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KMID : 1134820180470080857
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Journal of the Korean Society of Food Science and Nutrition
2018 Volume.47 No. 8 p.857 ~ p.862
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techin Contents of Green Tea Produced in Korea
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Hwang Byung-Soon
Jeong Yun-Sook
Oh Sung-Min
Kim Gi-Chang
Cho Yong-Sik
Hwang In-Guk
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Abstract
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The chemical composition of green tea is complex and includes polyphenols, alkaloids, amino acids, and other unidentified compounds. The contents of catechins and caffeine are considered a standard of green tea quality evaluation. In this study, an ultra performance liquid chromatography (UPLC) method was developed for the quantitative determination of five marker constituents in green tea; epicatechin, epigallocatechin, epicatechin gallate, epigallocatechin gallate, and caffeine. Reversed-phase UPLC analysis was conducted quantitatively to identify individual catechins and caffeine in teas extracted with 25% (v/v) aqueous ethanol. Content (mg/g, dry weight) of tea catechins decreased in the following order: Jeju-do 168.9 mg/g> Gyeongsangnam-do 156.8 mg/g> Jeollanam-do 148.2 mg/g. Based on their dry weights, the green teas contained 7.3 to 26.1 mg/g of caffeine. These results will be valuable as basic data for standardization of Korean green tea.
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KEYWORD
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green tea, catechin, caffeine, UPLC
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