HPLC analysis of Catechins in The Residues After Dyeing Silk Fabrics with Korean Green Tea Extracts

녹차 염색 견포의 카테킨 함량 분석

We focused our research interests on the characteristic of silk fabrics dyed with green tea extracts and, moreover, revealed the catechin content of silk fabrics after dyeing with Korean tea extract by measuring the residues. Three kinds of green tea samples were taken between April and May, 2003, from Bosung(southern province in South Korea), in different terms as the first corp, the second corp, and the third corp. Before and after dyeing the silk fabrics with these extracts, catechins in the residue were analyzed by HPLC. Four kinds of Catechins, such as (-)-epicatechin(EC), (-)-epicatechin gallate(ECG), (-)-epigallocatechin (EgC), (-)-epigallocatechin gallate(EgCG) were isolated from Korean green tea extracts. Catechine contents in Korean green tea leaves depend on the making process such as heating and steaming, and the younger the richer. The absorbed catechins in sillk fabrics after dyeing followed in a decreasing order of EgCG>EgC>ECG>EC. We have found a 68% uptake of EgCG, and 116.8mg/g of EgCG in the silk fabrics after dyeing with 1% Korean green tea extracts.