کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1188589 963492 2008 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Discrimination of teas with different degrees of fermentation by SPME–GC analysis of the characteristic volatile flavour compounds
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Discrimination of teas with different degrees of fermentation by SPME–GC analysis of the characteristic volatile flavour compounds
چکیده انگلیسی

As tea is traded all over the world, it is necessary for both customs officers and business investigators to develop an easy and reliable method to discriminate teas from each other. A total of 56 kinds of various green, Oolong, and black teas were collected from different countries and markets, and their catechin contents and volatile flavour compounds (VFC) were compared by analyses, using HPLC and solid-phase microextraction–gas chromatograph (SPME–GC). It was found that neither total catechin nor individual catechin contents in green and Oolong teas were significantly different among the samples investigated, but the fermentation processes altered the profiles of tea VFC. Because many of the individual VFC did not change in response to the fermentation levels, several VFC in combination might be more reliable than a single compound to identify broader ranges of teas. A total concentration of five VFC, trans-2-hexenal, benzaldehyde, methyl-5-hepten-2-one, methyl salicylate, and indole, was shown to be able to discriminate clearly unfermented and fermented teas, while that of trans-2-hexenal and methyl salicylate together supplied an index to differentiate semi- and fully-fermented teas. In addition, the SPME–GC analysis was also able to distinguish real jasmine teas from fake jasmine teas based on the disappearance of some grassy/green odorants.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Food Chemistry - Volume 109, Issue 1, 1 July 2008, Pages 196–206
نویسندگان
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