Effect of natural fermentation on the structure and physicochemical properties of wheat starch

In this study, the effects of natural fermentation on the multi-scale structure and physicochemical properties of wheat starch were investigated. The results showed that fermentation reduced weight-average molecular weight (M_w) and slightly eroded the starch granule surface. An obvious increase in relative crystallinity from X-ray diffraction was observed in all fermented starch (39.38-42.27%) when compared with native starch (37.15%). Data from small angle X-ray scattering revealed that fermentation increased the crystalline layer and decreased the amorphous region of the starch granules. The intensity of absorption related to hydrogen bonding by FT-IR (3000-3600 cm^-1) also increased in fermented starch. The rapid viscosity analysis results showed that fermented starch had a lower peak viscosity and final viscosity, and a lower setback value than native starch. The present results reveal that fermentation is an effective method to modify wheat starch and suggest its potential to improve the quality of starch-based foods.