Effects of cross-linking of rice protein with ferulic acid on digestion and absorption of ferulic acid

Though rice proteins have been applied to improve the stability of phenolic compounds, it is unclear how rice proteins affect phenolic acid's digestion and bioavailability. This study investigated the consequences of protein-ferulic acid interactions in the gastrointestinal environment. Ferulic acid and rice proteins formed complexes at room temperature, both with and without laccase. Rice protein was reported to be able to prevent ferulic acid from degrading in simulated oral fluid and remain stable in gastrointestinal fluids. With the hydrolysis of pepsin and pancreatin, rice protein-ferulic acid complexes degraded and released ferulic acid. While digested ferulic acid's DPPH scavenging activity was dramatically reduced, it was retained for the rice protein-ferulic acid complex. Moreover, the permeability coefficient of ferulic acid was not affected. Thus, rice protein is a promising food matrix to protect ferulic acid in the digestive tract and maintain the antioxidant functions of ferulic acid.

Automated summary

This study investigated the interaction between rice proteins and phenolic acid in the gastrointestinal environment. The results showed that rice protein can stabilize the structure of phenolic acid, preventing its degradation in oral fluid and gastrointestinal fluids. The rice protein-phenolic acid complex degraded and released the phenolic acid during digestion, while maintaining its antioxidant function and not affecting its permeability in the digestive tract.