Changes of Chemical Components in Persimmon Leaves during Growth for Processing Persimmon Leaves Tea

감잎차 제조를 위한 감잎의 성장시기별 함유 성분의 변화

  • Published : 1994.04.01

Abstract

As a foundational study for processing persimmon leaves tea, the physico-chemical characters were investigated in persimmon leaves from Chungdo Bansi, Sagoksi, Kyungsan Bansi and Hiratanenasi during growth. Flesh weights increased rapidly until the middle of May and then decreased slightly. Moisture contents decreased continuously from $79{\sim}81%$ at the beginning of May during growth. Water soluble tannin contents reached $1.55{\sim}2.25%$, maximum values at the middle of May and at the beginning of June, and increased again at the middle of July and then decreased. Contents of catechins, precursor of condensed tannin, indicated $12{\sim}27\;mg%$ at the middle of May and reached $17{\sim}34\;mg%$, maximum values at the middle of June. Contents of catechin were low in order of (+)-catechin, (-)-epicatechin, (-)-epicallocatechingallate, (-)-epigallocatechin and (-)-epicatechingallate. Sugars present in persimmon leaves were composed of sucrose, glucose, fructose, raffinose and mannitol. Sucrose increased continuously, glucose and fructose decreased during growth. Raffinose content was less than 0.1%. Glucose and fructose took more than 90% until the beginning of May, and then sucrose took up $60{\sim}80%$ of total sugar contents. Total vitamin C contents indicated maximum values at the middle of May and at the beginning of June in Chungdo Bansi, Sagoksi and Kyungsan Bansi, maximum vaule at the middle of July in Hiratanenasi. From the basis of these data It was suggested that proper period for picking persimmon leaves prior to processing persimmon leaves tea was from the middle of May to the beginning of June. Since maximum values for most of chemical components occurred at the middle of May and at the beginning of June and persimmon leaves thicken after the middle of June.

Keywords

persimmon leaves;tea;physico-chemical components