Soybean (Glycine max L.) is considered as an important and widely consumed legume due to its higher nutritional and bioactive potential as well as better functional characteristics. It is a rich source of numerous nutritional components such as essential amino acids, protein, and various dietary components which are suitable for all age groups. This research is aimed to assess the effect of soaking, germination, fermentation (natural and with Saccharomyces cerevisiae), and roasting on nutritional characteristics, anti-nutritional components, minerals (Fe, Zn, Mn, and Cu), and bioactive components of soybean. The effect of soaking was studied at 12 and 24 h, while that of germination at 24, 48, and 72 h, fermentation for 12, 24, and 36 h interval, and roasting at a temperature of 180°C. The results revealed that the antioxidant activity increased significantly (P ≤ 0.05) by 98.01% after 72 h of germination and 68% after the 36 h of fermentation with S. cerevisiae. Further, there was a 19.86 and 17.42% increase in the phenolic components during roasting and germination processes, respectively. The protein contents get increased significantly (P ≤ 0.05) by 6.54, and 23% during germination and fermentation treatments, respectively. The anti-nutrients such as phytic acid and tannin contents declined significantly (P ≤ 0.05) to the extent of 7.35, 27.94, and 58.82% and tannin contents as 8.70, 44.93, and 58.82%, after soaking, germination, and fermentation processes, respectively. There was a significant (P ≤ 0.05) increase in mineral contents after processing treatments of soybean. Therefore, the processing treatments were quite effective in increasing the nutritional value as well as the bioactive components and decreasing the antinutritional components.
Key words: Anti-nutrients, Antioxidant activity, Fermentation, Germination, Soybean