Studies on the interactional characterization of preheated silkworm pupae protein (SPP) with anthocyanins (C3G) and their effect on anthocyanin stability

•C3G and the SPP form complexes mainly through hydrophobic interactions.•C3G degradation rate constant decreased after SPP preheated at 80 °C.•C3G-SPP thermal stability increased effectively after SPP preheated at 80 °C.•C3G-SPP oxidative stability increased effectively after SPP preheated at 80 °C. In this paper, the interaction of silkworm pupae protein (SPP) with cyanidin-3-O-glucoside (C3G) was studied the protective anthocyanins stability. Characterization experiments suggested that C3G-SPP complexes mainly through hydrophobic interactions, with a decrease in the α-helix content and increases in the β-sheet and β-turn contents. Fluorescence results revealed that C3G quenched the intrinsic fluorescence of SPP by static quenching. The highest quenching constant, Kq, was recorded to be1.26 × 1012 M−1s−1 for the SPP preheated at 80 °C. Following the C3G-SPP complexes, the degradation rate constant decreased, and the half-life of C3G was prolonged from 64.81 ± 1.07 to 261.99 ± 13.32 min at 80 °C (p