MDA content was measured by the thiobarbituric acid (TBA)
method described by Hodges et al. (1999). One gram of spathe was
homogenized with 25 mL of 5% (w/v) trichloroacetic acid (TCA).
The mixture was centrifuged for 10 min at 10000
g. TBA
reactivity was determined by adding 2.5 mL of 0.5% TBA in 15%
TCA to 1.5 mL of the supernatant. The reaction solution was held for
30 min in bath containing boiling water, then cooled quickly and
finally centrifuged at 12000
g for 10 min to clarify the solution.
Absorbance was measured at 532 nm and corrected for nonspecific
turbidity by subtracting the absorbance at 600 nm,
calculated with an extinction coefficient of 1.55 nmol L1m1.
MDA content was expressed as nmol g1 spathe fresh weight (FW).