Aroma comparison of Qingke baijiu and other light-aroma baijiu produced with Daqu using molecular sensory science

Qingke baijiu (QKJ), also known as Highland barley wine, is a traditional Chinese fermented baijiu from the Tibetan Plateau. It is a kind of light-aroma baijiu (LAJ) with a unique flavor distinct from other LAJs produced using Daqu . In this work, QKJ and other LAJs ( Daqu ) were selected for comparison of their aroma differences using a molecular sensory approach. In total, 66 aroma compounds in QKJ and 73 in LAJ were identified via gas chromatography-olfactometry-mass spectrometry (GC-O-MS). After quantification, odor activity values (OAVs) calculation and orthogonal partial least squares discriminant analysis (OPLS-DA), ethyl butyrate , ethyl hexanoate , furfuryl alcohol and ethyl isobutyrate were recognized as the major aroma compounds distinguishing QKJ from LAJ. Further recombination and omission experiments revealed ethyl hexanoate, ethyl valerate , γ -nonanolactone, ethyl acetate and benzeneacetaldehyde diethyl acetal as critical aroma components in QKJ. This work provides valuable insights into the flavor and quality control of Chinese baijiu.