Study on the interaction mechanism of virgin olive oil polyphenols with mucin and α-amylase

The interaction mechanism of mucin and α-amylase with virgin olive oil (VOO) polyphenols (oleuropein (OL), tyrosol (TY), hydroxytyrosol (HT)) was analyzed by fluorescence, ultraviolet (UV) absorption, attenuated total reflection Fourier transform infrared (ATR-FTIR), circular dichroic (CD) spectroscopy and molecular docking. A total of 17 polyphenols have been identified in the selected VOO, and the TY, HT and OL were the main compounds. The quenching mechanism between mucin/α-amylase and three VOO polyphenols was static, mainly through van der Waals forces and hydrogen bonds. The results of UV absorption, ATR-FTIR, and CD spectroscopy revealed that the conformation of mucin changed after combining with the three polyphenols, while that of the α-amylase changed little. Molecular docking predicted the interaction sites of the three polyphenols with human salivary mucin and α-amylase. The present study could provide the theoretical foundation for further research on the interaction between human salivary protein and phenolic compounds in VOO. [Display omitted] •VOO polyphenols statically quenched intrinsic fluorescence of mucin and α-amylase.•The secondary structure of mucin was changed after combining with polyphenols.•Van der Waals forces and hydrogen bonds are the main driving force for interactions.•The affinity of hydroxytyrosol for mucin and α-amylase were the highest.