Can home-brewed Benifuuki green tea deliver health-relevant amounts of 3"-O-methyl epigallocatechin gallate?

Abstract

Benifuuki is a cultivar of tea (Camellia sinensis) that contains 3"-O-methylated epigallocatechin gallate (EGCg3"Me). In vitro, animal and human studies have shown positive health effects of Benifuuki tea (or more specifically of EGCg3"Me), such as allergy mitigation or prevention of cardiovascular diseases. In this article, suitability of the ISO 14502-2 method (slightly modified), that has been set up for the analysis of other flavanols in tea, was shown to be suitable for EGCg3"Me and validated. Eight Benifuuki green tea samples from Japan were analyzed and contained 2.3 to 10.5 mg EGCg3"Me per g in the leaves. Additionally, tea infusions were brewed according to the suppliers' recommendations and at 100 °C. The content of EGCg3"Me in the infusions was compared to the effective doses in human trials. Three Benifuuki infusions brewed at recommended temperatures of 60 or 85 °C deliver in less than 2.5 L at least 34 mg of EGCg3"Me, which is the minimal dose showing health effects in human studies. Using water of 100 °C, the EGCg3"Me concentration in the infusions is roughly doubled. Some infusions exceeded the safe level of caffeine of 400 mg within drinkable volumes.