Detoxification of Common bean (Phaseolus vulgaris) Flour Through Open and Controlled Fermentation Methods

The effect of open and controlled fermentation on the proximate composition, some mineral elements, antinutritional factors and flatulence- causing oligosaccharides of a domesticated bean (Phaseolus vulgaris) was studied. The open fermentation was carried out using the microorganisms present in the atmosphere, while the controlled fermentation was carried out using Aspergillus niger as a starter. The two types of fermentation brought about less than 20 % increase in the protein content. The lipids, carbohydrates, crude fibre and ash content were all reduced by less than 75 % during the two types of fermentation, except the moisture content which suffered from increase in controlled fermentation. Apart from calcium, the other elements (Fe, Na, Mg, Zn, and K) suffered from less than 90 % reduction by the two types of fermentation. The phytate, tannin, alkaloids, hydrogen cyanide, lectins, trypsin inhibitors and oxalate content all suffered from more than 20 % reduction by the two types of fermentation. The percentages of reduction due to controlled fermentation were higher than those of open fermentation in the eight antinutrients studied. So, considering the common beans as the main source of proteins in developing countries, fermentation is an efficient processing method for considerable reduction of the above studied antinutrients in the cultivated beans studied in this work with no much impact on the protein level.