fruits upto 6 days of storage and thereafter declined gradually.
On the other hand control fruits recorded maximum activity
upto 6 days of storage and thereafter a sharp decline was
noticed. Under OMC the shrink film packed fruits recorded
the lowest average enzyme activity closely followed by cling
film, whereas the control fruits recorded the highest enzyme
activity. Pectin methyl esterase removes themethyl groups of
the galacturonic acid polymers. De-esterification of
polygalacuronic acid chain by PME may make the chain more
susceptible to polygalacturonade degradation (Carpita and
Gibeaut 1993) facilitating rapid loss of cell wall structure.
The increase in PME activity for all samples on 6th day
(SMC) and 2nd day (OMC) may be due to increase in respiratory
activity which led to ripening of fruits and thereafter
decline in PME activity could be due to accelerated senescence
leading to over softening of fruits. The lowering of PME
activity in shrink film packed fruit may be due to slower
respiratory activity occurring inside the package due to creation
of modified atmospheric conditions (Sen et al. 2012;
Giacalone and Chiabrando 2013). Kaur et al. (2012) reported
lower PME activity during storage in pear fruits packed in
polymeric film.