Methods based on sensory and chemical analysis: Unveiling the effects of different compression degrees on key odor-active compounds in fu brick tea
He Xie, Yang Liu, Tian Huang, Yajie Xue, Guangmei Zhu, Liangliang Zhao, Xingyi Liu, Zhiyong Yu, Minh Thu An, Jian Hao, Jianan Huang, Zhonghua Liu, Silei Bai, Chao Wang
Abstract
Compression is a crucial step in the production of Fu brick tea (FBT), affecting its chemical composition and sensory quality. However, the impact of compression degree on its aroma remains unclear. This study investigates the effect of compression degree on the aroma quality of FBT (loose-pressed brick tea, medium-pressed brick tea, tightly-pressed brick tea). GC × GC-Q-TOFMS, GC-O, quantitative descriptive analysis (QDA), and relative odor activity (ROAV) were used to decode the aroma characteristics of Fu brick tea. Results showed that significant differences in sensory evaluation and volatile compounds based on compression degree. M-brick tea had a fungal aroma with fruity and sweet aroma, while L-brick tea was rough and grassy, and T-brick tea had floral characteristics. A total of 186 volatile compounds were identified and 26 key odor-active compounds with ROAV>1 and VIP>1. GC-O analysis confirmed 11 major differential compounds, such as 6-methyl-5-hepten-2-one and linalool enhancing floral aroma, benzaldehyde linked to fruity aroma, and decanal and methyl salicylate associated with green characteristics. These findings provide new insights into how compression degree affects the aroma of FBT. • Sensory evaluation shows aroma differences in FBT with different compression. • GC × GC-Q-TOFMS was used to identify aroma compounds in FBT with different compression. • Key aroma-active compounds were identified in FBT with different compression degrees. • Relationship between aroma compounds and aroma attributes was established.