The antioxidant activity was determined by TBA (thiobarbituric acid) method as described previously (Lin and Chang, 2000;Kim et al., 2003). Reaction mixture contained 0.6 ml of 20 mM SPB, 1 ml linoleic acid emulsion (0.1 ml linoleic acid; 99%, Sigma, 0.2 ml Tween 20 and 19.7 ml deionized water) and 0.2 ml of sample. Lipid peroxidation was started by addition of FeSO 4 (0.2 ml, 0.01%) and H 2 O 2 (0.2 ml, 0.56 mM), and incubated in water bath for 6 h at 37°C. Trichloroacetic acid (TCA; 0.2 ml, 4%), TBA (2 ml, 0.8%) and butylated hydroxytoluene (BHT; 0.2 ml, 0.4%) were then added, and the mixture was boiled at 100°C for 20 min. The antioxidant activity was