Dynamic changes and interaction between different aroma types during low-temperature roasting of bud green tea

As an important process for enhancing aroma of Wuyi rock tea, roasting has gradually been applied to the processing of bud green tea (BGT). However, there is a lack of comprehensive research on the impact of roasting on BGT aroma. This research provides a detailed analysis of the changes in aroma perception and compounds during the low-temperature roasting process (105°C, 90 minutes) of BGT. First, the changes in aroma perception were studied using quantitative descriptive analysis (QDA). The aroma perception of BGT transformed from fresh to chestnut like. Next, headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) analysis was conducted to characterize the volatile compounds during roasting. A total of 313 volatile compounds were identified, among which 72 showed significant differences. Compounds such as linalool, benzyl alcohol, ionone, and ethyl salicylate (floral aroma) and 2,6-dimethylpyrazine, 2,3-dimethylpyrazine, 2-acetylpyrrole, and 3-furfural (caramel-like aroma) were confirmed to be involved in the formation of the chestnut-like aroma during roasting process. In addition, representative aroma compounds with different characteristics were selected based on monomolecular olfactory results to simulate sensory-level aroma interactions. The results showed that fresh and tender aromas exhibited mutual enhancement at low concentrations, while sweet and chestnut-like aromas showed mutual enhancement at all concentrations.