Enhancement of vitamin B stability with the protection of whey protein and their interaction mechanisms

Vitamin B is easily degraded by light and heat during storage, which results in nutritional loss of food. Whey protein is expected to protect vitamin B by forming complexes through secondary bonds. The properties of the complexes and protective effects of whey protein on vitamins B1, B2, B3 and B6 were characterized. The percentage losses of vitamin B were decreased by more than 60% with the protection of whey protein. FTIR, fluorescence spectroscopy, thermodynamic analysis and molecular docking were used to investigate the binding interaction between vitamin B and whey protein. Vitamin B quenched the intrinsic fluorescence of whey protein, mainly with a static nature (Kq > 2.0 × 1010 L/(mol·s)). The interactions between whey protein and vitamin B were mostly mediated by hydrogen bonds and van der Waals forces, as demonstrated by the thermodynamic parameters and molecular docking. •Vitamin B losses were reduced by more than 60% in the presence of whey protein.•Vitamin B and whey protein interacted by hydrogen bonds and van der Waals force.•Vitamin B quenched the fluorescence of whey protein.