Investigation on the mechanism of Tartary buckwheat bitterness influenced by the interaction between Tartary buckwheat proteins and rutin.

To investigate the mechanism of Tartary buckwheat endogenous proteins on its bitter taste, this study focuses on the regulatory effects of different Tartary buckwheat proteins such as Tartary buckwheat albumins (BA), Tartary buckwheat globulins (BG) and Tartary buckwheat protein isolates (BPI) on the conversion from rutin (R) to bitter quercetin (Q). Comprehensive analyses showed that all Tartary buckwheat proteins form stable complexes with R, with BG binding most tightly to R through stronger hydrogen bonding, electrostatic, and hydrophobic interactions. Compared with BPI and BA, the bound BG underwent a more significant structural transformation, and the β-sheet content of BG decreased from 44 % to 28 %. When bound to Tartary buckwheat proteins, the percentage of R converted to Q after acid hydrolysis was reduced in all cases, with BG having the strongest inhibitory effect on conversion and the lowest bitter taste response value. These results provide a robust theoretical basis for elucidating the interaction mechanism between Tartary buckwheat proteins and R and offer an innovative perspective for optimizing the flavor profiles of Tartary buckwheat-derived products.