Development of a method for the mineralization of coffee husk (Coffea canephora P.) to obtain raw material for soap factories

Every year, large quantities of husk resulting from the dry method of treatment of robusta coffee are dumped into nature. This generates multiple harmful ecological effects. The downward trend of coffee prices and the rise in the cost of manure has urged coffee farmers to better exploit the by-products of coffee transformation. Thus, a test for the mineralization of coffee husk to obtain soap factory raw material was carried out in the coffee – cocoa technology laboratory at Nkolbisson in Cameroon. To start and improve combustion, three types of fuel namely; cocoa husk, palm bunches and palm nut cake was used. After 16 h of combustion, the highest rate of mineralization was obtained with the palm nut cake (86%) followed by cocoa husk (55%) and the palm bunches (43.4%).This first result turns out to be interesting for further research.Key words: Coffee husk of coffee, mineralisation, fuel

Assessment of Exposure to Ochratoxin -A (OTA) through Ground Roasted Coffee in two Cameroonian Cities: Yaounde and Douala

Abstract Occurrence of ochrato xin A (OTA) in ground roasted coffee fro m d ifferent brands and types available in Yaounde and Douala cities was assessed. Based on these data, exposure of the Cameroonian population to OTA through coffee consumption was estimated. Coffee samples were purchased in hypermarkets and supermarkets of the two selected cities of Cameroon. OTA was extracted, cleaned-up by immunoaffin ity columns, and detected by HPLC-fluorescence detection. OTA was found in 64.7% of pure Arab ica coffee, 75% of pure Robusta coffee, and 62% of Arab ica / Robusta mixtu re coffee, with OTA levels ranging fro m 0.3 to 4.9 µg.kg -1 , 0.6 to 18 µg.kg -1 and 0.3 to 7.4 µg.kg -1 respectively. Robusta Coffee brands are the most contaminated, follo w by coffee mixture brands and Arabica coffee brands. The daily intake of OTA is 0.065 ng / kg bw per day. Consumption of OTA fro m coffee in the cities of Douala and Yaoundé are then very lo w compared to that of Europe who is 2-3 ng/kg bw per day. Consumption of OTA fro m coffee in the cities of Douala and Yaounde is very low co mpared to that of Europe, for wh ich the rate is 2-3 ng/kg bw per day

Aspergillus noirs producteurs d ochratoxine A dans le cacao (biodiversité et incidence des traitements post-récolte au Cameroun)

L'incidence des procédés post-récoltes sur la contamination du cacao par l'OTA a été étudiée. Le type de fermentation (caisse ou tas) n'a pas influencé de façon significative la microflore fongique totale, la toxinogènèse, ou la teneur en OTA des fèves. Par contre l'intégrité de la cabosse et le délai d'écabossage constituent des facteurs aggravants de cette contamination. Les souches ochratoxinogènes isolées appartiennent aux espèces A. niger agg (moins producteurs d'OTA avec une teneur maximale de 3,6 ng.g-1) et A. carbonarius (dont la production maximale atteint 2772 ng.g-1). Tous les isolats d'A. carbonarius sont producteurs d'OTA tandis que 8 % seulement des isolats d'A. niger agg le sont. La croissance et la toxinogénèse de ces souches sont dépendantes des conditions physico-chimiques et environnementales. L'activité de l'eau est un facteur essentiel (production optimale entre 0,95 et 0,99). Parmi les alcaloïdes naturellement présents dans les fèves de cacao (caféine, théobromine et épicatéchine), seule la caféine a montré un effet sur la croissance et la toxinogénèse. L'identification des Aspergillus du cacao grâce aux techniques de PCR avec des amorces spécifiques a permis de séparer A. carbonarius et le complexe d'A. niger agg. Par contre, les composants de ce complexe ne sont pas dissociables, ni par cette technique, ni par le séquençage des amplifias des fragments partiels ITS1 / ITS2. Les Aspergillus noirs isolés présentent une biodiversité importante. L'étude des profils génomiques obtenus par RAPD-PCR a montré que cette biodiversité n'est dépendante, ni de l'année de la campagne cacaoyère, ni du type de traitement post-récolte subi ; mais elle peut être influencée par le degré de transformation de la fève. L'état de la cabosse et plus généralement les bonnes pratiques agricoles constituent les meilleurs gages de l'innocuitéThe effect of post-harvest processes on cocoa contamination by OTA was studied. The type of fermentation (box or heap) did not significantly influence total fungal microflora, toxigenesis, or bean OTA content. However, pod integrity and time to pod opening were aggravating factors for contamination. The ochratoxigenic strains isolated belonged to the species A. niger agg (producing less OTA with a maximum content of 3.6 ng.g-1) and A. carbonarius (for which the maximum reached 2772 ng.g-1). All the A. carbonarius isolates were OTA producers, whereas only 8% of the A. niger agg isolates were. The growth and toxigenesis of these strains depended on physico-chemical and environmental conditions. Water activity was an essential factor (optimum production between 0.95 and 0.99). Among alkaloids naturally present in cocoa beans (caffeine, theobromine and epicatechin), only caffeine exhibited an effect on growth and toxigenesis. Identification of Aspergillus species on cocoa using PCR techniques with specific primers made it possible to separate A. carbonarius and the A. niger agg complex. However, the components of the complex were neither dissociable by this technique, nor by sequencing of the amplificates of the ITS1/ ITS2 partial fragments. The black Aspergillus isolated displayed substantial biodiversity. A study of the genomic profiles obtained by RAPD-PCR revealed that this biodiversity depended neither on the year of the cocoa season, nor on the type of post-harvest processing; however, it could be influenced by the degree of bean processing. Pod condition and, more generally, good agricultural practices were the best guarantee of safetyMONTPELLIER-BU Sciences (341722106) / SudocSudocFranceF

Study of Ochratoxin: A complexation in coffee

International audienc

Effect of operating conditions on ochratoxin A extraction from roasted coffee

Operating conditions affect ochratoxin A (OTA) extraction from roasted coffee. The OTA content found in the beverage can thus be greater than that found in the roasted coffee used to prepare it. Three extraction parameters were studied for roasted coffee: type of extraction solvent (alkaline, neutral, acid), temperature (ambient temperature/23°C, 60°C and 85°C), and extraction time (5, 20, 30, 40, 50, 60 and 80 min). The alkaline solvent used in the method recommended by the European Union extracted OTA better, but a maximum content was obtained at 60°C after 50 min. At least a 100% improvement in extraction was obtained when compared with the European Union usual quantification method that is carried out at ambient temperature. It turned out that the OTA extraction parameters for roasted coffee, as defined by that method, were not optimum and needed to be modified. These results were verified in double-extraction experiments showing that OTA is not completely extracted by this method. Confirmation was obtained by comparison of extraction methods on several commercial samples of roasted coffee. (Résumé d'auteur