Effects of Removing Endogenous Proteins with Different Solubility on the Physicochemical Properties of Early Indica Rice Flour

In order to improve the quality of early indica rice flour products by using endogenous proteins to regulate its physicochemical properties, this paper studied the effects of removing endogenous proteins with different solubility (albumin, globulin, prolamin and oryzenin) on the solubility, swelling capacity, and pasting properties of the early indica rice flour, as well as on its water binding state, rheological properties and freeze-thaw stability after pasting. The results showed that the removal of globulin and oryzenin could improve the solubility of the early indica rice flour, while the removal of prolamin and oryzenin could improve its swelling capacity under high temperature. The removal of albumin made the peak viscosity, final viscosity, breakdown value and setback value of the early indica rice flour decrease by 16%, 21%, 50% and 43%, respectively. The removal of globulin could increased its gelatinization temperature and decreased its peak viscosity, while the removal of prolamin was the opposite. The removal of oryzenin made its peak viscosity, and final viscosity decrease by 22% and 12%, respectively, as well as made its breakdown value and setback value increase by 49% and 53%, respectively. The removal of oryzenin made the weak bound water content of the early indica rice flour decrease by 14% after pasting. The removal of both globulin and oryzenin could increase its water binding strength after pasting, while the removal of prolamin was the opposite. The removal of prolamin made the solid-like state of the early indica rice flour enhance by 20% after pasting. The removal of both globulin and oryzenin could decrease its elasticity after pasting, while the removal of prolamin was the opposite. The removal of globulin and oryzenin made the freeze-thaw stability of the early indica rice flour decrease by 121% and 56%, respectively, after pasting. This study would provide an important reference for improving the quality of early indica rice flour products by using endogenous proteins with different solubility.