Effect of rice protein on the retrogradation of waxy rice starch gels.

Abstract

This study investigated the effects of rice protein (RP) addition on the retrogradation of waxy rice starch (WRS) gels during storage. The retrogradation behavior was evaluated using a rapid visco analyser, a differential scanning calorimeter, an X-ray diffractometer, a texture analyser, and a scanning electron microscope. The incorporation of RP inhibited the swelling of WRS, leading to reductions in trough viscosities, as well as setback values. DSC analysis indicated a reduction in melting enthalpy, while XRD showed decreased peak intensity in retrograded WRS with RP addition. After 3 days of storage at 4 °C, gel hardness increased, but RP significantly mitigated this effect. SEM observations showed that a 5% RP addition produced larger pore sizes and a looser network structure, supporting the inhibition of retrogradation. These findings suggest that RP effectively retards the retrogradation of WRS, offering potential applications in enhancing the texture and shelf-life of starch-based food products.