Electronic tongue, proton-transfer-reaction mass spectrometry, spectral analysis, and molecular docking characterization for determining the effect of α-amylase on flavor perception

The effects of alpha-amylase on of flavor perception were investigated via spectrum analysis, electronic tongue, online mass spectrometry, and molecular docking. Aroma release results showed that alpha-amylase exhibited variable release patterns of different aroma compounds. Electronic tongue analysis showed that the perception of bitterness, sweetness, sour, and saltiness was subtly increased and that of umami was significantly increased (p < 0.01) along with the increasing enzyme activity of alpha-amylase. Ultraviolet absorption and fluorescence spectroscopy analyses showed that static quenching occurred between alpha-amylase and eight flavor compounds and their interaction effects were spontaneous. One binding pocket was confirmed between the alpha-amylase and flavor compounds, and molecular docking simulation results showed that the hydrogen, electrostatic, and hydrophobic bonds were the main force interactions. The TYP82, TRP83, LEU173, HIS80, HIS122, ASP297, ASP206, and ARG344 were the key alpha-amylase amino acid residues that interacted with the eight flavor compounds.