Flavor evolution in raw Pu-erh tea during manufacturing using different processing types

This study aimed to explore the relationship between the processing type and the flavor in raw Pu-erh tea (RPT). Liquid chromatography-mass, gas chromatography-mass spectrometry, and multivariate analyses were employed to measure the component of RPT and to determine the changes in the flavor evolution of RPT at processing type. Sensory evaluation indicated that the processing type enhanced the flavor of the RPT. Based on 12 detected taste-active compounds, PCA and heat map analysis showed the average content of 4 catechins (ECG?EGCG, EC, EGC) in RPTs was 132.27 mg/g, which was 21.19 mg/g less than sun-dried tea (SDT). Astringency and bitterness of RPT can be reduced by processing type. A total of 52 volatile compounds were perceived and 4 volatile components were identified as essential compounds related to PLS-DA (VIP 1, P < 0.05), including phytol, linalool, cis-geraniol, and trans-geraniol, which increased from 62.27% in SDT to 66.25% in brick tea, which significantly contributes to the floral flavor of brick tea. The findings presented in this thesis add to our understanding of the relationship between the processing type and the flavor of RPT.

Automated summary

The study suggests that processing type enhances the flavor of raw Pu-erh tea and reduces the astringency and bitterness. Analysis of taste-active compounds and volatile components showed differences in content between raw Pu-erh tea and sun-dried tea, with processing type playing a role in modifying the taste profile of the tea.