Papaya ripens at 15 - 30ºC and temperatures below 15ºC (as in the reefer) and low ambient temperature during winter will retard ripening.
To overcome this problem, fruits are removed from the MAP packaging on arrival
and ripened at 25ºC in the flow-through ripening room with relative humidity of 85-90%.
The fruits are induced to ripen with a 24-hour exposure to 5 ppm ethylene gas.
Another method is to induce papaya fruits to ripen with a short exposure to ethylene before packing into the refrigerated reefer containers.