title: The characterization of caffeine and nine individual catechins in the leaves of green tea (Camellia sinensis L.) by near-infrared reflectance spectroscopy.
abstract: Near-infrared reflectance spectroscopy (NIRS) was used to determine the contents of caffeine and nine individual catechins in tea leaves. A total of 665 samples were scanned by NIRS, and also by high performance liquid chromatography coupled to a diode array detector to determine the contents of caffeine and nine individual catechins. The calibration models for caffeine, EGC, C, EGCG, EC, ECG, and total catechins had high r(2) (more than 0.90) and RSP (the ratio of standard deviation of reference data to SEP(C) in the external validation set) values (more than 4.1), indicating a good correlation between reference values and NIRS predicted values. In contrast, the calibration models of GC and EGCG-3Me had low r(2) and RSP values (below 0.8 and 2.0). Therefore, these results suggest that NIRS could be applied for the rapid determination of the contents of caffeine, EGC, C, EGCG, EC, ECG, and total catechins in tea leaves for breeding programs that develop high-quality tea plants.
authors.affiliation: Sulloc Cha R&D Center, Jangwon Co., LTD, Seogwipo, Jeju 699-920, Republic of Korea.
authors.forename: Min-Seuk
authors.initials: MS
authors.lastname: Lee
authors.affiliation: Department of Herbal Medicine Resource, Dogye Campus, Kangwon National University, Hwangjori #3, Dogye-up, Samcheok 245-907, Republic of Korea.
authors.forename: Young-Sun
authors.initials: YS
authors.lastname: Hwang
authors.affiliation: USDA-ARS, Tree Fruit Research Laboratory, 1104 N. Western Ave., Wenatchee, WA 98801, USA.
authors.forename: Jinwook
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Herbal Medicine Resource, Dogye Campus, Kangwon National University, Hwangjori #3, Dogye-up, Samcheok 245-907, Republic of Korea; Department of Biology, University of Texas-Arlington, Arlington, TX 76019, USA. Electronic address: cmg7004@kangwon.ac.kr.
authors.forename: Myoung-Gun
authors.initials: MG
authors.lastname: Choung
mesh_terms: D002110:Caffeine / Q000032:analysis; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry; D019265:Spectroscopy, Near-Infrared / Q000379:methods*; D013662:Tea / Q000737:chemistry*
chemical_list: D010936:Plant Extracts; D013662:Tea; D002110:Caffeine; D002392:Catechin
keywords: Caffeine; Catechins; Green tea; High performance liquid chromatography; Near-infrared reflectance spectroscopy