Wright Jonathan, Wulfert Florian, Hort Joanne, Taylor Andrew J
Samworth Flavour Laboratory, Division of Food Sciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, United Kingdom.
J Agric Food Chem. 2007 Feb 21;55(4):1445-53. doi: 10.1021/jf062657v. Epub 2007 Jan 30.
The release of volatile compounds from infused tea was monitored using on-line atmospheric pressure chemical ionization (APCI) mass spectrometry. Assignment of the APCI ions to particular compounds was achieved using gas chromatography of tea headspace with dual electron ionization and APCI-MS detectors. Six ions in the APCI spectrum could be assigned to individual compounds, five ions were associated with isobaric compounds (e.g., 2- and 3-methylbutanal and pentanal) or stereoisomers (e.g., heptenals or heptadienals), and a further four ions monitored were identified compounds but with some unknown impurities. Reproducibility of infusion preparation and the analytical system was good with percentage variation values generally below 5%. The analysis was used to study the effect of infusion and holding temperatures on the volatile profile of tea headspace samples, and this was found to be compound-dependent. Both the extraction of volatiles from leaf tea and the release of volatiles into the headspace play a role in creating the aroma profile that the consumer experiences.
采用在线常压化学电离（APCI）质谱法监测泡制茶叶中挥发性化合物的释放。通过使用配备双电子电离和APCI-MS检测器的茶叶顶空气相色谱法，将APCI离子与特定化合物进行匹配。APCI光谱中的六个离子可归因于单个化合物，五个离子与等压化合物（如2-甲基丁醛和3-甲基丁醛以及戊醛）或立体异构体（如庚烯醛或庚二烯醛）相关，另外监测的四个离子是已鉴定的化合物，但含有一些未知杂质。泡制制剂和分析系统的重现性良好，百分比变化值通常低于5%。该分析用于研究泡制温度和保温温度对茶叶顶空样品挥发性成分的影响，发现这取决于化合物。从叶茶中提取挥发性物质以及挥发性物质释放到顶空中，都对消费者所体验到的香气特征的形成起到作用。
