A correct cooling preservation
gives us a longer life for onions
Onion storage will be made in wooden palots, previously dried. Its location inside the room should be made in order to allow a right air circulation as well for the evaporators as for supported fans, not overloading the storage maximum capacity. Storage should be made in constant humidity and temperature, avoiding fluctuations, and totally darkness, because bulb is still alive.
For this we need a specialized cooling room for onions.
Onion temperature changes should be made slowly, trying to keep the same temperature inside the bulb and in the external layers, because with abrupt changes in temperature bulb cells can be destroyed. It is recommended to cool or heat as maximum 2ºC per day, depending on different factors (temperature, humidity, etc…).
Onion must follow some rules to be storage:
- It must be a valid variety to be storage.
- Bulb must be firm and compact.
- Bulb must have a low content of superficial water (drying).
- Must be correctly cultivated under good agricultural practice.
Other important factor to bear in mind is shipping, un-storage must be planned during hot and humid conditions.