Effect of Lactiplantibacillus plantarum and Saccharomyces cerevisiae fermentation on the multi-scale structure and physicochemical properties of highland barley starch

Modified starch was better suitable for food processing, and fermentation was one of the effective methods to modify starch. This study investigated the separate and synergistic fermentation of Lactiplantibacillus plantarum and Saccharomyces cerevisiae could whether affect the multi-scale structure and physicochemical properties of highland barley starch (HBS). The results of multi-scale structure determination of HBS showed that compared with unfermented HBS (32.27%), fermentation showed a significant increase in relative crystallinity (35.49–39.81%), while the crystal type of HBS as observed from X-ray diffraction (A-type crystalline pattern) did not change. The small angle X-ray scattering revealed that fermentation reduced the amorphous region and increased the crystalline layer thickness of the HBS. Consequently, the changes in the physicochemical properties showed that the peak viscosity, trough viscosity, and final viscosity of HBS were reduced after fermentation, and the aging of starch gel was delayed significantly. Our results showed that Lactiplantibacillus plantarum and Saccharomyces cerevisiae fermentations improve the physicochemical properties of HBS by modifying the multi-scale structure of starch, especially the synergistic fermentation effect was more effective.