Biochemical changes in fermenting African locust bean (Parkia biglobosa) during ‘iru’ fermentation

The enzymic activities and biochemical changes in the principal food constituents of African locust bean were investigated. The reducing sugar level increased from 63 mg/g to 134 mg/g during the first 24 hr but subsequently decreased. Amylase activity was not detected. The lipase activities were detectable with the peak at 48 hr after the start of fermentation. The most significant activity during the fermentation is the rapid and steady increase in the quantity of free amino acids throughout the fermentation. This is due to a consistently active proteinase activity by the fermentative microorganisms. The number and quantities of each amino acids analysed also increased in the fermented beans. Glutamic acid, valine, aspartic acid and alanine were rapidly liberated during the fermentation. The changes observed are compared with the fermentation of other protein rich seeds.