Abstract: To identify the effects of different varieties of chili on the flavor characteristics of chili oil, the volatile flavor compounds were detected by electronic nose (E-nose) and gas chromatography-ion mobility spectrometry (GC-IMS), and the sensory characteristics were determined by quantitative descriptive analysis (QDA). Key flavor compounds were identified by relative odor activity value (ROAV), and the correlation between the sensory characteristics and the volatile flavor compounds was analyzed by partial least squares regression (PLSR). The results demonstrated that the electronic nose could clearly discriminate the odor profiles of five chili oil samples. A total of 82 compounds were identified by GC-IMS, including 28 aldehydes, 15 alcohols, 9 ketones, 10 terpenes, 7 esters, 10 heterocyclic, 2 benzenes, and 1 acid. The major component of chili oil was found to be aldehydes, followed by acids and terpenes. 3-Methylbutyraldehyde (ROAV = 40) was identified as the key flavor compound of chili oil. PLSR indicated that Erjingtiao oil chili had the best aroma attributes with a strong aroma. Qinjiao oil had a strong greasy aroma with several layers of flavor. The burn chili-like aroma and pungency of Xiaomijiao oil contributed to the long-lasting spiciness. Both Zhoupi and Neihuang Xinyidai oils had a weak flavor in balance overall. This study provides theoretical support and a basis for the targeted development of chili oil to meet the preference of consumers from different regions.

Key words: different varieties of chili, chili oil, gas chromatography-ion mobility spectrometry, multivariate chemometrics, flavor characteristics