Biochemical and microbial changes during traditional spontaneous lactic acid fermentation process using two varieties of cassava for production of a “Alladjan” starter

Cassava roots are used as human food in many processed forms and products. Fermentation is the initial step needed in the development of various flavour precursors in the cassava and generally conducted as traditional, indigenous processes leading sometimes to the undesirable quality of final products depending probably on the variety (bitter or sweet) of cassava. Both sweet and bitter varieties were purchased from Abidjan and then used for preparation of an Ivorian traditional starter. Lactic acid fermentation was carried out to investigate which variety between sweet and bitter ones is the best raw material for the best quality of starter. During fermentation, progressive acidification was observed in the pulp of both of sweet and bitter cassava varieties. At the beginning of fermentation process total reducing sugars content in bitter cassava pulp is higher than in sweet cassava. Total reducing sugars content decreased and reached the relatively same value of 0.7% in both sweet and bitter cassava. After 48 hours of fermentation, counts of most of micro organisms increased and reached 8 -10 log10 CFU/g and the lowest increase was recorded in the population of Enterococci. Among anaerobic fermenting bacteria, lactic acid bacteria were predominant. Among coliforms, thermotolerant counts population decreased significantly and reached 6 log10 CFU/g in the final stage. Yeast and moulds counts decreased slightly to 6.86 - 7.321 log10 CFU/g at the end of fermentation. The extensive scrutiny of microbial population revealed that micro flora consisted of Aerobic mesophilic counts, coliforms, lactic acid bacteria, enterococci, yeast and moulds in both of varieties