Abstract: This study aims to investigate the influence of the carboxyl substituent groups and the carbon chain length of acrylic acid of ferulic acid (FA) on its bitterness inhibitory effect. Molecular dynamics simulations were employed to analyze the conformational differences in the interaction between bitter taste receptors and bitterness inhibitors, including FA and 4-(2, 2, 3-trimethylcyclopentyl) butyric acid, and the bitterness activator Acesulfame K in order to determine the inhibitory structure F4 of FA for bitter taste receptors. Based on the interaction modes of F4, a series of FA derivatives were constructed. The structure-activity relationship of FA as a bitterness inhibitor was explored by electronic tongue. The results revealed that based on the premise that the interaction modes of the ligand and F4 would be consistent, the charge amount of the hydrogen bond acceptor on FA’s carboxyl substituent group was inversely proportional to the intensity of bitterness inhibition. Adjusting the length of FA’s acrylic acid carbon chain to two carbons destabilized the interaction between the ligand and the key residues, resulting in a reduction in the intensity of bitterness inhibition. In contrast, extending the carbon chain length to four carbons enhanced the bitterness inhibitory intensity. As a new bitterness inhibitor, FA has the potential for development to improve food quality.

Key words: ferulic acid; bitterness inhibition; structure-activity relationship; molecular dynamic simulation; electronic tongue