The green tea extract (4 L) thus prepared was combined with 1 g of tannase (Visionbiochem, Gyeonggi-do, Korea) and then incubated in a water bath at 35 °C for 20 minutes followed by centrifuging at 3000 g for 15 minutes at 5 °C. The supernatant was used as the TGE for further analyses. The compositions of the base formulation (vehicle), the formulation containing 5% NGE (FNGE), and the formulation containing 5% tannase-converted green tea extract (FTGE)