Differences in physicochemical properties and structure of red sorghum starch: Effect of germination treatments

Background and Objectives: Germination has been extensively studied, but the changes in different starch components have not yet been entirely elucidated. The aim of this study was to assess the effects of germination on the starch composition, physicochemical properties, and structure of red sorghum seeds. Findings: Germination of red sorghum starch led to decreased amylose, water absorption, and syneresis, but increased oil absorption, solubility, and swelling power. The freeze-thaw - thaw stability of germinated sorghum starch improved. However, the starch paste exhibited thinning under shear, suggesting its gel structure was susceptible to damage. The starch's peak viscosity and breakdown value increased significantly with the increase in germination time, whereas the setback value decreased. Germination treatment did not alter the chemical structure of the starch, but it increased the porosity and the number of dents on the surface of starch granules. Notably, the in vitro digestibility of the starch increased significantly after germination. Conclusions: The germination treatment of red sorghum affected the structure and physicochemical properties of the isolated starch to some extent.