Microbiological assay of vitamin B and biotin in some Nigerian fermented foods

Abstract

The B vitamins and biotin contents of raw seeds, cooked unfermented seeds and the fermented products of castor oil (Ricinus communis) and African oil bean (Pentaclethra macrophylla) were analysed using microbiological assay. Generally, there were decreases in vitamin values, especially in those of the B vitamins, when the raw seeds were cooked in water. Of the vitamins in castor oil bean, fermentation accounted for a significant increase only in riboflavin—about threefold that of the cooked unfermented beans. The niacin and thiamine values were, in fact, less than in the raw seed. In the fermentation of African oil bean seeds, all the B vitamins and biotin increased with fermentation. The most significant increase is also in riboflavin, about fourfold of that of the cooked unfermented beans. Generally, the biotin contents were only slightly higher than in the cooked unfermented beans. The marked increases in the riboflavin were ascribed to the activity of Bacillus subtilis in the fermentation. The patterns of results obtained were compared with those of other fermented vegetable protein foods.