Characterization and interaction mechanism of apigenin-loaded composite hydrogels based on whiteleg shrimp (Penaeus vannamei) powder and κ-carrageenan

The novel food composite hydrogel with delivery function consisting of shrimp powder (SP) and κ-carrageenan (κ-C) was constructed and used for loading apigenin (API). Binary mixtures of liquid SP and κ-C could form gels with solid behavior. Furthermore, the addition of API increased the initial modulus of elasticity of SP/κ-C by approximately 47.3%, as well as a 14.9% reduction in the relaxation time T 23 . Moreover, the O-H stretching band and the amide I band of SP/κ-C binary gel loaded with API were blue shifted, and the XRD characteristic peak of API disappeared in SP/κ-C/API. In addition, broken macropores and dispersed patch microstructures were presented in SP and κ-C, whereas the SP/κ-C and SP/κ-C/API hydrogels were homogeneously distributed with dense mesh and solid mesh walls. Hydrophobic interactions were the main forces in the SP/κ-C/API composite hydrogels, which were improved 1.3-fold. Furthermore, SP/κ-C/API was extended and released to more than 55% extent during simulated intestinal colonic digestion. These results suggested that a stable and dense binary gel was formed by SP and κ-C, which could seal and extended release effect of API to the colon.