The effect on PPO and PAL activities
Pineapple fruit had a low PPO activity at harvest time and there
was no significant difference between PSS and the control (Fig. 3A).
PPO activity in all treatments increased gradually with prolonged storage time and in the control the increase in PPO activity was
more rapid, while pre- or/and post-harvest SA treatments signifi-
cantly inhibited this trend.
At 5 days, PAL activity of the pineapple fruit in all SA treatments
decreased, but the control showed a reverse trend and then experienced
the decrease of PAL activity till the end of storage (Fig. 3B).
PAL activity in all SA treatments increased gradually and reached
the highest value at 10 days, then showed a similar trend as found
in the control. After 5 days of storage, there was significant difference
in PAL activity in the control and SA treatment. Therefore, SA
treatment significantly inhibited PAL activity, too.