Browsing by Author "Owusu-Kwarteng, J."
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Item Identification of lactic acid bacteria isolated during traditional fura processing in Ghana(Food Microbiology, 2012-10) Owusu-Kwarteng, J.; Akabanda, F.; Nielsen, D.S.; Tano-Debrah, K.; Glover, R.L.K.; Jespersen, L.Fura is a millet-based spontaneously fermented dumpling produced and consumed in parts of West Africa, particularly Nigeria, Burkina Faso and Ghana. From eight traditional fura production sites in northern Ghana, 862 lactic acid bacteria were isolated and identified to species level using a combination of genotypic and phenotypic methods including (GTG)5-based PCR fingerprinting and 16S rRNA gene sequencing, multiplex PCR by means of recA gene sequence comparison, conventional morphological characteristics and carbohydrate fermentation profiling. During millet dough fermentation, pH decreased from 5.6-6.4 to 4.1-3.7 and total lactic acid bacteria (LAB) counts increased from 4.4-5.3 to 7.9-9.2 log10 (cfu/g). The initial stages of the fermentation were characterized by co-dominance of homo- and heterofermentative species of Pediococcus acidilactici, Weisella confusa, Lactobacillus fermentum, Lactobacillus reuteri, Lactobacillus salivarius, and Lactobacillus paraplantarum whereas L. fermentum was dominating at the end of the fermentation. L. fermentum was predominant in all fermentations (p < 0.05) and a high uniformity was observed among production sites regarding the dominance of L. fermentum. L. fermentum and W. confusa were isolated in all production sites and almost at all fermentation stages indicating that they are indigenous to traditional fura processing. The other LAB bacteria species which comprised a minor proportion of the total LAB occurred occasionally and in an irregular pattern among the production sites. © 2012 Elsevier Ltd.Item Molecular Diversity and Technological Properties of Predominant Microorganisms Associated with the Processing of Millet into Fura, A Fermented Food in Ghana(University of Ghana, 2013-12) Owusu-Kwarteng, J.; Tano-Debrah, K.; Jespersen, L.Fura is a millet-based spontaneously fermented dumpling produced and consumed in parts of West Africa, particularly Nigeria, Burkina Faso and Ghana. From eight (8) traditional fura production sites in northern Ghana, lactic acid bacteria (LAB) and yeasts were isolated, characterized and identified using genotypic methods. These included (GTG) 5 -based rep-PCR fingerprinting, sequencing of the 16S rRNA gene, multiplex PCR by means of recA gene sequence comparison and sequencing of D1/D2 region of 26S rRNA genes. Following identification, the predominant LAB were assessed for some technological properties including rates of acidification, exopolysaccharide production, amylase production and bacteriocin activities. The identified yeasts were also assessed for their probiotic potential by measuring tolerance to low pH (2.5), bile salt (0.3% oxgall) and temperature (37°C). Based on the genotypes, the LAB species associated with fura processing include L. fermentum (40.8%), W. confusa (19.0%), L. reuteri (13.9%), P. acidilactici (11.8%), L. salivarius (8.1%) and L. paraplantarum (6.3%). L. fermentum predominated in all fermentations (p< 0.05) and uniformity was observed among production sites regarding the dominance of L. fermentum. L. fermentum and W. confusa were isolated in all production sites and almost at all fermentation stages indicating that they are indigenous to traditional fura processing. The yeast species identified include Candida krusei (60%), Kluyveromyces marxianus (38%), Candida tropicalis (0.6%), Candida rugosa (0.2%), Candida fabianii (0.4%), Candida norvegensis (0.6%) and Trichosporon asahii (0.4%). C. krusei and K. marxianus were found to be the dominant species throughout the fermentation and were isolated from all production sites. Generally, majority of predominant LAB strains showed faster acidification rates, high exopolysaccharides production and the ability to inhibit pathogens through the production of bacteriocins. Yeasts isolated from fura survived and grew at human gastrointestinal conditions of pH 2.5 and 0.3% (w/v) oxgall at 37°C over 4 h duration. Additionally, strains of C. krusei, K. marxianus, C. rugosa and T. asahii were able to increase the relative TEER of Caco-2 monolayers after 48 h, making them possible candidates for the development of starter/co-cultures with probiotic potentials. The study has shown the diversity of microorganisms associated with fura processing. It has also revealed the technological properties of the microorganisms that impact on the product and therefore provided the basis for development of starter cultures.Item Self-reported use and understanding of food label information among tertiary education students in Ghana(Food Control, 2019-08-23) Kunadu, A.P.H.; Madilo, F.K.; Owusu-Kwarteng, J.; Tano-Debrah, K.Food packaging labels attract consumers' attention in stores and market areas, and communicates relevant food safety and nutrition information that allows them to distinguish between food product alternatives. Therefore, the objective of this study was to assess consumers' self-reported use, knowledge and understanding of food labels among tertiary students in Ghana. A validated questionnaire was used to recruit 1478 students from fourteen (14) public tertiary institutions across the 10 regions to collect information on demographic characteristics of respondents, usage and understanding of information provided on food labels, using proportional quota and convenience sampling techniques. The majority of respondents 956 (64.7%) were between the ages of 21 and 30. A total of 463 (31.3%) students read food label ‘very often’ while 892 (60.4%) read food labels ‘sometimes’. While 963 (65.2%) of respondents indicated that information on food labels are very important, 934 (63.2%) still believe that food label information are often not credible. Respondents considered expiring date 1269 (85.9%), date of manufacture 1106 (74.8%) and health warning 1097 (74.2%) as the top three very important information on food labels whereas product value/weight, 654 (44.2%) was considered as least important in choosing particular food products. Respondents generally depend on television programs/advertisement, 1349 (91.3%); internets, 1290 (87.3%) and friends and neighbors, 1213 (82.1%) as sources of knowledge regarding food label information. When participants were provided with a sample food label to assess their understanding of food label information, 916 (62.0%) of respondents did not answer the question at all. Out of 562 (38%) who answered the question, only 243 (16.5%) correctly interpreted the information. No significant difference (P > 0.05) exist between ages, sexes, institutions, and university and training college students regarding their understanding of food label information. Eventhough tertiary education students in Ghana read and attach importance to food label information, they have limited understanding of the information provided on food labels.Item Taxonomic and molecular characterization of lactic acid bacteria and yeasts in nunu, a Ghanaian fermented milk product(Food Microbiology, 2013-06) Akabanda, F.; Owusu-Kwarteng, J.; Tano-Debrah, K.; Glover, R.L.K.; Nielsen, D.S.; Jespersen, L.Produced from raw unpasteurized milk, nunu is a spontaneously fermented yoghurt-like product made in Ghana and other parts of West Africa. Despite the importance of nunu in the diet of many Africans, there is currently only limited information available on the microorganisms associated with nunu processing. With the aim of obtaining a deeper understanding of the process and as a first step towards developing starter cultures with desired technological properties for nunu production, a microbiological characterization of nunu processing in three different towns in the Upper East region of Ghana, namely Bolgatanga, Paga and Navrongo, was carried out. Lactic acid bacteria (LAB) and yeasts associated with nunu processing were isolated and identified using a combination of pheno- and genotypic methods including morphological and carbohydrate fermentation tests, (GTG)5-based rep-PCR, multiplex PCR, and 16S and 26S rRNA gene sequencing. The LAB counts during nunu processing increased from 4.5 ± 0.4 log cfu/ml at 0 h to 8.7 ± 1.8 log cfu/ml at 24 h of fermentation while yeasts counts increased from 2.8 ± 1.2 log cfu/ml at 0 h to 5.8 ± 0.5 log cfu/ml by the end of fermentation. Lactobacillus fermentum was the dominant LAB throughout the fermentations with Lactobacillus plantarum and Leuconostoc mesenteroides playing prominent roles during the first 6-8 h of fermentation as well. Less frequently isolated LAB included Lactobacillus helveticus, Enterococcus faecium, Enterococcus italicus, Weissella confusa and a putatively novel Lactococcus spp. The yeasts involved were identified as Candida parapsilosis, Candida rugosa, Candida tropicalis, Galactomyces geotrichum, Pichia kudriavzevii and Saccharomyces cerevisiae with P. kudriavzevii and S. cerevisiae being the dominant yeast species. © 2012 Elsevier Ltd.Item Technological properties and probiotic potential of Lactobacillus fermentum strains isolated from West African fermented millet dough(2015-11-11) Owusu-Kwarteng, J.; Tano-Debrah, K.; Akabanda, F.; Jespersen, L.Abstract Background Throughout Africa, food fermentations are still driven by indigenous microorganisms which influence the nutritional, organoleptic and safety of the final products. However, for improved safety, consistent quality and beneficial health effects, a trend has emerged which involves the isolation of indigenous strains from traditional fermented products to be used as functional starter cultures. These functional starter cultures possess inherent functional characteristics and can contribute to food quality and safety by offering one or more organoleptic, nutritional, technological or health advantage (probiotics). With the aim of selecting potential probiotic starter cultures, Lactobacillus fermentum strains isolated from fermented millet dough were investigated for technological properties and probiotic traits in-vitro. Results A total of 176 L. fermentum strains were assessed for technological properties including rate of acidification, exopolysaccharide production and amylase activity. Following this, 48 strains showing desirable technological properties were first screened for acid resistance. Sixteen acid resistant strains were assessed for additional probiotic properties including resistance to bile salts, bile salt hydrolysis, antimicrobial property, haemolysis and antibiotics resistance. L. fermentum strains clustered into 3 groups represented by 36 %, 47 % and 17 % as fast, medium and slow acidifiers respectively. About 8 %, 78 % and 14 % of the strains showed strong, weak and no exopolysaccharides production respectively. Amylase activity was generally weak or not detected. After exposure of 48 L. fermentum strains to pH 2.5 for 4 h, 16 strains were considered to be acid resistant. All 16 strains were resistant to bile salt. Four strains demonstrated bile salt hydrolysis. Antimicrobial activity was observed towards Listeria monocytogenes and Staphylococcus aureus but not E. coli and Salmonella enteritidis. Lactobacillus fermentum strains were generally susceptible to antibiotics except 6 strains which showed resistance towards streptomycin, gentamicin and kanamycin. Conclusion In vitro determination of technological and probiotic properties have shown strain specific difference among L. fermentum strains isolated from fermented millet dough. Sixteen (16) L. fermentum strains have been shown to possess desirable technological and probiotic characteristics in vitro. These strains are therefore good candidates for further studies to elucidate their full potential and possible application as novel probiotic starter cultures.Item Technological properties and probiotic potential of Lactobacillus fermentum strains isolated from West African fermented millet dough(BMC Microbiology, 2015-11) Owusu-Kwarteng, J.; Tano-Debrah, K.; Akabanda, F.; Jespersen, L.Background Throughout Africa, food fermentations are still driven by indigenous microorganisms which influence the nutritional, organoleptic and safety of the final products. However, for improved safety, consistent quality and beneficial health effects, a trend has emerged which involves the isolation of indigenous strains from traditional fermented products to be used as functional starter cultures. These functional starter cultures possess inherent functional characteristics and can contribute to food quality and safety by offering one or more organoleptic, nutritional, technological or health advantage (probiotics). With the aim of selecting potential probiotic starter cultures, Lactobacillus fermentum strains isolated from fermented millet dough were investigated for technological properties and probiotic traits in-vitro. Results A total of 176 L. fermentum strains were assessed for technological properties including rate of acidification, exopolysaccharide production and amylase activity. Following this, 48 strains showing desirable technological properties were first screened for acid resistance. Sixteen acid resistant strains were assessed for additional probiotic properties including resistance to bile salts, bile salt hydrolysis, antimicrobial property, haemolysis and antibiotics resistance. L. fermentum strains clustered into 3 groups represented by 36 %, 47 % and 17 % as fast, medium and slow acidifiers respectively. About 8 %, 78 % and 14 % of the strains showed strong, weak and no exopolysaccharides production respectively. Amylase activity was generally weak or not detected. After exposure of 48 L. fermentum strains to pH 2.5 for 4 h, 16 strains were considered to be acid resistant. All 16 strains were resistant to bile salt. Four strains demonstrated bile salt hydrolysis. Antimicrobial activity was observed towards Listeria monocytogenes and Staphylococcus aureus but not E. coli and Salmonella enteritidis. Lactobacillus fermentum strains were generally susceptible to antibiotics except 6 strains which showed resistance towards streptomycin, gentamicin and kanamycin. Conclusion In vitro determination of technological and probiotic properties have shown strain specific difference among L. fermentum strains isolated from fermented millet dough. Sixteen (16) L. fermentum strains have been shown to possess desirable technological and probiotic characteristics in vitro. These strains are therefore good candidates for further studies to elucidate their full potential and possible application as novel probiotic starter cultures.Item The use of lactic acid bacteria starter culture in the production of Nunu, a spontaneously fermented milk product in Ghana(International Journal of Food Science, 2014-12) Akabanda, F.; Owusu-Kwarteng, J.; Tano-Debrah, K.; Parkouda, C.; Jespersen, L.Nunu, a spontaneously fermented yoghurt-like product, is produced and consumed in parts of West Africa. A total of 373 predominant lactic acid bacteria (LAB) previously isolated and identified from Nunu product were assessed in vitro for their technological properties (acidification, exopolysaccharides production, lipolysis, proteolysis and antimicrobial activities). Following the determination of technological properties, Lactobacillus fermentum 22-16, Lactobacillus plantarum 8-2, Lactobacillus helveticus 22-7, and Leuconostoc mesenteroides 14-11 were used as single and combined starter cultures for Nunu fermentation. Starter culture fermented Nunu samples were assessed for amino acids profile and rate of acidification and were subsequently evaluated for consumer acceptability. For acidification properties, 82%, 59%, 34%, and 20% of strains belonging to Lactobacillus helveticus, L. plantarum, L. fermentum, and Leu. mesenteriodes, respectively, demonstrated fast acidification properties. High proteolytic activity (> 100 to 150 μg/mL) was observed for 50% Leu. mesenteroides, 40% L. fermentum, 41% L. helveticus, 27% L. plantarum, and 10% Ent. faecium species. In starter culture fermented Nunu samples, all amino acids determined were detected in Nunu fermented with single starters of L. plantarum and L. helveticus and combined starter of L. fermntum and L. helveticus. Consumer sensory analysis showed varying degrees of acceptability for Nunu fermented with the different starter cultures. © 2014 Fortune Akabanda et al.