Effects of Calcium-Binding Peptide from Tilapia Scale Protein Hydrolysates on Calcium Absorption in Caco-2 Cells

Fish scales are usually discarded as an industrial solid waste. In this study the fish scale protein was recovered and employed to prepare protein hydrolysates using commercial proteases. The hydrolysates were further separated into four peptide fractions (F1, F2, F3, and F4) by Sephadex G-15. Among the fractions, the F3 fraction, with the highest calcium-binding activity, was further investigated to enhance calcium uptake in Caco-2 cells. The results showed calcium uptake from F3-Ca by Caco-2 cells after 2 h of incubation was significantly higher than those of CaCl2 and tilapia scale protein hydrolysates (TSPH), respectively, and was similar to that of casein phosphopeptide (CPP). Therefore, the F3 fraction improved Ca uptake versus the CPP samples and can be employed as an alternative to CPP in the manufacture of functional foods.