Diversity of yeasts involved in the fermentation of tchoukoutou, an opaque sorghum beer from Benin

Opaque sorghum beers are traditional alcoholic beverages in several African countries. Known as tchoukoutou in Benin, the beer is often obtained from an uncontrolled fermentation. It is consumed in an actively fermenting state and has a sour taste. The present study characterized and identified the yeasts involved in the fermentation process of this type of beer using the phenotypical approach. Of 12 beers from 4 different locations, the mean values of the pH, titratable acidity, dry matter content and refractive index were respectively 3.67, 0.70 (% as lactic acid) 18.08% and 7.00. Lactic acid bacteria and yeasts were the predominant microorganisms involved in the fermentation of tchoukoutou. Their counts were respectively 9.1 log cfu/ml and 9.1 logcfu/g. Enterobacteriaceae were not detectable in the beer. Based on the phenotypic characters and the assimilation profiles of 40 isolated yeasts, four genera with seven species of yeasts were identified. The yeast species predominant in the Benin opaque sorghum beer tchoukoutou was Saccharomyces cerevisa

Extraction of antioxidant pigments from dye sorghum leaf sheaths

Extraction of antioxidant biocolorant pigments from leaf sheaths of dye sorghum was optimized. Effects of temperature and ethanol concentration of the extraction solvent on the concentrations of the 3-deoxyanthocyanidins, total phenolics and total anthocyanins, and the colour parameters of the biocolorant extract were evaluated using the response surface methodology. Extraction parameters affected the extraction rate of the biocolorant pigments and the colour characteristics of the extract. Maximum pigment yields were obtained at 50 °C and an ethanol concentration of the solvent of 51 mL 100 mL-1. Addition of HCl (1 mL 100 mL-1) to the solvent significantly improved the extractability of the biocolorant pigments. The crude extract from the leaf sheaths showed high antioxidant capacity with a total antioxidant capacity of 1026 mg of Trolox equivalent (TE) g-1 of DM. -------------------------------------------------------------------------------

Uncommonly high levels of 3-deoxyanthocyanidins and antioxidant capacity in the leaf sheaths of dye sorghum

Extracts from leaf sheaths of farmers varieties of dye sorghum cultivated and used in Benin as a source of biocolorings were analyzed for their anthocyanidin and phenolic contents, as well as their antioxidant capacity. The aim was to identify and quantify the types of anthocyanin and phenolic acids. The total anthocyanin content of the leaf sheaths ranged from 13.7 to 35.5 mg of cyanidin 3-glucoside equivalent/g of dry matter (DM), with an average of 27.0 mg/g. The total anthocyanin content is 90 times higher than levels usually reported in fruits and vegetables. Anthocyanin consisted essentially of apigeninidin and luteolinidin, two 3-deoxyanthocyanidins with many applications in food, beverage, and pharmaceutical industries. The apigeninidin content of the leaf sheaths was 30 times higher than that in cereal bran and ranged from 14.7 to 45.8 mg/g, with an average of 31.3 mg/g. The amount of luteolinidin ranged from 0.4 to 2.4 mg/g, with a mean of 1.2 mg/g. The total phenolic content expressed as gallic acid equivalent averaged 95.5 mg/g. The free phenolic acids identified were benzoic acid, p-coumaric acid, and o-coumaric acid at amounts of 801.4, 681.6, and 67.9 µg/g, respectively. The leaf sheaths of dye sorghum have an antioxidant capacity [3.8-5.6 mmol of Trolox equivalent (TE)/g of DM] much higher than that reported for cereal bran and fruits and vegetable

Optimisation de la torrefaction des amandes de P. Butyracea pour la production du beurre

Pentadesma butyracea kernels roasting during butter production is an operation which affects the extraction yield and the quality of butter. In order to produce a good quality of P. butyracea butter and improve yield extraction, this work aims to determine the optimal roasting time and temperature. Thus, the dried P. butyracea kernels were roasted at temperature from 100 to 180°C during 15 to 45min using Response Surface Method with central composite design. In response to these different treatments, yield of cold extraction with hexane, kernels (color : lightness (L*), redness (a *) and yellowness (b*)) and butter quality (color : lightness (L*) and yellowess (b*) ; acidity ; peroxide index) were assessed. The linear and/or quadratic effect of the duration and the temperature of roasting as well as the interaction between these two factors strongly influenced extraction yield, physical characteristics of the kernels and physicochemical characteristics of the butter. At 135°C for 45 min it is possible to produce Pentadesma butter for cosmetic  and food industries uses (acidity : 0.31 % ; peroxide index : 3.22 méq O2/Kg ; L* : 75.10 ; b* : 35.02) with an extraction yield of about 40 % (39.5 %).Keywords: Shea butter, Chocolate industry, Cosmetics, Peroxide index, Beni