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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.

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%.