Effect of milling degree on vitamin B1 stability in rice: A perspective on cooking-induced component interactions

To investigate the influence of degrees of milling (DOM) on the stability of rice nutrients, this study focused on vitamin B1 (VB1)'s stability during rice cooking and digestion at different DOMs. The results showed VB1's stability in brown rice (DOM 0%), moderately-milled rice (DOM 8.06%), and white rice (DOM 12.82%) after cooking were 92.91%, 84.54%, and 94.57%, respectively, and after digestion were 84.82%, 67.64%, and 95.97%. Considering the variation of VB1's bound content, there was an interaction between VB1 and rice components during cooking, which affected VB1's stability. Analysis of ultraviolet spectroscopy, thermodynamics, molecular structure changes, and intermolecular forces confirmed the non-covalent forces between VB1 and other nutrients, among which starch had the strongest affinity for VB1, compared with protein and dietary fiber. These results reveal the mechanism that milling altered VB1's stability by changing the composition of components that interact with VB1 in the rice matrix.