Effects of pile-fermentation on the aroma quality of dark tea from a single large-leaf tea variety by GC × GC-QTOFMS and electronic nose

• Published in: Food research international 2023-12, Vol.174, p.113643-113643, Article 113643
• Main Authors: Wen, Shuai, Jiang, Ronggang, An, Ran, Ouyang, Jian, Liu, Changwei, Wang, Zhong, Chen, Hongyu, Ou, Xingchang, Zeng, Hongzhe, Chen, Jinhua, Sun, Shili, Cao, Junxi, Pu, Songtao, Huang, Jianan, Liu, Zhonghua
• Format: Article
• Language: English
• Subjects: Aroma quality; Dark tea; Electronic nose; GC × GC-QTOFMS; GC-olfactometry; OAV; Pile-fermentation
• ISSN: 0963-9969; 1873-7145
• DOI: 10.1016/j.foodres.2023.113643

[Display omitted] •1. The tea samples were processed from a single large-leaf tea variety.•2. Naphthalene and 2-methylnaphthalene and dibenzofuran could enhance the woody aroma.•3. 2-Nonenal and 1-hexanol were associated with increasing the fatty and sweet odors.•4. (Z)-4-heptenal contributed to the formation of a mushroom smell in dark tea.•5. 1-Octen-3-ol was linked to reducing pungent fishy smell during the pilling process. Aroma is one of the significant quality factors of dark tea (DT). However, for a single large-leaf tea variety, there are few studies analyzing the effect of pile-fermentation on the aroma quality of DT. The GC × GC-QTOFMS, electronic nose (E-nose) and GC-olfactometry (GC-O) techniques were employed to analysis the difference of tea products before and after pile-fermentation. A total of 149 volatile metabolites (VMs) were identified, with 92 VMs exhibiting differential characteristics. Among these, 31 VMs with OAV > 1.0 were found to be correlated with E-nose results (|r| > 0.8). Additionally, GC-O analysis validated seven major differential metabolites. Notably, naphthalene, 2-methylnaphthalene, and dibenzofuran were found to enhance the woody aroma, while (Z)-4-heptenal, 2-nonenal and 1-hexanol were associated with an increase in mushroom, fatty and sweet odors, respectively. Moreover, 1-octen-3-ol was linked to reducing pungent fishy smell. These findings could provide a certain theoretical basis for understanding the influence of pile-fermentation on the aroma quality of dark tea.