Effects of heat treatment on protein molecular structure and in vitro digestion in whole soybeans with different moisture content

•Heat-induced protein digestibility was related to moisture content in whole soybeans.•Loose protein structure and increased digestibility was observed in 7S-denatured soybeans for each moisture content.•Protein digestibility reduced at 10.68% and 29.70% moisture content, but rose at 46.29% and 62.05% when 11S denatured.•Protein oxidation and β-sheet content were negatively correlated with in vitro digestibility.•A positive correlation was found between non-covalent interactions and in vitro digestibility.