Analysis of Volatile Flavour Components in Four Pomelo Peel Essential Oils Based on GC-MS and GC-IMS

The volatile components in the peel essential oils of Mi pomelo and Shatian pomelo from Meizhou city, Guangdong province , Mi pomelo from Jinggangshan city, Jiangxi province and Four season pomelo from Fuding city, Fujian province were analyzed by Gas Chromatography-mass Spectrometry (GC-MS) and Gas Chromatography-Ion Mobility Spectrometry (GC-IMS) technology. GC-MS and GC-IMS identified 56 and 58 volatile componentsin the four kinds of pomelo peel essential oil samples, mainly terpenes, followed by alcohols and aldehydes. The results of GC-MS indicated that the unique volatile components of Meizhou Mi pomelo was terpenes, alcohols and aldehydes; the unique volatile components of Jinggang Mi pomelo was terpenes, alcohols and esters; the unique volatile components of Meizhou shatian pomelo was terpenes and the Fuding Four season pomelo was terpenes, alcohols, aldehydes, ketones and esters. GC-IMS indicated that the subjectival volatile components of Meizhou Mi pomelo was terpenes, alcohols and aldehydes, the subjectival volatile components of Jinggang Mi pomelo was alcohols, aldehydes and esters, the subjectival volatile components of Meizhou shatian pomelo was terpenes and the Fuding Four season pomelo was alcohols, ketones, esters and furan. The results of GC-MS and GC-IMS showed some differences. Most of the volatile components detected by GC-MS were larger molecules（C₁₀~C₁₅）at high contents, while most of the volatile components detected by GC-IMS were smaller molecules（C₂~C₁₁）at low contents, and the two technologies expanded the detection scope of the volatile components in the sample. The types and numbers of volatile components in the samples detected by GC-IMS were more than those by GC-MS. The principal component analysis and heat map clustering analysis could well distinguish four kinds of pomelo peel essential oil samples, which proved that they differed from each other to a certain extent in volatile components. The combination of GC-MS and GC-IMS could comprehensively and intuitively reflect the changes of volatile components in four kinds peel essential oil and provided scientific basis for the comprehensive utilization of the peel essential oil.