Extraction and application of proteins from distiller's grains: A review

As a solid by-product of ethanol-beverage production, distiller's grains (DGs) contain high water content and are rich in nutrients, while their improper disposal poses environmental risks and resource wastage. Notably, DGs contain 15-44 % protein content with diverse amino acid composition, establishing them as a high-quality protein source. Prolamin constitutes over 60 % of the protein fraction in DGs. Furthermore, enzymatic treatment of DG proteins has yielded peptides demonstrating multiple functional activities, including antioxidant and antihypertensive properties etc. This review systematically analyzes extraction methodologies for DG protein, prolamin, and peptides, while comprehensively evaluating their associated biological activities. These findings provide theoretical foundations for proteins and their derivatives utilization from DGs and facilitate their high-value applications. Future research should prioritize establishing a standardized definition of DGs to enable precise categorization.