Janet Too, J. Wanyoko, T. Kinyanjui, K. O. Moseti, F. Wachira
{"title":"市售茶中β-谷氨乙胺含量的定量分析[茶树]O. Kuntze,山茶科]产于肯尼亚","authors":"Janet Too, J. Wanyoko, T. Kinyanjui, K. O. Moseti, F. Wachira","doi":"10.20425/IJTS.V0IOF.9575","DOIUrl":null,"url":null,"abstract":"A study was carried out to quantitatively estimate the L-theanine content in 19 teas commercially available in the Kenyan market by High Performance Liquid Chromatography (HPLC). The test tea samples analyzed were green (n = 4), black (n = 8) and flavored (n = 7) teas from different origins viz., Kenya (n = 4), Uganda (n = 2), Tanzania (n = 5), Rwanda (n = 4), Cameroon (n = 1) and Sri-Lanka (n = 2) commercially available in the Kenyan market. The estimated Limit of Detection (LOD) of the current method was 0.01% L-theanine. The L-theanine content ranged from below the detection limit (<0.01% L-theanine) to 1.60% L-theanine on a dry weight (d.w) basis. Statistically significant differences (p < 0.05) were observed in the L-theanine contents of black, green and flavoured teas. Rwandan green tea contained the highest L-theanine content with 1.60% d.w. whereas six of the seven flavoured teas had very low theanine levels (<0.01%) that could not be quantified by the current method.","PeriodicalId":17156,"journal":{"name":"Journal of Tea Science","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2016-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":"{\"title\":\"Quantitative estimation of β-glutamylethylamide in commercially available made teas [ Camellia sinensis (L.) O. Kuntze, Theaceae] in Kenya\",\"authors\":\"Janet Too, J. Wanyoko, T. Kinyanjui, K. O. Moseti, F. Wachira\",\"doi\":\"10.20425/IJTS.V0IOF.9575\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"A study was carried out to quantitatively estimate the L-theanine content in 19 teas commercially available in the Kenyan market by High Performance Liquid Chromatography (HPLC). The test tea samples analyzed were green (n = 4), black (n = 8) and flavored (n = 7) teas from different origins viz., Kenya (n = 4), Uganda (n = 2), Tanzania (n = 5), Rwanda (n = 4), Cameroon (n = 1) and Sri-Lanka (n = 2) commercially available in the Kenyan market. The estimated Limit of Detection (LOD) of the current method was 0.01% L-theanine. The L-theanine content ranged from below the detection limit (<0.01% L-theanine) to 1.60% L-theanine on a dry weight (d.w) basis. Statistically significant differences (p < 0.05) were observed in the L-theanine contents of black, green and flavoured teas. Rwandan green tea contained the highest L-theanine content with 1.60% d.w. whereas six of the seven flavoured teas had very low theanine levels (<0.01%) that could not be quantified by the current method.\",\"PeriodicalId\":17156,\"journal\":{\"name\":\"Journal of Tea Science\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2016-04-15\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"1\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Tea Science\",\"FirstCategoryId\":\"1087\",\"ListUrlMain\":\"https://doi.org/10.20425/IJTS.V0IOF.9575\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Tea Science","FirstCategoryId":"1087","ListUrlMain":"https://doi.org/10.20425/IJTS.V0IOF.9575","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Quantitative estimation of β-glutamylethylamide in commercially available made teas [ Camellia sinensis (L.) O. Kuntze, Theaceae] in Kenya
A study was carried out to quantitatively estimate the L-theanine content in 19 teas commercially available in the Kenyan market by High Performance Liquid Chromatography (HPLC). The test tea samples analyzed were green (n = 4), black (n = 8) and flavored (n = 7) teas from different origins viz., Kenya (n = 4), Uganda (n = 2), Tanzania (n = 5), Rwanda (n = 4), Cameroon (n = 1) and Sri-Lanka (n = 2) commercially available in the Kenyan market. The estimated Limit of Detection (LOD) of the current method was 0.01% L-theanine. The L-theanine content ranged from below the detection limit (<0.01% L-theanine) to 1.60% L-theanine on a dry weight (d.w) basis. Statistically significant differences (p < 0.05) were observed in the L-theanine contents of black, green and flavoured teas. Rwandan green tea contained the highest L-theanine content with 1.60% d.w. whereas six of the seven flavoured teas had very low theanine levels (<0.01%) that could not be quantified by the current method.