Impact of the Degree of Hydrolysis on the Functional Properties of Rice Proteins – A Review

Background and Objectives Enzymatic hydrolysis has been established as an effective strategy to improve the functional properties of plant proteins. Rice proteins are particularly attractive because of their hypoallergenic nature, high nutritional value, and sustainability, although their technological applications remain limited by their low water solubility. This review evaluated the effects of the degree of hydrolysis (DH) on the technological properties of rice proteins, focusing on functional attributes relevant to food applications. Findings A total of 33 studies published between 2012 and 2025 were critically reviewed to evaluate the relationship between the degree of hydrolysis and the technological properties of rice proteins. Overall, low to moderate degrees of hydrolysis (5%–10%) produced hydrolysates with improved solubility over a wide pH range, enhanced emulsifying properties, greater foam stability, and increased water and oil holding capacities. In contrast, higher DH values (> 12%–15%) generally resulted in a greater proportion of short peptides, which were associated with reduced colloidal stability, lower foaming capacity, and more pronounced undesirable flavors. Gel‐forming ability was more effective at low hydrolysis levels (< 5%). Conclusions The findings demonstrate that careful control of the degree of hydrolysis is essential to maximize the technological functionality of rice proteins while minimizing adverse sensory effects. Optimized enzymatic hydrolysis enhances the potential of rice protein hydrolysates as sustainable and versatile ingredients for the development of innovative food products.