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

The aroma profile of Chinese roasted sesame-like flavor type liquor was investigated by means of headspace solid phase microextraction-aroma extract dilution analysis (HS-SPME-AEDA). Sixty-three odor-active regions were detected by HS-SPME-AEDA with flavor dilution (FD) factors >5, and 58 of these were further identified. Among them, ethyl hexanoate, 2-furfurylthiol, dimethyl trisulfide, 3-methylbutanal, ethyl butanoate, ethyl 2-methylbutanoate, ethyl pentanoate, and ethyl 4-methylpentanoate appeared with the highest FD factors. In particular, eight sulfur-containing odorants were identified to be potentially important to roasted sesame-like flavor type liquor. The concentration of these odor-active compounds was further quantitated by combination of four different quantitative measurements, and 36 odorants had concentrations higher than their corresponding odor thresholds. On the basis of the odor activity values (OAVs), 2-furfurylthiol (OAV 1182), dimethyl trisulfide (OAV 220), β-damascenone (OAV 116), and methional (OAV 99) could be responsible for the unique aroma of roasted sesame-like flavor type liquor. An aroma recombination model prepared by mixing 36 aroma compounds with OAVs >1 showed a good similarity to the aroma of the original roasted sesame-like flavor type liquor. For the first time, 2-furfurylthiol was determined to be a typical potent odorant in roasted sesame-like flavor type liquor by omission study.