Analysis of coumarin and its glycosidically bound precursor in Japanese green tea having sweet-herbaceous odour

Abstract

Coumarin is a natural product well-known for its pleasant sweet-herbaceous and cherry flower-like odor. Despite coumarin is widely found in the plant kingdom, its occurrence in tea leaves is very poorly characterized. In this work, the cultivars, "Shizu-7132", "Koushun" and "Tsuyuhikari" were found to have sweet-herbaceous odor from the 11 Japanese green teas by the sensory descriptive analysis. Application of the stable isotope dilution assay for the quantification of coumarin revealed that the levels of coumarin in these Japanese green tea products with sweet-herbaceous and cherry flower-like odor ranged from 0.26 to 0.88 µg/g of green tea product, whereas the concentrations were generally below 0.2 µg/g of common green tea products. The "Shizu-7132" was found as naturally coumarin-rich green tea. The natural level of

Identification of coumarin-enriched Japanese green teas and their particular flavor using electronic nose

“…GC-MS analysis showed that the concentrations of coumarin in common green tea products were generally below 0.2 lg/g, whereas ''Shizu-7132"and ''Koushun" contained 0.88 and 0.67 lg/g coumarin, respectively, so called coumarin-enriched green teas (Yang et al, 2008).…”

“…et al, 2008). Furthermore, application of GC-MS for volatile analysis revealed that these green teas with sweet-herbaceous odour contained comparatively high content of coumarin, a character impact compound for the sweet odour quality of Japanese green tea, so called ''coumarin-enriched" Japanese green tea" (Yang et al, 2008). The objective of this study is to investigate whether it is possible to develop a rapid, accurate, and nondestructive E-nosebased approach to distinguish the Japanese green teas with different content of coumarin and evaluate the role of coumarin in the total flavor of coumarin-enriched green tea.…”

Gas phase ion chemistry of coumarins: ab initio calculations used to justify negative chemical ionization trends

“…Methods employing liquid chromatography-mass spectrometry (LC-MS) and in some cases gas chromatography mass spectrometry (GC-MS) in different matrices have been reported [4][5][6][7][8][9][10][11][12][13][14][15][16]. Fragmentation patterns of some coumarins using high and low resolution mass spectrometry in electron ionization (EI) mode have been reported in the literature [17][18].…”

Simultaneous determination of diethylene glycol, diethylene glycol monoethyl ether, coumarin and caffeine in food items by gas chromatography

“…Coumarin and related compounds are commonly analysed using reversed-phase HPLC (Ahn, Lee, Kim, & Sung, 2008;de Jager, Perfetti, & Diachenko, 2007;He et al, 2005;Naik & Nagalakshmi, 1997;Sproll, Ruge, Andlauer, Godelmann, & Lachenmeier, 2008), although other techniques such as gas chromatography-mass spectrometry (GC-MS) (Yang et al, 2009), capillary electrophoresis (CE) (Bogan, Deasy, O'Kennedy, Smyth & Fuhr, 1995;Ochocka, Rajzer, Kowalski, & Lamparczyk, 1995) and spectrophotofluorometry (Tan, Ritschel, & Sanders, 2006) have also been reported. By virtue of their volatility, GC technique is the method of choice for the determination of DEG and DEGME (Maurer, Peters, Paul, & Kraemer, 2001;Savchuk, Brodskii, & Formanovskii, 1999;Williams, Shah, Maggiore, & Erickson, 2000).…”