title: Determination of volatile organic compounds, catechins, caffeine and theanine in Jukro tea at three growth stages by chromatographic and spectrometric methods.
abstract: Tea contains characteristic volatile organic compounds, polyphenols, caffeine and catechins, and is therefore among the most widely consumed beverages all over the world. In this study, fresh Jukro tea leaves collected from Damyang-gun (Jeollanam-do) at 40, 60 and 90day growth stages, were semi-fermented. The volatile organic compounds (VOCs) were extracted by simultaneous distillation-solvent extraction (SDE) and analyzed by gas chromatography/mass spectrometry (GC/MS). Catechins, caffeine and theanine were analyzed by high performance liquid chromatography (HPLC). A total of 159 VOCs were identified in the analyzed Jukro tea leaves. Comparatively, the increase in the concentrations of VOCs was high in 60day leaves. The content of catechins increased along the three growth stages, whereas caffeine, compared to 90day leaves, was higher for 40 and 60day leaves. Based on the results, the 60day leaves were found to be the most suitable and useful for making semi-fermented Jukro tea.
authors.affiliation: Department of Food and Nutrition, Chosun University, Gwangju 61452, Republic of Korea; Department of Ceramic Art and Tea Culture, Jeonnam Provincial College, Damyang 57337, Republic of Korea.
authors.forename: Dong Bok
authors.initials: DB
authors.lastname: Jeon
authors.affiliation: Department of Food and Nutrition, Chosun University, Gwangju 61452, Republic of Korea.
authors.forename: Young Shin
authors.initials: YS
authors.lastname: Hong
authors.affiliation: Department of Food and Nutrition, Chosun University, Gwangju 61452, Republic of Korea.
authors.forename: Ga Hyun
authors.initials: GH
authors.lastname: Lee
authors.affiliation: Department of Food and Nutrition, Chosun University, Gwangju 61452, Republic of Korea.
authors.forename: Yu Min
authors.initials: YM
authors.lastname: Park
authors.affiliation: Department of Food and Nutrition, Chosun University, Gwangju 61452, Republic of Korea.
authors.forename: Cheong Mi
authors.initials: CM
authors.lastname: Lee
authors.affiliation: Department of Food and Nutrition, Chosun University, Gwangju 61452, Republic of Korea.
authors.forename: Eun Yeong
authors.initials: EY
authors.lastname: Nho
authors.affiliation: Department of Food and Nutrition, Chosun University, Gwangju 61452, Republic of Korea.
authors.forename: Ji Yeon
authors.initials: JY
authors.lastname: Choi
authors.affiliation: Department of Food and Nutrition, Chosun University, Gwangju 61452, Republic of Korea.
authors.forename: Nargis
authors.initials: N
authors.lastname: Jamila
authors.affiliation: Department of Chemistry, Kohat University of Science & Technology, Kohat 26000, Khyber Pakhtunkhwa, Pakistan.
authors.forename: Naeem
authors.initials: N
authors.lastname: Khan
authors.affiliation: Department of Food and Nutrition, Chosun University, Gwangju 61452, Republic of Korea. Electronic address: kskim@chosun.ac.kr.
authors.forename: Kyong Su
authors.initials: KS
authors.lastname: Kim
mesh_terms: D002110:Caffeine / Q000032:analysis*; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D005971:Glutamates / Q000032:analysis*; D018515:Plant Leaves / Q000737:chemistry; D013057:Spectrum Analysis; D013662:Tea / Q000737:chemistry*; D055549:Volatile Organic Compounds / Q000032:analysis*
chemical_list: D005971:Glutamates; D013662:Tea; D055549:Volatile Organic Compounds; D002110:Caffeine; C026166:theanine; D002392:Catechin
keywords: High performance liquid chromatography (HPLC); Jukro tea; Simultaneous distillation solvent-extraction gas chromatography-mass spectrometry (SDE-GC/MS); Theanine; Volatile organic compounds