This research aimed to screen the characteristic volatile compounds of morels from different origins and to reveal the flavor characteristics of morels from different origins.

The same variety of Morchella sextelata were grown in six producing areas of Shanghai, Jiangsu, Yunnan, Qinghai, Hunan and Hubei according to the local production model. The freeze-dried morels were analyzed by gas chromatography-ion mobility spectrometry (GC-IMS) and comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (GC×GC-ToF-MS) to identify the types and content of volatile components. Principal component, cluster and multi-factor analysis were performed for these compounds, and a basic database was established.

A total of 183 volatile compounds were detected by GC-IMS. Compared with other regions, morels from Yunnan had a higher abundance and significant differences in alcohols and heterocyclic substances. The content of 1-octen-3-ol in morels from Hunan was higher than that from other regions. Meanwhile, morels from Jiangsu contain the highest aldehyde content. A total of 245 volatile compounds were detected by GC×GC-ToF-MS, and multivariate statistical analysis revealed differences in the volatile components of morels from Yunnan compared wtih five other regions, which was consistent with the results obtained from GC-IMS. In order to further reveal the characteristic flavors and environmental factors of different production areas, the odor activity value (OAV) of the differential compounds was analyzed and the correlation analysis with environmental factors was performed. The results showed that 3-methyl-1-butanol, n-hexanol and 1-octen-3-ol were common aroma substances in various production areas, providing fruity and mushroom aromas. Taking Yunnan as the reference object, 12 of the common differential volatile compounds with other provinces were identified as key aroma compounds (OAV>1). The characteristic volatile substances of morels in Yunnan were 2,5-dimethylpyrazine (OAV=387.97), 2,3-dimethylpyrazine (OAV=209.65), 2-methylpyrazine (OAV=13.02) and methyl acetate (OAV=3.13), and the characteristic aroma was roasted and fruity, which was related to the local sandy soil, high temperature and large temperature difference. The characteristic volatile substances of morels in Hunan were 1-octen-3-ol (OAV=17930.58) and 2-methyl-2-butenal (OAV=8.60), and the characteristic aroma was floral and mushroom aroma. The characteristic volatile substances of morels in Shanghai were benzeneacetaldehyde, ethylidene- (OAV=387.97), and ethane, (methylthio)- (OAV=7.78), and the characteristic aroma was floral and pungent. The characteristic volatile substance of morels in Jiangsu was 2-pentylfuran (OAV=97.23), and the characteristic aroma was licorice smell, which was related to the high organic matter content in the soil. The characteristic flavor of morels in Hubei and Qinghai was not obvious. In addition, the content of volatile substances in Qinghai was related to altitude.

The characteristic volatile substances of morels from Yunnan, Hunan, Jiangsu, Shanghai, Hubei and Qinghai were screened by GC-IMS and GC×GC-ToF-MS techniques, and the environmental influencing factors of their flavor formation were preliminarily explored. The results indicated that it was feasible to distinguish morels from different origins by characteristic volatile flavor substances.