Investigation on molecular and morphology changes of protein and starch in rice kernel during cooking

•The degradation of protein shows different mechanical and thermal properties of rice.•SEM, CLSM, and TEM reflect the stability of protein and its interaction with starch.•The hydrophobic behavior and secondary structure change of protein were observed.•Different distribution of protons in H2O and D2O reflect molecular changes in rice.•The weak surface hydrogen bond interactions between starch and protein were observed.