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African locust bean (Parkia biglobosa) is a legume widely spread in west Africa. The major consumed part is the seeds after processing in the so-called Soumbala in Ivory Coast. It is rich in proteins and lipids and used as a condiment to enhance sauce flavour. The seeds processing can be generalized as a first cooking to allow the dehulling of the seeds, a second cooking of the almond, an alkaline spontaneous fermentation of 2 to 3 days before final sun-drying. During fermentation, microorganisms belonging to the genus Bacillus are responsible of an extensive proteolysis (Odunfa et Adewuyi, 1985) and lipolysis (Ouoba et al. 2003). This gives the specific flavour to the product but may lead to toxic compounds such as biogenic amines. Biogenic amines accumulate by microbial decarboxylation of free amino acids and are thus susceptible to be present in fermented protein rich foods. They were reported in wine, cheese and fermented fish while they have not been studied yet in processed African locust bean seeds. The objective is to evaluate amino acids decarboxylation activities of Bacillus spp. isolates from Soumbala and biogenic amines content. Soumbala samples were collected among 6 producers in 3 regions of Ivory Coast. 52 Bacillus spp. strains were isolated and identified using API 50 CHB kits. Histidine, lysine, arginine, phenylalanine and ornithine decarboxylation activities and arginine dehydrogenase activities were determined in order to study their ability to produce histamine, cadaverine, phenylethylamine and putrescine. Soumbala samples were analysed for histamine, cadaverine, phenylethylamine and putrescine content. Bacillus spp. strains were identified as followed: B. subtilis (16); B. lentus (3), B. pumilus (1), Geobacillus stearothermophillus (5), B. megaterium (9), B. firmus (2), B. circulans (2), Brevibacillus non reactive (5), B. licheniformis (4), Aneurinibacillus aneuriniliticus (4), B. cereus (1). 16 strains did not show arginine deshydrogenase activities and histidine, lysine, ornithine, or phenylalanine decarboxylation activities. Biogenic amines content of Soumbala was in average 82 mg.kg-1 for histamine, 36 mg.kg-1 for cadaverine, 45 mg.kg-1 for putrescine and 272 mg.kg-1 for phenylethylamine, some samples reaching high levels. Strategies for the control of biogenic amines production in African locust bean fermented seeds are discussed.

Chocolate is a “pleasure” food whose organoleptic quality is essential to the product's value. The aromatic quality of chocolate comes from many parameters, some are intrinsic to the raw material, and others are driven by the manufacturing process. In the frame of a research project dealing with the management of cocoa fermentation process, we investigated the impact of specific yeasts inoculation on the quality of cocoa beans after fermentation and on the final sensory quality of the chocolate Two different yeasts have been inoculated and fermentations were compared to a spontaneous fermentation (standard cocoa). Then, the beans were transformed into chocolate via a standard process and the sensory characterization of these samples was carried out. The analysis of the volatile fraction and the biochemical composition have also been done on beans and chocolate. The results of the beans fermented by selected yeasts show levels of sugars (sucrose, glucose and fructose) lower than in standard cocoa. The polyphenol contents are also impacted by depending on the fermentation process. The analysis of the volatile compounds were also performed on all fermented beans, and important differences were detected. Among the various chemical families measured, the alcohols and esters are more abundantly present in the fermentations carried out with the yeast starters. The sensory tests also confirm that the quality of these beans are also considered better. In conclusion, these studies confirmed the high interest to better control the fermentation step with specific yeast inoculation, in order to improve the final quality of chocolate.

PAH occurrence in raw cocoa and derivative products is more and more worrying for the health of chocolate consumers. Consequently, European Union has fixed PAH maximal content in cocoa products by EU Standards 835/2011 and 2015/1933. Present research dealt with the impact of post-harvest treatments on PAHs formation in raw cocoa.

Alarming presence of polycyclic aromatic hydrocarbons (PAHs) in various foodstuffs and particularly in cocoa butter is a priority of the European Food Safety Authority (EFSA), PAHs are suspected to occur. in foods from smoke. Up today, no simple, fast and safety method for the determination of major toxic PAH4 (Benzo (a) Anthracene (BaA); Chrysene (Chr), Benzo (a) Pyrene (BaP), Benzo (b) Fluoranthene (BbF)) in cocoa beans exists. This research aimed to validate a specific method for the identification and quantification of PAHs in raw cocoa.

In this deliverable the main results of sensory profile of reengineered products from group I are presented. Group I included Akpan and Gowé (Benin), Kenkey (Ghana) and Kishk Sa'eedi (Egypt). In this stage all products were submitted to reengineering process to overcome food safety and product quality issues (identified in the first stage of the project in traditional food) to facilitate their promotion and introduction to EU markets. Although all products were tested in Europe for consumer acceptance, in the case of SENSORY, for Kenkey and Akpan in Europe, the results although not obtained by a trained panel, were generated by Consumers through CATA test. The use of check-all-that-apply (CATA) questions for sensory product characterizations with consumers has been gaining acceptance by several authors (G. Ares and S.R. Jaeger, 2015) and for that we considered an equivalent test to replace the classical descriptive analysis by the trained panel that would take longer time. Due to the restrictions of delayed reengineering processes, we did not have an enough frame time to train adequately the panel. However, the characterisation of product attributes was also achieved. In the case of Gowe, due to restrictions in the productions of reengineered product due to contaminations of raw material, these results for sensory profile could not be obtained, but this was the only case in group I. However, the differences in main attributes were not so far from the traditional ones. In sensory studies of reengineered products, we´ve tried to integrate quantitative characterization of the perceivable product attributes and in consumer studies hedonic profiles (Worch, Lê, and Punter, 2010). So, in the sensory profiling of a specific group of reengineered products, once performed by a trained panel for a specific group of attributes by a specific African or European country panel, it must be considered unique and reproducible for all other panels that can test the product, afterwards. So in our sensory study of Kishk Sa'eedi as it was performed in Africa or Europe by a trained panel performing quantitative and reproducible characterization of the perceivable (Kishk Sa'eedi) attributes, herein will be used the same results for European sensory description of the product. Akpan: In terms of consumer perception of sensory attributes performed in Europe for the three Akpan products did not significantly. If we remove the terms such as “artificial”, “strong in taste”, “floral” due to a manufacturing error (use of a few drops of citronella essential oil instead of citronella infusion as a traditional flavouring of Akpan in Benin), it remains the terms “mealy”, “liquid” “drinking yoghurt” that better describe the product and were previously used for describing traditional Akpan product. This means that sensory properties of traditional Akpan were not totally improved during re-engineering to meet French consumer taste. Kenkey: The results of this study based on CATA testing allowed to provide a basis of understanding on how the reengineered Kenkey (RK) compares to standard commercial Kenkey (SK) in terms of its sensory properties. An interesting finding was that the sensory properties of RK were very different from that of the standard Ga Kenkey (SK): consumers scored differently the new product from the standard one. RK was globally perceived as too weak whilst SK was too strong. RK was perceived as bland and crumbly and SK as sour, salty and fermented. Kishk Sa'eedi (KS) was evaluated by a trained panel by QDA and analysed using QFD and PCA analysis. The results of KS sensory characteristics provide in depth understanding of the sensory quality criteria as perceived by the sensory trained panel. The present study showed that substantial differences in sensory character were noted between the traditional and re-engineered KS in particular, differences in colour, fresh odor, KS taste, fracutability and mouth coating. This work showed that the application of techniques could provide the useful information to KS and helped to identify the importance of product attributes. So in general, it can be observed that sensory properties of reengineered products of Akpan and Kenkey did not differed significantly from traditional ones, however the opposite was observed for the new KS compared to the traditional one.

This deliverable concerns the sensory evaluation of the reengineered group 1 African products in the AFTER project. Specifically, it related to reengineered akpan and gowe from Benin, kenkey from Ghana and Kishk Sa'eedi in Egypt. Concerning reengineered akpan from Benin, the sensory evaluation was undertaken in Montpellier, France. Re-engineering of akpan has focused primarily on improvement of sanitary properties of the product, which was a great achievement and will allow producing Akpan on a larger scale in SMEs in Africa. Sensory evaluation of the Akpan products was carried out using CATA and JAR techniques that have been developed for use with consumers instead of a trained panel. Three Akpan products were tested by 102 consumers: Akpan added with 10% sugar (AS10), Akpan added with 3% spray-dried milk and 8.7% sugar (AMS8.7) and Akpan added with 3% spray-dried milk and 15% sugar (AMS15). Independently of the Akpan tasted, Acidity or Sweetness attributes were scored “Just About Right, as I like” by 56 to 77% of consumers. Odour perception was perceived differently, depending on consumers. However, Texture was found “Too weak”, too liquid by the majority of consumers (49 to 55%) and Taste “too strong” (46 to 54%). The most frequently CATA descriptors checked by consumers which better described Akpan products were: “Artificial”, “Floral”, “New/Different”, “Strong in Taste”, “Mealy”, followed by “Liquid”, “Drinking yoghurt”, “Sweet”, “Acidic”, and “Rough”. At the opposite, an ideal-yoghurt was described as Creamy, Natural, Good for health, Refreshing, Homogeneous, with a texture of a Bulgarian yoghurt-type, Thick, Sweet, Attractive, Nutritious and Milk taste. In terms of sensory evaluation, the three Akpan products did not significantly. If we remove the terms such as “artificial”, “strong in taste”, “floral” due to a manufacturing error (use of a few drops of citronella essential oil instead of citronella infusion as a traditional flavouring of Akpan in Benin), it remains the terms “mealy”, “liquid” “drinking yoghurt” that better describe the product and were previously used for describing traditional Akpan product. This suggests that sensory properties of the reengineered Akpan may not be acceptable to French consumers who prefer a product with a creamy, homogeneous, Bulgarian yoghurt-type taste. Gowe in Benin was not tested using sensory evaluation. Sensory testing of Gowe in Benin was not undertaken because this was planned to be undertaken in Europe. The reason is because the methodology used in sensory evaluation is independent of the location provided the samples are the same. However, the particular samples provided for French sensory testing contained a concentration of aflatoxin that was higher than the minimum EU allowable limit. It was not possible to repeat the sensory test in France because it would have taken too long to obtain a replacement supply from Benin and to repeat the processing (takes one week). In which case the samples would have been took different to enable a comparison. The sensory evaluation of kenkey was carried at the Food Research Institute, Ghana. Current trends in urbanization, and the increasing popularity of kenkey among consumers, require larger scale production with consistent quality. Testing was conducted to determine the sensory profile of white reengineered kenkey made using the optimum pre-process conditions of steeping time (30 and 45h), steeping temperature (30ᵒC and 35ᵒC) and dough fermentation time of 12 hours. The qualitative descriptive analysis showed that the sensory profile of white kenkey was dependent on preprocessing variables. Thus merely optimizing the pre-processing variables with regards to acid production and other readily measurable constituents though could shorten the production process could not guarantee the best product sensory quality. The results show that all the descriptors generated were appropriate for differentiating sensory qualities among samples and could be used for basic research and product development for white kenkey. Soft and sticky texture in white kenkey was highly appreciated. Sensory evaluation of Kishk Sa'eedi (KS) was undertaken in Egypt. KS is an Egyptian indigenous wheat-based fermented food prepared traditionally according to the method applied by Upper Egyptians. This work is done to characterize sensory properties and sensory profile of the reengineered KS. Quantitative descriptive analysis (QDA) coupled with principal component analysis (PCA) was used to study the interrelationship among and between sensory attributes. 14 terms regarding appearance, odour, flavour and texture of the samples, was selected and a glossary describing each descriptor was developed. Three KS samples were profiled by 11 assessors using the chosen 14 sensory descriptors. Mean intensity ratings of the descriptive attributes showed that there were significant differences (p

Consumer acceptance of three re-engineered Kong products compared to a traditional one was explored. No difference was observed among the re-engineered products regarding their overall acceptability (average score of 6-7: like slightly-like moderately). The traditional one differed from the three others with a least score of 4.9. Three groups of consumers were identified using a Cluster Analysis: Re-engineered Kong likers (34%), Traditional Kong dislikers (25%) and Kong indifferent likers (42%). The most liked Kong product was the liquid smoke re-engineered one (KRLS) for 69% of traditional Kong dislikers, while it was as most liked as the salted re-engineered one (KRS) for 78% of all likers. The least liked Kong product was the traditional one (KT) for 37% of Kong indifferent likers, 91% of re-engineered Kong likers, and for 56 % of traditional Kong dislikers. A majority of consumers would most likely buy this product if easily available: 81% of Kong likers, 68% of Re-engineered Kong likers and 50% of Traditional Kong dislikers.

The Gowe is a Beninese traditional cooked paste pre pared from sorghum. It is sold as is and then diluted and consumed in as a sweet, slightly acidic drink. The traditional manufacture of Gowe includes the unit operations of malting, fermentation and cooking. A Gowé of high quality relies on a sufficient acidification during fermentation and th e hydrolysis of starch by the malt amylases which produces fermentable substrates and imparts a sweet taste. The kinetic of lactic fermentation thus depends on the malt amylasic activities that are in return inhibited by the acidification due to the production of lactic acid. In addition, the Gowe sh all present a good sanitary quality that will be promoted by a fast and sufficient acidification. Th e objective of this study is to propose a global model combining predictive microbiology and predictive biochemistry, for predicting and optimizing the preparation of a Gowe with high organoleptic an d sanitary qualities. Two strains of Lactobacilli ( Lb casei and Lb brevis ), known to have different potentialities for acidification were grown on liquid medium MRS. A pathogenic strain of Bacillus cereus was grown on nutrient broth to test the resistance to contamination of the gowe and thus ensure the sanitary quality. We modelled the growth of the strains at constant pH according to a logistic model that determines the growth rate and the duration of the lag phase. Secondly, a cardinal model was used to model the effect of temperature and pH on the gr owth. The kinetics of mortality of B. cereus with pH has also been modelled using reaction of order 1 . We then determined the speed of production of lactic acid, which increases linearly with the r ate of growth of lactic acid bacteria, and modeled the effect of lactic acid on the pH of the medium. The variation of α-amylase activity with temperature and pH was also modeled with empirical laws and the rate of the hydrolysis of starch and of the production of free sugars (mainly glucose and maltose) was modelled by enzymic kinetic with competitive inhibition by the products of reactions (sugar free). A global fermentation simulator was then built. The comparison of measured and predicted values showed that the model gave a fairly good prediction of the microbial populations (Lactobacilli and B. cereus ), but also the acidity and the rate of free sugars . This tool thus allowed proposing scenarios of fermentation to optimize both the organoleptic and sanitary qualities of gowe. Several optimized scenarios could be offered to economic operators, depending on their technological level.

French consumer acceptability of Akpan, a traditional Beninse yoghurt-like product, was carried out in Montpellier, France. A sort of “All in one” method was used comprising an hedonic scoring (appearance, odour, taste, texture and overall liking using a 9-point scale, but also sweetness and acidity using a JAR scale), a Check-All-That-Apply (CATA) question with 25 sensory and 6 perceptions descriptors, and a questionnaire on the views about the product with some socio-demographic information. Four Akpan products were tested by 104 consumers: Natural Akpan AN, and Natural Akpan added with three ingredients (sugar AS; condensed milk AM; condensed milk and sugar AMS). The overall acceptability of Akpan products significantly differed. Only Akpans added with sugar were on average acceptance (mean score around 5-6) but found too sweet by most of consumers. The two others, with no sugar added, were the least liked, with a mean score lower than 5. Acidity was perceived differently by the consumers depending of the products and their sensibility. Three groups of consumers were identified: the Akpan dislikers (25%), the sweet Akpan likers (32%) and Natural Akpan dislikers (44%). Through a MFA analysis of CATA results, AN was described as tasteless, watery, mealy, sour, with fermented taste, pasty consistency, neutral odour and was associated to bitter, astringent and rough perceptions. AMS was related to cereal and yoghurt taste, creamy consistency, milk odour, smooth appearance and to nutritious perception. AS was related to Bulgarian yoghurt appearance, citrus or floral taste and odour, homogenous consistency and, to artificial perception. AM was related to compact appearance, cereal and fermented odour, milk taste, and to natural perception. Sensory terms were found close to perception terms in MFA plan and both were highly correlated to overall acceptance. Most of the consumers disliked by the Akpan products and would not buy them (86%). For the least liked product, 44% of consumers would like to change everything except colour. For the most liked product, 37% would like to change odour, taste and texture. 42% thought that Akpan could not replace any product they know well and 36% thought that it could replace soy yoghurt. 30% of the respondents could buy this product for intolerance to dairies and pleasure and 60% for all the reasons except pleasure and diet.

Mango fruit (Mangifera Indica L.), one the most important tropical fruits, is highly perishable and required therefore to be quickly stabilized. Among the technological solutions, drying appears to be a very promising stabilization solution. The traditional drying of mango can be separated in two phases: the first one carried at ?80°C for 10 to 12 hours makes the water activity (aw) decline from 0.99 to 0.8. During the second phase, the drying temperature is reduced to 40°C until the aw reach ~ 0.5. These conditions are highly favorable to enzymatic (1st drying) step and non-enzymatic (Maillard) reactions (2nd drying step). The focus of this work was therefore to highlight the coupled effects of aw and T°C on the development of these classes of reactions all along the process. For a global comprehension of the browning of mango during the drying process, we used lyophilized powder reconstituted to the required water activities and thenafter heated during various times. Several precursors (reducing sugars) and intermediary products of the Maillard reaction (5-hydroxymethyl furfural (5-HMF) and other neo-formed furan- and pyran-derivated compounds) were analyzed to estimate non-enzymatic reaction intensity while polyphenoloxidase (PPO) and peroxidase (POD) were associated to enzymatic browning. We confirm that the highest production of 5-HMF as a marker of the Maillard reaction mainly occurs for water activities of 0.6. Kinetic analysis of Maillard reactions precursors and intermediate products in model mango system permit to identify asparagine and glutamic acid as limiting precursor, and 5-HMF among significant awdependent products. Furoic acid and furfural linked to the ascorbic acid degradation followed the same tendency. The impact of the water activity on the thermal degradation of PPO and POD was proved to be strongly different. After 4h at 40°C, the PPO, POD remaining activity at aw 0.65 was 22 and 97% respectively while these values being 82 and 64% at 0.98 respectively. As a conclusion, we identified critical points in the drying process making the fruit turn to brown and thus improved our global comprehension of the involved mechanisms. The approach we developed could be useful to help to understand the biochemical mechanisms in complex matrices such as fruit and vegetables. (Texte intégral)

Sorghum is a crucial food crop in Africa and Asia and has a significant role as feed in the Americas and Europe. Grain quality determined by amylose and protein contents is an important trait for varietal acceptance by consumers. The genetic traits have been previously explored using QTL approaches. To validate candidate genes, we started association studies in a sorghum core collection of 210 accessions whose structure is already well understood. Using cereal sequences of the Waxy and Opaque-2 genes involved in amylose and protein content respectively, we designed primers and sequenced the amplification products to detect single nucleotide polymorphism (SNPs). Using a set of 22 accessions representative of the core collection diversity, we sequenced 53 and 47% of the Waxy and Opaque-2 genes, respectively. We found 21 SNPs in the Waxy gene, 5 being non-synonymous, which allowed grouping the 22 accessions into 7 haplotypes. For Opaque-2, we found 9 SNPs, one being non-synonymous, defining 3 haplotypes. These SNPs will be genotyped in the whole core collection. We phenotyped the core collection for amylose and protein contents using near infra-red spectrometry (NIRS). From the results of a first NIRS run, a sample of 110 accessions was selected to be analyzed chemically and was used for the establishment of calibration equations. The phenotypes of the remaining accessions were predicted by NIRS. Prolamine profiles were established by HPLC. All accessions were phenotyped for vitreousness and hardness index. Association tests will be carried out. (Texte intégral)