Combination of chemical modifications improves rice protein solubility

Rice (Oryza sativa) is one of the most widely cultivated crops in the world, which makes it a promising source of non-animal protein. However, the utilization of RP in food is still limited due to its poor solubility. The present study modified RP through combinational methods and determined the changes in its solubility and functionality. Different combinations of three chemical modification methods, including deamidation, phosphorylation, and disulfide reduction, were employed. Disulfide reduction and following deamidation effectively improved the RP solubility from 1.29% to 51.45%, while if deamidation was applied before disulfide reduction the RP had the solubility increased to 40.46%. Phosphorylation showed little effect in enhancing RP solubility, rather it lowers the solubility when applied after the other two methods. Furthermore, the foaming properties, the water holding capacity, and the oil absorption capacity were also improved through the combinational methods. This study offers a potential avenue for enhancing the applicability of RP in various food applications.