Stability of (-)- epigallocatechin gallate (EGCG) in a strawberry sorbet.

Hirun, S.; Roach, P. D.

Background -- Epigallocatechin gallate (EGCG) is suggested to be the active constituent of green tea involved in reducing the risk of cardiovascular disease and cancer. However, EGCG is unstable at high temperature and at neutral or alkaline pH and it may therefore be unsuitable as an ingredient in functional food products. Strawberry sorbet is one of the lowest pH food products (pH < 4), it does not need any heat treatment and is stored frozen. Objective -- The purpose was to test the stability of EGCG in a strawberry sorbet immediately after the sorbet was made and during storage in order to determine the feasibility of making a functional food containing EGCG. Design -- Three batches of strawberry sorbets with 0.15% and 0.30% (w/w) EGCG were made and the pH measured. The EGCG was then measured by high pressure liquid chromatography (HPLC) immediately after the sorbets were made and after storage at -18°C for 4, 8 and 12 weeks and the results were expressed as mean + standard deviation. Outcomes -- Immediately after the sorbets were made 95% and 92% of the added EGCG was measured in the 0.15% and 0.30% (w/w) EGCG sorbets, respectively. After storage at -18°C for up to 12 weeks, the lowest recoveries represented 81% and 90% of the added EGCG from the 0.15% and 0.30% (w/w) EGCG sorbets, respectively. The pH of the sorbets ranged from 3.45 to 3.59. Conclusion -- The EGCG was stable in the strawberry sorbet, especially at the highest concentration of 0.30% (w/w). This is likely to be because the sorbets had a low pH, no heat treatment was involved in making them and they were stored frozen at -18°C. Strawberry sorbet may therefore be useful for making a functional food containing EGCG.

CATECHIN; STRAWBERRIES; FROZEN desserts; DESSERTS; FROZEN foods; COOKING

Asia Pacific Journal of Clinical Nutrition, 2005, Vol 14, pS108

0964-7058

Academic Journal