不同储存条件下绿茶中挥发性香气物质的特征分析

Characteristic analysis of volatile aroma components in green tea underdifferent storage conditions

中文关键词:  绿茶  不同储存条件  挥发性成分

英文关键词:green tea  different storage conditions  volatile organic compounds

中文摘要:

      目的 探讨绿茶在不同储存条件香气成分的特征性变化。方法 茶叶存储条件为常温(自然保存)、冷藏(5 ℃)、冷冻(?18 ℃), 在3个不同储存条件下, 利用顶空固相微萃取与全二维气相四级杆飞行时间质谱相结合(headspace solid-phase microextraction and comprehensive two-dimensional gas chromatography-quadrupole time-of-flight mass spectrometry, HS/SPME–GC×GC/QTOFMS)的方法测定茶叶中的挥发性香气物质成分, 并进行数据偏最小二乘判别分析(partial least square-discrimination analysis, PLS-DA)。结果 绿茶在3种储存条件下, 挥发性香气物质具有差异性。其中短链碳氢化合物含量大小分别为冷冻>冷藏>常温, 长链碳氢化合物含量分别为冷藏>冷冻>常温, 萜烯类化合物含量大小分别为冷藏≈冷冻>常温。结论 从挥发性香气物质总量来看, 冷藏条件要优于冷冻和常温条件, 常温对保持茶叶挥发性香气成分较为不利, 本研究可为绿茶的品质控制提供参考依据。

英文摘要:

      Objective To investigate the characteristic changes of aroma components in green tea under different storage conditions. Methods The storage conditions of tea were normal temperature (natural preservation), cold storage (5 ℃), freezing (?18 ℃). After storaging under 3 different conditions, headspace solid-phase microextraction coupled withcomprehensive two-dimensional gaschromatography-quadrupoletime-of-flight mass spectrometry (HS/SPME-GC×GC/QTOFMS)was used to determine the volatile aroma components in tea and data partial least square-discrimination analysis (PLS-DA) was performed. Results The volatile aroma components of green tea are different under 3storage conditions. The content of short-chain hydrocarbons was frozen>refrigerated>normal temperature, and the content of long-chain hydrocarbons was refrigerated>frozen>normal temperature. The content of terpenes was equal to that of refrigeration and freezingand was greater than normal temperature. Conclusion From the total amount of volatile aroma substances, the refrigeration condition is better than the freezing and normal temperature conditions. Normal temperature is not good for maintaining the volatile aroma components of tea. It provides useful information forthe quality control of green tea.