基于GC-TOF-MS技术优化青钱柳茶挥发性物质的萃取条件

Optimization of the Extraction of the Volatile Substances in Cyclocarya paliurus Tea Based on GC-TOF-MS

摘要:

为了优化青钱柳茶挥发性物质萃取的关键因素，进一步为其挥发性物质鉴定提供合适的理论方法, 本研究采用顶空固相微萃取法（SPME）对青钱柳茶叶中的挥发性物质进行萃取，并用气相色谱高通量飞行时间质谱（Gas chromatograph high flux time of flight mass spectrometer, GC-TOF-MS）技术对其进行分析。通过设计不同的萃取头、萃取温度、萃取时间，以及不同料液比进行萃取实验，以确定HS-SPME的最佳条件。结果表明：选取75 μm CAR/PDMS的萃取头，在萃取温度为80 ℃、料液比为1:15的条件下萃取60 min为最优萃取条件。在此条件下，共检测出青钱柳茶叶229种挥发性物质，包括酸类、醛类、酮类、醇类、酯类、烷烃类、烯烃类及杂环类化合物。其中，醛类、杂环类和醇类化合物的相对含量较高，相对含量排在前五位的分别为己醛、1-石竹烯、正己醇、2-甲基丙烯醛、2-己烯醛。

Abstract:

In order to optimize the key variables for the extraction of the volatile substances in Cyclocarya paliurus tea and further provide theoretical methods for the identification of the volatile substances, headspace-solid phase microextraction (HS-SPME) was used in this study to extract volatile substances from Cyclocarya paliurus tea before analysis by high-throughput gas chromatography-time of flight-mass spectrometry. The optimum conditions for HS-SPME were determined by designing different SPME fiber assemblies, extraction temperatures, extraction times and tea-to-water ratios. The results revealed the optimal extraction conditions: the use of CAR/PDMS (75 μm) as SPME fiber for a 60-min extraction at 80 ℃ and a tea-to-water ratio of 1:15. Under these conditions, 229 volatile substances were detected，including acids, aldehydes, ketones, alcohols, esters, alkanes, olefins and heterocyclic compounds. Among them, aldehydes, heterocyclics and alcohols had relatively high contents, with the top five contents derived from hexanal, 1-carophyllene, n-hexanol, 2-methylpropenal, and 2-hexenal.