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
Conclusion
One of the major benefits of modified atmosphere packaging
(MAP) is the prevention or retardation of fruit senescence
(ripening) and associated biochemical and physiological
changes. Packaging of peach fruits in paper moulded trays
followed by wrapping with heat shrinkable film seems to hold
promise in improving the shelf life andmaintaining the quality
under super market and ordinary market conditions by 9 and
4 days respectively as against 6 and 2 days only in case of
unpacked control. This technology can be helpful in minimizing
the postharvest losses of peach fruits during retail
marketing.