Effect on the epigallocatechin gallate/epigallocatechin ratio in a green tea (Camellia sinensis L.) extract of different extraction temperatures and its effect on IgA production in mice.

ABSTRACT

We found that the epigallocatechin gallate (EGCG)/epigallocatechin (EGC) ratio in a green tea (Camellia sinensis L.) extract was affected by the extraction temperature. The EGCG/EGC ratio in the 4 °C extract was around 13-4, whereas in the 100 °C extract, it was around 10.7. Oral administration of the mixture with a high EGC ratio (12-3 = EGCG/EGC) resulted in greater IgA production by murine Peyer's patch cells.