Characterization of the dynamic retronasal aroma perception and oral aroma release of Baijiu by progressive profiling and an intra-oral SPME combined with GC × GC-TOFMS method

This study aims to present retronasal aroma perception and oral aroma release of Baijiu by progressive profiling and intra-oral solid-phase microextraction (SPME) combined with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC × GC-TOFMS). Fruity, alcohol, grain, and cellar were the active retronasal aroma attributes of the strong aroma type Baijiu S, and soy sauce, burnt, and roasted were attributes of the soy sauce aroma type Baijiu SS. The dynamic release behaviors of 91 oral aroma compounds of two Baijiu samples were characterized and classified into four or five groups of different oral persistence. Principal component analysis showed that vapor pressure and Henry constant were negatively correlated with the oral persistence of aroma compounds, of which the cumulative interpretation rate was 71.67%. Partial least squares regression analysis showed that aroma compounds, such as ethyl benzeneacetate, β-phenylethanol, and tetramethylpyrazine, were related to the long-persistence retronasal aroma of Baijiu (Q2 = 0.806).