Changes of Polyphenol Contents in Unripe Apples According to Heat Treatments

열처리 조건에 따른 애사과의 Polyphenol 함량 변화

  • 이정준 ((주)한국야쿠르트 중앙연구소) ;
  • 김창식 ((주)한국야쿠르트 중앙연구소) ;
  • 김성훈 ((주)한국야쿠르트 중앙연구소) ;
  • 허철성 ((주)한국야쿠르트 중앙연구소) ;
  • 백영진 ((주)한국야쿠르트 중앙연구소)
  • Published : 1999.02.28

Abstract

HPLC was used for determining polyphenols which are known as the functional compounds in the unripe apples Fuji and Aori. The changes in their contents caused by heat treatments were monitored. The carbohydrate contents in Fuji and Aori were 14.1% and 13.5% respectively. Both apple juices showed pH 3.2 and $8.0\;brix^{\circ}$, which were relatively low levels. The major polyphenols were composed of (+)-catechin, chlorogenic acid, (-)-epicatechin, and tannic acid. Total polyphenol contents in Fuji and Aori were 0.11, 0.12% by Folin-Denis method. HPLC analysis of polyphenols showed that four major components were contained by 0.06% in Fuji and 0.07% in Aori. Chlorogenic acid was three times higher in Fuji than in Aori. After water blanching, the area percent of polyphenols resulted in an increase by 3.54% in Fuji but a decrease by 2.93% in Aori. Pasteurization of juices led to decrease by 1.39% and 3.31% respectively. Blanching and pasteurization of unripe apple juices induced negligible changes in polyphenol contents during storage. During concentration, polyphenol contents increased in proportion to the concentration of unripe apple juices.

Keywords

unripe apple;polyphenol;water blanching;pasteurization;concentration