Abstract:The variations of the volatile flavour components in Lao Xianghuang fermented for different years were investigated by electronic nose (E-nose), headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS), and headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). The orthogonal partial least squares discriminant analysis (OPLS-DA) method was used to distinguish Lao Xianghuang fermented for different years. The principal component analysis of the E-nose data could clearly distinguish the fermented Lao Xianghuang from the unfermented one, as the difference in their flavors was relatively large. The volatile components of those fermented for 3 and 4 years resembled the most, with those of the other samples showing large differences. HS-GC-IMS detected 39 volatile components, including terpenes, alcohols, aldehydes, esters, ketones, phenols, acids, heterocyclic compounds and others. HS-SPME-GC-MS identified 50 volatile components, including terpenes, alcohols, aldehydes, phenols, esters, ethers, heterocyclic compounds, and others. There were 14 commonly detected volatile components (which were identified 8 marked volatile compounds (VIP>1) by the OPLS-DA model), including α-Pinene, β-pinene, myrcene, terpinene, limonene, isoterpinene, 1-caryophyllene, valencia limonene, linalool, α-terpinene, furfural, maltol, anethol and 2,4-dimethylstyrene. In summary, the flavors of unfermented Lao Xianghuang and those fermented for 1~5 years old differed greatly, and the 8 volatile components screened out would provide a basis for distinguishing Lao Xianghuang fermented for different years.
