Development of a flavour fingerprint by GC-MS and GC-O combined with chemometric methods for the quality control of Korla pear (Pyrus serotina Reld)

Based on solid-phase micro-extraction/gas chromatography-mass spectrometry (SPME/GC-MS) and gas chromatography-olfactometry (GC-O), a new method was described for the first time to establish flavour fingerprint for the quality control of Korla pear. Twenty-three batches of Korla pear collected from different regions in Xinjiang, China were analysed via GC-MS, among which 21 were selected to establish the fingerprint. The results of the analysis were combined with GC-O assessment to obtain 26 common odour-active compounds as the characteristics of the Korla pear flavour fingerprint. The method for flavour fingerprint analysis was then validated on the basis of the relative retention time and relative peak area of the common peaks, sample stability and similarity analysis. The similarities in the 21 Korla pear samples were more than 0.80, thereby indicating that the samples from different batches were consistent to a particular extent. The chemometrics method (principal component analysis, PCA) was performed to develop a flavour fingerprint that is suitable for identifying and differentiating Korla pears and can be used for quality control.