Search

Given the persistent poor livelihood of cocoa-farming households, future climate predictions and the worldwide demand pressure for higher cocoa quality and productivity, there is still a strong need to find new approaches that guarantee a sustainable cocoa future in cocoa-producing countries amongst which Cameroon is one of them. This exploratory research investigates potential future pathways for the cocoa sector in Cameroon by mapping the perceptions of actors involved in the socio-technical regime. Qualitative expert interviews, structured questionnaires and field observation, as well as a focus group discussion have been applied to understand how a sustainability transition can be triggered. The study shows that actors envisage a sustainability change which determines their actions; however, their perceptions towards future transitions are not actively coordinated. Actors are not finding a way of adopting new organizational structures and letting a transition occur effectively, like in the case of certification standards. An alignment of perceptions and activities, and a stronger cooperation between the private and public are strongly recommended. The study encourages to consider a coordination of actors' perceptions towards future scenarios as a starting point to study sustainability transitions.

Cocoa pod-opening delay and bean fermentation promote the organoleptic quality of chocolate. The present research investigated the changes in the volatile fingerprint of cocoa harvested at a traditional plantation. Cocoa beans extracted from 2-days pod-opening delay were simultaneously fermented for 5 days using container and then sun-dried to 7-8% moisture content at five different locations: Akoupé, San Pedro, Soubré, Djekanou and Daloa. The aromatic analysis were done on cocoa using the HS-SPME-GC/MS technique. Professional panelists evaluated the sensory perceptions of the chocolate. The results shows that cocoa fermented in both Daloa and Soubré regions were differentiated by 2,3-butanediol while those processed in other regions presented highest acetoin content. However, fermented cocoa from Soubré region exhibited most amount of 2,3-butanediol, diacetate A whereas 2,3,5,6-tetramethylpyrazine differentiated those from Daloa region. Sensory properties of chocolate were not linked to the aromatic compound precursors profile of beans. The fermentation performed in San Pédro region promote both the generation of more desirable aromatic compounds of cocoa and sensory attributes of the finished chocolate. The fermentation location generates a greater differentiation of the volatile fingerprint of cocoa and the sensory perceptions of the finished chocolate.

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.

The aromatic quality of chocolate requires the use of cocoa with high aromatic potential, this being acquired during the fermentation of cocoa beans. Traditional fermentation is still often carried out on a small scale with wild strains of yeasts and acetic bacteria and under poorly controlled conditions leading to cocoa quality ranging from best to worst. This study is the first part of a project aiming to control quality of cocoa to produce high aromatic quality chocolate by using a mixed starter of selected strains of yeast and acetic bacteria and by controlling the conditions of fermentation. To achieve this objective, a mathematical model of the alcoholic fermentation of cocoa beans has been developed. The growth, glucose consumption and ethanol production of Saccharomyces cerevisiae LM strain in synthetic broth were modeled for the most important intrinsic (pH, glucose, ethanol, free nitrogen and oxygen levels) and extrinsic (temperature, oxygen level) fermentation parameters. The model was developed by combining the effects of individual conditions in a multiplicative way using the gamma concept. The model was validated in liquid synthetic medium at two different inoculation levels 104 and 106 CFU/mL with an increase in temperature that recorded during spontaneous fermentations. The model clearly shows that the level of inoculation and the speed of the increase in temperature clearly drive yeast growth, while other factors including pH and ethanol, free nitrogen and oxygen levels have no significant impact on yeast growth.

Despite the importance of fermentation for cocoa quality, process parameters are not controlled under spontaneous conditions at farms. This study evaluates the influence of spontaneous fermentation and processing under laboratory-controlled conditions using the acidic reagents acetic and lactic acids on the cocoa quality of two cultivars, FEAR 5 and CCN 51, at the sensory and metabolomic levels. Under spontaneous conditions, cocoa differs in flavour quality. While FEAR 5 produces chocolate with good global quality, chocolate made with CCN 51 does not have outstanding quality attributes. Transformation under controlled conditions with acidic reagents increases the perception of fine aromatic notes such as fruity, nutty and floral attributes in chocolates made from both cultivars of cocoa. Metabolomic profiles allowed grouping of cocoa samples as a function of postharvest treatment. Twenty-five differential metabolites were identified during the postharvest processes, and these metabolites may be related to the expression of fine sensory attributes; however, more research is needed.

International audience; The present study aims at developing an analytical methodology which allows correlating sensory poles of chocolate to their chemical characteristics and, eventually, to those of the cocoa beans used for its preparation. Trained panelists investigated several samples of chocolate, and they divided them into four sensorial poles (characterized by 36 different descriptors) attributable to chocolate flavor. The same samples were analyzed by six different techniques: Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS), Solid Phase Micro Extraction-Gas Chromatography-Mass Spectroscopy (SPME-GC-MS), High-Performance Liquid Chromatography (HPLC) (for the quantification of eight organic acids), Ultra High Performance Liquid Chromatography coupled to triple-quadrupole Mass Spectrometry (UHPLC-QqQ-MS) for polyphenol quantification, 3D front face fluorescence Spectroscopy and Near Infrared Spectroscopy (NIRS). A multi-block classification approach (Sequential and Orthogonalized-Partial Least Squares – SO-PLS) has been used, in order to exploit the chemical information to predict the sensorial poles of samples. Among thirty-one test samples, only two were misclassified.

The selection of fine flavour cocoa and coffee varieties can lead to attractive niche markets but germplasm need to be analysed for non-volatile compounds and aroma precursors. In the present study, green beans of 202 Theobroma cacao L. accessions (acc.), 64 Coffea arabica L. acc., 35 C. canephora Pierre ex A. Froehner, 7 C. arabusta Capot & Ake Assi and 2 C. canephora × C. congensis A. Froehner hybrids cultivated in Santo, Vanuatu, and harvested at full maturity, were analysed using High Performance Thin Layer Chromatography (HPTLC). In cocoa, 11 compounds were quantified: two alkaloids, two catechins, five proanthocyanidins, and two anthocyanins. Multivariate analyses revealed that Amenolado acc. are differentiated from Criollo, Forastero and Trinitario acc. due to their low caffeine, catechins, and proanthocyanidins contents. Hybrids involving an Amenolado parent also produce low non-volatile compounds contents. In coffee, 11 compounds were quantified: sucrose, two alkaloids, and eight chlorogenic acids. The two major species were differentiated by their mean caffeine content (12.69 mg/g in C. arabica vs. 16.04 mg/g in C. canephora), which is highly correlated with CGA and other chlorogenic acids. Each of the eight chlorogenic acids presented higher values in C. canephora. The ratio sucrose/alkaloids + chlorogenic acids was significantly higher in C. arabica (3.24) than in C. canephora (1.68) which could be an explanation for its comparative sweetness. Coffea arabusta interspecific hybrids presented an intermediate value (2.64). Congusta hybrids were low in sucrose. HPTLC is a cost-efficient technique when applied to germplasm characterization of non-volatile compounds in green cocoa and coffee beans. Chemotype selection appears promising for the development of fine flavor varieties.

The average weight of cocoa beans is not generally taken into account during breeding processes, although it is a trait of interest. Several studies indicate that the weight of the beans has a high heritability in Theobroma cacao. However, the values obtained from different countries for the same clone often vary. In this study, we analyzed the effect of different factors on the weight of the beans. Apart from the clone effect, three main factors had an impact: i) the number of beans per pod: a good filling of the pod with beans tended to limit the weight of the beans, ii) the position of the beans in the pod: beans in the apical part of the pod were significantly lighter than the others and iii) the longer the duration of the fructification cycle the heavier the beans were (positive genetics correlation). These results lead us to propose protocols aimed at normalizing the phenotypic values of the genetic material. To obtain a reliable estimate of the bean weight, the following is proposed: either to use beans obtained from manual pollination to saturate the pods with beans, or to systematically use the number beans in the pods as a covariable.

A large fraction of the South-American cacao production is affected by new cadmium (Cd) regulations in cacao. This work was set up to characterize the distribution and speciation of Cd within the cacao fruit and to monitor potential Cd redistribution during cacao fermentation. In cacao fruits from four locations, Cd concentrations decreased with testa > nib ~ placenta ~ pod husk > mucilage. The distribution of Cd within cacao beans was successfully visualized using laser ablation inductively coupled plasma spectrometry (LA-ICP-MS) and confirmed higher Cd concentrations in the testa than in the nib. Speciation analysis by X-ray absorption spectroscopy (XANES) of unfermented cacao beans revealed that Cd was bound to O/N-ligands in both nib and testa. Fermentation induced an outward Cd migration from the nibs to the testa, i.e. against the total concentration gradient. This migration occurred only if the fermentation was sufficiently extensive to decrease the pH in the nib to

Chocolate is a widely consumed product worldwide due to its exquisite flavor, which comes from the unique and fascinating cocoa flavor. This flavor depends on little controllable variables such as the genotype and the agroecological niche, and on the other side, on postharvest operations: (1) cocoa transformation from seeds to beans that comprises cocoa seeds preconditioning, fermentation, and drying, and (2) the production of chocolate from the bean in which roasting is highlighted. Postharvest transformation operations are critically important because during these, cocoa flavor is formed, allowing the differentiation of two categories: bulk and specialty cocoa. In this sense, this article presents an overview of cocoa postharvest operations, the variables and phenomena that influence and control the physical and biochemical transformation from seeds to cocoa beans, and their relation to the formation of chocolate flavor. Moreover, research perspectives in terms of control and management of postharvest practices in order to obtain cocoa with differentiated and specialty characteristics "from bean to bar" are discussed.

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.

Fermentation is a critical step in the processing of high quality cocoa; however, the biochemistry behind is still not well understood at a molecular level. In this research, using a non-targeted approach, the main metabolomic changes that occur throughout the fermentation process were explored. Genetically undefined cocoa varieties from Trinidad and Tobago (n = 3), Costa Rica (n = 1) and one clone IMC-67 (n = 3) were subjected to spontaneous fermentation using farm-based and pilot plant controlled conditions. Samples were collected daily, and acetone/water/acetic acid (70/29.5/0.5%) extracts were obtained and measured using a UPLC-ESI+-Q-Tof-MS system. Analysis of pre-processed data, applying a PLS-DA model, highlighted significant differences between the three fermentation periods, observed at 0–2, 3–4 and 5–6 days, respectively. Among the most discriminating metabolites, sucrose, flavanols such as (epi) catechin, procyanidin dimers and trimers, anthocyanins and oligopeptides ranging in size from 3 to 12 amino acids were tentatively identified. In general, flavanols and sugars tended to decrease throughout fermentation, whereas most oligopeptides increased to maximal levels after 3 to 4 days of fermentation and decreased thereafter. These results shed new insight into cocoa fermentation optimization strategies and may also contribute to the development of novel alternatives for cocoa processing based on biochemical and functional values. UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro Nacional de Ciencia y Tecnología de Alimentos (CITA)

According to the cocoa cycle model constructed over the four centuries of cocoa history, after a commodity boom in a region, there comes a recession. When the world price increases again, that region can benefit marginally or has at least to wait for a long period before rebounding; meanwhile, a new region takes over. The case of the Thai rubber economy with continuous, long-term growth shows that several factors—ecological (physiology of the crop), technical (high yielding planting material), political (strong support from public policy) and social (important role of local populations)—can explain some of the divergence from the cocoa cycle model. This suggests a need to update and enrich the model with new scenarios and options.

La OTA es una micotoxina producida por los géneros Aspergillus y Penicillium, la cual ha sido clasificada por la Agencia Internacional de Investigación para el Cáncer (IARC) como posible carcinógeno en humanos. La presencia de OTA y las especies de hongos que la producen, han sido asociadas a los tratamientos de cosecha y post-cosecha del cacao. Actualmente no existen reportes sobre las poblaciones microbianas presentes durante el beneficio de cacao en México y su interacción con la flora fúngica, por lo que el objetivo de este trabajo fue estudiar la dinámica de bacterias y levaduras y determinar su influencia sobre la presencia de hongos toxigénicos y la contaminación por OTA. Se obtuvieron muestras de mazorca y de grano de cacao durante el proceso de dos haciendas productoras (A y B) en 2013 y 2014. Se obtuvo el % total de infección por hongos, estos fueron aislados y caracterizados por biología molecular y su capacidad de producir OTA fue evaluada. Se realizó la extracción y la amplificación de ADN de las muestras de cacao por PCR, y se obtuvo el perfil DGGE de hongos. Se identificacron 59 cepas de hongos, de las cuales A. carbonarius, Penicillium sp., P. lividum, P. sizovae y A. steyni, resultaron altamente productoras de OTA (5141.05 - 14307.5 μg/kg). El cacao almacenado por 30 días presentó 304.6 μg de OTA/kg acorde con la presencia de especies aisl adas en esta etapa. Se mostró que lavar el grano al final de la fermentación en la hacienda B eliminó parcialmente la pulpa pegada al grano (sustrato disponible), disminuyendo la presencia de especies altamente ocratoxigénicas y el riesgo de contaminación por OTA en etapas posteriores. Los perfiles DGGE mostraron un mayor número de especies presentes 2 en el proceso de la hacienda B. La calidad de la materia prima, la etapa final de la fermentación y el almacenamiento fueron puntos críticos en la contaminación por hongos toxigénicos y producción de OTA. Este estudio permitió identificar los peligros y los puntos críticos de contaminación por OTA, precursores para la implementación de un sistema de Análisis de Riesgos y Puntos críticos de control (HACCP), para minimizar la contaminación en la cadena de producción de cacao.

Malgré des caractéristiques organoleptiques très appréciées par les chocolatiers, la grande majorité des productions de cacao malgaches est achetée en " cacao standard " aux petits paysannats. Seules les plantations industrielles mettent en marché du cacao de qualité supérieure. Le cacao de Madagascar figure parmi les rares cacaos fins de la planète. Peu d'études concernant la filière cacaoyère malgache ont été réalisées. Ce travail a pour but de mettre en lumière des liens pouvant exister entre les modes de transformation post-récolte des divers producteurs de fèves de cacao et leur qualité sensorielle. Deux études conduites dans le Sambirano en 2013 dans le cadre du réseau de coopération scientifique en océan Indien QualiREG1 ont permis de faire un point sur les vergers cacaoyers et sur les procédés de transformation dans les différentes zones du Sambirano et les différentes structures de production du petit paysan à la plantation industrielle. Ces études remettent en cause les affirmations communément publiées que le verger cacaoyer est en déclin et que le cacao du Sambirano se dégrade par manque d'encadrement et de compétence des petits producteurs. Elles montrent en effet l'intérêt des familles rurales pour le produit cacao puisque ces dernières sans appui technique ni aide financière cultivent et rénovent à leur rythme les cacaoyères par la mise en oeuvre de dispositifs de plantation et de pratiques culturales comparables à ceux des compagnies industrielles. Les échantillons provenant de divers producteurs de la région du Sambirano (Madagascar) ont été comparés du point de vue biochimique et sensoriel. Les analyses sensorielles et chimiques ont confirmé la qualité des cacaos malgaches et ont montré que les procédés de transformation du cacao mis en oeuvre par les paysans, principalement en sacs, permettent d'obtenir des produits de qualités biochimique et sensorielle équivalentes à celle du procédé suivi par les industriels, lorsque la durée de fermentation est de 5 à 6 jours L'augmentation d'année en année des produits de moindre qualité quel que soit le type d'exploitation découle non d'une méconnaissance par les paysans mais de fécondations croisées entre Forastero et Trinitario et d'une forte demande en cacao standard pour laquelle les producteurs et les collecteurs réduisent la durée de fermentation. Il convient d'enrayer cette dégradation continue par la distribution massive d'un matériel végétal Trinitario à amande claire. Ce constat milite pour une relance de la sélection variétale qui devra être suivie de la distribution de matériel végétal quantitativement et qualitativement performant. Dans cette optique, la création de champs semenciers biclonaux et des essais de multiplication végétative par greffe- bouturage et embryogenèse somatique ont été démarrés dans le cadre des travaux du projet PARRUR QUALIKKO.

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.

Cocoa flavor is the most important organoleptic property according to chocolate consumers. Raw cocoa beans sourced from Ivory Coast are not known for their fine aroma quality. In the global framework of raw cocoa quality improvement, this study dealt with the determination and control of the conditions of the aroma compound formation and aimed to determine the potential contribution of yeast associated with the fermentation to the formation of sensory profiling for cocoa beans. Using the method of SPME–GC–MS, the potential for flavor contribution of some predominant yeasts isolated from cocoa fermentation assays performed around Abidjan and then grown on Sabouraud-chloramphenicol medium was determined. Also, the flavor precursor compounds of final corresponding raw cocoa bean samples prepared according to specific post-harvest processing were analyzed. A total of around ten species of yeast involved in cocoa fermentation but among them, six strains were namely identified as Saccharomyces cerevisiae, Candida tropicalis, Pichia kudriavzevii, Pichia galeiforms, Galactomyces geotrichum and Wickerhamomyces anomalus. These identified yeasts produced a total of 33 aroma compounds grouped into four families such as esters, alcohols, acids and others. Among all yeasts involved in fermentation performed in Abidjan, P. kudriavzevii, S. cerevisiae, G. geotrichum and W. anomalus could be considered as the most important contributors to the formation of cocoa specific aroma compounds. These cocoa aroma producing capacities of yeast isolates could be used to improve the sensory profiling raw cocoa beans or other fermented food stuffs. Furthermore some specific yeast isolates could be used as biological markers to predict the determining of chocolate sensorial characteristics and to indicate the geographical origin or processing story of cocoa bean batches.

The roasting of green coffee beans ( Coffea arabica) artificially contaminated by Ochratoxin A (OTA) after inoculation with Aspergillus westerdijkiae was carried out with two different roasting techniques (Rotating Cylinder [RC] and Fluidized Bed [FB]). The green coffee beans were contaminated at two different toxin levels (L1 = 5.3 μg kg −1 and L2 = 57.2 μg kg −1 ). Different roasting points (light, medium, dark and very dark) were set according to the L ∗ color coordinate. The cylinder roasting conditions were 0, 3, 6, 9, 12, and 15 min at 230 °C and the fluidized bed roasting conditions were 0, 0.9, 1.7, 2.6, 3.5 and 4.3 min, at 230 °C. The roasted beans were compared for their physical properties (bean swell and weight loss) as well as for their residual OTA content. The results indicated that the OTA reduction was similar for the two contamination levels: 95.1% and 97.2% with the rotating cylinder and 81.3% and 79.2% with the fluidized bed at the maximal roasting time. The OTA degradation kinetics differed between the two processes. The complete degradation of OTA within the limit of this study (230 °C) was not observed but the rotating cylinder roasting was the most efficient technical process for the OTA reduction in a commercial dark roasted coffee (88%).

The effects of heat treatment on the survival of isolated Ephestia kuehniella Zeller larvae were examined. Larvae were treated in a specific device at a temperature range of 46 to 70 °C. Statistical analysis of the data demonstrated that the thermal survival kinetics was best represented by a 2-parameter Weibull model above 50 °C. The mortality of larvae only occurs beyond a critical temperature of 41.6 °C ± 2.5 °C. A 2D axial-symmetric model of heat transfer (convection, microwave at 915 MHz) was developed for cocoa bean and date palm. It was combined with the survival rate of larvae (Weibull model) and some z -values (from literature) are used for calculating a “food quality index” degradation kinetics. The intensive heating/convection process may not be adaptable for food products at low water activity due to high surface product temperatures. The use of microwave heating for date fruits and conventional hot air treatments for cocoa beans is recommended.

Ochratoxin A (OTA) is a mycotoxin that contaminates several foodstuffs, including cocoa. It has nephrotoxic, teratogenic and carcinogenic properties in humans. The effect of post-harvest processing and storage on the OTA contamination of cocoa was studied over three successive cocoa seasons (2005, 2006 and 2007) in Cameroon. The type of fermentation (box or heap) did not significantly influence bean OTA content, which varied from undetectable (

The selection of productive varieties of modern Criollo cocoa, showing fine aromatic qualities in their beans, is of major interest for some producing countries, such as Venezuela. Cultivated populations of Modern Criollo or Trinitario varieties may be suitable for admixture mapping analysis, as large blocks of alleles derived from two identified divergent ancestors, recently admixed, are still preserved, after a few generations of recombination, similar to experimental mapping progenies. Two hundred and fifty-seven individuals from a cultivated population of Modern Criollo were selected and analysed with 92 microsatellite markers distributed along the genome. This population exhibited a wide range of variability for yield factors and morphological features. Population structure analysis identified two main subgroups corresponding to the admixture from the two ancestors Criollo and Forastero. Several significant associations between markers and phenotypic data (yield factors and morphological traits) were identified by a least squares general linear model (GLM) taking into account the population structure and the percentage of admixture of each individual. Results were compared with classical QTL analyses previously reported for other cacao populations. Most markers associated to quantitative traits were very close to QTLs detected formerly for the same traits. Associations were also identified between markers and several qualitative traits including the red pigmentation observed in different organs, mainly associated to common markers in linkage group 4.

Cocoa and coffee are the most traded agricultural commodities in the world. They undergo many post-harvest transformations in producing countries (tropical) before being exported. Post-harvest processes differ from one country to another and from one production site to another. The technological transformation of cocoa on commercial beans and of coffee to green coffee requires a primary process handling. These practices play a crucial role in global and organoleptic quality of the products that will be processed. Our work hypothesis isthat different post-harvest processing applied to coffee and cocoa have an influence on the structure of microbial communities. The main objective was to measure this effect by performing a global analysis of microbial ecology using a molecular biology tool (PCR-DGGE, PCR amplification coupled to denaturing gradient gel electrophoresis). This technique allows variations in microbial communities to be detected and the main microbial species to be identified by sequencing.Our approach permitted to discriminate treatments, and the geographical origin of Cameroonian and Indonesian coffees. Notably, we showed that geographical origin and coffee species have a minor impact on the structure of the microbial communities when compared to the type of process used (wet or dry).By applying the approach to cocoa, we could link the global analysis of microbial ecology (PCR-DGGE) to the analysis of volatile compounds (SPME-GC-MS) to discriminate the different post-harvest treatments. Micro-fermentation were carried out with strains isolated from cocoa (L. fermentum, A. pasteurianus, P. kudriavzevii and P. mashurica) in order to identify the origin of the volatile compounds detected in the fermented cocoa. This study contributed to to show that fermentation combined with a short storage duration before fermentation is the best method to obtain cocoa beans with more desirable aromatic compounds. The statistical analysis was used to combine the results of the two types of analyzes (microbial ecology and aromatic compounds) and get relations between the detected microbial species and volatile compounds. The identified aromatic profiles prompted us to consider the use of the tested microbial strains as starter culture for cocoa fermentation.; Le cacao et le café sont les produits agricoles les plus échangés dans le monde. Ils subissent de nombreuses transformations post-récolte au niveau des pays producteurs (tropicaux) avant d'être exportés. Les procédés de traitements post-récolte diffèrent d'un pays à l'autre voire d'un agriculteur à l'autre. La transformation technologique du cacao en fèves marchandes et des grains de café en café vert nécessite un processus primaire de manutention. Ces pratiques participent et influencent, en général, la qualité marchande et organoleptique des produits destinés à la transformation. Notre hypothèse de travail est que les différents procédés de transformation post-récolte appliqués sur le café et le cacao ont une influence sur la structure des communautés microbiennes. L'objectif principal était de pouvoir mesurer cet effet en réalisant l'analyse globale des communautés microbienne en utilisant un outil de biologie moléculaire, la PCR-DGGE (Amplification par PCR couplée à l'électrophorèse sur gel en gradient dénaturant). Cette technique a été associée au séquençage afin d'identifier les espèces microbiennes majoritaires. Cette étude a montré que les communautés microbiennes associées aux grains de café et aux fèves de cacao varient au cours des différentes étapes pour chaque type de traitement post-récolte appliqué.Notre approche a permis de discriminer les voies de traitements, et l'origine géographique du café Camerounais et Indonésien. Notamment, nous avons montré que l'origine géographique et l'espèce de café utilisée ont un impact sur l'écologie microbienne du café moins important par rapport à celui du procédé. L'application au cacao nous a permis de relier l'analyse globale de l'écologie microbienne (DGGE) à l'analyse des composés volatils (SPME-GC-MS) afin de discriminer les différents traitements post-récolte. Des micro-fermentations ont été réalisées avec des souches microbiennes isolées du cacao (L. fermentum, A. pasteurianus, P. kudriavzevii et P. mashurica) dans le but d‘identifier l'origine des composés volatils détectés sur le cacao fermenté. Notre étude a contribué à montrer que la fermentation combinée à une courte durée de stockage avant fermentation est le procédé qui permet d'obtenir des fèves contenant plus de composés aromatiques désirables sur le cacao. Une analyse statistique a permis de combiner les résultats des deux types d'analyses (écologie microbienne et composés aromatiques) et de créer des relations entre les espèces détectées et les composés volatils présents. Les profils aromatiques identifiés ont permis d'envisager l'utilisation des souches testées comme starters de culture pour la fermentation du cacao.

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)

Dans les conditions de Paracou-Combi (Sinnamary, Guyane française), 77 ortets de cacaoyers spontanés locaux, appartenant à neuf populations des bassins des rivières Camopi et Tanpok, ont été caractérisés pour leur nombre moyen de fèves normales par cabosse et leur fertilité apparente (rapport du nombre moyen de fèves normales par cabosse au nombre moyen d'ovules par ovaire). La comparaison avec le clone Forastero haut-Amazonien NA 32 et divers clones Amelonado et Trinitario locaux montre une sensibilité générale des cacaoyers spontanés guyanais étudiés au remplissage incomplet des cabosses. Le nombre moyen de fèves normales par cabosse est faible (25,3), le coefficient de variation du nombre de fèves normales par cabosse est élevé (43%) et la fertilité apparente est faible (0,57). Ce mauvais remplissage n'est pas corrélé avec leur taux de compatibilité.

L'article décrit l'ensemble des activités se rapportant aux cacaoyers (Theobroma cacao L.) spontanés du sud-est de la Guyane, depuis leur découverte en 1729 jusqu'aux perspectives découlant de leur étude récente : prospections scientifiques (1987, 1990, 1995), matériel collecté et distribué, sauvegarde en Guyane, caractérisation, étude de la variabilité et de la structuration génétique des populations, sélection et étude de leur valeur en croisement. Une synthèse des recherches menées en Guyane et ailleurs (France, Trinidad, Côte-d'Ivoire, etc.) et des principaux résultats obtenus est présentée. La conclusion insiste sur l'intérêt de ce nouveau matériel en amélioration génétique du Cacaoyer, en particulier pour ses grandes potentialités quant à la productivité, le rapport production/vigueur, les résistances à certaines maladies et la qualité du cacao produit.

Under the conditions prevailing at Paracou-Combi (French Guiana), 96 local wild cocoa trees belonging to ten populations from the Camopi and Tanpok rivers, and already pre-selected for other agronomic criteria, were characterized for their average fresh bean weight, an important selection criterion. Other traits, such as the average length and width of a bean, along with the percentage of flat beans, were also studied. The variability found for average fresh bean weight was substantial, with a coefficient of variation of 10.5% and extremes of 2.20 and 3.82 g. The average of 2.97 g (i.e. 1.04 g for a fermented dried cocoa bean) was higher than the control, the Upper Amazon Forastero clone NA 32. The main five populations were not statistically different for the three morphological bean descriptors (average weight, average length and width), but they were for the percentage of flat beans, which was relatively high on average (6.9, on fresh beans). An analysis of variance of the basic data (i.e. per pod on 3250 pods) showed a highly significant tree effect, enabling ortets selection. Given the high heritability of the average bean weight, these ortets could be used as clones, or as parents in crosses with other genetic groups. A list of trees with small beans, hence which ought theoretically to be avoided in breeding programmes, is provided.

Moniliophthora Pod Rot (MPR) caused by the fungus Moniliophthora roreri (Cif.) Evans et al., is one of the main limiting factors of cocoa production in Latin America. Currently insufficient information on the biology and epidemiology of the pathogen limits the development of efficient management options to control MPR. This research aims to elucidate MPR development through the following daily microclimatic variables: minimum and maximum temperatures, wetness frequency, average temperature and relative humidity in the highly susceptible cacao clone Pound-7 (incidence = 86% 2008–2013 average). A total of 55 cohorts totaling 2,268 pods of 3–10 cm length, one to two months of age, were tagged weekly. Pods were assessed throughout their lifetime, every one or two weeks, and classified in 3 different categories: healthy, diseased with no sporulation, diseased with sporulating lesions. As a first step, we used Generalized Linear Mixed Models (GLMM) to determine with no a priori the period (when and for how long) each climatic variable was better related with the appearance of symptoms and sporulation. Then the significance of the candidate variables was tested in a complete GLMM. Daily average wetness frequency from day 14 to day 1, before tagging, and daily average maximum temperature from day 4 to day 21, after tagging, were the most explanatory variables of the symptoms appearance. The former was positively linked with the symptoms appearance when the latter exhibited a maximum at 30°C. The most important variables influencing sporulation were daily average minimum temperature from day 35 to day 58 and daily average maximum temperature from day 37 to day 48, both after tagging. Minimum temperature was negatively linked with the sporulation while maximum temperature was positively linked. Results indicated that the fungal microclimatic requirements vary from the early to the late cycle stages, possibly due to the pathogen’s long latent period. This information is valuable for development of new conceptual models for MPR and improvement of control methods.

En el estado Portuguesa específicamente en las zonas de Biscucuy y Chabasquén, el desarrollo y producción de cacao (Theobroma cacao L.) en los últimos años, ha representado una alternativa de diversificación de los sistemas productivos puesto que se han caracterizados principalmente por el cultivo de café, indicando esto que no existe una amplia experiencia relacionada con el manejo del cultivo y tratamiento poscosecha. Por lo que, se planteó explicar el efecto de la ubicación y época de cosecha en el control de fermentación de las almendras de cacao. El estudio se realizó en las épocas de abril-junio y noviembre-enero desde el 2010 al 2012; se recolectaron entre 800 y 1000 mazorcas de cacao en cada cosecha. Las almendras fueron fermentadas en cajones de madera de dimensiones 60x60x60 cm durante seis días, posteriormente se secaron al sol. En el laboratorio de Tecnología de Alimentos de La Universidad del Zulia, se determinó el contenido de humedad, pH, acidez total y volátil. Tomando en consideración la ubicación, época de cosecha y tiempo de fermentación, los resultados se compararon por análisis de varianza (ANOVA), utilizando el software estadístico (XLSTAT-2012). Finalmente, se dedujo que en el cacao de Biscucuy los niveles máximos de temperatura se presentaron en la época de noviembre-enero; no obstante en el de Chabasquén se observaron en el periodo de abril-junio.Asimismo, se mostró mayores niveles de humedad en la época de abril-mayo en ambos cacaos y el cacao de Chabasquén presenta más niveles de acidez que el de Biscucuy en la época mencionada.