Volatolomics-assisted characterization of the key odorants in green off-flavor black tea and their dynamic changes during processing

Yanqin Yang; Jialing Xie; Qiwei Wang; Lilei Wang; Yan Shang; Yongwen Jiang; Haibo Yuan

doi:10.1016/j.fochx.2024.101432

Volatolomics-assisted characterization of the key odorants in green off-flavor black tea and their dynamic changes during processing

Food Chem X. 2024 May 1:22:101432. doi: 10.1016/j.fochx.2024.101432. eCollection 2024 Jun 30.

Authors

Yanqin Yang¹, Jialing Xie¹, Qiwei Wang¹, Lilei Wang¹, Yan Shang², Yongwen Jiang¹, Haibo Yuan¹

Affiliations

¹ Key Laboratory of Biology, Genetics and breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China.
² Hangzhou Zhishan Tea Industry Co., LTD, Hangzhou 310000, China.

Abstract

Aroma plays a pivotal role in the quality of black tea. However, the acceptability of black tea is greatly limited by the green off-flavor (GOF) resulting from the inappropriate processing control. In this study, the key odorants causing GOF were investigated by volatolomics, and their dynamic changes and formation pathways were in-depth understood. Significant alterations in volatile metabolites were observed in the withering stage. A total of 14 key odorants were identified as contributors to GOF, including 2-methylpropanal, 3-methylbutanal, 1-hexanol, nonanal, (E, E)-2,4-heptadienal, benzaldehyde, linalool, (E, E)-3,5-octadiene-2-one, β-cyclocitral, phenylacetaldehyde, (E, E)-2,4-nonadienal, methyl salicylate, geraniol, and β-ionone. Among them, (E, E)-2,4-heptadienal (OAV = 3913), characterized by fatty, green, and oily aromas, was considered to be the most important contributor causing GOF. Moreover, it was found that lipid degradation served as the primary metabolic pathway for GOF. This study provides a theoretical foundation for off-flavor control and quality improvement of black tea.

Keywords: Black tea; GC-E-nose; GC-IMS; GC-O-MS; GC–MS; Green off-flavor.