Palletised orange export cartons standing in the cold store

Which Egyptian crops give off ethylene, which are damaged by it, and the pairings that should never share a cold room or a reefer. Production rates and sensitivity ratings by crop.

Ethylene sensitivity decides which crops can share a cold room and which cannot. Ethylene is a gas that ripening fruit releases and that other produce reacts to, and the reaction is not subtle: a pallet of mango held next to a pallet of green beans will yellow the beans in a matter of days. The rule is simple to state. Keep high producers away from high responders, whatever the temperature agrees.

Export pallets in a cold store where ethylene sensitivity governs which crops can be held together
A shared cold store is where most ethylene damage is done, not the container.

Ethylene production by crop, in microlitres per kilo per hour

Production is measured at 20 degrees Celsius and grouped on the standard scale: very low under 0.1, low 0.1 to 1.0, moderate 1.0 to 10, high 10 to 100, very high above 100. Cooling reduces the rate but does not stop it.

Ethylene production and ethylene sensitivity for the main Egyptian export crops.
CropEthylene productionSensitivity to ethyleneDamage if exposed
MangoModerate to highModerateAccelerated softening, shortened window
Cantaloupe and melonHighModerateFlesh softening, faster decay
FigModerateLowOver-ripening in a warm hold
Tomato (ripening)Moderate to highHighUneven colour run-on
Orange, mandarin, lemonVery lowModerateCalyx browning, higher decay pressure
Table grapeVery lowLowLimited
PomegranateVery lowLowLimited
StrawberryVery lowLowLimited
Green bean, sugar snapVery lowHighYellowing, loss of snap
Broccoli and leafy greensVery lowVery highYellowing, leaf abscission
CucumberLowHighYellowing, softening
CarrotVery lowHighBitterness from isocoumarin
Sweet potatoVery lowModerateDiscolouration, off flavour
WatermelonVery lowHighRind softening, mealy flesh

The pairings that cause most of the loss

Mango or melon held with green beans, broccoli, cucumber or leafy herbs is the combination that does the damage most often, because the temperature ranges look close enough to justify one room. Ethylene sensitivity does not care that both crops want 10 degrees. Watermelon with any moderate producer is the second, and it is easy to miss because watermelon shows the damage as mealy flesh only after cutting. Carrots picking up bitterness from a nearby ripening pallet is the third, and the buyer usually blames the variety.

What to do when one room is all you have

Ventilation is the practical control. Fresh air exchange dilutes accumulated ethylene, which is why vent settings on a reefer matter as much as the set point on a mixed load. Physical separation across the room, first-in first-out rotation and short holding times all reduce exposure. Potassium permanganate absorbers help at low concentrations and are not a substitute for separation. For the temperature half of the problem, see our reefer set points by crop, and for removing field heat before any of this becomes relevant, our guide to cooling methods by crop.

PEI Trade is the exporter, not a neutral laboratory. The production and sensitivity groupings above follow standard postharvest classifications and are given as planning guidance, not as a guarantee of outturn.

If you are building a mixed load for the 2026/2027 season and want the combination checked before you book, send the crop list and the destination to PEI Trade on WhatsApp at +20 10 9911 1918.