抄録
Some black teas were analyzed by electron spin resonance (ESR) spectroscopy. Yabukita cultivar contained more “radical” than Benifuji cultivar, but the Benifuji infusion showed stronger visible absorption at 380 nm. With increased fermentation, the “radical” content increased with the absorption at 380 nm. The amount of “radical” content in over-fermented teas increased greatly. Black teas preserved at room temperature for five years showed a decrease in “radical, ” but the color of the preserved tea became deeper and black. The present experiment revealed that the Benifuji with a good flavor and aroma had a spin concentration of 50×1015 spins/g.
