2.9. Measurements of antioxidant activities
The DPPH radical-scavenging activities of the extracts were
measured according to the method of Yamaguchi, Takamura,
Matoba, and Terao (1998). The reducing power and Fe2þ-chelation
activity were determined according to Oyaizu (1986) and
Deiezak (1986), respectively. The half maximal inhibitory concentration
(IC50) was calculated as the antioxidant concentration
required for providing 50% of the antioxidant activity