Recently, researchers from Nagoya Institute of Technology in Japan have revealed, for the first time, that the choice of glazing on ceramic tea sets used to prepare tea plays a key role in the retention of catechin flavonoids., Associate Professor Takashi Shirai, along with Dr. Yunzi Xin, Mr. Sota Shido, and Dr.
To examine the effect of the glaze on tea catechins, the researchers brewed a green tea solution using ion-exchanged water at 80°C for three minutes. The tea leaves were separated, and the supernatant was mixed with glaze powders coated on ceramic tiles. The glaze–tea mixture was then allowed to react for six hours, followed by the removal of the glaze powder through centrifugation and filtration.
Additionally, the researchers also observed a selective reduction in the amount of altered catechins in tea. The tea solutions mixed with Oribe, Namako, and Irabo glazes showed significantly lower concentrations of epicatechin, epicatechin gallate, epigallocatechin, and epigallocatechin gallate, while the Toumei glaze selectively degraded epigallocatechin gallate.