Terpenes are very important impact aroma compounds in wines, and we discovered some trace volatile terpenes in Chinese liquors in this study. The volatile compounds in Kweichow Moutai liquor (Maotai) were enriched and isolated by liquid-liquid extraction (LLE) and further separated by silica gel normal phase chromatography, then investigated by gas chromatographyolfactometry (GC-O) and gas chromatography-mass spectrometry (GC-MS). A total of 55 terpenes were finally identified in Moutai liquor by mass spectrum data from NIST11 a.L and wiley7n.L mass-spectral library, retention indices (RIs) and authentic standards. A majority of terpenes were reported in Chinese liquors for the first time. A headspace-solid phase microextraction (HS-SPME) coupled with GC-MS was developed to determine terpenes in * A c c e p t e d M a n u s c r i p t 2 Moutai liquor and other aroma type Chinese liquors. According to the GC-O and odor activity values (OAVs) analysis, terpenes were the important aroma compounds in Moutai liquor which led the liquor more elegant and delicate.

Two-step high-performance liquid chromatography (HPLC) separation in combination with taste dilution analysis was used to screen the retronasal burnt aroma compounds in soy sauce aroma-type Chinese Baijiu (Chinese traditional liquor). A major retronasal burnt aroma region was purified by Sephadex LH-20 column chromatography and HPLC separation from the soy sauce aroma-type Baijiu sample. A novel retronasal burnt aroma compound was identified as 6-(2-formyl-5-methyl-1H-pyrrol-1-yl)­hexanoic acid (1) by means of high-resolution mass spectrometry and 1D/2D nuclear magnetic resonance. The retronasal burnt aroma threshold of compound 1 was determined to be 209.5 μg/L in 53% ethanol aqueous solution. Quantitative analysis showed that the concentration of compound 1 ranged from below the limit of quantitation (3.8 μg/L) to 224.2 μg/L in the Baijiu samples. Moreover, the sensory evaluation also revealed that compound 1 may contribute to the retronasal burnt aroma of the Baijiu at its subthreshold concentration by the additive effect with the recently reported retronasal burnt aroma compound 2-hydroxymethyl-3,6-diethyl-5-methylpyrazine.