Comparison of volatile flavor components of original strong-flavor Baijiu with different spatial levels based on electronic nose and HS-SPME-GC-MS

Abstract

The volatile flavor compounds of original strong-flavor (Nongxiangxing) Baijiu with different spatial levels were compared by electronic nose combined with headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) technology, the key difference flavor compounds in the upper and lower layers of original strong-flavorBaijiu was screened by partial least squares-discriminant analysis (PLS-DA) model, and the electronic nose results were analyzed by principal component analysis (PCA) and linear discriminant analysis (LDA). The results showed that a total of 76 volatile flavor compounds were identified, including 39 esters, 9 acids, 9 aromatics, 8 alcohols, 4 ketones, 3 aldehydes, 3 furans and 1 other, and the total contents of esters, acids, acetals and organic acids in the lower layers of original strong-flavor Baijiu were significantly higher than those in the upper layers of original strong-flavor Baijiu(P<0.05). Among them, 13 volatile flavor compounds such as isoamyl acetate, ethyl acetate, 2-hexanone, hexanal, butyric acid, 3-methylbutyric acid, and ethyl caproate were the key difference flavor compounds. In addition, electronic nose results could distinguish the upper and lower layers of original strong-flavorBaijiu by PCA and LDA, which could assist HS-SPME-GC-MS to analyze the volatile flavor components in original strong-flavor Baijiu with different spatial levels, and provide a certain theoretical basis for ensuring the quality stability of originalstrong-flavor Baijiu.

Keywords

• electronic nose|original strong-flavor baijiu|volatile flavor compound|key difference flavor component