Characterization of the Influence of Extraction Factors on Instant Pu-Erh Tea: Focusing on Changes in Sensory Quality and Aroma Profile

Abstract

The objective of this study is to explore the influence of extraction factors, including extraction temperatures, extraction time, and tea-water ratios, on the sensory quality and aroma characteristics of instant Pu-erh tea (IPET). Sensory evaluation, quantitative descriptive analysis (QDA) and HS-SPME-GC×GC-TOF/MS were utilized for analysis. The result showed that the optimal process condition of IPET was a solid-liquid ratio 1:8, an extraction temperature 75 ℃, and an extraction time 60 min. A total of 235 volatile compounds were identified and 65 key odor-active compounds with ROAV>1 in all samples. Based VIP>1, 19 key differential odor-active compounds were selected, including linalool oxide I, 1-dodecanol, linalool oxide II, etc. Further Pearson correlation analysis of key differential odor-active compounds and aroma characteristics showed that positive correlations between woody and ethyl nonanoate and 1-dodecanol, and between herbal and 1-methylnaphthalene. This research provides theoretical support for the production of high-quality IPET.

Keywords: Instant Pu-erh tea, Key odor-active compounds, HS-SPME-GC×GC-TOF/MS, Relative odor activity value