Protective effect of amino acids on the stability of bayberry anthocyanins and the interaction mechanism between l-methionine and cyanidin-3-O-glycoside

•l-methionine was associated with greater protection of bayberry anthocyanins.•l-methionine extended the half-life of bayberry anthocyanins by co-pigmentation.•l-methionine and cyanidin-3-O-glucoside bonded via hydrogen bonds and Van der Waals forces. The protective effects of three amino acids (l-phenylalanine, l-tryptophan and l-methionine) on the stability of bayberry anthocyanins were investigated. The anthocyanin stability under constant illumination (5000 Lux, 50 Hz) or in the presence of ascorbic acid were evaluated by degradation kinetic parameters, and the interaction between l-methionine and cyanidin-3-O-glucoside (C3G) in a model beverage system was analyzed using Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance, X-ray diffraction, molecular docking, and molecular dynamics simulation. Results indicated that the three amino acids significantly reduced the degradation rate of bayberry anthocyanins (p