Pepper (Zanthoxylum bungeanum) oil was produced by deep-frying using 17 Chinese red pepper samples from different geographical origins as raw materials, and sensory evaluation and high performance liquid chromatography-mass spectrometry (HPLC-MS) were used to determine the temporal dynamic curves of numb taste intensity and the content and composition of numb taste-active substances, respectively. The numb taste characteristics of pepper oil from different production areas were investigated by partial least squares-discriminant analysis (PLS-DA) and systematic cluster analysis (CA). The results showed that the numb taste characteristics and the composition of numb taste-active components of pepper oil from different production areas were significantly different (P < 0.05). In addition, the 17 oil samples were clustered into four clusters. Cluster Ⅰ included the cultivars Fujiao and Mianjiao from Gansu, and Dahongpao from Maoxian and Wenchuan of Sichuan. Cluster Ⅱ included the cultivar Nanjiao from Sichuan. Cluster Ⅲ included the cultivar Dahongpao from Shaanxi, Shanxi and Hebei. Cluster Ⅳ included small- and large-sized peppers from unknown cultivars.

The volatile flavor components of fried Zanthoxylum bungeanum oil from 17 geographical origins were identified by headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). The results showed that a total of 55 volatile flavor components (18 of which were common to all oil samples) were identified, including 22 hydrocarbons, 17 aldehydes and ketones, 9 alcohols, 5 esters and 2 other substances. Odor activity value (OAV) analysis showed that linalool, eucalyptol, myrcene and limonene were the key aroma substances in fried Z. bungeanum oil. Through principal component analysis (PCA) and partial least squares discrimination analysis (PLS-DA), a discriminant model for the classification of fried Z. bungeanum oil samples according to geographical origin was established, and eight key differential flavor substances were selected using the model, namely phellandrene, ocimene, linalool, eucalyptol, linalyl acetate, (-)-β-pinene, p-cymene and myrcene. The 17 oil samples were divided into four categories according to the aroma substances. Production area and cultivar were important factors for the difference in the aroma of fried Z. bungeanum oil. The results of this study will provide a theoretical reference for the quality evaluation and geographical origin discrimination of Z. bungeanum oil on the market.