Effects of Different Pepper Powder Particle Sizes on Volatile Aromatic Compounds in Zanthoxylum Oil Based on GC-IMS, GC-MS, and OAV

To understand the effects of particle size on the extraction of volatile huajiao (HJ) Zanthoxylum oils, Hanyuan pepper powder of 20, 30, 40, 60, and 80 mesh sizes was fried at 130 ℃ for 20 minutes with rapeseed oil as the extract oil. E-nose, gas chromatography-ion mobility spectrometry (GC-IMS), gas chromatography-mass spectrometer (GC-MS), odor activity value (OAV), and quantitative descriptive analysis (QDA) were applied to analyze the volatile Zanthoxylum oil components extracted from different sizes of pepper particles. Cluster analysis and Pearson correlation were performed to explore the differences in aroma profiles between samples. The E-nose and CA results indicated that the HJ-1 (20 mesh) sample was clearly different from other samples in terms of aroma, the aroma characteristics of HJ-4 (60 mesh) and HJ-5 (80 mesh) samples were similar, and the aroma characteristics of HJ-2 (30 mesh) and HJ-3 (40 mesh) samples were similar to each other. A total of 118 aromatic components were detected by GC-IMS, comprising 20 unidentified components and 98 identified components. The identified compounds included 13 aldehydes, 11 ketones, 12 alcohols, 22 esters, 16 heterocycles, seven acid, two phenolic compounds, and eight miscellaneous components. Moreover, the OAV values of 14 key aromatic components were greater than 1, including linalool, 2-furanmethanol, 2-phenylethanol, linalyl acetate, methyl phenyl acetate, γ-terpinene, phellandrene, and β-pinene. The key aromatic components of the HJ-4 sample contributed the most to the aroma of Zanthoxylum oil. QDA analysis revealed that the HJ-4 samples had very strong woody, lemon, nutty and fatty flavors. The Pearson correlation coefficient showed that the sensory property of lemon, woody, nutty and fatty flavors and concentrations of most key aromatic were strongly and positively correlated. From comprehensive analysis, the HJ-4 sample prepared from 60 mesh pepper powder was determined to have the best aroma sensory quality. In conclusion, GC-IMS and OAV values were able to identify the effect of different sizes of pepper particles during the extraction of volatile components of Zanthoxylum oil. This information could be used to provide a theoretical and practical reference for the production of Zanthoxylum oil.