(R)-Ethyl lactate is an important contributor to fruity flavor of Baijiu as revealed by chiral GC–MS and sensory evaluation

In this study, the enantiomeric isomers of Ethyl lactate (EL) in 12 aroma types of commercial Baijiu, Baijiu from different years, and rounds of Sauce-based Baijiu were investigated using DI-chiral-GC-MS. The results showed pure grain brewed Baijiu and rounds of Sauce-based Baijiu were mostly dominated as (<i>R</i>)-EL with significant difference (<i>P</i> < 0.001) content between (<i>R</i>)-EL and (<i>S</i>)-EL. (<i>R</i>)-EL was the dominant conformation in Soy sauce aroma-type Baijiu from different years. The olfactory threshold of (<i>S</i>)-EL (214.22 mg/L) in 46 % (<i>v</i>/v) ethanol solution was approximately twice the (<i>R</i>)-EL (103.92 mg/L). (<i>R</i>)-EL exhibited a distinctive fruity aroma, while (<i>S</i>)-EL could produce an unpleasant aroma. The fruity flavor of the solution was more pronounced when the (<i>R</i>)-EL predominated with the racemate solution as the control. This study method is easy to follow and these results could help to understand the chiral flavor of EL in Baijiu from the molecular configuration level.