Study on the influence mechanism of endogenous protein components on the characteristics of distiller's grains starch

Some starch in distiller's grains has low utilization rate and serious waste of resources due to its combination with endogenous non-starch components (proteins). This study explored the impact of removing different endogenous proteins on starch molecules' physicochemical structure and brewing characteristics. Results revealed β-sheet-dominated proteins in fermented grains, with alkali-soluble proteins being most abundant (37.47 %). The removal of protein resulted in the formation of a porous structure on the surface of starch. The swelling degree, freeze-thaw stability and in vitro digestion characteristics of each sample were significantly improved except as solubility. Among them, alcohol-soluble protein had obvious promoting effect on pore formation and gelatinization, and both alcohol-soluble protein and alkali-soluble protein could weaken the interaction of starch complex and improve the brewing performance. This provides a new idea for improving the efficient utilization of starch and reducing the waste of resources in the future liquor brewing process.