Storage of apples and pears

Regarding the storage of apples and pears, three types of can be distinguished: natural storage, cold storage and CA storage. ULO storage may also be considered as an independent storage method.

Natural storage

This method usually consists of putting fruit into a simple a chilled cellar, which preferably has high air humidity. However, this method of storage only plays a role only in the domestic and with fruit growin for a hobby. If thin transparent bags from polyethylene, which may occasionally need airholes are used a kind of CA storage may be achieved in the household.

Cold storage

In a cold storage is achieved by by refrigerating at a consistent tempature, which best suits the variety on a value from 1 °C to +4 °C. Apples and pears are stored between -1 °C to +0 °C. This is done to slow down the ripening process. Additionaly, cold storage equipment have an air humidification feature, which guarantees an air humidity between 90 % and 95 % to slow down the drying up of the fruits.

CA storage

CA storage (Controlled Athmosphere) is a method of storage that is airtight cold storage. This process, in addition to controlling the temperature and air humidity, the composition of the air with reference to oxygen and carbon dioxide is controlled. The oxygen level in the air is reduced and the carbon dioxide level is increased to slow down the maturation process. The desired values in oxygen and carbon dioxide are technically adjusted or originate after some time through the ripening process of the fruits in airtight storage because as maturation (respiration) takes place, oxygen is consumed and carbon dioxide is generated.

ULO storage

A further development of the CA storage is the so-called ULO storage (Ultra Low Oxygen), which limits amount of oxygen to the necessary minimum limit for the maintenance of the biological ripening activity and thereby radically can be reduces the maturation process.