Changes in the enzymes, amino acids, metal ions and flavor profile during fermentation of African locust bean seeds ‘Parkia biglobosa’ to Daddawa

Daddawa/iru, a product of African locust bean (Parkia biglobosa) seeds, is widely used as food condiment by many tribes in West Africa. This study aimed to determine some of the changes which occur during the microbial fermentation of African locust bean seed. The daily changes in pH, amylase, lipase and protease secretion were monitored. Changes in amino acid concentration, mineral ion composition were also monitored; the presence of hydrocarbons and volatile flavor compounds were also determined. The pH increased throughout fermentation and was above 8.5 by 96 h fermentation. Enzyme production was highest after 48 h fermentation. The highest increase in amino acid concentration was observed after 72 h fermentation. The essential amino acids which increased after 72 h fermentation include arginine (48.8%), threonine (25.2%), valine (24.8%), and methionine (20.0%), histidine (10.3%), isoleucine (19.2%), leucine (15.9%), lysine (15.24%), phenylalanine (14.9%), and tryptophan (12.5%). A higher metal ion concentration was observed before fermentation (0 h) than during or after fermentation of the locust bean seeds. Various hydrocarbons, fatty acids, esters and alcohols were observed at different stages of the fermentation.