Evaluation des parametres biochimiques du mout de sorgho durant dix-huit heures de fermentation discontinue [ Assessment of biochemical parameters of sorghum wort for eighteen hours of batch fermentation ]

The fermentation process of Sorghum wort is one of the fundamental steps that determine the quality of tchapalo (traditional beer). Its assessment through biochemical parameters such as pH, temperature, total soluble solids (substrate), biomass, released carbon dioxide and alcohol (ethanol) content allowed capitalizing values during the experiments. Analysis of the evolution of these biochemical parameters showed significant variations (P < 0.05) during the batch fermentation process of sorghum wort. Thus, the biomass reached a maximum average of 27.64 ( plus or minus 7.83) g/L at the eleventh hour of fermentation and then decreased drastically, untill an average of 4.40 ( plus or minus 1.00) g/L at the end of fermentation. The maximum temperature value (32.50 ( plus or minus 0.69) degree C) was recorded at the ninth hour of fermentation while that of the carbon dioxide (88.11 ( plus or minus 4.48) ppm) is obtained at the fourteenth hour of fermentation. While considering the eighteenth hour of fermentation, it was noted that the pH of sorghum wort stays very acid (2.88 ( plus or minus 0.55)). Similarly, it was observed a decrease of more than half the levels of total soluble solids in sorghum wort after fermentation. In contrary, the alcohol content increased to reach a maximum average of 5.24 ( plus or minus 1.14)% (v / v) at the end of fermentation. These results constitute an important data base for the industrialization of the manufacture of tchapalo whose consumption is rising.