Abstract: In order to explore the role of artificial fermentation in the formation of the volatile flavor of ripe Zijuan tea, seven samples from the same batch were collected at different processing stages from the raw material piled up (day 0) to the end of fermentation (day 42) to analyze their volatile components by headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography-mass spectrometry (GC-MS). A total of 92 volatile components were identified including alcohols, ketones, aldehydes, hydrocarbons, acids, phenol ethers, and oxygen-containing heterocyclic compounds. The fermentation process enriched the aroma of the tea. According to correlation analysis, the period from day 7 (F1) to day 35 (F5) was key to forming the aroma characteristics. Aroma qualitative analysis and sensory evaluation indicated that dehydrolinalool, β-caryophyllene, and myrrholene were the signature contributors to the spicy aroma of Zijuan tea. During the fermentation process, a nutty aroma namely bitter apricot kernel-like aroma (benzaldehyde), uniquely produced by fermentation, an animal-like aroma namely milky aroma (p-methoxystyrene) and a microbial fermentation-derived odor were produced. Sun-dried Zijuan tea leaves had floral, fruity and spicy aromas, and during fermentation into ripe Zijuan tea, floral (violet flower-like and rosy), sweet, mild woody and faint spicy aroma characteristics were generated. The results of this study lay the foundation for further research on the relationship between the flavor of ripe Zijuan tea and microbial metabolism.

Key words: Zijuan tea; fermentation; headspace solid-phase microextraction-gas chromatography-mass spectrometry; aroma characteristics