Study on the influential mechanism of catechin on the volatility of aroma compounds in ethanol-water solution by instrumental analysis and theoretical calculation.

In this work, the influential mechanism of catechin on the volatilities of aroma compounds (ACs) in ethanol-water solution was investigated using solid-phase microextraction and gas chromatography mass spectrometry (SPME-GC/MS), combined with thermodynamic analysis, and theoretical calculations. The volatilities of a series of esters, pyrazines, and phenolic compounds with similar structures in 46 % ethanol solution at different concentrations of catechin were detected by SPME-GC/MS. The volatilities of ACs with less methyl numbers were suppressed by catechin. As the increase of methyls in the molecular, their volatilities tended to be promoted. As the increase of concentration of catechin, the volatilities of ACs were gradually promoted. Thermodynamic analysis showed that the hydrophobic interaction was the main interaction between ACs and catechin. Theoretical calculations showed that the catechin affected the volatilities of ACs by changing the micro ethanol concentration (MEC) around the aroma molecular in ethanol-water solution.