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Aims: Evaluation of the biochemical and microbiological characterization of Parkia biglobosa seeds added with wood ash during the fermentation for the preparation of "soumbala" (traditional condiment used across West Africa). Study Design: Food safety Methodology: 32 soumbala samples due to eight samples per commune were collected in the markets of Dimbokro (city in the center of Côte d'Ivoire) and three communes from Abidjan district, namely Adjamé, Abobo and Cocody. Also, 5 kg of Parkia biglobosa seeds divided into 14 samples were collected on Adjamé’s market. The loads of microorganisms (mesophilic aerobic germs, lactic acid bacteria, Bacillus, yeasts and moulds) were determined by counting after culture in agar medium. The physico-chemical composition (pH, titratable acidity and soluble sugars) of Soumbala and Parkia bigloboda seeds has been determined according to standard methods. Results: The results of physico-chemical analyses showed that the pH varied from 5.53 to 7.95 for the control and from 8.2 to 8.6 for the "soumbala" produced in the presence of ash during 72 hours of fermentation, while that of the commercial "soumbala" was between 6.4 and 7.7. The protein, reducing sugar and fat contents increase while the dry matter and total carbohydrate contents of the seeds decrease during the fermentation process. Microbiological analyzes showed that the Bacillus loads varied from 5.2 to 9.9 log (CFU/g) for the control and 4.2 to 10.9 log (CFU/g) with the addition of wood ash with a respective optimum of 60 hours, those of lactic acid bacteria varied respectively by 2.3 log (UFC/g) and 3.1 log (UFC/g) in the control and supplemented with wood ash to reach an optimal load similar of 5.5 log (CFU/g). Yeast and mold loads varied from 2 to 5.2 log (CFU/g) for the control and from 3 to 4.5 and 5.6 log (CFU/g) respectively with the addition of wood ash. Bacillus was the only microorganism with the highest load both in commercial soumbala [10.2 log (CFU/g)] and in laboratory-produced soumbala [9.7 log (CFU/g)]. Conclusion: Wood ash had a enhancing effect on the fermentation of Parkia biglobosa seeds where Bacillus are in the majority. "Soumbala" produced in the laboratory were free of lactic acid bacteria and fungi at the end of fermentation.

Aims: Mold contamination of foods especially by mycotoxin producing fungi is not only a global food quality concern for food manufacturers, but it also constitutes a high risk for human and animal health resulting in massive economic losses globally. This study investigated the effect of Lactic Acid Bacteria (LAB) on the growth of Aspergillus carbonarius strains and their production of ochratoxin A (OTA). Methodology: Seven fresh coffee cherry and 9 dry coffee cherry samples were collected from Man, Daloa and Akoupé 3 main coffee producing regions in Côte d’Ivoire. LAB were isolated from fresh coffee cherries while mold strains were from both fresh and dry coffee cherry. The inhibitory effect against mold growth and the ability for OTA removal of selected LAB strains were tested successively in vitro and then during coffee cherry primary postharvest processing before evaluating their influence on sensory quality of beverage. OTA production ability of molds strains are studied using both solid (CYA) and liquid (CYB) Cazapeck Yeast medium. Results: About 34 fungal isolates belonging to Aspergillus and Penicillium genus were studied for their OTA production using the agar plug technique and HPLC-FD. Five A. carbonarius strains were capable of OTA production between 15.9 and 83mg.kg-1.Out of seven isolates of Lactobacillus plantarum, two were successful in inhibition of mycelial growthproduced fungicidal activity; five were successful in retarding it produced fungistatical activity All of L. plantarum isolates exhibited OTA reduction ability at about 99 %. The inoculation of two highest anti-ochratoxigenic LAB to fermenting coffee cherries resulted in great inhibition of mold growth and OTA contents reduction varying from 63.2 to 82.2%. The addition of LAB to coffee cherries did not influence the sensory attributes of the beverages produced thereof. Conclusion: This study highlighted that LAB are very promising biological candidates for reduction of mold contamination and removal OTA from coffee cherry during primary postharvest processing.

Aims: Free fatty acids (FFA) result from hydrolysis of cocoa butter triacylglycerides due to various abiotic and biotic factors. The resurgence of high FFA contents above 1.75% in cocoa beans depended on Ivorian geographical origin. High FFA contents have become a serious quality problem because they induced serious consequences for some beneficial properties of cocoa butter and chocolate. This study investigated the improvement of quality of Ivorian cocoa beans by reducing their FFA contents. Methodology: Samples: 240 cocoa beans batches were sampled from cocoa farmers of some big cocoa producing regions for their FFA contents analysis. Also, influence of primary post-harvest processing such as pod’s sanitary status, pod opening delay, fermentation duration and dry cocoa beans storage under various relative humidity (RH) ranged 80-90% on FFA’s formation of Ivorian cocoa beans was investigated. Data interpretations were performed according to the Fisher’s test. Results: Main results showed that dry cocoa beans recorded FFA content varying from 0.99 to 14% in function of the geographical origin. Beside, 53% of tested cocoa bean samples exhibited FFA content up to 1.75%. Poor sanitary status of pods and 7-days fermented cocoa beans recorded FFA content above 1.75%. Dry cocoa beans stored at RH above 85% promoted more the FFA’s formation (14%) than those stored under lower RH values. 53% of tested cocoa beans samples presented FFA contents up to 1.75%. Controlled primary post-harvest processing highlighted that poor sanitary status of pods, 7-days fermentation and storage of dry cocoa beans at RH above 85% lead to FFA content above 1.75%. Conclusion: So, in order to produce fermented and dried cocoa beans containing a suitable FFA content in the context of climate change, mitigation strategies need to integrate good crop conditions regarding postharvest processing and to improve beneficial ones.

Cocoa quality depends on several parameters, such as cocoa variety, environmental growth conditions, cultivation technique, and post-harvest treatments applied to coca beans. In this work, we studied the impact of cocoa post-harvest processing on both microbial communities structure and volatile composition. Cocoa beans samples were fermented in wooden boxes in Ivory Coast at different time intervals with turning and without turning, and derived from pods stored for two different duration times. Cocoa beans were analyzed using a molecular fingerprinting method (PCR-DGGE) in order to detect variations in microbial communities' structure; this global analysis was coupled to SPME-GC-MS for assessing cocoa volatile profiles. The results showed that the main parameter that influenced microbial communities structure was fermentation time, followed by turning, whereas, pods storage duration had a minor impact. Similar results were obtained for aromatic profile, except for pods storage duration that significantly affected volatile compound production. Global statistical analysis using Canonical Correspondence Analysis (CCA), showed the relationship between microbial communities and volatile composition. Furthermore, this study allowed the identification of discriminating microbial and chemical markers of cocoa post-harvest processing.

This research describes on-farm-inoculated cocoa bean fermentation with two selected strains of high aroma-producing Saccharomyces cerevisiae isolated from wine fermentation and their effects on volatile profile of resulted raw cocoa material and sensory characteristics of chocolates produced. Both strains produced suitably flavour-active esters, aldehydes, ketones and pyrazines in raw cocoa. Inoculation of S. cerevisiae at 0.5 g kg−1 significantly improved the volatile profile of raw cocoa beans and enabled production of chocolate with enhanced intense fresh fruits and floral notes. Chocolate produced thereof presented better overall quality attributed whatever the fermentation time in comparison to the chocolate issued from spontaneous fermentation. Our results suggested the ways of using selected enhanced yeasts as S. cerevisiae for on-farm implementation of bean fermentation as promising alternative possibilities to improve the cocoa fermentation process, desirable flavourful raw cocoa material and high-aroma-quality chocolates produced.

Most of volatile flavour compounds occurred during the cocoa postharvest operations including pod storage and fermentation whom effects on these metabolites were aimed by the present study. Three different spontaneous fermentation treatments were performed on the farm, and the main isolated yeasts were identified using PCR-DGGE technique. Fermented cocoa beans were solar-dried, and their flavour compounds were identified using solid phase microextraction technique–gas chromatography–mass spectrometry. The main results showed that Pichia kudriavzevii was common yeast involved in the cocoa fermentation. Thirty flavour precursor compounds grouped into six chemical families including alcohols and pyrazines were identified in raw cocoa samples. ACP showed that short durations of pod storage and fermentation promote the formation of flavour precursors of cocoa. No spontaneous cocoa fermentation treatment influenced the occurrence of aroma compounds. The generation of flavour compounds depends only on the pod storage and the fermentative microorganisms of cocoa.

International audience; Soumbala is made from African locust bean seeds (Parkia biglobosa), a legume widely spread in west Africa. It is a lipid and protein-rich condiment obtained by three main steps: cooking, fermentation and drying. Ten different analysis were made on AFLBS samples at each step with a particular focus on protein and lipid fates. Results showed that cooking decreased markedly the carbohydrate content leaving mainly proteins and lipids as substrates for fermentation. During this step, 20% of the proteins were converted into free amino acids, mainly glutamic acid and tyrosine. Significant biogenic amines release occurred and reached 50 mg per 100 g of dried ALBS. Di-glycerides and fatty acids increased markedly and represented 11% and 7% of the total lipids of dried ALBS. These results give a complete view of the nutritional characteristics of dried ALBS, its benefit but also its defects that arise during fermentation and not suppressed by the subsequent processing steps.

A simple, fast and ecological analytical method using a semi-automatic fat extractor and HPLC-FLD (fluorescence detection) for determination of polycyclic aromatic hydrocarbon markers i.e. benzo(a)anthracene (BaA), chrysene (Chr), benzo(a)pyrene (BaP) and benzo(b)fluoranthene (BbF) in cocoa butter has been validated. Validation's procedure performed out in concordance with French standard NF V03-110 (2010) was based on existing polycyclic aromatic hydrocarbon (PAH) determination methods in various smoked foodstuffs and edible vegetable oils. Determination of correlation coefficients for specific PAHs ranged from 0.9992 to 0.9998. Respective values of limits of detection were 0.010, 0.011, 0.033 and 0.029 μg kg−1 and those of quantification were 0.035, 0.038, 0.111 and 0.098 μg kg−1 for BaA, Chr, BbF and BaP. Both values of repeatability and intermediary precision tests coefficients of variation were less than 5%. Recovery scores of four PAH markers matched EU standard 836/2011 recommendations. Sum of four PAH markers (BaA, Chr, BbF, BaP) contents varied from 5.42 ± 0.58 to 11.37 ± 0.01 μg kg−1 whereas those of BaP was comprised between 0.26 ± 0.00 and 1.75 ± 0.13 μg kg−1 in 20 cocoa butter samples extracted from raw cocoa bean stored at Ivorian cocoa farmer levels.

Cocoa beans are the principal raw material for chocolate manufacture. Moulds have an important place in the change in the quality of cocoa beans due to their role in the production of free fatty acids and mycotoxins, namely ochratoxin A (OTA). This study investigated the impact of the key post-harvest treatments, namely the fermentation and drying methods on OTA contamination of raw cocoa beans. Analytical methods for OTA detection were based on solid-liquid extraction, clean-up using an immunoaffinity column, and identification by reversed-phase HPLC with fluorescence detection. Of a total of 104 randomly selected cocoa samples analysed, 32% had OTA contents above 2 µg kg(-1). Cocoa sourced from pods in a bad state of health had a maximum OTA content of 39.2 µg kg(-1), while that obtained from healthy pods recorded 11.2 µg kg(-1). The production of OTA in cocoa beans increased according to the pod-opening delay and reached 39.2 µg kg(-1) after an opening delay of 7 days after harvest, while 6.1 and 11.2 µg kg(-1) were observed when pods were opened after 0 and 4 days. OTA production also seemed to depend considerably to the cocoa fermentation materials. When using plastic boxes for bean fermentation, the OTA production was enhanced and reached an average OTA content of about 4.9 µg kg(-1), while the raw cocoa treated in banana leaves and wooden boxes recorded 1.6 and 2.2 µg kg(-1) on average respectively. In parallel, the OTA production was not really influenced by either the mixing or the duration of the fermentation or the drying materials.

Summary This study aims to compare the effect of three cocoa fermentation methods and their duration on raw cocoa quality. Results showed a decrease in percentage of physical quality defects on fermentation method. Cocoa fermented for 4 days presented higher percentage of purple beans reached 45% and about 10% of slaty beans than cocoa fermented for 6 days whatever the process. Fermentation duration did not influence the mouldy beans that were around 1%. Formation of brown beans increased from 16% to 50% depending on the fermentation duration and process. Using wooden boxes allowed higher percentage of 77%–90% brown beans than others materials. Acidity of cocoa decreased on fermentation duration but beans treated in boxes were significantly (P = 0.05) acidic from 1.40 and 3.07 meq of NaOH g−1. Fungal population did not vary in number depending both on the duration and the fermentation method with rates that ranged from 3.32 × 107 to 8.63 × 107 CFU g−1.

Studies were carried out to investigate the impact of different drying processes on the chemical quality traits of raw cocoa beans. The pH of less fermented cocoa is higher than the well-fermented cocoa's. The sun-dried beans pH ranged from 4.5 to 5.5, while the pH of both oven- and mixed-dried beans was between 3.8 and 5.2. The sun-dried beans contained lower volatile acidity than oven-dried beans. Artificially dried beans resulted in higher free acidity content when compared to both sun- and mixed-dried beans. Ammonium nitrogen content in raw cocoa beans is not influenced by the drying methods. Free fatty acid content increases slowly but remains below the critical value of 1.75% whatever the drying processes. While oven-dried beans show the FFA content above 0.70% both of sun- and mixed-dried beans are associated with FFA content below 0.70%.

This study aimed to evaluate molecular microbial markers associated with cocoa fermentation and drying steps. The dynamics of microbial populations were analyzed during postharvest processing (fermentation and sun drying) of cocoa from Ivory Coast. The variations in bacterial and yeast communities structure were monitored by a molecular technique (PCR-DGGE) using 16S rRNA and 26S rRNA profiles. Dominant microbial species were determined by sequencing. Our results showed that treatments of cocoa generated great variations in the microbial ecology in terms of number of species detected. The bacterial ecology quickly underwent dramatical changes during the fermentation step after two days. The dominance of Enterobacteria was first observed and then accompanied by Lactic acid bacteria and at the latest stages by acetic acid bacteria. Furthermore, Hanseniaspora opuntiae yeast species predominated during cocoa bean fermentation and drying processes. In addition, two bacterial species were only identified during the drying step of fermented cocoa beans and are potential candidates for biological markers of this process. (Resume d'auteur)