Mulberry anthocyanins exert anti-AGEs effects by selectively trapping glyoxal and structural-dependently blocking the lysyl residues of ß-lactoglobulins.

Advanced glycation end-products (AGEs), which instigate many disorders, are mostly mediated by dicarbonyl rearrangements. We studied the corresponding mechanisms of the anti-glycation effects of two anthocyanins purified from mulberry fruits, namely cyanidin 3-glucoside (C3G) and cyanidin 3-rutinoside (C3R), on glycated ß-lactoglobulins (ß-Lg). Both mulberry anthocyanins (MAs) inhibited the AGEs-formation in a dose-dependent manner, but the effect of C3R was significantly stronger than that of C3G (p < 0.05). MAs inhibited AGEs-formation by selectively trapping dicarbonyls, especially glyoxal. The UPLC-ESI-Q-TOF-MS results characterized that C3R formed mono- and di-glyoxal adducts, where C3G only created di-glyoxal adducts. Additionally, C3R could directly interact with some of the glycation sites of ß-Lg. Overall, GO-trapping and ß-Lg-MAs covalent/noncovalent binding are disclosed as the key mechanisms of the anti-AGEs activity of MAs on ß-Lg, which could be valorised as effectual AGEs inhibitors in proteins-rich matrices.

Anti-glycation and anti-hardening effects of microencapsulated mulberry polyphenols in high-protein-sugar ball models through binding with some glycation sites of whey proteins.

Assembling between polyphenols and proteins has been freshly spotlighted. We studied the antiglycation and anti-hardening effects of microencapsulated mulberry polyphenols (MMPs) in a high-protein-sugar ball (HPSB) model during storage using multi-dimensional approaches, including UPLC-ESI-MS/MS, SDS-PAGE, MALDI-TOF-MS, FTIR, and a molecular docking study. It was found that MMPs significantly relegated the browning development, AGEs, and/or CML levels of HPSB after 45 d of storage at 45 °C. MMPs also downgraded the protein insolubility, aggregation, oligomerization, and glycoxidation during late-storage. A molecular docking scrutiny proved that cyanidin 3-O-rutinoside and quercetin 3-O-rutinoside interacted with whey proteins subunits via H-bonding and π-π interactions. This binding blocked some glycation residues of whey proteins especially lysyl residues, namely Lys5, 16, 60, 69, 93, 94, and 122. Our data disclosed that MMPs could be valorized as promising antiglycative ingredients to mitigate AGEs-generation and other subsequent unwanted changes in protein-rich food matrices.