Homogenization of cocoa beans fermentation to upgrade quality using an original improved fermenter

Cocoa beans (Theobroma cocoa L.) are the main components for chocolate manufacturing. The beans must be correctly fermented at first. Traditional process to perform the first fermentation (lactic fermentation) often consists in confining cacao beans using banana leaves or a fermentation basket, both of them leading to a poor product thermal insulation and to an inability to mix the product. Box fermenter reduces this loss by using a wood with large thickness (e>3cm), but mixing to homogenize the product is still hard to perform. Automatic fermenters are not rentable for most of producers. Heat (T>45°C) and acidity produced during the fermentation by microbiology activity of yeasts and bacteria are enabling the emergence of potential flavor and taste of future chocolate. In this study, a cylindro-rotative fermenter (FCR-V1) has been built and coconut fibers were used in its structure to confine heat. An axis of rotation (360°) has been integrated to facilitate the turning and homogenization of beans in the fermenter. This axis permits to put fermenter in a vertical position during the anaerobic alcoholic phase of fermentation, and horizontally during acetic phase to take advantage of the mid height filling. For circulation of air flow during turning in acetic phase, two woven rattan with grid have been made, one for the top and second for the bottom of the fermenter. In order to reduce air flow during acetic phase, two airtight covers are put on each grid cover. The efficiency of the turning by this kind of rotation, coupled with homogenization of the temperature, caused by the horizontal position in the acetic phase of the fermenter, contribute to having a good proportion of well-fermented beans (83.23%). In addition, beans'pH values ranged between 4.5 and 5.5. These values are ideal for enzymatic activity in the production of the aromatic compounds inside beans. The regularity of mass loss during all fermentation makes it possible to predict the drying surface corresponding to the amount being fermented. (Résumé d'auteur

Organisation des filières bananes ivoiriennes : Une étude de terrain expérimentale

In Ivory Coast, the plantain sector is insufficiently organized. Is it due to the selfish behaviour of its agents? A field study was conducted to compare this sector with the sweet banana. The degree of altruism was measured via a repeated public good game. Agents of plantain appear more cooperative than their counterparts in sweet banana. The lack of organisation is rather due to the market conditions than to selfish behaviour. These agents are willing to coordinate their activities, but they some favourable conditions

La réponse à la stimulation des clones d\'une même classe métabolique varie chez Hevea brasiliensis Muell Arg. (Euphorbiacea)

Différents travaux ont montré que, chez l\'hévéa (Hevea brasiliensis), la réponse d\'un clone à la stimulation chimique à l\'acide chloroéthyl phosphonique ou Ethephon est fonction de la classe métabolique à laquelle il appartient. Ainsi, les clones à métabolisme modéré répondent moyennement à la stimulation à l\'Ethephon. Ceux à métabolisme lent s\'expriment fortement, à la différence des clones à métabolisme rapide qui réagissent faiblement à cette même stimulation. Toutefois, il peut arriver que des clones d\'une même classe métabolique se comportent différemment suite à la stimulation à l\'Ethephon. La présente étude a pour objet d\'évaluer la réponse des clones à la stimulation à l\'Ethephon à l\'intérieur de deux principales classes métaboliques (métabolismes moyen et lent). Différents régimes de stimulation ont été appliqués pendant neuf années. L\'étude a révélé qu\'il existe au sein de ces deux clases d\'activité métabolique une variation de la réponse de certains clones à la stimulation à l\'Ethephon. Le métabolisme de production de caoutchouc de ces clones a été accru par le régime de stimulation.Many studies showed that response of a clone to chemical stimulation with Chloroethyl phosphonic acid or Ethephon depends on it\'s metabolic group. Therefore, clones with an intermediate metabolism respond meanly to stimulation with Ethephon. Those with a low metabolism respond highly at the opposite of clones with high metabolism that respond weakly to this same stimulation. Sometimes, clones belonging to a given metabolic group react differently to stimulation with Ethephon. The present study aims to assess response to stimulation with Ethephon within two metabolic groups. Different treatments of stimulation were applied over nine years. The study revealed a variation in teh response to stimulation with Ethephon in some clones delonging to moderate and low metabolic activity groups. Metabolism of latex production in these clones was increased by chemical stimulation. Keywords: Hevea brasiliensis, variation de réponse, métabolisme, stimulation chimique.Hevea brasiliensis, response variation, metabolism, chemical stimulationSciences & Nature Vol. 4 (1) 2007: pp. 57-6

Morphologie et hydrodynamique à l'embouchure du fleuve Bandama

This study deals with the present morphology of the Bandama river mouth in Grand-Lahou (Côte d'Ivoire). At the interface water-sediment channels and shallows appear, covered respectively by fine and medium sands. Topographic surveys conducted from 1989 to 1993 show significant migration of the river mouth from east to west. The average migration rate is about 1.1 meter per mouth. Although for the past two years , a rate of about 3.5 meters per month was observed

Contamination aux metaux lourds de la matrice eau-sediment et muscle du tilapia Oreochromis niloticus de trois fermes piscicoles en Cote d’Ivoire

La présente étude a pour objectif de déterminer le niveau de contamination du mercure, du cadmium, de l’arsenic et du plomb dans l’eau, les sédiments et le muscle du tilapia Oreochromis niloticus dans trois fermes piscicoles en Côte d’Ivoire. L’eau, les sédiments et les spécimens de poisson ont été prélevés par mois de février à juillet 2017 en cage dans la lagune Aghien (ST1), en étang continental (ST2) à Agboville et en cage dans le barrage de Taabo (ST3). Les paramètres physico-chimiques mesurés ont montré qu’à l’exception de la conductivité, des matières en suspension et des solides totaux dissous, aucune variation saisonnière n’a été observée. En revanche, les valeurs moyennes des paramètres physico-chimiques calculées sont significativement différentes entre les fermes. Les valeurs de chaque métal mesurées dans la matrice eau-sédiment-muscle varient significativement entre les deux saisons dans toutes les fermes. Cependant, aucune différence entre les fermes échantillonnées n’a été observée. Les concentrations des métaux lourds mesurées dans le muscle sont inférieures aux valeurs seuils établies par l’OMS à l’exception de l’As. Cette contamination élevée en arsenic pourrait porter atteinte à l’intégrité biologique et à la santé humaine.Mots clés : Métaux lourds, Accumulation, Oreochromis niloticus, Ferme piscicole ivoirienn

Détermination de la durée de vie géochimique du stock de déchets miniers de Carnoulès (France) à partir d\'un modèle hydrodynamique.

Le stock de déchets miniers de Carnoulès forme un aquifère bicouche constitué de sable très fin à sulfure et de sable fin à passage de blocs grossiers. L\'écoulement de l\'eau à l\'intérieur est guidé par un drain souterrain. Le modèle hydrodynamique a permis d\'évaluer les flux de matières à partir de la reconstitution de débits à l\'exutoire. Les fortes teneurs en sulfates de l\'eau observées à la source proviennent de la dissolution de la pyrite qui détermine l\'essentiel des réactions géochimiques à l\'intérieur du stock de déchets miniers. La durée de vie du stock de déchets miniers estimée à partir des flux annuels de pyrite oxydée est de plus de 100 ans. Les méthodes de rémédiation appropriées ne doivent donc pas être des installations qui exigeront un entretien continu compte tenue de cette longue durée de vie.The mining waste stock of Carnoulès is a double-layered aquifer made up of very fine clay and sand with sulphide and of sand ends to passage of coarse blocks. The groundwater circulation is guided by an underground drain. The hydrodynamic model made it possible to evaluate matter flows starting from the reconstitution of flows to the catchment discharge system. It arises a strong content sulphate of water coming from the dissolution of the pyrite which guides the main geochemical reactions inside the stock of mining waste. The lifetime considered starting from annual oxidized pyrite flows is of more than 100 years. Methods of remediation should not be installations requiring a Keywords: Drainage acide minier, modélisation, hydrodynamique, Modflow/Mining acid drainage, modelling, hydrodynamics, ModflowSciences & Nature Vol. 4 (1) 2007: pp. 105-11

Investigation of rodent reservoirs of emerging pathogens in Côte d'Ivoire, West Africa

Background: One of the main health problems in West Africa remains upsurge of emerging pathogens. Ebola virus disease outbreak occurred in 2014 in Liberia, Guinea and Sierra Leone, Monkeypox virus in Nigeria in 2017 and most recently Lassa virus in Nigeria, Togo and Benin in 2018.  These pathogens have animal reservoirs as vectors for transmission. Proper investigation of the pathogens in their rodent vectors could help  reduce and manage their emergence and spread. Methodology: This study was conducted with an approval from the Côte d’Ivoire Bioethics Community. Small mammal trappings were carried out in  9 sites within three zones namely, peri-urban, peri-rural and protected areas. Liver, lung and kidney tissues from trapped small mammals were  sampled in accordance with the recommended conditions of biosafety and bioethics. The organs were transported in liquid nitrogen to the  laboratory. Molecular tests were used to detect pathogens. Orthopoxviruses and Monkeypox virus were detected in the organs by PCR using  consensus primers targeting the virus surface membrane haemagglutinin (HA) genes, while Leptospira species were detected by PCR using primers  targeting the rrs and lfb1 genes. Results: Out of 4930 night-traps, 256 (5.19%) small mammals were trapped including Crocidura, Rattus, Lophuromys, Praomys, Mus and Mastomys.  Leptospira species were detected in 6 genera from 7 study sites and the infected small mammals accounted for 13.3%. Leptospira sp was detected  mainly in the rodent vector genera Rattus (32.3%), Lophuromys (29.0%), and Praomys (16.1%). Three species of Leptospira were detected and  Leptospira interrogans was the most common frequent species (74.2%). Monkeypox virus was not detected from studied small mammals. Conclusion: The initial data from our investigation indicates the presence of Leptospira sp in rodent vectors, Rattus, Lophuromys and Praomys,  which are the potential small mammalian reservoirs of this pathogen in Cote d’Ivoire