Lipid peroxidation was determined by the presence of malondialdehyde (MDA), a product of lipid peroxidation that reacts with thiobarbituric acid (TBA). A 250-mL of the supernatant from the TCA extraction was added to 1 mL of a solution containing 20% (w/v) TCA and 0.5% (w/v) TBA. The samples were incubated for 30 min at 95 C and centrifuged for 5 min at 10,000 g; the absorbance was measured at 535 and 600 nm using a spectrophotometer. The MDA content was assessed by a 535 nm value e 600 nm value calculation. The result was expressed in nmol g1 fresh weight.