The specific activity was expressed as U mg1 protein, while the
unit was defined as one DOD398 min1 mg1 protein. For POD
activity, 0.5 mL of enzyme in 2 mL buffer substrate (100 mmol L1
sodium phosphate, pH 6.4 and 8 mmol L1 guaiacol) was incubated
for 5 min at 30 C and the increase in absorbance at 460 nm for
120 s after adding 1 mL of H2O2 (24 mmol L1) was measured.