The regulation of the texture, rheological properties, and moisture distribution of rice flour gel by ultrasonically modified soybean protein isolate

Abstract

Ultrasound treatment enhances protein functionality through structural modifications and active site exposure, leading to improved solubility, dispersibility, and potential for broader food applications. In this study, soybean protein isolate (SPI) was treated with ultrasound and incorporated into rice flour (RF) to evaluate its effects on RF gel's properties. Results showed that under ultrasonic treatment for 20 min at 0–500 W, the particle size of SPI gradually decreased, and its solubility increased from 33.2 % to 56.1 %. SPI-RF gels with SPI treated at 300 W showed an 8.04% increase in elasticity, 19.48% in water-holding capacity, and maximum hardness of 573.45 g. The increased moduli and decreased loss tangent indicated a more elastic gel structure. DSC, XRD, and FT-IR analyses indicated the formation of V-type complexes and enhanced thermal stability, with no new chemical groups detected. This study aims to provide a theoretical foundation for the production of superior rice-based products in the food industry.