A study of stability of (-)-Epigallocatechin gallate (EGCG) from green tea in a frozen product

Abstract

Epigallocatechin gallate (EGCG) from green tea has a potential to reduce the risk of cardiovascular disease and cancer. However, EGCG is unstable at high temperature and at pH ≥ 5. Strawberry sorbet is a high acid food product (pH < 4.6) that is stored frozen. The aim of the study is to examine the stability of EGCG in the strawberry sorbet by determining the amount of EGCG immediately after made and stored at 18°C for up to 16 weeks. In addition, the stability of EGCG in a strawberry sorbet and in distilled water as well as those under simulated intestinal digestion (pH 7.5 and at 37°C for up to 12 hours) was compared. The data showed that > 90% EGCG was in the strawberry sorbets after storage for 16 weeks. EGCG were also more stable in the strawberry sorbets than in distilled water under the simulated intestinal digestion significantly (p<0.05). © 2008 IFRJ, Faculty of Food Science & Technology, UPM.