Sensory Flavor Characteristics and Characteristic Volatile Compounds of Different Aroma Types of Baijiu

The sensory flavor characteristics and characteristic flavor composition of Baijiu are an important basis for recognizing different aroma types of Baijiu and identifying Baijiu quality. However, at present, there are few studies on the sensory quality and flavor compounds of different aroma types of Baijiu. In this study, the major volatile compounds of four aroma types of Baijiu, Jiangxiangxing, Nongxiangxing, Qingxiangxing and Qingjiangxiangxing, were determined by sensory evaluation and headspace-solid phase microextraction/liquid-liquid microextraction coupled to gas chromatographymass spectrometry (HS-SPME/LLME-GC-MS) and gas chromatography-flame ionization detector (GC-FID), and their characteristic volatile compounds were identified by their odor activity values (OAV). Besides, a correlation evaluation model was developed using partial least squares regression (PLSR). The results showed that there were significant differences in the flavor profiles of the aroma types of Baijiu. A total of 251 volatile compounds were detected across all samples, including 54 characteristic flavor compounds. Ethyl isovalerate, dimethyl trisulfide, ethyl butyrate, furfural, 2,3,5-trimethylpyrazine, 2,3,5,6-tetramethylpyrazine contributed significantly to the flavor of Jiangxiangxing Baijiu. The key flavor compounds of Nongxiangxing Baijiu were ethyl hexanoate, p-cresol and γ-nonolactone. Nonanal, ethyl decanoate and phenylethanol were the characteristic flavor compounds in Qingxiangxing Baijiu. The most significant contributors to the characteristic flavor of Qingjiangxiangxing Baijiu were dimethyl trisulfide, phenethyl acetate, phenethyl alcohol, nonanal, decanal, ethyl laurate and 3-methyl-1-butanol.