Mechanism of the effect of mixing guar gum and fish collagen peptide with rice on in vitro digestibility, gastric emptying and postprandial response.

This study investigated the effects of adding guar gum (GG) and fish collagen peptide (FCP) during rice cooking on postprandial blood glucose and satiety of rice and the related mechanisms. The results showed that the combined intervention of GG and FCP (GG-FCP) significantly reduced the postprandial blood glucose levels. The GG increased the viscosity of the digesta, and the physical barrier of GG and FCP formed on the surface of the rice limited the disintegration of the rice granule. The chyme containing GG and FCP displayed a larger particle size and gastric emptying were delayed. GG-FCP alleviated the digestion rate of rice, with the rapidly digestible starch content decreasing from 77.68 % to 65.01 %. Low-field nuclear magnetic resonance (LF-NMR) analysis indicated the GG and FCP reduced the binding water content of starch. DSC analysis showed that the addition of GG and FCP reduced the enthalpy of gelatinization of rice flour from 5.87 to 3.13 J/g, and the gelatinization degree of the rice flour was reduced. This study investigated the mechanisms of exogenous additives in regulating rice digestion and postprandial response. The findings would provide evidence-based strategies for developing rice products with the potential to mitigate the effects of blood glucose.