Effects of mannoprotein on the stability and in vitro digestion of cyanidin-3-glucoside

Although mannoprotein (MP) is known to increase the stability of anthocyanins, the MP-anthocyanin interactions and structural changes induced by the same remain underexplored. To bridge this gap, this work examined the complexation of cyanidin-3-glucoside (C3G) by MP and probed its effect on C3G properties. As a result, this complexation was shown to induce the static fluorescence quenching of MP and increase the thermal stability and antioxidant activity of C3G while decreasing its susceptibility to ascorbic acid, sucrose, and Fe3+-induced degradation and increasing its bioavailability during simulated in vitro digestion. Hydrogen bonding and van der Waals interactions were identified as the main complexation drivers and were demonstrated to change the self-aggregation behavior of both compounds and favor the formation of a cross-linked structure. Thus, our results show that MP addition is an efficient anthocyanin protection method and provide a theoretical basis for the utilization of MP and C3G.