Polyphenolic compounds and antioxidant activity of CTC black tea of North-East India.

Sixty black tea samples from different agro climatic zones of northeast India were assessed for biochemical constituents that determine quality and also influence organoleptic perception. The antioxidant activities such as α,α-diphenyl-β-picrylhydrazyl (DPPH) free radical scavenging, lipid peroxidation inhibition, nitrite scavenging and super oxide scavenging, of the collected samples were analysed. Out of the four antioxidant activities, the super oxide scavenging activity was lowest and nitrite scavenging activity was highest.