Tea Research Institute, Zhejiang University, 866 Yuhangtang Road, Hangzhou, Zhejiang 310058, China.
Food Chem. 2024 May 30;441:138301. doi: 10.1016/j.foodchem.2023.138301. Epub 2023 Dec 30.
Longjing tea is renowned for its fresh aroma and high value. However, during storage, the emergence of an off-flavor known as "stale odor" can significantly impact the flavor quality and economic benefits of Longjing tea. Yet, the specific volatiles responsible for this stale odor in Longjing tea remain unknown. In this study, Longjing tea samples with varying degrees of stale odor intensity were analyzed using simultaneous distillation extraction coupled with gas chromatography-mass spectrometry (SDE-GC-MS). Through odor activity value (OAV) and fractional omission testing, hexanoic acid and trans-2-nonenal were identified as the primary contributors to the stale odor. Moreover, the concentration of hexanoic acid was found to be valuable in predicting the intensity of the stale odor in Longjing tea. The oxidative degradation of linoleic acid was proved as the generation pathway of stale odor in Longjing tea. These findings provide essential theoretical principles for Longjing tea production and preservation.
龙井茶叶以其清新的香气和高价值而闻名。然而，在储存过程中，出现了一种被称为“陈味”的异味，这会显著影响龙井茶叶的风味质量和经济效益。然而，龙井茶叶中导致这种陈味的确切挥发性物质仍不清楚。在这项研究中，使用同时蒸馏萃取结合气相色谱-质谱联用（SDE-GC-MS）分析了具有不同陈味强度的龙井茶叶样品。通过气味活度值（OAV）和部分排除测试，己酸和反-2-壬烯醛被鉴定为陈味的主要贡献者。此外，己酸的浓度被发现可以用来预测龙井茶叶陈味的强度。龙井茶叶中陈味的生成途径被证明是亚油酸的氧化降解。这些发现为龙井茶叶的生产和保存提供了重要的理论依据。
