Korean Journal of Food Science and Technology (한국식품과학회지)

Korean Society of Food Science and Technology (한국식품과학회)
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Changes of Some Chemical Compounds of Korean (Posong) Green Tea according to Harvest Periods

보성산 녹차의 채엽시기에 따른 화학 성분의 변화

  • Published : 2004.08.31
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Abstract

Changes in contents of catechins, caffeine, free amino acids, and minerals in green tea loaves according to harvest periods were compared. Total catechin content increased from 40.61 to 52.04 mg/g, while that of caffeine decreased from 17.56 to 14.61 mg/g according to harvest periods. Regardless of harvest periods, composition of catechins was epigallocatechin (EGC)>epigallocatechin gallate (EGCg)>epicatechin (EC)>gallocatechin (GC)>epicatechin gallate (ECg)>catechin (C)>gallocatechin gallate (GCg)>catechin gallate (Cg). Free amino acid content in green tea leaves was highest in young loaves, and gradually decreased according to harvest periods. Theanine content was markedly decreased with leaf aging, suggesting taste of green tea may be changed from mild to bitter with increasing harvest period. Analyses of mineral elements in green tea leaves showed that Fe, Mn, and Mg increased with leaf aging, while Cu showed opposite trend. Results reveal that content of some chemical compounds in Korean (Posong) green tea was highly dependent on harvest period.

국내산 녹차의 채엽시기가 녹차 중의 카테킨, 카페인, 아미노산 및 무기질 함량과 조성에 미치는 영향에 대하여 조사하였다. 녹차의 총 카테킨 함량은 40.61-52.04mg/g으로 채엽시기가 늦을수록 증가하였으며, 카테킨 조성은 채엽시기에 관계없이 EGC, EGCg, EC, CC, ECg, C, GCg 및 Cg의 순으로 함유되어 있음을 알 수 있었다. 카테킨류 중 기능성 작용이 우수한 EGC 및 EGCg는 전체의 50% 이상을 차지하였고 온화한 떫은맛으로 후미에 감미를 남기는 유리형 카테킨인 EC와 EGC는 전체의 53.21%에서 57.09%를 차지하였다. 카페인 함량은 4월차 17.56mg/g, 5월차 15.71mg/g, 6월차 14.92mg/g 및 7월차 14.61mg/g으로 채엽시기가 늦을수록 감소하는 경향을 나타냈다. 총 아미노산 함량은 4월차 45.84mg/g, 5월차 22.64mg/g, 6월차 12.22mg/g 및 7월차 10.45mg/g으로 채엽시기가 늦을수록 감소하였으며 특히, 중요한 생리적 기능을 갖는 theanine의 감소 폭이 큰 것으로 타났다. 무기질 함량은 채엽시기가 늦어질수록 Fe, Mn 및 Mg는 증가하였으며, Cu는 감소함을 알 수 있었다.

Keywords

References

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