CHELATION of WALNUT PROTEIN PEPTIDE with CALCIUM and CALCIUM ABSORPTION PROMOTION in VIVO

Abstract In this study, walnut meal was used to prepare walnut protein. Papain was used to hydrolyze walnut protein to obtain active protein peptides. Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy(SEM), and energy dispersive spectroscopy(EDS) were used to study the chelating ability of walnut protein peptides and Ca 2+ and complete structural characterization. A Caco-2 monolayer model and a rat calcium deficiency model were established to study the calcium absorption capacity and increase bone mineral density(BMD) of walnut protein peptide chelated calcium. The results showed that the appearance and internal structure of walnut peptides had changed after chelated with calcium. Infrared spectroscopy analysis indicated that walnut peptides may participate in the coordination of Ca 2+ to form calcium chelating peptides through groups such as -COOH, -OH, and -NH 2 . Caco-2 monolayer model experiments show that walnut peptides-Ca can promote the absorption and transport of calcium by regulating the TRPV6 signaling pathway. Calcium deficient rat model experiments show that the combination of walnut peptides and calcium can effectively increase BMD and improve bone formation, thereby preventing calcium deficiency. Walnut protein peptide chelated calcium could be a potential new product for calcium supplements.