Gas Chromatography and Electronic Nose Combined with Chemometrics to Investigate Differences in Key Aroma Components in Eight White-Fleshed Peach Cultivars

In order to explore the differences in the aroma quality of different white-fleshed peach cultivars, an electronic nose and headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS) were used to analyze the volatile components of eight cultivars of white-fleshed peach including Baiyintao (BYT), Longmi 5 (LM5H), Xinchuanzhongdao (XCZD), Qiutong (QT), Xindajiubao (XDJB), Yihongmi (YHM), Yihongshuimi (YHSM) and Okayama (GSB). Relative odor activity value (ROAV) and variable importance in projection (VIP) were used to analyze the contribution of each volatile component to the overall aroma of white-fleshed peaches. In the electronic nose radar fingerprint, the W1W, W5S, W1S and W2W sensors showed different responses to the eight cultivars. Principal component analysis (PCA) demonstrated differences in the overall aroma of white-fleshed peach cultivars. In total, 49, 46, 46, 47, 49, 47, 47, 53 volatile compounds were identified in BYT, LM5H, XCZD, QT, XDJB, YHM, YHSM, and GSB by HS-SPME-GC-MS, respectively, the major ones being aldehydes, alcohols, lactones and esters. 2-Hexenal, hexanal, trans-2-hexenal and trans-2-hexen-1-ol, contributing to grass aroma; linalool, contributing to floral aroma; and n-hexanol, responsible for fruity aroma, were identified as key aroma compounds due to their ROAV ≥ 1 and VIP > 1. Variations in their concentrations caused differences in the key aroma of the eight white-fleshed peach cultivars.