HS-SPME/GC-MS and chemometrics for volatile composition of Chinese traditional aromatic vinegar in the Zhenjiang region

The main purpose of this study was to determine the volatile composition of Zhenjiang aromatic vinegar, one of the four famous China-style cereal vinegars, by using headspace solid-phase microextraction (HS-SPME)/gas chromatography-mass spectrum (GC-MS) and chemometrics. For this purpose, the HS-SPME sampling method for the volatile compounds of Zhenjiang aromatic vinegar was optimized by a second-order rotatable central composite experimental design (CCD). A HS extraction of the volatile compounds by incubation on a 65 µm thickness polydimethylsiloxane/divinylbenzene (PDMS/DVB) fibre during 44.2 min at 69.5°C with 1.9 g NaCl add gave the most effective and accurate extraction. By the optimized method, a total of 58 volatile compounds, including 9 alcohols, 13 acids, 16 esters, 5 aldehydes, 4 ketones and 8 heterocycle compounds, were identified from 13 aromatic vinegar samples manufactured in Zhenjiang region. By principal components analysis (PCA), the thirteen vinegar samples were classified into 3 groups, and 10 volatile compounds were chosen as characteristic compounds of Zhenjiang aromatic vinegars.