Characterization and comparison of the structure and antioxidant activity of glycosylated whey peptides from two pathways.

Glycosylated whey peptides (WPP-Gal A and WPP-Gal B) were formed from two pathways. WPP-Gal A showed higher browning intensity and fluorescence intensity than WPP-Gal B. Loss of amino groups and reducing sugar was heavier for WPP-Gal A than WPP-Gal B. Size exclusion chromatography revealed that WPP-Gal A and B had similar curves, but the molecular weight distribution of WPP-Gal B was more extensive than that of WPP-Gal A. Particle size was larger for WPP-Gal B than WPP-Gal A. Furthermore, WPP-Gal A showed greater antioxidant activity than WPP-Gal B. FT-IR analysis indicated that vibrations of several chemical bonds in amide I, II and III bands of WPP-Gal A were more obvious than those of WPP-Gal B. WPP-Gal A showed greater Caco-2 cell proliferation than WPP-Gal B. Therefore, WPP-Gal A showed more significant structural and characteristic changes, higher antioxidant activity and better proliferative activity than WPP-Gal B.