Polymerization of wheat gluten and the changes of glutenin macropolymer (GMP) during the production of Chinese steamed bread

•Less depolymerization of gluten was observed during dough processing of CSB.•SDS extractability of gluten decreased significantly during steaming of CSB.•Microstructure of gluten network was investigated by CLSM.•Glutenin depolymerization led to weakening of GMP gels in G′ and G″.•Gluteinin depolymerization negatively correlated with GMP quantity and subunits. Polymerization of gluten and the changes of glutenin macropolymer (GMP) during the production of Chinese steamed bread (CSB) were investigated, providing a theoretical basis to improve and regulate the quality of CSB. Protein extractability and free sulfhydryl (SH) contents increased to some degree during the dough preparation stage, but significantly (P