Cold Storage Conditions
Cold storage is the primary method for extending the life of fruits. Apples and pears quickly soften and become mealy in texture when kept at ambient temperatures. To maintain the quality longer than one week, fruit must be kept in refrigeration.
Apples and pears have the longest storage life of the tree fruits, and can be kept in cold storage up to four months under ideal conditions and up to 12 months in controlled atmospheres. Temperatures in cold storage range from 32 to 38ºF, depending on the chilling sensitivity of the variety. Most varieties can be stored at temperatures near 32ºF, but regular monitoring of room temperature is recommended to prevent freezing in rooms that do not maintain a consistent temperature. Honeycrisp is prone to chilling injury when stored at temperatures below 36ºF. Honeycrisp and other chilling sensitive apples should be stored at a temperature of 37ºF.
Stone fruit can be kept for one to several weeks in cold temperatures, a duration much shorter than for pome fruits. Peaches, plums, cherries and apricots are susceptible to chilling injury. Symptoms develop more quickly when fruit are held at temperatures in the range of 36 to 40ºF, known as the “killing zone.” The flesh can become translucent, turn brown, or become mealy. To prevent chilling injury, store stone fruit at temperatures in the range of 29 to 34ºF.
Cold storage rooms should be cleaned before use. Remove all fruit and bins to sanitize walls and floors. Bins should be sanitized, and be free of decayed fruit and debris. By removing sources of decay, the chance for fruit rot is lessened.
Refrigeration units should be operable before the start of harvest. Ideally, they should be able to maintain a temperature near 32ºF (0ºC). For varieties that are chilling-sensitive, store fruit at temperatures in the range of 36 to 38 (2 to 3ºC). Fans should be operable and able to maintain air circulation. High humidity will reduce water loss and fruit shriveling which is common in Golden Delicious apples. If these conditions can be met, fruit will come out of storage in better condition.
|Recommended storage temperatures of tree fruit.|
|Apples (most varieties)||32 – 33||0 – 1|
|Apples (chilling sensitive)||36 – 38||3 – 4|
|Stone fruit||31 – 33||-0.5 – 0.5|