Characterization of the key aroma-active compounds in Qingke baijiu by application of the sensory approach

Qingke baijiu is a typical light-flavor baijiu and considered as one of the geographical indication products in China. The aroma of newly fermented original Qingke baijiu is unique and popular with consumers. In this work, the key aroma-active compounds of original Qingke baijiu (QKJ) were characterized by combined instrument analysis with sensory analysis. A total of 54 aroma compounds with high flavor dilution factors (FD values≥ 9) were screened out by gas chromatography–olfactometry (GC–O) combined with aroma extract dilution analysis (AEDA). After quantitation, 28 aroma-active compounds had odorant activity values (OAVs) > 1 in QKJ. Recombinant and omission experiments further proved that the esters and alcohols, especially ethyl lactate, phenylethyl acetate, ethyl hexanoate , 2-methyl-1-butanol, ethyl acetate , γ -nonalactone and 2,3-dimethyl-5-ethyl pyrazine were critical to the flavor of QKJ. Consequently, this research reveals the characteristics of QKJ and provides theoretical support for production and quality control assurance.