Abstract:

In order to understand the quality change of Pu-erh tea, separate scavenging capacities against DPPH free radicals and NO2 － as well as inhibition effect on α -amylase of Pu-erh tea with different storage years were evaluated using a spectrophotometer. Results indicated that the antioxidant activity of Pu-erh tea was similar to that of vitamin C and all of the tested Pu-erh tea samples with different storage years had a strong NO2－ scavenging capacity, with a scavenging rate of higher than 50%. The separate scavenging capacities against DPPH free radicals and NO2 － of Pu-erh tea failed to exhibit an obvious increase with prolonged storage year; however, the inhibition effect onα-amylase activity increased.

Key words: Pu-erh tea, storage, antioxidant activity, NO2 － scavenging capacity, &alpha, -amylase