiment on ice from the point of purchase to the laboratory to arrest changes in the fish. Tropical countries which have a lot of annual sunshine, have for years mostly smoked, cured, and sun dried salted and or un-salted fish (Bremner, 2002), while the temperate countries such as Northern Europe, which has refrigeration as main method of preservation, smoke fish using mechanical smokers to produced desired products (Bremner, 2002). Shelf life studies showed that anchovies made into patties can be stable for 6 days under cold storage temperature of 4±2oC, spoilage occurs on 8th day onwards (Turhan et al., 2001). A large amount of agricultural products in developing countries such as Ghana gets spoilt along the value chain before reaching the buyer (Kuwornu et al., 2011). 19 University of Ghana http://ugspace.ug.edu.gh This level of spoilage must be reduced through proper post-harvest processes (Kuwornu et al., 2011). Drying is a relatively inexpensive ancient method used in Ghana for fish, livestock and agricultural products of all kinds (Kuwornu et. al, 2011). The products are dried on table tops, roof tops, on mats or exposed to the sun on bare floors (Kuwornu et. al, 2011). Food is dried primarily for preservation or to impact some quality attributes to achieve benefits such as (1) ensuring stability under ambient conditions, (2) make food easy for handling (3) reducing foods into forms for easy cooking (Jemai, 2013). Traditionally fish is open sun, or smoke dried. Solar drying is a modern method being adapted by some countries globally. 2.4.1 Fish drying and importance of solar drying Solar drying is an improvement on the open sun drying, in terms of efficiency and the quality of final product (Immaculate et al., 2012). Fish is open sun dried by exposing it to the sun, allowing natural air and the heat to drive out moisture from within and the immediate surface of the fish being dried (Hii and Nielsen, 2012). Although this method is very cheap it yields poor quality fish. Solar drying on the other hand is drying in an enclosure, i.e. a solar dryer (Chavan et al., 2011). Studies by Jain and Pathare (2007) showed that open sun drying happens under the falling rate period. Mujaffar and Sankat, (2005), also mentioned only falling rate periods for a 100 x 50 x 10 mm cut shark fillets that were salted at 16% NaCl (wet basis), and dried in a solar cabinet for 72 hrs at air velocity of 1.5m/s and oven temperatures of 50 oC and 60oC. Whereas those dried at 20 University of Ghana http://ugspace.ug.edu.gh ambient temperatures of 30 oC and 40oC occurred at both the constant rate and falling rate periods. Open sun drying of fish is done using whole or split-cut brined or un-brined fish which as placed directly on the ground, or on mats placed on the bare ground under the sun for between 1-3 days (Bremner, 2002). This process contaminates the fish with sand or dust, and allow infestation of fly larvae leading to product loss and rancidity (Bremner, 2002). Brining and use of raised platforms for drying has been done to control fly larvae especially from soil to fish transfer (Bremner, 2002). 2.7 Types and uses of solar dryers The increase in use of solar dryers stems from the present situation of unstable prices of fossil fuel, environmental concerns and the fear of depletion of the conventional fossil fuel reserves (Fudholi et al., 2010). Issues with availability of appropriate equipment which are affordable and requires minimum training or skills to operate still remains a challenge in the full scale adoption of solar drying (Fudholi et al., 2010). Different types of solar dryers, based on their technological and economic benefits have been developed globally for use (Fudholi, 2010). Hii and Nielsen (2012) broadly categorized solar dyers into three main group: (1) Direct, (2) Indirect and (3) Hybrid solar dryers. Fudholi et al., (2010) is of the view solar dryers are within three groups based on the type of drying air used, i.e. (1) Passive (Natural circulation), (2) Active (Forced air circulation) and (3) Hybrid. In solar dryers heat for drying of the fish is impacted through two main fluid media, air or water (Fudholi et al., 2010). 21 University of Ghana http://ugspace.ug.edu.gh The advantages, disadvantages, costs and benefits of the various major types of solar dryers have been reviewed by Fudholi et al., (2010); Tables 4-5. A review of three solar drying methods by Bremner (2002) showed that solar drying was a superior method in terms of quality of product dried compared with open sun drying on volcanic rocks. Bremner (2002) also looked at the cost of different solar dryers. The cheapest was the solar tent dryer (slightly cheaper than a solar cabinet dryer). By his estimation, the solar cabinet dryer from Brace Research Institute was the cheapest on the market. All three dryers however were more efficient in terms of mass of fish dried/min/day. The principles, design, operations and economics of solar dryers have been studied by Bremner (2002). A review of three solar drying methods by Bremner (2002) showed that solar drying was a superior method in terms of quality of product dried compared with open sun drying on volcanic rocks. Bremner (2002) also looked at the cost of different solar dryers. The cheapest was the solar tent dryer (slightly cheaper than a solar cabinet dryer). By his estimation, the solar cabinet dryer from Brace Research Institute was the cheapest on the market. All three dryers however were more efficient in terms of mass of fish dried/min/day. The principles, design, operations and economics of solar dryers have been studied by Bremner (2002). 22 University of Ghana http://ugspace.ug.edu.gh Table 4. Advantages and disadvantages of different types of solar dryers Classification Advantages Disadvantages Passive dryers Low capital and running costs Low capacity Active dryers Independent of the ambient climatic More complex and expensive conditions than passive dryers Short drying periods than passive dryers Hybrid solar dryers Allow better control of drying Ability to operate without sun reduce Expensive, and may cause of product loss fuel/ gas dependence May be faster than passive and active dryers (Fudholi et al., 2010) Sablani et al., (2003) compared the performance of a convection cabinet solar dryer (CC), a top and bottom type multi-rack dome solar dryer (DM) and an open rack solar dryer (OR). Their study showed that convection cabinet dryer produces higher air temperature and relative humidity of the former were better 11-53oC / 11-37oC and 20-87%/ 22-96% respectively depending on the time of day. Moisture values for the CC were also lower than the OR followed by the DM, this was because the CC offered a faster drying rate. The CC also produced fish of higher protein, ash and fat, this was followed by the OR and the DM, although the bottom DM sample gave higher values possibly due to leaching of fish 23 University of Ghana http://ugspace.ug.edu.gh oils from the top DM. The higher temperatures in the CC also helped reduce microbial load lower than the other methods. The peroxide values recorded for samples dried with the CC was the lowest, which as attributed to a possible antioxidant effect as a result of the compound produced from heating of the protein and non-fatty part of the fish. The CC however gave a poorer colour compared with the others. In spite of all these the DM was preferred due to its capacity, suggestions of improvement were made. Table 5. Sample prices of solar dryers Type Figure No. Price ($) Direct solar cabinet dryer (passive) 1 14 PAU domestic-mode 2 36 Passive mixed-mode 3a 152 Passive indirect- mode 3b 220 Mixed-mode types forced convection solar tunnel dryer 4 939 (active) Hybrid solar dryer 5 5333 Hybrid solar dryer 6 6000 (Fudholi et al, 2010). Studies on drying in Ghana have been carried out by institutions such as the Energy Commission of Ghana, the Directorate of Agricultural Engineering Services (DAES) of the Ministry of Food and Agriculture (MoFA), the Food Research Institute of the Council for Scientific and Industrial Research (CSIR-FRI) Accra Ghana and the German Technical 24 University of Ghana http://ugspace.ug.edu.gh Co-operation (GTZ) with varying results, which has proven the method to be practical, economical and environmentally friendly (Kuwornu et al., 2011). Chavan et al., (2011) successfully tested a solar tunnel dryer designed by the Asian Institute of Technology (AIT) for the drying of mackerel. The study showed that the dryer was good for manufacture of products with better biochemical, microbiological, as well as soft textural qualities and pleasant odour. The dryer had an efficiency of 19.87%, and dried fish could stay up to 120 days in storage. 2.7.1 Dryer design and parameters; Chavan et al., (2011) gave some of the features of the solar tunnel dryer. It had a width of 1.8m, length of 8.25 m, the initial 4m served as the solar heating part, while the other 4.25m was the drying area within the tunnel. It had a side height of 0.07m which is for air flow of around the drying trays. The air flow rate was controlled 300-600 m3/h by means of three AC- driven fans of 14W capacity placed in front of the collector. Heat loss prevention was done with a 4cm thick glass wool. A 0.2 mm thick UV protected polythene sheet was used as a glazing material. The transmissivity of the plastic cover was around 0.89 for beam radiation. The dryer was designed so that the covering sheet remains tilted over it to prevent rain water from entering. The dryer capacity was 100kg per batch Bala and Mondol (2001) also used a solar tunnel dryer in Figure 4 for drying silver jew (Johnuis argentatus) fish. Their design was made up of a flat air heating collector, a tunnel drying unit and a series of four small DC fans powered by a photovoltaic module to drive air through the tunnel. The collector and the drying chambers were both covered with 25 University of Ghana http://ugspace.ug.edu.gh transparent plastic and a black paint was used as an absorber in the collector. The products for drying were spread thinly on a bamboo split net in the tunnel dryer. Glass wool was the heat loss prevention insulator. The tunnel rests on a horizontal, raised platform. The transparent cover was sloped over the dryer to prevent water entering the dryer. Solar radiation passes through the transparent cover and collector to heat up the absorber which transfers its heat to the drying ambient air forced through it by the fans over the products to be dried. Temperatures obtained range between 35.1oC to 52.2 oC. about 150kg of the silver jew fish, which has been dry salted (salt : fish ratio of 1:4) and stack for 16 hours before drying fish at full capacity, between the hours of 9:00 am and discontinued at 4:00pm each day for 5 days. Some proximate analysis of the fish dried showed that the solar tunnel dryer was a better option and yield fish safe for human consumption compared with the open sun drying method. Figure 4. Solar tunnel dryer; (1) air inlet, (2) fan, (3) solar module, (4) solar collector, (5) side metal frame, (6) outlet of collector, (7) wooden support (8) plastic net (9) roof structure 26 University of Ghana http://ugspace.ug.edu.gh for supporting the plastic cover, (10) base structure for supporting the tunnel dryer, (11) rolling bar (12) outlet of the drying tunnel. (Bala and Mondol, 2001). Wazed et al. (2009) also used a tunnel solar dryer for drying salted silver jew (powa) fish (salt: fish 1:4) kept for 16 hours before solar drying. The maximum air velocity was 0.5m/s and temperature at 52oC. They also reported positive results from proximate analysis of the fish dried, which proved that the method is able to yield fish safe for human consumption compared with the open sun drying method. They dried the fish between 9:00am -5:00pm for the months of November and December 2008 and January 2009 and listed the following conclusions: I. Fish drying with a solar tunnel dryer reduces the drying time considerable when compared with the conventional sun drying method II. Fish dried in a solar dryer is protected from the rain, insects and dust leading to a high quality fish III. The dryer design is simple and can be made using locally available material and a craftsman. Forced air for drying can be provided by means of a photovoltaic powered fan independent of the electrical power grid. The photovoltaic power has the ability to regulate the temperature as the solar radiation changes. The photovoltaic driven solar tunnel must be optimized for efficient operation. Kituu et al., (2009) carried out thin layer drying modelling for tilapia fish using the tunnel dryer and showed a strong linear correlation between the simulated and actual data obtained; plenum chamber temperature (R2=0.961) and the moisture ratio (R2=0.995). Basunia et al., (2011), dried 51.5kg of sardines using a solar tunnel for a period of 5 three 27 University of Ghana http://ugspace.ug.edu.gh days discontinuous. The average air drying tunnel temperature was 45oC-50oC, while the air flow rate was 0.2m/s. The dryer was 29.5% efficient and helped reduced the drying time when compared to the open sun drying method. 2.8 Quality of solar dried fish Studies by Steiner-Asiedu et al., (1993) on small pelagic fish; Chinsense (Neobolu rnweruensis) and Sardines harvested from Rift Valley of Africa, showed high protein content, made up of good amino and fatty acids which make the fish suitable for production of weaning foods, for children under 5 years. The study indicated that the limiting amino acid was tryptophan. The authors suggested that the high ash value is evidence of the potential high levels of Ca, Zn and Fe. Later studies by Owaga et al., (2009) on dagaa (Rostrinebola argentea) fish showed that oven drying as compared to sun-drying yielded lower ash values. It was established that the sun-drying on mats placed on the bare floor exposed the fish to grits, hence the high ash values. Other studies by Immaculate et al., (2012) also showed higher ash values for traditionally sundried fish compared with hygienically solar dried fish. This therefore implies that for Steiner-Asiedu et al., (1993) to have a very strong point on the relationship of high ash value to the presence of dietary Ca, Zn and Fe there is the need for analysis such as the acid-insoluble test or other standard analytical methods for determination of specific minerals in foods. Bremner (2002) studied the effect of pre-drying processes on the quality of dried fish. The effect of the pre-drying process on the water activity of the dried fish is shown in Table 6. 28 University of Ghana http://ugspace.ug.edu.gh Studies on improving on the processing of the Indian “musmin” showed that dip-washing tuna in saturated brine for 30min, followed by steaming on an open mesh screen for 1hr before drying or smoking helped retain 76.6% of fish protein which would have been lost if the fish was traditionally boiled in sea water (Bremner, 2002). Although salting before drying is effective for some fishes and drying methods, Omodara and Olaniyan (2012) found out salting, sugaring and blanching did not affect the quality parameters of catfish (Claria gariepinus) dried using an electrical dryer. Subarkah et al., (2013) reported on the drying characteristics of anchovies. The study identified anchovy changes from constant rate period to falling drying rate at the stage where the critical moisture content has reached about 48.8%-50.3% (wet basis). There was no case hardening observed as temperatures even reached 70oC. Further increase in the temperatures and air flow rate was believed to possibly reduce the efficiency of the drying system because the surface water evaporation of the fish is smaller than the drying capacity of the surrounding air. The study suggested the optimization of the drying condition into a three stage process; first 70oC for 150min, followed by 50oC for 100min and then 40oC till equilibrium moisture content is attained. 29 University of Ghana http://ugspace.ug.edu.gh Table 6. Fish drying processes and effect on water activity Country Fish Part of fish Pre-treatment Drying operation Final fish species dried of fish quality Malaysia anchovies Whole fish Boiling in 10% Fish packed in bamboo aW=0.79 brining basket boiled in brine for 1min with agitation on base of basket, then spreading to dry on the sun for one day Norway Stockfish- Lengthwise No pre- Fish rinsed in fresh water and aW=0.74 Cod splitted treatment hung to dry for 36hrs-2 (Gadnus whole, months in a relative humidity morrhua) joined at tail of 70-80%. Post-drying carried out in well-aired store rooms Japan Sand lance Whole fish 10-20% brine Brining for 10min followed aW=0.98 by sun drying for 2-3days. (Bremner, 2002). The FAO (1992) have indicated that over 80% of Ghana’s fish is obtained from the sea. Maximum utilization is therefore important to ensure food security through the development, introduction and good use of novel drying technologies such as solar drying. 30 University of Ghana http://ugspace.ug.edu.gh The strategic position of Ghana within tropical West African zone can be an advantage for harnessing the sun energy to produce high quality dried fish, at lower cost of production. The success of introduction of any new drying method must be preceded with a perception and need assessment. 31 University of Ghana http://ugspace.ug.edu.gh 3.0 MATERIALS AND METHODS 3.1 Assessment of current fish handling practices at the artisanal levels in Ghana This study was carried out at two major artisanal fishing communities in Ghana (Tema in the Greater Accra region and Kasoa in the Central region). The project was aimed at assessing prevailing fish handling, processing, packaging, marketing, operational challenges and sanitation in these two locations, which would serve a guide for policy and direct the need other interventions. 3.1.2 Sample Size A total of 25 artisanal fish processors were identified and interviewed with a pre-tested questionnaire as shown in Appendix B, for the Tema and Kasoa study sites; making 50 participants in all. The sample size was arrived at because there was no available data as at the time of the study on the population of processors, and those interviewed where processors who were willing to be part of the study. Since this was an explorative study, twenty five majority female fish processors were assessed for each location, comprising people from five locations (North, South, East, West and Central locations). 3.1.3 Study Locations: The study was carried out at the Tema Canoe beach of the Tema New Town District of the Greater Accra Region and Kasoa Nyanyano Landing beach, of the Gomoa East of the Central Region of Ghana. 32 University of Ghana http://ugspace.ug.edu.gh 3.1.4 Data Collection: 1. Questionnaires for the study were self-administered for a total of 50 processors for each sampling site. 2. Focus group discussions were held for 14 members from Kasoa and Tema respectively. o Discussions were held around themes that needed consensus and have not been captured on the individual base questionnaires. o A facilitator moderated the discussions, and in times of translation a gentleman who could interpret the Akan and English was on hand. Effort was made to keep in check dominant interviewers 3. Other guiding sources such as personal communications with staff of Ministry of Fisheries Ghana, personal observations of processing sites and operations at the landing beaches as well as photographic evidence were used to get more information. 4. Qualitative data was analyzed using content analysis. 5. Quantitative data was analyzed by SPSS version 16, and summaries of data were displayed as tables and pie charts. 3.2 Design of the solar tunnel dryer The solar tunnel dryer Figure 4 and appendix C was used for the study was a Hoheiheim type solar tunnel dryer installed earlier by the GTZ German NGO in Ghana at the CSIR- Food Research Institute, Shiashi Greater Accra Ghana, which was refurbished and the cover modified. For this study the auxiliary energy source i.e. firewood heat conducted through hot water lines were not used, because the days drying was adequate. The initial cover was a UV protected polythene, which was later replaced with Perspex glass covers 33 University of Ghana http://ugspace.ug.edu.gh on hinges. The dryer had the air inlet facing the South direction and the air outlet facing the North direction in response to the natural air flow pathway. The tunnel dryer was equipped with calibrated sensors; temperature sensors; one placed at the solar area point 4 that is the solar radiation absorption point, the drying area point 8 to measure the internal changed while a third was placed outside to measure ambient temperature. Humidity and air velocity sensors were also placed at the point 8 that is the fish drying area, while solar insolation meter was placed at the point 4 shown in Figure 4. The data collected was stored unto a data logger attached to the solar dryer and the actual reading read off using the device software on a computer. 3.2.1 Operation of the Solar Tunnel Dryer. About 1k anchovies fish samples were spread thinly on plastic nets placed on 16 metallic mesh trays inside the point 8 and dried between 9:00am and 4:00pm on a hot sunny day. Natural air was carried over the solar heating absorption area and heated by help of the two Photovoltaic powered fans. The heated air was passed over the fish for drying, generating a more humid air which is then driven out of the tunnel at the north end. Senor readings were logged directly and read later using the device software on a computer. 3.3 Development of process for producing high quality solar dried fish (anchovies) using a solar tunnel dryer Positive lessons from the traditional open sun drying (OSD) process of fish, obtained from literature and local processors was used to design a drying process for a solar tunnel dryer 34 University of Ghana http://ugspace.ug.edu.gh and used in drying anchovies which is of higher quality and safety. The Figures 5 and 6 shows the two methods, the processes and durations. The OSD were methods identified at the Tema Canoe Beach of the Tema East district of the Greater Accra Region and Kasoa Nyanyano of the Gomoa East district of the Central Region of Ghana. 3.4 Materials 3.4.1 Reference Samples Open air dried anchovies samples were obtained from Kasoa Nyanyano in the Gomoa East District of the Central Region in the month of May 2014. These were used as reference samples. The fish samples were randomly taken from the two main drying platforms at the Kasoa Nyanyano, Samples labelled DAK-A open sun dried anchovies dried near salt mining beds in Nyanyano, while samples labeled DAK-B are anchovies dried near the seashore of Nayanyano. Handling: The samples were transported in labeled polythene sacks with inner liners, to the fish laboratory of the CSIR-Food Research Institute, Shiashi Accra, for further analysis. Storage of dried samples: Dried samples were stored in polythene sacks with air tight inner liners for analysis. 35 University of Ghana http://ugspace.ug.edu.gh Freshly landed marine Anchovies Washing in sea water Wetting ground with water Spreading fish on floor to dry * OSD METHOD Turning fish after (14 hours) * Transfer of fish unto polythene sacks* Further drying on sack for (12 hours)* Collection after the 12 hours drying Packaging into wooden baskets Storage as a pile in a wooden houses or wooden baskets with old cement bag paper and high density polythene sheets in an open field Figure 5. Flow chart of traditional open sun drying of anchovies in Ghana. *Drying at ambient conditions (Air velocity, relative humidity, Temp.). 36 University of Ghana http://ugspace.ug.edu.gh Freshly landed marine anchovies Washing in sea water STD METHOD Spreading on sanitized mesh trays Solar tunnel drying (7-8 hours) Air velocity (0.28 ± 0.13 m/s) Tunnel temp. (63.99 ± 10.25 OC) Relative humidity (14.9 ± 6.57 %) Collecting Transfer into air-tight polythene sacks Storage in CSIR-Food Research fish laboratory Figure 6. Flow chart of for drying of anchovies using a solar tunnel dryer. 37 University of Ghana http://ugspace.ug.edu.gh 3.4.2 Experimental sample (STD) Fresh sea water rinsed anchovies (8.30±0.64 cm, 3.341± 0.90 g) obtained from James Town landing beach from the Ododiodoo district of the Greater Accra region was used for preparation of Hoheiheim Solar Tunnel drying experiment, due to their availability at that part of Accra. Handling: The fish samples were transported to the fish laboratory of the CSIR-Food Research Institute, Shiashi Accra. In the laboratory, the samples were stored on ice flakes (ration of 1:1) in a cold chest with small perforations on the bottom sides which allowed for a controlled draining of fish blood before plugging. This was to follow "Recommended International Code of Practice for Fresh Fish" (CAC/RCP 9-1976) (FAO, 1998) which recommends ice storage of fresh anchovies. Solar drying: About 16kg of anchovies samples were dried (1Kg/tray). Samples were spread thinly on polythene meshes placed over mesh type metallic drying trays placed inside the Hohenheim Solar Tunnel Dryer. Drying carried out from 9:35am to 10:50 am and discontinued due to threat of rains. The samples were taken to the fish laboratory and stored covered in aluminum foil. Drying continued the next day from 9:20am to 2:20pm. Sensor meters were used to log the drying parameters within the STD and the outside ambient temperature for the period of drying. Storage of dried samples: Dried samples were stored in polythene sacks with air tight inner liners for analysis. 38 University of Ghana http://ugspace.ug.edu.gh 3.5 Chemical analysis on solar and open sun dried anchovies. The solar and open sun dried fish were hand de-boned, scaled, gutted, headed and homogenized using a laboratory blender (Panasonic Mx-Ac 300 Mixer Grinder), samples were taken from the homogenates for the tests. The analysis were carried out in duplicates and the averages taken for computing. Proximate analysis for protein, fat and ash was carried out on all samples. Free fatty acid, peroxide value and level of histamine was determined to measure the extent in the fish samples. 3.5.1 Proximate Analysis on fish Moisture content Percentage moisture was determine by AOAC (925.10, 1990 15th Edition). The air-oven method was used for 20g replicate samples. Sample were dehydrated at 105-106oC for 5hrs. The loss in weight after dehydration was calculated as a ration of the original sample before dehydration: % Moisture= Loss in weight of sample after drying X 100% Initial weight of sample Ash content Dry ashing was done using the Muffle furnace method for 20g replicate samples AOAC (2000). Ashing was done at 550oC for 6-8hrs. The weight of the ash was expressed as a 39 University of Ghana http://ugspace.ug.edu.gh ration to the initial weight of samples: Percentage % Ash = weight of ash X 100% Initial weight of sample Fat content The percentage fat was determined by AOAC (2000) using the continuous soxhlet extraction method for used for 20g replicate samples in petroleum ether as solvent at a temperature of 40-60oC for 5hrs. The percentage fat was calculated as; % Fat= weight of fat in sample after extraction X 100% Weight of original sample taken before extraction Percentage crude protein About 0.2g replicate de-fatted samples digested and analysed by the Kjeldhal method AOAC 1990). 3.5.1 Fish spoilage analysis To assess the effect of the two drying method on the type and extent of spoilage of the dried anchovies, the free fatty acid, peroxide and histamine levels of the dried anchovies samples were analysed. 3.5.2.1 Free Fatty Acid Analysis (FFA) The free fatty acid content of the samples was determined by the Pearson (1970) method. 40 University of Ghana http://ugspace.ug.edu.gh FFA = Factor x T x Conc. Of NaOH (g/100g) W x 10 Where factor used if oleic acid (282), T is the titre value of the NaOH and W is the weight of fish fat taken. 3.5.2.2 Peroxide Value (PV) The peroxide value was analysed using the AOAC (2005) . Extracted oil sample (1g) was dissolved in 25ml of glacial acetic acid-chloroform (2:1 v/v) and 1.0 ml of KI (4g of KI in 3ml H2O) was added and the sample was kept in the dark for 1min. After this drops of 5% starch solution (0.5g starch in 50ml H2O g/v) was added (colour turns black), this resulting mixture was titrated with 0.1ml of 0.002N sodium thiosulphate until colourless. A blank (T) titration was run alongside the samples. PV = (T-B) N x 1000 (mEq/kg) W Where T is titre or volume of normal sodium thiosulphate consumed during titration blank titration, W is the weight of sample (g) and N is the normality of sodium thiosulphate multiplied by a factor 3.5.2.3 Histamine Analysis Histamine levels were measured following Hardy and Smith (1976) method. About 10g of dried fish devoid of scales, skin, guts and other undesirable parts. 41 University of Ghana http://ugspace.ug.edu.gh Histamine (ppm/ µg/g) = 3.3 F/E x Conc. (µg/g) read off from standard curve* F= Volume of sample after neutralization E= Volume of extract after filtration through Amberlite CG-50 resin column. * Standard curve plotted for 1ml of aliquot of a standard histamine solution (0-80 µg histamine/ml of 0.2N HCL). Absorbance readings were carried out at 95nm using distilled water as reference. 3.6 Physical analysis To determine the effect of the two drying methods on the physical properties of the final dried anchovies, the sample were analysed for water activity and colour. 3.6.1 Colour Determination The surface colour of randomly sampled fish samples placed inside a covered transparent glass pertri dish was measured in three zones, by the CIE LAB. (L*, a*, b*) using a Hunter Lab. Minolta Chroma meter, Japan, colorimeter equipped with a CR-310 measuring head. The colour coordinate .L* (darkness/ whiteness), was recorded at three zones for replicates of seven samples. The colour meter was calibrated with a white tile L (97.57), a (+2.29), b (1.88) before measurement. The average values of the L* was used to calculate the means and the standard deviations using Minitab software version 14. 42 University of Ghana http://ugspace.ug.edu.gh 3.6.2 Water Activity (AW). Randomly sampled dried fish was blended using a Panasonic Mixer blender. The water activity container was then filled to the brim and leveled. Anaylysis was done using a Hygro-Lab. Ro-tronic water activity meter calibrated with saturated salt (NaCl) solution. Average temperature during the analysis was 30oC. Readings were run in triplicates and the data was used to calculate the means and standard deviation using the Minitab version 14 software. 3.7 Sensory evaluation of dried anchovies To assess the effect of the two drying process on the sensory quality of the dried anchovies, a seven point hedonic test was carried out on the samples. 3.7.1 Samples and Sample preparation  Two batches reference samples from the two OSD platforms (i.e. one batch near the sea shore and the other near the salt mining beds) would be obtained from Kasoa Gomoa Nyanyano landing beach in the Central region of Ghana.  The experimental samples i.e. three treatments of STD fish prepared at the CSIR-Food Research Institute, Shiashi Accra Ghana. 3.7.2 Method; The OSD and STD (appendix D) samples were dressed (gutting, heading, removal of fins and scales) and assessed for physical soundness before using in preparation of anchovies in tomato sauce, following the flow chats in Figures 7-9. Materials and equipment shown 43 University of Ghana http://ugspace.ug.edu.gh in appendix A were used for the process. The anchovies in tomato sauce were assessed smelling, physical observation, tasting and chewing . Dry OSD and STD anchovies as well as the anchovies in tomato sauce appendix E were transported from the storage at the CSIR-Food Research Institute Shiashi in transparent labeled poylthene bags and labeled food warmers respectively to the Nutrition laboratory of the department of Nutrition and Food Science, University of Ghana Legon for the studies. Between 50 panelists, screened on the basis of age, gender, profession, evidence of allergy to fish and or anchovies, willingness to participate were used for the sensory. Solar tunnel dried anchovies and two samples of open sun dried anchovies were made into a tomato sauce A subjective test was carried out using a questionnaire for a seven scale hedonic, with 50 untrained panelist for the preferred attributes. Portable water at room temperature and bland biscuits were used for rinsing of pallet by panelist in-between tests, using sample questionnaire in appendix F. 3.7.3 Analysis of results; Qualitative data was presented as using the web plot showing the sensory scores for various attributes assessed for the three fish samples Quantitative data was analysed using for simple means and standard deviations, using Minitab software version 14. And Friedman’s test was used to establish the significance difference for overall acceptability for the three fish samples. 44 University of Ghana http://ugspace.ug.edu.gh OSD or STD Anchovies Sorting Cleaning (sand or grits For OSD) Dressing (heading, gutting, removal of fins and scales) Washing (potable water at room temp.) Cleaned and washed ready for cooking OSD/STD anchovies Figure 7. Flow chat for preparation of dried fish for cooking Figures 7-9 shows the methods for preparation of OSD and STD anchovies in tomato sauce 45 University of Ghana http://ugspace.ug.edu.gh Vegetables (fresh pepper, onions, tomatoes) Sorting Cleaning (removal of unwanted parts) Washing (potable water at room temp.) chopping weighing Pulse blending (5min) Blended vegetables Figure 8. Flow chat for preparation of mixed vegetables for tomato sauce 46 University of Ghana http://ugspace.ug.edu.gh Pre-heated vegetable oil (measured vol.) Addition of weighed tomato paste Addition of weighed blended vegetable Cooking for 50 min Addition of iodized salt Addition of weighed anchovies (1 teaspoon) Cooking for 10 min Anchovies in tomato sauce Figure 9. Flow chat for preparation of OSD/STD anchovies in tomato sauce. 47 University of Ghana http://ugspace.ug.edu.gh 3.1 RESULTS AND DISCUSSIONS 4.1 Survey on open air-drying of fish and quality of dried anchovies A survey was carried out at two landing sites at Kasoa (Central Region) and Tema (Greater Accra Region). A total of 25 processors were interviewed from each site. The study revealed that fish processing in Tema and Kasoa is dominated by women (Table 1). This supports earlier reports by the Ministry of Fisheries (2008). The survey also showed that Kasoa was largely Akan (large group of Fante and others Twi tribes), and Tema showed a combination of different tribes of processors, i.e. comprising Ga, Akan and Nzema. This is because as stated earlier there are two main processor groups; the local indigenous women, and the transitional or migrant women processors from different coastal regions of Ghana. Ninety nine percent of processors from Kasoa and 76% from Tema were between the ages of 30-40 years, 12% from Tema who were between 41-50 years and another group in the same area above 50years. These observation indicates that due to the tedious nature of the trade, as the processors grow older there retire to their homes as the younger and more energetic women take over. Introduction of alternatives such as solar dryers, which are mostly above ground can help eliminate the difficulty associated with fish drying and if adopted can improve the health of processors and allow the processors extend the retirement time from their work. The survey also revealed that most of the processors, i.e. from Tema and Kasoa respectively were married. This could mean they do the trade to support their families. There were 24% and 12% who were divorced from Kasoa and Tema respectively, while 4% and 8% from the respective locations were divorced. Seventy five percent of processors from Kasoa and 56% had no schooling, 12% and 24% from the two 48 University of Ghana http://ugspace.ug.edu.gh locations had primary education, 4% and 12% from Kasoa and Tema respectively has secondary education and 4% and 8% from Kasoa and Tema respectively had vocational education. This means planning of trainings and any form of intervention must be done incorporating the best method of communicate that will help both processors and policy makers. 4.1.1 Socio-Demographics The social-demographic details of fish processors interviewed at the Kasoa and Tema fish landing beaches is given in Table 7. From Table 8, it was observed that 8% from both Kasoa and Tema respectively have spent 1-10 years, 8% and 36% from Kasoa and Tema respectively have spent 11-20 years, 72% and 40% for Kasoa and Tema respectively have spent between 21-30 years and 12% and 16% from Kasoa and Tema respectively have spent 31 years and above doing open sun drying of fish, This shows that the trade has been traditionally their main source of livelihood. 4.1.2 Knowledge about fish processing. The study profiled processors knowledge about the open sun drying operations. The responses were summarised in Tables 8. 49 University of Ghana http://ugspace.ug.edu.gh Table 7. Summary of demographic information of respondents interviewed (n=100) Demographics Kasoa (%) Tema (%) Male 0 0 Sex Female 100 100 TOTAL 100 100 30-40 92 76 41-50 4 12 Age Above 50 4 12 TOTAL 100 100 Akan (Fante/ Twi) 100 44 Ga 0 52 Ethnicity Nzema 0 4 TOTAL 100 100 Married 72 72 Single 0 8 Marital status Divorced 4 8 Widowed 24 12 TOTAL 100 100 No schooling 76 56 Primary 12 24 Secondary 4 12 Educational level Vocational 4 8 TOTAL 100 100 50 University of Ghana http://ugspace.ug.edu.gh Table 8. Summary of years of experience of processors at landing site (n=100) Years of practice of open sun drying of fish by processors Landing site (%) 1-10 11-20 21-30 31 and above TOTAL Kasoa 8 8 72 12 100 Tema 8 36 40 16 100 The processors knowledge about fish preservation is summarised in Table 9. Table 9. Summary of the most appropriate fish preservation method (n=100) Method of preserving fresh fish before arrival at landing site (%) Landing site Iced Not Covered in In an By any means at iced a container uncovered the discretion of Total container fisher Kasoa 16 60 4 20 0 100 Tema 12 56 8 16 8 100 From Table 9, 16% and 12% from Kasoa and Tema respectively agreed that fish must be iced offshore before landing, 60% and 56% from Kasoa and Tema said fish must not be iced offshore before landing, 4% and 8% from Kasoa and Tema respectively agreed that fish must be kept covered without ice, 20% and 16% from Kasoa and Tema respectively agreed fish should be kept in a container uncovered and 8% from Tema alone agreed to 51 University of Ghana http://ugspace.ug.edu.gh any method suitable by discretion. The majority that chose no ice supports earlier works by Abbey (1998) observed the negative impact of prolong cold storage of anchovies on the quality of the fish. However the current practice of harvesting the fresh fish onto the unprotected canoe floors, must be addressed, since it is a source of contamination. Processors were interviewed about the preference for open sun drying and the responses are given in Table 10. Table 10. Summary of why processors use open sun drying methods (n=100) Landing Reasons for preference of open sun drying method site (%) Profit Nutrition Better Taste preservation Total Kasoa 68 4 20 8 100 Tema 92 0 4 4 100 Table 10 revealed that 68% and 92% from Kasoa and Tema respectively said they dried fish for profit, 4% from Kasoa alone dry fish for nutrition, 20% and 4% from Kasoa and Tema dried fish for preservation purposes and 8% and 4% from Kasoa and Tema respectively dried fish because of the taste. The results showed evidence that processors were more concerned about the economic and shelf life of the fish they dry more than other reasons. 52 University of Ghana http://ugspace.ug.edu.gh The Processors also provided evidence on the cheaper method of drying fish as shown in Table 11. Table.11. Summary about the cheapest method of fish processing (n=100). Drying method Landing site (%) Open sun drying Smoke drying Total Kasoa 92 8 100 Tema 92 8 100 Table 11, showed that 92% of processors from both Kasoa and Tema agreed that open sun drying was an inexpensive method, and 8% each from both Kasoa and Tema agreed that smoke drying was a cheaper method. The minority that stated smoking as inexpensive may largely be processors who dried fish using both methods, and may have taken their stand because of the unique nature of their trade and the market they target. Table 12. Summary on the cheapest source of fuel used by processors (n=100) Energy source for drying Landing site (%) Firewood Sun Total Kasoa 28 72 100 Tema 24 76 100 53 University of Ghana http://ugspace.ug.edu.gh The results from Table 12 indicated that 72% and 76% of processors from Tema and Kasoa respectively agreed that open sun drying was relatively inexpensive compared to the use of fuel wood. Those who said that fuel wood was cheaper perhaps did not really mind spending on energy for processing. The low statistics of those who smoke dry is good news that should the current open sun method be improved with realizable gains, we may soon have almost 100% usage of non-fuel based fish drying method. Although fish drying on bare ground is hazardous as shown in Figures 10 and 11, and Table 13 it is still done. All the processors admitted drying fish on the bare ground. About 76% or processors from Kasoa and 68% from Tema agreed that drying on the bare ground made the process faster. Very few from the two sampling sites assigned reasons such as the process yielding tastier fish, being a cheaper process, and lack of alternatives for their drying on the bare ground. This practice always yields fish or low quality or in some case leads to losses. Pictures from Kasoa and Tema shows spoilage especially from the gut area of the fish as enzymes and microorganisms act on the fish. In Tema, there was contamination of the fish being dried with animal excreta. Although they acknowledged losses from erratic rainfall patterns, pest, theft and other losses factors, the processors have kept to the business. Although some consumers; both the educated and un-educated consumers were aware the method of processing of anchovies in Ghana, it has not significantly affected patronage of the commodity. This should be an advantage for processors to work on improving upon the quality of the anchovies for better market value. 54 University of Ghana http://ugspace.ug.edu.gh The processors also explained why they dry fish on bare ground. This is summarised in Table 13. Table 13. Summary of reasons why processors dry on bare ground (n=100) Reasons for drying fish on bare ground during open sun drying (%) Landing Makes Cheaper Faster Saves money Lack of Norm site fish process process since no fuel is alternatives from past Total tastier required Kasoa 0 16 76 4 0 4 100 Tema 4 4 68 4 4 16 100 The results from Table 13 shows that, seventy six percent and sixty eight percent of processors from Kasoa and Tema respectively agreed drying on bare floor accelerates the process. It was also observed that 4% and 16% for Kasoa and Tema saw the process as a norm. Figure 10, 11 and 13 depicts unhygienic open sun drying method on bare ground. There were evidence of animal excreta within the fish being dried at Tema, while at Kasoa dust contamination was observed. The observations indicate a need for better drying methods that will eliminate the bare floor placement of fish as a unit operation. 55 University of Ghana http://ugspace.ug.edu.gh Figure 10. Drying fish on polythene at Kasoa. Figure 11. Drying fish on bare ground in Tema (black substance is dog excreta) The introduction of a solar dryer therefore will not only help accelerate the drying process but also solve the challenge of bare floor drying of fish. The cost of such innovation to processors must be calculated taking into consideration the willingness to adopt such methods, and the income level of processor, so they can adopt the technology Processors indicated how they acquired their skills for drying as shown in Table 14. The results from Table 14 shows that 28% and 16% from Kasoa and Tema respectively learnt open sun drying of fish by personal observation, 64% and 80% from Kasoa and Tema acquired the skills from family members, i.e. elderly women as at the time, 4% each from Kasoa and Tema said a church group trained them. Observation of animals excreta is an evidence of poor hygienic nature of open sun drying, and this can be linked to the level of education of processors who have traditionally processed fish with knowledge passed on by older parents who themselves are not privy to 56 University of Ghana http://ugspace.ug.edu.gh best practice methods. A few others mentioned friends and church as their sources of training, which indicates that social and religious organisations such as churches do play a role of poverty alleviating. Table 14. Summary of how processors acquired skills for open sun dry fish (n=100) LANDING MEANS BY WHICH PROCESSORS ACQUIRED SKILLS FOR SITE OPEN SUN DRYING (%) Personal Family Friends Church observation group Total Kasoa 28 64 4 4 100 Tema 16 80 4 0 100 4.1.3 Knowledge about Unit Operations for Open Sun Drying Process From the general focus group discussions, processors from both Kasoa and Tema said they wash fresh fish in sea water, then spread over the ground which has been dampened with some sea water. Drying is done in the open sun for 14 hours accompanied by turning of fish with sticks and sometimes long brooms. An additional 12 hour drying is done to ensure a good dried fish. This is done on the same ground for the case in Tema, however in Kasoa the dried fish is collected into wooden baskets and the 12 hour drying done at home where the fish is spread over black or white polythene sheets spread over the floor. The process is very unhygienic for sampling sites. Aside the contamination from liquid and solid waste from both animate and inanimate sources, there is also the problem of 57 University of Ghana http://ugspace.ug.edu.gh chemical contamination as these locals have little to no knowledge about the hazards associated with the use of solvents like kerosene etc. near food. 4.1.4 Knowledge about Harmful Substances in Fish Processing. The study also investigate to establish if processors have been using harmful chemicals for their operations. The responses are as shown in Table 15. Table 15. Information about use of harmful methods during storage of dried fish (n==100) Method of pest control for open sun dried fish Landing site (%) Insecticides Smoke Storage in baskets By discretion covered with of processor Total polythene bag Kasoa 40 4 52 0 100 Tema 8 4 84 4 100 The results from Table 15 revealed that 40% of processors from Kasoa and 8% from Tema admitted using insecticides for the protection of dried fish during storage. About 4% from same locations used smoke as also as an insecticide to protect stored dried fish. About 52% and 84% from Kasoa and Tema respectively stored dried fish in wooden baskets in the open compound, and 4% stored by other means. These responses meant that processors did not have knowledge about the effect of some of their operations in reducing the quality of the dried fish. The processors denied the presence of pests, contaminants and dust that 58 University of Ghana http://ugspace.ug.edu.gh affects the quality of the fish although at the time of the survey, these were very evident. Some processors interviewed initially denied the use of chemicals or insecticides during operations. The major problem mentioned by the women in Tema was the poor quality fish they sometimes get due to some fishers using light or chemical fishing methods banned by government. 4.1.5 Knowledge about Sanitation Personal observation and photographic evidence was gathered to assess the level of environmental cleanliness of the fish processing areas. There were unique issues of contamination between the two landing sites. Whereas in Kasoa the fish is exposed to the biological hazards such as animal or human excreta, the case in Tema is different. In Tema huge volumes of hybrid industrial effluents from nearby and far companies are emptied into the sea. These effluent most likely may contain harmful substances that can affect the aquatic environment, the processed fish and transfer heavy metals and other toxic agents into the food chain. Hence Tema suffers from both biological and chemical contamination. Both processors from the two survey sites showed little knowledge about the importance of keeping a sanitary environment for processing. In the case of Kasoa, there was the provision of place of convenience, however the locals prefer open defecation near the processing sites, and with reasons being the fact that they cannot afford having to pay for usage of the facility each time there is a need. There were no visible sight of structure as public places of convenience in Tema, although one fisher group have built a shed for their 59 University of Ghana http://ugspace.ug.edu.gh operations. Information on the ground revealed that the land belonged to the Ghana Naval base stationed at that part of town, and the operations of the fishers and processors over the years have been less like those of squatters. This could be perhaps reason for the lack of motivation for more permanent structure for place of convenience which has resulted in open defecation along the beach threatening the environmental safety of the place. The open sun drying in Tema and Kasoa exposes the fish to contamination as shown in Figures 10 to 16. In Kasoa, the fish dried at location A which is near salt mining area was close to an open dump site and dirty ponds. 4.1.6 Assessment of Knowledge about fish storage Processors were interviewed concerning their knowledge about the best method of fish storage, and the responses listed in Table 16. Table 16. Summary of processor’s knowledge about best storage practices (n=100) Mode of storage of open sun dried fish by processors (%) Landing Wooden Kitchen Living In covered wooden At storage site store room baskets on raised pallets facilities in Total houses outside markets Kasoa 44 8 36 8 4 100 Tema 4 0 0 88 8 100 60 University of Ghana http://ugspace.ug.edu.gh From the results in Table 16, 44% and 4% from Kasoa and Tema respectively said they store dried fish in wooden store houses, 8% from Kasoa mentioned they store dry fish in their kitchen, 36% from Kasoa said they store dry fish in their living room, 8% and 88% from Kasoa and Tema respectively said they stored fish covered. From Figures 10-16 and Table 16, dried fish was stored in covered wooden baskets lined with old cement paper, on raised pallets, outside and in wooden store houses. Four percent and eight percent from Kasoa and Tema respectively stored dried fish at market places. Contamination from traces of cement which may contain harmful substances was very possible for fish stored in old cement bag material. Figures 12-16 show poor drying, packaging and storage of dried anchovies at Kasoa and Tema. These storage practices were observed not to be the best. Figure 12 Packaged dried anchovies at Kasoa. Figure 13. Final 12 hours drying of anchovies at Kasoa 61 University of Ghana http://ugspace.ug.edu.gh Figure 14 Dried anchovies stored in wooden store houses in Kasoa Figure 15. Fish stored outside at Tema Figure 16. Dried fish on pallets in Tema The storage methods for dried fish in both Kasoa (Figures 12 and 14) and Tema (Figures 15 and16) are not ideal. In Kasoa the fishes are stored in dirty wooden baskets lines with old cement papers, and covered with same paper, or in used polythene sacks used for sugar or rice. The fish is then stored in wooden store houses full of insects, vermin and rain water in case of rains because of the leaky roofs. The use of the cement paper also add cement 62 University of Ghana http://ugspace.ug.edu.gh dust unto the dried fish. In Tema the fish is stored in the wooden baskets lined with old cement paper, and covered with the same paper. They are then placed on wooden pallets in an open field and covered with high density polythene sacks. This can expose the dried fish to contamination from dirt as well as traces of cement material. 4.2 Determination of solar tunnel dryer conditions over a three day period Drying parameters within and outside the solar tunnel dryer were measured using sensors. This was process was necessary because the solar drying process relies on the sun energy which is variable. The solar insolations and temperatures were recorded. Figure 17 shows solar insolation sensor readings for a three days solar tunnel dryer test. 1400 1200 1000 800 600 400 200 0 11.03.14 12.03.14 13.03.14 14.03.14 DATE AND TIME Figure 17. A three days solar insolation reading for the Hohenheim solar tunnel dryer 63 SOLAR INSOLATIONS (Wm) 11:55:01 12:55:01 13:55:01 14:55:01 15:55:01 8:55:00 9:55:00 10:55:00 11:55:00 12:55:00 13:55:00 14:55:00 15:55:00 8:19:38 9:19:38 10:19:38 11:19:38 12:19:38 13:19:38 14:19:38 15:19:38 16:19:38 9:25:25 10:25:25 11:25:25 12:25:25 13:25:25 14:25:25 15:25:25 16:25:25 University of Ghana http://ugspace.ug.edu.gh The results shows that peak solar radiations can be achieved from noon time. The insolation after noon then gradually reduces until around 3:00 -3:30pm where it reduces to the minimum. This follows the natural behavior of the sun as it rises in the morning from the East, peaks at noon and drops around getting to night. Since the photovoltaic powered fans are a part of the dyer which provide the drying air for the process, it means drying on a non-rainy and non- cloudy day can be achieved within the observed optimal time zones. Figure 18 shows temperature sensor readings for a three days trial of the unloaded solar tunnel dryer compared with ambient temperature (oC) 120 Temp. Fish Dryn (øC) Temp. Solar gen (øC) Temp. outside (øC) 100 80 60 40 20 0 11.03.14 12.03.14 13.03.14 14.03.14 DATE AND TIME Figure 18. Temperature sensor readings for a three days trial of the unloaded solar tunnel dryer compared with ambient temperature (oC) 64 TEMPERATURE( oC) 11:55:01 12:45:01 13:35:01 14:25:01 15:15:01 16:05:01 8:55:00 9:45:00 10:35:00 11:25:00 12:15:00 13:05:00 13:55:00 14:45:00 15:35:00 16:25:00 8:39:38 9:29:38 10:19:38 11:09:38 11:59:38 12:49:38 13:39:38 14:29:38 15:19:38 16:09:38 9:05:25 9:55:25 10:45:25 11:35:25 12:25:25 13:15:25 14:05:25 14:55:25 15:45:25 University of Ghana http://ugspace.ug.edu.gh The readings as shown in Figure 18 shows that the solar generation area is mostly hotter (>110oC) than the sample drying area not loaded with any fish sample (40oC-80oC). This is because the solar drying area is fixed with a black solar absorbing background that is able to trap more sun radiation. This hotter area heats up the drying air which is directed through that zone towards the fish drying area. The results also gives an indication for the optimal time for drying using the solar tunnel dryer on a non-rainy and non-cloudy day, i.e. 9:00am and 3:00pm. Any time outside these zones will not result in satisfactory drying during the day and can lead to spoilage of the fish. The ambient temperature was however between 29oC-40oC compared with the temperature of the solar tunnel dryer, which ranged between 40oC and 80oC during the day. This observation accounts for the faster drying using the solar tunnel dryer compared with the open sun method. The lower ambient temperatures accounts for the better fish texture (i.e. springy and not too hard), compared with the solar tunnel dryer which produced a very dry and brittle final product. 4.3 Development of the process for the production of solar dried anchovies using a solar tunnel dryer 4.3.1 Process development The process developed involved transfer of fresh fish in a cold chest and on ice for a minimum time before from the landing beach to the processing site, where it is stored for just one day on ice before drying. This process was a measure to ensure fresh fish is preserved for a minimum time as stated by Abbey (1998) in times of erratic rains. The 65 University of Ghana http://ugspace.ug.edu.gh challenge encounter was the delay in drying as the fish placed in the dryer had to take time to lose the ice before picking up the hot drying air, hence drying in the tunnel started at 0.5 ± 0.11 oC. Although the unit process had more operations than the traditional method, it presented removed the drudgery of bending down to work on fish, as the dryer for the work is elevated above ground. Dried fish under the new process were better kept in a lined polythene sack, from absorbing moisture and also insect and contaminants after processing. Figures 19 and 20 shows open sun dried anchovies from Kasoa, while appendix D is a sample of the anchovies obtained after drying in the solar tunnel dryer. The fish samples appeared dryer than those dried using the open sun method. Their appearance were also darker due to browning under the high temperature drying in the solar tunnel dryer. The texture was also hard and brittle between the fingers compared to the fish dried using the open sun drying method, which were more springy and tender. In spite of the improvement the new process sought to introduce consumers still preferred the traditionally open sun dried anchovies overall because it retained the texture and favour typical of the open sun dried anchovies. 66 University of Ghana http://ugspace.ug.edu.gh Figure 19 Sample of DAK-A Figure 20 Sample of DAK-B 4.4 Quality of traditional open sun and solar dried anchovies The quality of the open sun and solar tunnel dried anchovies were assessed by chemical, physical and sensory evaluation. Sample DAK-A represents open sun dried anchovies done close to salt mining beds in Kasoa Nyanyano, Central Region, DAK-B: Open sun dried anchovies done close to beach in Kasoa Nyanyano, Central Region and STD: Solar tunnel dried anchovies, dried in Shiashi Greater Accra respectively. 4.4.1 Proximate analysis Proximate analysis was carried out on as is basis to determine the effects of the two drying methods on the protein, fat, ash and moisture content of the dried anchovies as shown in Table 17. 67 University of Ghana http://ugspace.ug.edu.gh Table 17. Proximate values for open sun and solar dried anchovies. Sampling Moisture Protein Fat Ash point (%) (%) (%) (%) DAK-A 14.16 ± 0.03a 62.17 ± 0.16 a 4.25 ± 0.15 a 11.11 ± 0.08 a DAK-B 13.22 ± 0.06b 70.01 ± 0.28 b 4.12 ± 0.01 a 12.03 ± 0.06 b STD 11.84 ± 0.08c 74.83 ± 0.45 c 4.00 ± 0.10 a 9.57 ± 0.04 c Values are means ± Standard deviation. Values in the same column with then same letters for each parameter are not significantly deferent at a confidence level of 95%. 4.4.1.1 Moisture: The results shows moisture values of 14.16 ± 0.03%, 13.22 ± 0.06% and 11.84 ± 0.08 % for DAK-A, DAK-B and STD respectively, the difference between the results were statistically significant at p<0.05. The trend was expected because DAK-A was processed by open sun drying method near salt mining ponds in surrounding mostly wet, DAK-B which was also dried by open sun was done on the beach sand, hence no incidence of wetting. Sample STD, was dried in a solar tunnel dryer under controlled conditions hence recorded the lowest moisture content. Another source of variation in the moisture values can be the origin of the fresh anchovies used for drying. Sample DAK-A and DAK-B were obtained and processed at Kasoa, while STD was obtained from Jamestown Accra and 68 University of Ghana http://ugspace.ug.edu.gh processed at Shiashi because there was no fresh anchovies available at Kasoa as at the time of the study. These fishes were harvested on different days. Abbey (1998) and ŠIMAT V and BOGDANOVIĆ T. (2012) have both reported that seasonal variations is a key factor which affects quality of anchovies. 4.4.1.2 Protein: The results shows DAK-A, DAK-B and STD had protein values of 62.17 ± 0.16%, 70.01 ± 0.28 % and 74.83 ± 0.45% respectively. The difference between the results obtained were statistically significant at p<0.05. It is believed that the source variation and the differences in drying methods accounts for the observed trend. The samples DAK-A and DAK-B were obtained from Kasoa, while STD was obtained from Jamestown in Accra and dried using a solar tunnel dryer. The higher protein content of sample STD is due to its lower moisture content. It may also be due to the high heating regime in the solar tunnel dryer may have broken more peptide bonds, and since the analysis was total nitrogen the values were higher compared to samples DAK-A and DAK-B. 4.4.1.3 Fat: The percentage fat recorded were 4.25 ± 0.15%, 4.12 ± 0.01% and 4.00± 0.10% for DAK- A, DAK-B and STD respectively. There were no statistical difference between the results at P<0.05. 69 University of Ghana http://ugspace.ug.edu.gh 4.4.1.4 Ash: The total ash values for DAK-A, DAK-B and STD were 11.11 ± .08%, 12.02 ± 0.06% and 9.57 ± 0.04 % respectively. Differences between the results were statistically significant p<0.05. Research showed that open sun drying increases the level of sand or grits in dried fish, while solar drying eliminates such occurrence (Immaculate et al., 2012). The higher ash values recorded for values recorded therefore shows evidence to support the studies. Among the two open sun drying methods, DAK-B recorded the highest ash values, this is true because the sample was dried on the sandy beach. 4.4.2 Fish spoilage properties. The peroxide value (PV), free fatty acid content (FFA) and histamine values are among the analytical methods for detecting spoilage in fish oils. Generally oils in food deteriorate by chemical means (initiated by oxygen, oxidative rancidity) or by microbial activity (ketonic rancidity). Oxidative rancidity involves the attraction of oxygen by the fat molecules leading to the production of peroxides; this varies with the type of oil. Spoilage of oils is also measured by the free fatty acid value. This is a measure of quantity released in oils alongside the triglycerides also gives an indication of the keeping quality of oil rich product. The free fatty acid and peroxide values of the open sun dried fish (DAK-A and DAK-B) and the solar tunnel dried anchovies (STD) were analysed and the results shown in Figures 21 and 22 respectively. 70 University of Ghana http://ugspace.ug.edu.gh 4.4.2.1 Free fatty acid content: The results of the free fatty acid values of the dried anchovies samples is as shown in Figure 21. 80 70 60 50 40 30 20 10 0 DAK-A DAK-B STD SAMPLE Figure 21. Free fatty acid value of three dried anchovies samples (DAK-A, DAK-B and STD). The Free Fatty Acid (FFA) values of samples DAK-A, DAK-B and STD were 61.47%, 57.03% and 39.19% respectively The differences between the results were statistically significant at P<0.05. The observation can be due the extent of spoilage associated with the DAK samples which were produced under very unhygienic conditions and poorly stored. Source variation is also believed to have resulted in higher FFA for the DAK samples, because those samples had more fat, hence the extent of measured FFA will be relative to the oil content. Studies have suggested higher FFAs is an index of the extent of microbial spoilage, an ideal value of between 0.5% - 1.5% as Oleic acid was believed to be best for good keeping (Immaculate et al., 2012). The values obtained were all above the standard 71 FREE FATTY ACID (%) University of Ghana http://ugspace.ug.edu.gh limit. It can be assumed that the high FFA values for the DAKs may be due to extent of microbial degradation, while the STD can be attributed to the breakdown of fatty acid chains due to the high temperatures in the solar dryer. 4.4.2.2 Peroxide Value (PV): The values of peroxide content of the dried anchovies samples is as shown in Figure 22 80 70 60 50 40 30 20 10 0 DAK-A DAK-B STD -10 -20 SAMPLE Figure 22. Peroxide values of three dried anchovies samples (DAK-A, DAK-B and STD) The results shows a high PV (55.47 meq 02/kg) for DAK-A. Samples DAK-B and STD showed 3.25 meq 02/kg and 4.29 meq 02/kg respectively, the differences between the results were significantly different at P<0.05. The observed differences is however not a strong evidence of differences in the actual peroxide substance formed in the fish within the period of harvest, processing and analysis, since PV is highly unstable and hence can decompose along the line and hence can give some false positives. Turhan et al., (2011) showed that heat processing of fish showed increased the peroxide and free fatty acid 72 PEROXIDE VALUE (MEQ 02/KG) University of Ghana http://ugspace.ug.edu.gh values, especially baking or frying. Other works by Uran and Gokoglu (2014) on the other hand approved of baking of anchovies, which gives it a better textured compared with grilling. This was not observed for the current study although the solar tunnel dryer produced higher temperatures for the fish. 4.4.2.3 Histamine Value: The histamine content recorded of the dried anchovies samples is as shown in Figure 23. 30 25 20 15 10 5 0 DAK-A DAK-B STD SAMPLE Figure 23. Histamine values for three dried anchovies samples (DAK-A, DAK-B and STD) The results shows histamine values of 22.2 ppm, 13.12ppm and 18.55ppm for DAK-A, DAK-B and STD respectively. Source variation may be a factor for the observed trends. This can be from the initial handling of the fresh fish offshore since anchovies is not protected with ice and most fishers harvest the fish into the bare canoe floors exposing them to a lot of microbial agents. All values were lower than values given by önal 73 HISTAMINE (PPM) University of Ghana http://ugspace.ug.edu.gh (2007); between 50–100 mg/kg and 100–800 mg/kg, as well as CODEX (2007) and FAO (1998); 10mg/ 100g limits. This provides proof that the present method of not icing anchovies offshore is not harmful, if fish are processed immediately after landing. 4.4.3 Physical properties The water activity (aW) and colour of the dried anchovies samples were analysed. The results are as part of the quality measurements of the dried anchovies. 4.4.3.1 Water Activity The results for the water activity measurements of the dried anchovies is as shown in Figure 24. 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 DAK-A DAK-B STD SAMPLE Figure 24. Water activity (aW) values for (DAK-A, DAK-B and STD) The results shows water activity values of 0.64%, 0.64% and 0.51% for DAK-A, DAK-B and STD respectively (Figure 26). The differences between the observed results were 74 WATER ACTIVITY (AW) University of Ghana http://ugspace.ug.edu.gh statistically significant at P<0/05. All the samples were below the water activity limit of 0.75 stated by the FAO (1998) for dried salted anchovies. Higher moisture content was expected for the DAK because they are open sun dried, and also not well stored. The storage of the DAK near a fishing coast presents a storage area with higher ambient relative humidity. Sample STD however was produced under higher drying condition, and stored beyond above sea level at Shiashi Greater Accra, where air humidity was lower than that of the coastal regions. The source variation cannot also be ignored, as different morphology of fish can affect the total moisture that is can hold within the muscles. The water activity of samples DAK were higher than STD. It is believed that source variation and the variation in method of processing are factors responsible for the observations. 4.4.3.2 Colour The colour of a fish is a key quality attribute, and can affect its marketability, and it depends on the factors such as the pH and proximate such as water, fat and protein (Ariyarathna, 2011). 75 University of Ghana http://ugspace.ug.edu.gh The results of the colour measurement of the dried anchovies samples is as shown in Figure 25. 60.00 58.00 56.00 54.00 52.00 50.00 48.00 46.00 DAK-A DAK-B STD SAMPLE Figure 25. L* (whiteness) measurement for DAK-A, DAK-B and STD The results show that sample DAK-A recorded the highest L* values of 56.46 on the CIB Lab scale, followed by DAK-B and STD which recorded 52.47 and 52.76 respectively. The difference in the results were statistically significant at P<0.05. It was expected that open sun dried anchovies DAK-A should be whiter because it was dried near solar salt mining beds, contradicts the observations of Owaga et al., (2009) who recorded higher L* values for dagaa washed with 100ppm chlorinated compared with those treated with 3% NaCl. Ariyarathna (2011) also mentioned that salinity reduces the whiteness of dried fish, perhaps due to presence of halophiles in the salty water coupled with the high water activity of above 0.70 Bremner (2002). Although in the current study lower whiteness was undesirable because of the expected quality of the final products, in other products Maillard type discolouration was desirable (Bremner, 2002) 76 L* University of Ghana http://ugspace.ug.edu.gh 4.5 Sensory quality of dried anchovies. Sensory evaluation is a major tool for assessing the organoleptic attributes of a food and the effect of storage, processing and serving processes on the food. A process for drying was developed, and the method tried for the solar tunnel dryer (STD) to produce high quality solar dried anchovies (HQSDA) at the CSIR-Food Research Institute Accra. 4.5.1 Results for consumer acceptability of traditional sun dried and solar tunnel dried anchovies in tomato sauce Table 18 shows the results for the sensory evaluation carried out on the dried fish samples. Where samples DAK-A and DAK-B open sun dried anchovies from Kasoa and sample STD represents solar tunnel dried anchovies at CSIR- Food Research Institute, Shiashie in Greater Accra Region. From the results, all the dried anchovies analysed for all the attributes had scores below 5 on the 7 point hedonic scale. This shows that panelists generally liked the anchovies in tomato sauce. 77 University of Ghana http://ugspace.ug.edu.gh Table 18. Mean Scores for consumer acceptability of traditional sun dried and solar tunnel dried anchovies in tomato sauce Code Appearance Colour Springines Hardness Taste Mouthfeel Smell Aftertaste Overall s acceptability DAK-A 2.54±1.01 2.72±1.07 3.02±1.52 2.78±1.59 3.20±1.56 3.16±1.66 2.94±1.61 3.50±1.82 3.02 ±1.63 DAK-B 2.94±1.42 2.86±1.28 2.56± 1.20 2.62±1.54 3.02±1.52 2.70±1.45 2.80±1.55 2.64±1.45 2.58±1.42 STD 2.44±1.21 2.46±1.33 2.62±1.56 2.60±1.53 2.52±1.33 2.65±1.55 2.64±1.43 2.76±1.49 2.37±1.34 *A 9 point hedonic scale was used where 1= like extremely and 7=dislike extremely. Values recorded are means ± Standard deviation 78 University of Ghana http://ugspace.ug.edu.gh 4.5.1.1 Appearance: Sample STD scored the highest for appearance, followed by the two traditional open air dried samples DAK-A and DAK-B respectively.. The source of the fish and seasonal variation could have influenced the appearance of the fish; i.e. Jamestown and Kasoa Nyanyano. Another possibility for the preference of the colour of STD could be due to its appeal in the stew since that sample was darker than the DAKs when analysed for whiteness. 4.5.1.2 Colour: Sample STD scored the highest, followed by DAK-B and DAK-A respectively. The earlier explanation concerning the cause of preference being possibly due to the darker colour of STD from the colour analysis compared with the DAKs which were whiter. 4.5.1.3 Texture (Springiness): The anchovies sample DAK-B was scored highest for texture (springiness) followed by STD and DAK-A respectively. The texture of fish is affected by seasonal and source variation, proximate composition, processes such as handling, processing and storage. The DAKs were also high in water activity and moisture. These factors made them springier than the STD after drying. 4.5.1.4 Texture (Hardness): The anchovies sample STD was scored highest for texture (hardness) followed by DAK-B and DAK-A respectively. The reasons assigned for the observation for the score for 79 University of Ghana http://ugspace.ug.edu.gh springiness relates very much to hardness. The higher the moisture and water activity the softer the dried fish. 4.5.1.5 Taste: The sample that was scored highest was STD followed by DAK-B and DAK-A respectively. The proximate composition of a fish such as the fat content affects the taste of the fish, because most organic flavour substances are found in the fat phase of fish. The DA-F had the highest protein content followed by the DAK-B and DAK-A. This means the protein content may have accounted for the taste enhancement for the STD. 4.5.1.6 Mouthfeel: The sample, STD was scored highest followed by DAK-B and DAK-A respectively. The trend of mouth feel can be linked to the lower FFA values obtained for STD and DAK-B. Since fat which contains dissolved flavour substances have been less broken down in the two samples, they may have yielded better appeal to tasters. 4.5.1.7 Smell: The anchovies sample STD was scored highest followed by DAK-B and DAK-A respectively. Although it was anticipated that the tomato sauce will mask the real smell of the fish, people still scored yielding an interesting trend. The observation can also be linked to the better FFA scores for STD and DAK-B compared with DAK-A. 80 University of Ghana http://ugspace.ug.edu.gh 4.5.1.8 Aftertaste: Sample DAK-B scored highest followed by STD and DAK-A respectively. The score for aftertaste can also be attributed both to the FFA values. 4.5.1.9 Overall Acceptability: Sample STD was scored highest followed by DAK-B and DAK-A respectively Analysis of the overall acceptability using the Friedman’s test ranked DAK-A as the most preferred followed by DAK-B and STD respectively. This proved that the experimental sample failed the acceptability test. 81 University of Ghana http://ugspace.ug.edu.gh 4.5.2 Friedman test: The Friedman test of significance between the sensory results established that the sample are different in the sensory attributes measured, as shown in Table 19. Tables 19. Summary of rank sums on anchovies in tomato sauce sensory evaluation test Overall acceptability Sample Sum of ranks Order of ranks DAK-A 107.5 1st DAK-B 101.5 2nd STD 91.0 3rd 82 University of Ghana http://ugspace.ug.edu.gh 5.0 CONCLUSIONS AND RECOMMENDATIONS 5.1 Conclusions I. This study has documented that open sun drying is of fish is still a major activity in Ghana, and this trade is dominated by women who belong mainly to the coastal ethnic groups. While Kasoa landing beach is mainly Akans (Fante or Twi), Tema is made up of Gas, Akans and Nzema, with the Ga being resident processors, the others are migrant processors. The low level of education and lack of some social interventions and amenities affects the quality of fish processed as best practices are not followed, and in some case production of fish that can be of public health risk fish produced and the pollution of the environment. The Kasoa fish processing location is mainly affected by biological pollutants. Processors showed willingness to try newer methods of processing to improve their trade and as well as their health. II. The study showed that the optimum time for drying during the day is between 9:00am-3:30pm. A reliable weather prediction system is vital to effectively use the solar drying system. A solar tunnel can give drying temperatures between 30oC- 80oC on a good sunny day. III. Variations in the moisture, fat, ash, protein value, water activity, histamine, FFA, peroxide value, colour and sensory qualities of the dried fish occurred based on the type of drying system used. The higher moisture water activity values of the open sun dried anchovies (DAK-A and DAK-B) compared with the solar tunnel dried anchovies (STD) shows that the solar tunnel drying cannot produce fish of the same 83 University of Ghana http://ugspace.ug.edu.gh quality as the traditional process which depends on ambient conditions. The higher protein content recorded for sample STD compared with the DAKs shows that the higher drying parameters in the solar dryer can leads to break down of the more peptide bonds in fish. The fat contents of samples DAK-A and DAK-B were higher than the sample STD. This shows that the traditional process is able to preserve more of the fish fat because fish is dried immediately upon landing, as compared with the tunnel drying process which involves storage of fish on ice before drying. The hgher total ash values for DAK-A, DAK-B is an indication that the traditional method adds more contamination from sand and grits to the fish. The solar tunnel drying process is more hygienic. IV. The lower FFA and water activity values recorded for sample STD also shows the solar tunnel drying process is a better process and can improve the shelf life of dried fish. The observation of high FFA in the STD also shows that the higher temperatures within a solar tunnel dryer can cause non microbial increase in free fatty acid in dried fish. It also indicates that lower water activity produces products with lower rancidity in dried fish. The observation from the peroxide value analysis means that method is not the best for assessing spoilage in fish. Since the test due to the unstable nature of peroxides formed, which can change during process of analysis. 84 University of Ghana http://ugspace.ug.edu.gh V. The darker colour of sample STD compared with DAK-A and DAK-B shows the solar tunnel drying process cannot produce the whiteness as exists open sun dried fish. 5.2 Recommendations 1. Further studies must be carried out in other fish processing locations in Ghana to profile the status of their trade and gather information to guide policy and future research. 2. There is a need to create synergies between Government Ministries, Departments and Agencies such as Ministry of Agriculture; Fisheries and agencies like the Ghana Statistical Services, Ghana Meteorological services and the Ministry of Fisheries Research and Extension Services that have information needed by researchers. This will ensure uninterrupted flow of vital information for improvement in Ghana’s fisheries. 3. There is a need for follow up technical support for fish processors in Tema to re- commission the greenhouse solar dryer and put it to use. 4. Future studies must be directed at transferring the new method to the processors who are eager to try it. 85 University of Ghana http://ugspace.ug.edu.gh REFERENCES Aba I. P. and Ifannyi N. (2013). 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Chemists, Washington, DC. Pp 1-5. 87 University of Ghana http://ugspace.ug.edu.gh Chavan1, B. R., Yakupitiyage, A. and S. Kumar. (2011). Drying Performance, Quality Characteristics, and Financial Evaluation of Indian Mackerel (Rastrilliger Kangurta) Dried by a Solar Tunnel Dryer. Thammasat Int. J. Sc. Tech., 16 (2): 11-25. Chukwu O. (2009). Influences of Drying Methods on Nutritional Properties of Tilapia Fish (Oreochromis nilotieus). World Journal of Agricultural Sciences 5 (2): 256-258. Codex. (2007). Codex standard for canned sardines and sardine-type products. Codex Alimentarius Codex stan 94 – 1981 (revised 2007). [Available online : http://www.codexalimentarius.net/download/standards/108/CXS_094e.pdf] 25/05/2015. 3:50pm Czerner, M. and María Yeannes, I. (2013). Modelling the effect of temperature and lipid content on anchovies (Engraulis anchoita) salting kinetics. Journal of Food Engineering. 115:164–172 Davies, R. M., & Davies, O. A. (2009). 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B. and Givskov M. (2002). Food Spoilage Bacteria. International Journal of Food Microbiology: 78: 79-92. Hii C. L., Jangam S. V. Ong S. P. and Mujumdar A. S. (2012). Solar drying: Fundamentals, Applications and Innovations. Available online [http://www.arunmujumdar.com/file/Publications/books/Solar%20Drying_F undamentals_Applications_and_Innovations.pdf]. 2/11/2015 4:34pm Hardin R. and Smith, J. G. M. (1976). The storage of mackerel (Scomber scombrus). Development of histamine and rancidity. Journal of Science of Food and Agriculture. 27:595-599 Hovda M. B. Lunestad B. T. Sivertsvik M and Rosnes J. T. (2007). Characterisation of the Bacterial flora of modified atmosphere packaged farmed Atlantic cod (Gadus morhua) by PCR-DGGE of conserved 16S rRNA gene regions. International Journal of Food Microbiology. 117: 68-75. Hyldig, G. and Nielsen D. (2001). A review of sensory and instrumental methods to evaluate the texture of fish muscle. Journal of texture studies. 32: 219-242. Ida, Aba I. P and Nwankwo, Ifannyi. (2013). Effects of smoke-drying temperatures and time on physical and nutritional quality parameters of Tilapia (Oreochromis niloticus). International Journal of Fisheries and Aquaculture 5(3): 29-34, [Available online at http://www.academicjournals.org/IJFA] DOI: 10.5897 Immaculate, K., Sinduja P., Velammomal and Patterson J. (2013). International Food Research Journal 20 (4):1855-1859. 90 University of Ghana http://ugspace.ug.edu.gh Immanculate, J., Sinduja, P. and Jamila, P., (2012). Biochemical and microbial qualities of Sardinella fimbriata sun dried in different methods. International Food Research Journal 19(4): 1699-1703. Jain D. and Pathare, P. B. (2007). Study the drying kinetics of open sun drying of fish. Journal of engineering. 78: 1315-1329. DOI: 10.1016./ j.jfoodeng.2005.12.044. Jangam, S. V., LaW, C. L. and Mujumdar, A. S. (2010). Basic concepts and definitions, in Drying of Foods, Vegetables and Fruits - 1: 1-30 Jemai A. B. (2013). Characterizing The Drying Kinetics of High Water Content Agro- Food Particles Exhibiting Non-Fickian Mass Transport. 32: 1759-1764. Kituu, G.M., Shitanda, D. Kanali1, C.L., Mailutha1, J.T., Njoroge, C.K., Wainaina, J.K. and Ondote, P.M.O. (2009). “Influence of Brining on the Drying Parameters of Tilapia (Oreochromis Niloticus) in a Glass-Covered Solar Tunnel Dryer”. Agricultural Engineering International: the CIGR Ejournal. Manuscript number. EE 1349, Vol. XI. Koffi-Nevri, R. and Kouseéman. M. (2002). Microbiological composition, processing, and consumer characteristics of Adjeuvan, a traditional Ivorian fermented fish. Tropicultura. 30 (1): 9-14. Koranteng, K. (1993). Size at first maturity of the anchovies (Engraulis encrasicolus) in Ghana waters and suggestions for appropriate mesh size in its fishery. Reprinted from Naga, ICLARM, Q. 16(1): 29-30. Kuwornu, J. K., Egyir, I. S. and Anyinam A. F. D. (2011). Design of Solar Drying Technology Equipment for Drying Food Consistent with Farmers 91 University of Ghana http://ugspace.ug.edu.gh Willingness to Pay: Evidence from Ghana. Innovative Systems Design & Engineering. 2( 6): 13-38. Kwenin, W. K. Seidu, J. M. and Bodi-Amoah F. (2013). Nutritional profile, Sensory properties and Microbial quality of solar-dried tilapia (Oreochromis niloticus). International Journal of Engineering and Innovative Technology (IJEIT), 2 (7): 285-290. Mbarki, R., Sadok , S. and Barkallah, I.. (2008). Influence of Gamma Irradiation on Microbiological, Biochemical, and Textural Properties of Bonito (Sarda sarda) During Chilled Storage. Food Sci Tech Int;14(4):367–373. DOI: 10.1177/1082013208097444 [Available online at :http://fst.sagepub.com/content/14/4/367] 2/5/2014 5:00pm. McManus, A and Newton W. (2011). Seafood, nutrition and health: A synopsis of the nutritional benefits of consuming seafood. Center for Excellent Science, Seafoods and health. Cutin Health Innovation Research Institute, Curtin University of Technology, Perth. Australia. Pp. 1-8 Ministry of Fisheries. (2008). National Fisheries and Aquaculture Policy. Fish for tomorrow. Republic of Ghana. Ghana Publishing Company limited. Accra Ghana. Pp. 1-14. Mujaffar, S. and Sankat, C.K. (2005). The air drying behaviour of shark fillets. Canadian Biosystems Engineering. 47(3):11-3.21. Omodara, M. A. and Olaniyan, A. M. (2012). Effects of Pre-Treatments and Drying Temperatures on Drying. Journal of Biology, Agriculture and Healthcare. 2 (4): 1-11. 92 University of Ghana http://ugspace.ug.edu.gh Önal A. (2007). A review: Current analytical methods for the determination of biogenic amines in foods. Food Chemistry 103:1475–1486 Owaga, E. E., Onyango C. A., and Njoroge C. A. (2009). Assessment of insect contamination, acid insoluble ash content and colour characteristics of traditionally sun-dried and oven-dried dagaa (Rastrineobola argentea). 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S.., Azimuddin K. M., Islam M. N. and Kamal M. (2006). Influence of Ice Storage on Raw materials for the production of high quality dried fish products. Journal of Biological Sciences: 6(1): 130-134. 93 University of Ghana http://ugspace.ug.edu.gh Sablani, S. S., Rhaman, M. S., Haffan, I., Mahgoub, O. Al-Ruzeiqi, M. H., Al-Habsi, N. H. and Al-Belushi, R. H. (2003). Drying rates and quality parameters of fish sardines processed using solar dryers. Agriculture and Marine Science, 8(2): 79-86. Sadasivan, S. (1996). Biochemical Methods. Second edition. New age International (P). Limited publishers. New Delhi India. Pp. 23-28. ŠIMAT V and BOGDANOVIĆ T. (2012). Seasonal changes in proximate composition of anchovies. (Engraulis encrasicolus, L.) from the Central Adriatic. ACTA ADRIATICA, 53(1): 125 - 132, Steiner-Asiedu M. Lied, E., Lie, Ø., Nielsen, R. and Julshamu, K. (1993). The nutritive value of sun dried pelagic fish from the Rift Valley in Africa. J. Sci. Food Agric. 63: 439-443. Subarkah, R., Abdurrachim, Hendrarsakti, J. and Belyamin. (2013). Drying Characteristic of Anchovies Fish. Journal of Food Science and Engineering 3: 87-93. Taylor, W. W., Schechter, M. G. and Wolfson L. G. (2007). Globalization: Effect on Fisheries Resources. Cambridge University Press. Cambridge. UK. Pp. 426- 432. Turhan S , Ustun N. S & Temiz H. (2011). Lipid Quality of Anchovies (Engraulis encrasicholus) Fillets Affected by Different Cooking Methods, International Journal of Food Properties, 14:(6)1358-1365. Turhan, S., Evren, M. and Yazici F. (2001). Shelf-Life of Refrigerated Raw Anchovies (Engraulis encrasicholus) Patties. E.U. Journal of Fisheries & Aquatic Sciences.18 (3-4): 391 – 398. 94 University of Ghana http://ugspace.ug.edu.gh Uran H and Gokoglu, N. (2014). Effects of cooking methods and temperatures on nutritional and quality characteristics of anchovies (Engraulis encrasicholus). J Food Sci Technol. 51(4):722–728. Wazed, M. A., Islam, M. T. and Uddin, N. (2009). Solar tunnel fish dryer for seasonal application in the perspective of Bangladesh. Engineering e-Transaction (ISSN 1823-6379). Vol. 4, No. 2. Pp 73-80 [Available Online at http://ejum.fsktm.um.edu.my]. Weiss, W., and Buchinger, J. (2012). Solar Drying. AEE INTEC Publication, A-8200 Gleisdorf, Feldgasse, 19. [Available online at: http://t.aee- intec.at/0uploads/dateien553.pdf] Zulema C., Pavlisko A. and De Vecchi S. (2002). Texture Measurements in Fish and Fish Products, Journal of Aquatic Food Product Technology, 11:(1) 89-105. 95 University of Ghana http://ugspace.ug.edu.gh APPENDICES A. Preparation of solar dried anchovies in tomato sauce Materials Quantity Item Description (multiplied by 3 for each fish sample) Fresh tomatoes Burkina Faso type 759.3g Fresh onions Large type 282.3g Fresh pepper Green and red types 30.3g Tomato paste Gino 70.6g Vegetable oil Soybean type 200ml Powdered salt Iodized type - Anchovies OSD or STD types 226.5g Water Portable water 250ml 96 University of Ghana http://ugspace.ug.edu.gh Equipment Item Description Quantiy Electric stove Ariston [Heating Temp used point 6] 1 Electric blender Panasonic Mx-Ac 300 mixer [2nd speed] 2 Glass beaker (500ml) Transparent type 1 Analytical balance Mettler Toledo-PB 3001 [Max. limit 1 3100g] Cooking pot with cover Stainless steel 3 Ladle Wooden 3 Bowls Plastic 3 Table spoons Stainless steel 3 Kitchen knife Stainless steel 1 Food warmer - 3 97 University of Ghana http://ugspace.ug.edu.gh B. Sample survey questionnaire SOLAR DRIED FISH PROJECT ------ CHARACTERISATION OF TRADITIONAL PRODUCTS AND KNOW-HOW SURVEY QUESTIONNAIRE Prepared by Emmanuel Adokwei Saka Name of interviewer: .................................................................... ............ Date:...................... Landing site: ............... District:........................ Area:........................ 98 University of Ghana http://ugspace.ug.edu.gh CONSENT: The study is aimed at assessing the challenges affecting solar dried fish operations in Ghana, and finding out the needs of processors to develop a holistic solution for players in the sector. Your objective view will help make the study a success for the benefit of my schooling and to influence policy to add value to your operation for better returns. Confidentiality regarding the information you provide is assured, and you have the right to call for removal of your information from the study at any time without any consequence to you. If you agree to continue please sign below. Signed: ..................................................... date:......................................... INSTRUCTIONS Please provide answers that corresponds to the questions asked by a ticking/ underlining/circling/ or writing in the appropriate answers. A. Demographic characteristics 1. Name:............................................................................. [ optional] 2. Age: (a) 30-40 (b) 41-50 (c) 51 and above 3. 3. Gender: (a) Male (b) Female. 4. Ethnic/ Socio-cultural group: (a) Akan (Fante/ Twi) (b) Ga (c) Nzema 5. Marital status: (a) married (b) single (c) divorced (d) widowed 6. What is your level of education?: (a) no schooling (b) primary (c) secondary (d) tertiary (e) vocational 7. How long have you been at this landing?: (a) 1-10year (b) 11-20years (c) 21-30 years (d)31 and above 99 University of Ghana http://ugspace.ug.edu.gh B. Fish handling characteristics Fish handling offshore: 8. i. What are some of the challenges you believe can negatively impact on the quality of fish offshore? (a) over packing (b) not draining blood before packing (c) sitting on fish (d) keeping fresh fish together with other non fish items (e) not keeping fish over ice (f) wrong packaging containers for fish e.g. jute sacks etc ii. What in your view is the best form of package for fish offshore from the time of catch to landing? (a) iced (b) not iced (c) covered (d) not covered Handling at the landing site: 9. i. Do some people drag fish on the ground along the shoreline? (a) Yes (b) No (c) don’t know ii. Why do some members of the fishing community drag fish along the shoreline ground? (a) lack of awareness (b) negligence (c) lack of fish landing facilities (d) poor community leadership (e) don’t know (f) to avoid blood leaking on porter Handling during distribution to processors: 10. Why do fish traders/ transporters stack fish poorly while transporting it? (a) inadequate means of transport (b) lack of proper handling facilities (c) poor community leadership (d) high cost of transport (f) don’t know (g) makes work faster 11. Why do some traders / transporters sit on it in transit? (a) lack of knowledge (b) poor community leadership (c) lack of transport (d) negligence (e) don’t know (f) makes work faster 100 University of Ghana http://ugspace.ug.edu.gh 12. How is fish moved from the shore to processing sites? (a) porters (b) on push trucks (c) in wheel burrows (d) in cars (e) by a donkey draWn cart (f) don’t know 13. Which of the following are used in packing fish in transit to the processing sites (a) head pans (b) baskets (c) plastic bowls (d) sugar sacks (e) paper crates (f) wooden crates (g) plastic crates (h) polythene bags (i) jute sacks C. Artisanal fish processing characteristics: Fresh fish quality 14. Please rank in order of importance any of the three listed quality criteria that are of interest to you? (a) weight (b) size (c) shape (d) appearance (e) colour (f) smell (g) texture (h) feel/ touch (i) defects 15. From the key quality indices selected in (13) rank in order of importance which three of the sub-quality criteria applies your operations (a) overall appearance; (a1) shiny, (a2)metallic wet sheen, (a3) eyes must be bulging or projecting (a4) eyes must be clear and transparent, (a5) gills must be bright red/pink (a6) gills must be free from mucous (a7) skin tone must be elastic and firm (a8) skin must be whole unbroken (b) smell; (b1) fresh, (b2) seaWeedy odour, (b3) gills must smell fresh (c) texture; (c1) firm (c2) elastic feel/ touch; smooth like clean washed plate, (d) colour; (d1) uncoloured (d2) not red or any shade of it (d3) not pink or any shade of it (d4) not green or any shade of it (e) mucus coating on the skin; (f1) free-flowing (f2) fine lubricant (f5) aqueous transparent 101 University of Ghana http://ugspace.ug.edu.gh (f) defects free; must not be bruised, indented, bloody, contaminated (chemical, physical) Fresh fish cleaning 16. Which of the following is needed for washing fresh fish? (a) salt (b) lime (c) kerosene (d) formalin (e) chloride bleach (f) tap water (g) sea water (h) alum 17. What advantages do we obtain using the chemicals? (a) deters insects (b) keeps fish fresh (c) reduces the drying time (d) improves upon the taste of the fish (e) makes it easy for future storage after drying (f) don’t know 18. Do you have any difficulties using chemicals in fish processing? (a) yes (b) No 19. Where do you dispose of solid and liquid fish waste? (a) into the sea (b) in a waste bin (c) close to home (d) feed for animals (e) into a nearby gutter (f) in dug pits (g) into biogas plants. Fish drying 20. At what age did you learn how to dry fish? ………………………….. 21. How did you learn the skills of drying? (a) personal observation (b) family (c) friends (d) By Religious groups (f) Government 22. Why do people dry fish? (a) profit (b) nutrition (c) preservation (d) taste (e) don’t know 23. What type of fish do you dry? (a) pelagic (c)dermesals 24. Which of the following specific fishes do you dry? (a) Anchovies-Amoni or Abobi (b) Horse Mackarel-Kpanla (c) Tuna-Opoku (d) Carangidae-Anteley (e) Sea bream- 102 University of Ghana http://ugspace.ug.edu.gh Wiriwiriwa or Yiyiwa (f) Scad Mackerel-Emule (g) Long-fin herrings-Kanfla (h) Borito-Boboi (i) Cassava fish-Nkan (j) Kingfish-Saflo (k) Spanish Mackerel-Saman (l) Groupers-Klala (m)...............-.Sofee (n) ............. Ansang (o).............- Tiorkor other (s) Spotted box crab-Nsor mli Kaa (t) PraWns-Song (u) Lobsters- Gnyaa Tsentsen (v) Tilapia-Koobi, Didei 25. What type of drying method do you use? (a) open air (sun) drying (b) smoke drying (c) solar drying (d) mechanical drying 26. What type of fuel or energy do you use for drying? (a) firewood (b) gas (c) kerosene (d) sun (e) waste wood 27. Which of the above do you find cheaper to use for your operations? (a) firewood (b) gas (c) kerosene (d) sun (e) waste wood 28. What steps do you follow to produce open air dried fish and the time taken? ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… …………………….................................................................................................... 29. Which of the following factors do you think influence the drying of fish? please list in order of importance (a) species or type of fish (b) size (c) shape (d) age (e) type of storage of fresh fish (f) season of fish harvest (g) type and level of defect (h) salting or not salting 30. What is the average time for drying under the following conditions? (a) Fatty fish.............. Non fatty fish..........(b) Pelagic............. Dermesals........... (c) Iced/ Non 103 University of Ghana http://ugspace.ug.edu.gh iced............... (d) salted/ unsalted.......... (e) early year catch/ end of year catch............. (f) whole fish/ defective fish............................... (g) Harmattan season. 31. Which of the following process do you follow during open air drying of fish? (a) sorting (b)cleaning and washing (c) salting (d) spreading (e) drying (f) stirring (g) packing (h) cleaning (i) Quality check (j) packaging (k) labelling (l) storing (m) spreading insecticide 32. Which type salt do you use in your operation? (a) local sea salt (b) iodized salt- (c) recycled salt-from previous day’s work 33. Do some spread fish for drying on the ground? (a) yes (b) no 34. Why do some fish processors dry on the ground? (a) lack of l lack of awareness (b) poor community leadership (c) negligence (d) lack of spreading facilities (e) lack of alternative means (f) cheaper space for work (g) don’t know 35. What challenge do you face during open air drying? (a) loss of fish due to run off water/ rain, (b) high tide water (c) insects (d) birds and vermin (e) theft (f) nearby waste dumps 36. How do you deter pest and vermin from the fish being dried? (a) periodic chasing (b) scare crows (c) Nothing (d) traps (e) poisons (f) pets like dogs and cats 37. Which aspect of this process is most challenging to you? (a) bad weather (b) flooding during high tides (c) land ownership (d) sanitation (e) labour (f) access to funds (g) inadequate equipment (h) Inadequate or lack of training (i) lack of standards (i) theft 104 University of Ghana http://ugspace.ug.edu.gh Dried fish quality 38. Which of the following quality criteria for fish is of importance to you? (a) weight (b) size (c) shape (d) appearance (e) colour (f) smell (g) texture (h) feel/ touch (i) defects 39. What in your view are the key quality indices for air dried fish? (a) appearance; (a1) fresh, (a2)not dull or bloody looking, (a3) body must be full, firm looking and whole not bruised, punched or flabby (b) smell; (b1) fresh dried, (b2) not stale, (b3) not rotting, (c) feel/ touch; hard (c1), must not be brittle (c2) (d) texture; firm with snap sound on breaking (e) colour; must be typical whitish, (f) defects free; (f1) must not be bruised, (f2) indented, bloody, (f3) contaminated (chemical, physical), (f4) should be sand free, (f5) insect free D. Artisanal processed fish storage: Packaging 21 What type of packaging do you use for large quantity dried fish? (a) Jute sacks (b) woven sugar sacks (c) flour bags (d) baskets (e) boxes (f) old cement paper bags (f) polythene bags 22. In what quantities do you pack dried fish for storage? (a) below 1Kg (b) 1-5 Kg (c) 5-20 Kg (d) Above 20 Kg 23. How do you store the packaged fish? (a) in wooden built store houses (b) in the kitchen (c) in the room (d) outside covered (e) in store house at the market 105 University of Ghana http://ugspace.ug.edu.gh 24. How do you prevent insect attack on dried fish during storage? (a) poisons (b) insecticides (c) smoke (d) proper covering with polythene bags 25. Artisanal processed fish processing marketing: Packaging 26. What type of packaging do you use for large quantity dried fish for sale? (a) jute sacks (b) woven sugar sacks (c) flour bags (d) baskets (e) boxes 27. Which of the following quality indices influences the final price of the dried fish? (a) weight (b) size (c) shape (d) appearance (e) colour (f) smell (g) texture (h) feel/ touch (i) defects 28. How much does a given quantity of dried fish cost? (a) one carton .................. (b) one small basket ..........(c) One medium size basket ...................................... (d) One big basket ............(e) one 50kg sack .....................(f) one 100kg sack...................... (g) one 150kg sack.......................Where do you sell your dried fish? (a) local area market (b) Accra (c) other parts of Ghana (d) overseas 106 University of Ghana http://ugspace.ug.edu.gh C. 1. Hoheiheim solar tunnel dryer stationed at CSIR-Food Research Institute (FRI) Shiashi Accra Ghana. 107 University of Ghana http://ugspace.ug.edu.gh C.2 Technical details of tunnel dryer Length 18m Width 2m Collector area 16m2 Drying area 20m2 Air flow rate 400-1200m3/h Air temperature 30-80oC Power requirement 20-40W Thermal energy gain from solar radiation Up to 60kWh/d (≈ 15 kg firewood) Drive of fans Solar panel Number of fans 3 Price US$ 5,25 (+US$ 250 for PV) Products Indirect operation ideal for sensitive products Climate Operation in arid and humid regions; adaptable to local climate Control Self-regulated airflow and temperature (solar panel type) (Weiss and Buchinger, 2012) 108 University of Ghana http://ugspace.ug.edu.gh D. Solar tunnel dried anchovies (7hrs) E. Solar tunnel dried anchovies in tomato sauce 109 University of Ghana http://ugspace.ug.edu.gh F. Sample questionnaire Test of open air and solar tunnel dried fish in tomato sauce Consumer consent: You have been invited to partake in this study aimed at developing a suitable process for developing high quality solar dried fish for the local market. Kindly fill in your details below if you will like to help and follow the directions for assessing the product. Your views are very important, but not subject to change should you later choose to redraw your information during or after the study. Thank you for your kind support. Best assured your views will be treated with the honour and discretion it needs. Name:…………………………………………….. Product: ……………………………. Date: ……………………. You have been presented with dried fish samples. Please assess by breaking, smelling and tasting and indicate your level of liking using the scale hedonic scale bellow: Like extremely----------------1 Like moderately---------------2 Like slightly-------------------3 Neither like nor dislike------4 110 University of Ghana http://ugspace.ug.edu.gh Dislike slightly---------------5 Dislike moderately----------6 Dislike extremely------------7 ATTRIBUTES SAMPLE CODE SAMPLE CODE SAMPLE CODE ……………… ……………….. …………… Appearance Texture (sponginess/ crispiness) Taste (level of freshness) Smell (level of off flavours) Mouth feel (Level of grittiness) Aftertaste (Level or rancidity) Overall acceptability Which of the samples will you be willing to buy and why?: ……………………………………………………………………………………………… ……………………………………………………………………………………………… 111 University of Ghana http://ugspace.ug.edu.gh Comments: ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… 112 University of Ghana http://ugspace.ug.edu.gh G. ANOVA results on dried anchovies One-way ANOVA: MOISTURE versus SAMPLE Source DF SS MS F P Sample 2 5.44990 2.72495 414.97 0.000 Error 3 0.01970 0.00657 Total 5 5.46960 S = 0.08103 R-Sq = 99.64% R-Sq(adj) = 99.40% One-way ANOVA: PROTEIN versus SAMPLE Source DF SS MS F P Sample 2 163.296 81.648 403.23 0.000 Error 3 0.607 0.202 Total 5 163.903 S = 0.4500 R-Sq = 99.63% R-Sq(adj) = 99.38% One-way ANOVA: ASH versus SAMPLE Source DF SS MS F P Sample 2 4.53343 2.26172 264.01 0.000 Error 3 0.02570 0.00857 Total 5 4.54913 S = 0.09256 R-Sq = 99.44% R-Sq(adj) = 99.06% 113 University of Ghana http://ugspace.ug.edu.gh One-way ANOVA: FAT versus SAMPLE Source DF SS MS F P Sample 2 0.0601 0.0300 1.45 0.000 Error 3 0.0621 0.0207 Total 5 0.1222 S = 0.1439 R-Sq = 49.18% R-Sq(adj) = 15.30% One-way ANOVA: Peroxide Value ( PV) versus SAMPLE Source DF SS MS F P Sample 2 3564.935 1782.467 66058.09 0.000 Error 3 0.081 0.027 Total 5 3565.016 S = 0.1643 R-Sq = 100.00% R-Sq(adj) = 100.00% One-way ANOVA: Free Fatty Acid Value (FFA) versus SAMPLE Source DF SS MS F P Sample 2 3564.935 1782.467 0.000 Error 3 0.081 0.027 Total 5 3565.016 S = 2.019 R-Sq = 98.22% R-Sq(adj) = 97.03% 114 University of Ghana http://ugspace.ug.edu.gh One-way ANOVA: WATER ACTIVITY (aW) versus SAMPLE Source DF SS MS F P Sample 2 0.032614 0.016307 159.35 0.000 Error 6 0.000614 0.000102 Total 8 0.033228 S = 0.01012 R-Sq = 98.15% R-Sq(adj) = 97.54% One-way ANOVA: L versus SAMPLE Source DF SS MS F P Sample 3 118.30 39.43 12.88 0.000 Error 24 73.48 3.06 Total 27 191.78 S = 1.750 R-Sq = 61.68% R-Sq(adj) = 56.90% 115