Characteristic Biomarkers Identification of Lycium barbarum L. from Ningxia Zhongning Based on Comprehensive Two-Dimensional Gas Chromatography Time-of-Flight Mass Spectrometry

In order to identify the origin of Lycium barbarum L. from Ningxia Zhongning, headspace-solid phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOF MS) was used to analyze the relative contents of volatile components in goji berries samples from Ningxia Zhongning, Xinjiang Jinghe, Gansu Jingyuan, Qinghai Xining, and Inner Mongolia Urad Front Banner. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to preliminarily complete the separation of Lycium barbarum L. from the five production areas, and the potential differential compounds of Lycium barbarum L. from Ningxia Zhongning compared with the other four production areas were found out through orthogonal partial least squares discriminant analysis (OPLS-DA). The results showed that there were 85 volatile compounds common to goji berries samples from five origins, and the compounds with relatively high proportion of relative peak area included methyl nonanoate, methyl hexanoate, 3-methylbutanal, etc. Through PCA and HCA analysis, it was found that Lycium barbarum L. samples from Ningxia Zhongning could be well separated with those from the other four origins, and 15 potentially different compounds were obtained through OPLS-DA analysis for Ningxia Zhongning sample compared with the others, of which 10 volatile compounds were detected only in Ningxia Zhongning sample, such as 6, 10-dimethylundecan-2-one and (E, E)-2, 4-hexadienal, while five compounds including ethyl octanoate and methyl butanoate were not detected in Ningxia Zhongning sample. This result could provide reference and technical guidance for the component analysis and origin identification of Lycium barbarum L from Ningxia Zhongning.