Using GC–O–MS, GC–IMS, and chemometrics to investigate flavor component succession regularity in the Niulanshan Erguotou Baijiu brewing process

The volatile compounds in Dacha liquor (DL) and Ercha liquor (EL) from Niulanshan Erguotou Baijiu (NEB) were analyzed. The results demonstrated that a total of 34 odorants were identified. For the first time, the products of different brewing stages were analyzed using temperature-programmed headspace gas chromatography-ion mobility spectrometry (TP-HS-GC-IMS). The 3D fingerprint obtained revealed that the compounds exhibited different change patterns during the brewing process. Furthermore, the results of principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) revealed that hexanal, 3-hydroxy-2-butanone, trans-2-pentenal, and ethyl hexanoate could be used to distinguish different types of fermented grains; and hexanal, 1-pentanol, methyl isovalerate, isoamyl acetate, 3-hydroxy-2-butanone, ethyl hexanoate, ethyl acetate, ethyl 2-methylbutanoate, and ethyl pentanoate could be used to distinguish different types of distilled spirits. This study serves as a useful reference for enhancing quality control measures in the production of NEB.