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Item Pod storage with roasting: A tool to diversifying the flavor profiles of dark chocolates produced from ‘bulk’ cocoa beans? (part I: aroma profiling of chocolates)(Food Research International, 2019-01-23) Afoakwa, E.O.; Hinneh, M.; Abotsi, E.E.; de Walle, D.V.; Tzompa-Sosa, D.A.; De Winne, A.; Simonis, J.; Messens, K.; Durme, J.V.; De Cooman, L.; Dewettinck, K.The impact of pod storage (PS) and roasting temperature (RT) on the aroma profiles of dark chocolates were evaluated. Cocoa liquor samples comprised of ten different combinations of PS and RT, whilst keeping the roasting time fixed at 35 min. Additionally, commercial cocoa liquors from renowned origins (Ecuador, Madagascar, Venezuela, Vietnam, Ivory Coast and Ghana) were acquired for comparison. From these, 70% dark chocolates were produced under the same conditions after which they were subjected to headspace solid-phase microextraction-gas chromatography–mass spectrometry (HS-SPME-GC–MS) analysis. Although both PS and RT were found to influence the aroma volatile concentrations, the impact of RT over PS seemed to be greater. An agglomerative hierarchical clustering (AHC) of all chocolates on the basis of their aroma profiles revealed a similar impact as earlier observed, where major clustering of the chocolates was in accordance with the intensity of the roasting process applied. However, within each group, the dissimilarities owing to PS among the chocolates was clearly depicted. Comparatively, chocolates with low (100–120 °C), instead of moderate to high (135–160 °C) RT's, rather showed a low dissimilarity with those from the commercial cocoa liquors of the different origins. Although from the same beans, the diversity of aroma profiles of these chocolates as well as the similitude of some treatments to some chocolates from commercial grade cocoa liquors, unequivocally underscores the possibility for steering diverse distinct flavors from ‘bulk’ cocoa through PS and roasting, with beneficial implications, both from an application and an economic point of view.Item Pod storage with roasting: A tool to diversifying the flavor profiles of dark chocolates produced from ‘bulk’ cocoa beans? (part I: aroma profiling of chocolates)(Food Research International, 2019-05) Hinneh, M.; Abotsi, E.E.; Van de Walle, D.; Tzompa-Sosa, D.A.; De Winne, A.; Simonis, J.; Messens, K.; Van Durme, J.; Afoakwa, E.O.; De Cooman, L.; Dewettinck, K.The impact of pod storage (PS) and roasting temperature (RT) on the aroma profiles of dark chocolates were evaluated. Cocoa liquor samples comprised of ten different combinations of PS and RT, whilst keeping the roasting time fixed at 35 min. Additionally, commercial cocoa liquors from renowned origins (Ecuador, Madagascar, Venezuela, Vietnam, Ivory Coast and Ghana) were acquired for comparison. From these, 70% dark chocolates were produced under the same conditions after which they were subjected to headspace solid-phase microextraction-gas chromatography–mass spectrometry (HS-SPME-GC–MS) analysis. Although both PS and RT were found to influence the aroma volatile concentrations, the impact of RT over PS seemed to be greater. An agglomerative hierarchical clustering (AHC) of all chocolates on the basis of their aroma profiles revealed a similar impact as earlier observed, where major clustering of the chocolates was in accordance with the intensity of the roasting process applied. However, within each group, the dissimilarities owing to PS among the chocolates was clearly depicted. Comparatively, chocolates with low (100–120 °C), instead of moderate to high (135–160 °C) RT's, rather showed a low dissimilarity with those from the commercial cocoa liquors of the different origins. Although from the same beans, the diversity of aroma profiles of these chocolates as well as the similitude of some treatments to some chocolates from commercial grade cocoa liquors, unequivocally underscores the possibility for steering diverse distinct flavors from ‘bulk’ cocoa through PS and roasting, with beneficial implications, both from an application and an economic point of view.Item Tempering, polymorphism and fat crystallization during industrial chocolate manufacture: Regimes, behaviours and their effects on finished chocolate quality(New Topics in Food Engineering, 2011-01) Afoakwa, E.O.; Paterson, A.Tempering, a technique of shearing chocolate mass at controlled temperatures is used to promote cocoa butter crystallization in a thermodynamically stable polymorphic form. During chocolate manufacture, the process is used to obtain the stable form V (or β2) of cocoa butter having a melting temperature of 32-34 °C, which gives the desired glossy appearance, good snap, contraction and enhanced shelf life characteristics. However, the tempering sequences, their behaviour during pre-crystallization, the consequential regimes attained and their effects on product quality characteristics are not very well understood. Variations in temper regimes attained during pre-crystallization of chocolates influence their crystallinity, polymorphic status and other physical quality characteristics. Over-tempering causes increases in product hardness, stickiness with reduced gloss and darkening of product surfaces. Under-tempering induces fat bloom in products with consequential quality defects in structure, texture, melting properties and appearance (colour and surface gloss). Thus, the different temper regimes attained during pre-crystallization result in wide variations in product quality attributes with varied influences on quality. In a modern competitive confectionery market, understanding the variables leading to chocolate pre-crystallization during tempering and effects of the regimes attained on the quality of the finished products are vital to assurances in quality and shelf characteristics. © 2011 by Nova Science Publishers, Inc. All rights reserved.Item Optimisation of chocolate formulation using dehydrated peanut-cowpea milk to replace dairy milk(Journal of the Science of Food and Agriculture, 2012-01) Aidoo, H.; Sakyi-Dawson, E.; Abbey, L.; Tano-Debrah, K.; Saalia, F.K.BACKGROUND: The rheological properties of chocolate, based upon its acceptability by consumers, are determined largely by the ingredients and their proportions used in the formulations. Milk chocolates are very popular because milk provides flavour and smooth texture to the product. This study aimed to determine the optimal ingredient formulation for vegetable milk chocolate using peanut-cowpea milk as a substitute for dairy milk. The study followed a four-component constrained mixture design, with cocoa liquor, vegetable milk, cocoa butter and sugar as the components. Lecithin and vanillin were added at a constant amount to all formulations. Critical attributes of the chocolates were evaluated using descriptive sensory tests and instrumental techniques. RESULTS: Regression models were fitted to the data, and the optimum ingredient formulation for acceptable vegetable milk chocolate was determined. The vegetable milk had significant (P = 0.05) influence on flavour, mouth feel, hardness and after taste of chocolates. CONCLUSIONS: The optimum ingredient formulation for acceptable vegetable milk chocolates was determined to be cocoa liquor (18.00%), sugar (30.75%), peanut-cowpea milk (28.93%), and cocoa butter (22.32%). The results demonstrate that it is feasible to use vegetable source milk for chocolate. The findings also provide clues for scale-up criteria for large-scale production of vegetable milk chocolate. © 2011 Society of Chemical Industry.Item Application of ISO 22000 in comparison with HACCP on industrial processing of milk chocolate(International Food Research Journal, 2013-01) Afoakwa, E.O.; Mensah-Brown, H.; Crentsil, G.K.; Frimpong, K.; Asante, F.Hazard analysis was conducted to identify critical control points (CCPs) during cocoa processing and milk chocolate manufacture and applied into a hazard analysis and critical control point (HACCP) plan. During the process, the different biological, physical and chemical hazards identified at each processing stage in the hazard analysis worksheet were incorporated into the HACCP plan to assess the risks associated with the processes. Physical hazards such as metals, stones, fibres, plastics and papers; chemical hazards such as pesticide residues, mycotoxins and heavy metals; and microbiological hazards such as Staphyloccous aureus, coliforms, Salmonella, Aspergillus and Penicillium were identified. ISO 22000 analysis was conducted for the determination of some pre-requisite programmes (PrPs) during the chocolate processing and compared with the HACCP system. The ISO 22000 Analysis worksheet reduced the CCPs for both cocoa processing and chocolate manufacture due to the elimination of the pre-requisite programmes (PrPs). Monitoring systems were established for the CCPs identified and these included preventive measures, critical limits, corrective actions, assignment of responsibilities and verification procedures. The incorporation of PrPs in the ISO 22000 made the system simple, more manageable and effective since a smaller number of CCPs were obtained. © All Rights Reserved.Item Optimization of inulin and polydextrose mixtures as sucrose replacers during sugar-free chocolate manufacture - Rheological, microstructure and physical quality characteristics(Journal of Food Engineering, 2014-04) Aidoo, R.P.; Afoakwa, E.O.; Dewettinck, K.Inulin and polydextrose have in recent times form basic ingredients in the manufacture of many sugar-free products. However, the applicability and suitability of inulin and polydextrose mixtures as sucrose replacers during manufacture of sugar-free chocolate is yet to be fully understood. This work investigated optimum conditions as well as influences of inulin and polydextrose mixtures as sucrose replacers on rheological properties, microstructure and physical qualities during manufacture of sugar-free chocolate. Increasing inulin concentrations with simultaneous reduction in polydextrose resulted in consistent increases in the Casson plastic viscosity while that led to decreases in Casson yield stress. Chocolate formulated with 100% polydextrose revealed large crystals with dense smaller particles and minimal inter-particle spaces compared to large crystals with more void spaces in chocolates formulated with 100% inulin. Chocolate formulation consisting of 75.3594% polydextrose and 24.6406% inulin was found as the optimum concentrations producing the most acceptable rheological and physical quality characteristics. © 2013 Elsevier Ltd. All rights reserved.Item Optimisation of processing conditions and rheological properties using stephan mixer as conche in small-scale chocolate processing(International Journal of Food Science and Technology, 2014) Aidoo, R.P.; Clercq, N.D.; Afoakwa, E.O.; Dewettinck, K.This study investigated the suitability of Stephan mixer for use as conche during small-scale chocolate production in an attempt to reduce cost and processing time. Molten chocolate was processed using the Stephan mixer under different temperature and time combinations and Buhler Elk'Olino conche (as reference), and the flow properties (Casson plastic viscosity, Casson yield stress and thixotropy) were studied using a shear-rate-controlled rheometer. Optimum settings of 65 °C for 10 min at 443 g dry conching followed by 50 °C for 15 min at 443 g wet conching in the Stephan mixer resulted in similar flow properties as the reference sample. Increasing the blade rotary speed for both dry and wet conching resulted in a decrease in flow properties. The Stephan mixer proved to be suitable for conching small-scale (approximately 1 kg) chocolate productions and could be explored as a fast and cost-effective method for small-scale chocolate conching processes. © 2013 Institute of Food Science and Technology.Item Rheological properties, melting behaviours and physical quality characteristics of sugar-free chocolates processed using inulin/polydextrose bulking mixtures sweetened with stevia and thaumatin extracts(LWT - Food Science and Technology, 2015-06) Aidoo, R.P.; Afoakwa, E.O.; Dewettinck, K.Demand for use of natural sweeteners and prebiotic compounds for manufacture of sugar-free chocolates has dramatically increased over the past decennium. However, their applicability in product formulation and how these will affect the flow (rheological) and physical quality characteristics still remains a big challenge. This study investigated the rheological properties, melting behaviours and other physical quality characteristics of sugar-free chocolates processed from inulin and polydextrose mixtures as bulking agents sweetened with stevia and thaumatin extracts. Standard reference chocolate was developed using sucrose and the effects of the inulin/polydextrose and stevia/thaumatin ingredients on the rheological properties, melting profiles, colour and hardness of the derived products measured using standard methods. Generally, the sugar-free chocolates showed similar flow (rheological) and melting properties as compared to the reference chocolate. Sucrose replacement with the inulin/polydextrose and stevia/thaumatin extracts resulted in significantly higher Casson viscosity. There were however no significant differences in the melting behaviour and texture of the sugar-free chocolates and the reference. Chocolates containing the sugar substitutes recorded lower onset temperatures and higher peak widths than the reference sample. Inulin and polydextrose mixtures could be used for sugar-free chocolate manufacture with satisfactory physicochemical properties when sweetened with stevia or thaumatin extracts. © 2014 Elsevier Ltd.Item Matrix effects on flavour volatiles release in dark chocolates varying in particle size distribution and fat content using GC–mass spectrometry and GC–olfactometry(2009) Ohene Afoakwa, E.; Alistair, P.; Fowler, M.; Ryan, A.Influences of matrix particle size distribution (PSD) (18, 25, 35 and 50 μm) and fat content (25%, 30% and 35%) on flavour release of dark chocolate volatiles were quantified by static headspace gas chromatography using GC–MS. Sixty-eight (68) flavour compounds were identified, comprising alcohols, aldehydes, esters, ketones, furans, pyrans, pyrazines, pyridines, pyroles, phenols, pyrones and thiozoles. From GC–olfactometry, 2-methylpropanal, 2-methylbutanal and 3-methylbutanal had chocolate notes. With cocoa/roasted/nutty notes were trimethyl-, tetramethyl-, 2,3-dimethyl-, 2,5-dimethyl-, 3(or 2),5- dimethyl-2(or 3)-ethyl- and 3,5(or 6)-diethyl-2-methylpyrazine and furfuralpyrrole. Compounds with fruity/floral notes included 3,7-dimethyl-1,6-octadien-3-ol and 5-ethenyltetrahydro-R,R,5-trimethyl- cis-2-furanmethanol. Caramel-like, sweet and honey notes were conferred by 2-phenylethanol, phenyl- acetaldehyde, 2-phenylethylacetate, 2,3,5-trimethyl-6-ethylpyrazine, 2-carboxaldehyde-1H-pyrrole, furancarboxaldehyde, furfuryl alcohol and 2,5-dimethyl-4-hydroxy-3(2H)furanone. There were direct relationships of fat content with 3-methylbutanal and branched pyrazines but inverse ones with 2-phen- ylethanol, furfuryl alcohol, methylpyrazine, phenylacetaldehyde, 2, 3, 5-trimethyl-6-ethylpyrazine and 2- carboxaldehyde-1-H-pyrrole. Particle size influenced higher alcohol, aldehyde, ester, ketone and pyrazine concentrations at all fat contents. A multivariate product space suggested flavour effects of the interacting factors.Item Microstructure and mechanical properties related to particle size distribution and composition in dark chocolate(2009) Ohene Afoakwa, E.; Alistair, P.; Fowler, M.; Vieira, J.Composition in dark chocolate was varied and the effects determined on microstructure, using light microscopy, and mechanical properties of molten and tempered chocolates, using a TA.HD Plus Texture Analyser. Compositional parameters were particle size distribution (PSD) (D90 of 18, 25, 35 and 50 lm), fat (25%, 30% and 35%) and lecithin (0.3% and 0.5%) contents. Micrographs revealed wide variations in sugar crystalline network structure and inter-particle interaction strengths related to PSD and fat level. Samples containing 25% fat had more crystal agglomerates, well flocculated with greater particle-to-particle interaction strengths than those with higher (30% and 35%) fat contents. Increasing the D90 to 35–50 lm caused broadening of the PSD, with particles becoming coarser, which were similar at all fat levels. Mechanical analysis showed that PSD, fat and lecithin content significantly influenced firmness of molten chocolate and hardness of solid (tempered) chocolate with significant interactions among factors. Particle size was inversely correlated with firmness (1235–173 g) and hardness (7062–5546 g). Greatest effect of PSD was with 25% fat and 0.3% lecithin. With higher fat and lecithin contents, the PSD influence was reduced. It was concluded that PSD, fat and lecithin contents and their interactions were central to mechanical properties of dark chocolates.