HS-SPME/GC-MS and E-nose-based characterization of volatile compounds in purple garlic across eight Chinese regions.

Garlic (Allium sativum) as an important specie of the Allium genus, is one of the earliest plants cultivated due to its culinary and medicinal uses. In this study, headspace-solid phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME/GC-MS) and electronic nose (E-nose) technologies were employed to analyze the volatile profiles of the edible portions of eight purple garlic varieties from China. A comprehensive total of 36 volatile compounds was identified and quantified, representing various classes including phenols, aldehydes, alcohols, sulfur-containing compounds, hydrocarbons, ethers, ketones, and furans, among these, diallyl disulphide was most abundant compound, followed by 3H-1, 2-dithiole, together accounting for 25 % of the total sulfide content. The average concentration of total volatile compounds was 139.13 μg/g. E-nose analysis revealed that the sensors W5S and W2W exhibited heightened sensitivity to the distinct flavor characteristics of garlic. Multivariate statistical analysis, including Hierarchical cluster analysis (HCA) and principal component analysis (PCA) effectively distinguish eight purple garlic varieties into three categories. Correlation analysis between E-nose and GC-MS data showed that sensors, W2W and W5S, were positively correlated with diallyl disulphide and 2-Vinyl-4H-1, 3-Dithiine. These findings provide robust theoretical basis for the identification, classification, and breeding of high-quality garlic varieties, highlight the distinct regionalizing flavor profiles and characterizations of garlic grown in local areas of China.