Study on the mechanism of non-covalent interaction between rose anthocyanin extracts and whey protein isolate under different pH conditions

The non-covalent interaction between anthocyanin and dietary protein had an impact on their physicochemical property. The purpose of this study was to study the non-covalent interaction mechanism between rose anthocyanin extract (RAEs) and whey protein isolate (WPI), and further compare the interaction mechanism with pure anthocyanin (PC) and WPI. At pH 3.0 and pH 7.0, RAEs and WPI had non-covalent interactions in the two systems with two types of unequal and mutually influencing binding sites, and the interaction forces were both hydrogen bonds and van der Waals forces. Interestingly, PC and WPI also had non-covalent interactions in both systems, the number of which binding sites was about one type, and the forces were hydrogen bonds and van der Waals forces. In addition, a variety of spectral combination techniques indicated that RAEs and PC caused similar changes in the secondary structure of WPI.

Automated summary

This study investigated the non-covalent interaction mechanism between rose anthocyanin extract (RAEs) and whey protein isolate (WPI) and compared it with the interaction mechanism between pure anthocyanin (PC) and WPI. The results showed that RAEs and WPI had non-covalent interactions under different pH conditions, with hydrogen bonds and van der Waals forces playing a role. Interestingly, PC and WPI also exhibited non-covalent interactions, with hydrogen bonds and van der Waals forces as the driving forces. Additionally, changes in WPI's secondary structure were observed in both RAEs and PC.