Barley fermentation on nutritional constituents: structural changes and structure–function correlations

Over the past few years, the demand for healthy grains has become increasingly important. Barley is a basic material for food and animal feed, which is considered an excellent source of multiple nutrients. However, due to limitations in processing techniques, the nutritional attributes of barley have not been completely realized. The functional profile of barley nutrients can be effectively improved by fermentation, due in large to the structural alteration of barley nutrients. The current review outlines the structural changes of barley nutrients during fermentation and summarizes the potential mechanisms by which structural alteration occurs. Correlations between the nutrient structures and their nutritional properties are also discussed. In general, fermentation leads to decreased particle size and modified internal structures of macromolecular nutrients. Enzyme action, pH alterations and interactions between nutrient matrices may contribute to these structural alterations. Barley nutrients with modified structure exhibit enhanced health promoting functions and digestive characteristics, which will further contribute to the utilization of barley resources in the food industry.