The term orange, both in the botanical and culinary sense, refers to several different species of citrus fruit known to be a result of interbreeding between the pomelo and mandarin fruits. Most often found with a fittingly orange colored peel and a slightly lighter inner flesh, oranges can be purchased nearly everywhere on the globe in many forms.
However, much like other kinds of fruit and vegetables, oranges have a relatively short shelf-life that is reduced even further by a variety of factors such as ambient air humidity and mechanical damage. Because of this low shelf-stability characteristic of oranges, they often require some form of preservation in order to prevent spoilage and wastage.
Oranges may be frozen, though certain concessions must be made pertaining to its top quality, especially if it is stored in the freezer at its base form with no other form of processing done. In order to ensure that oranges will last for an acceptable length of time in the freezer, however, certain steps must be taken prior to storing them.
How Long Do Oranges Last at Room Temperature?
Generally, most types of oranges will last for up to seven days out in the open before displaying signs of spoilage or degradation of quality. This is due to several different factors that may be controlled for while choosing to keep oranges at room temperature, allowing the citrus fruits to reach the full length of their shelf-life.
It is best to store oranges in an area with relatively low air humidity and to avoid subjecting the fruit to extreme temperatures at either end of the spectrum. Direct sunlight will also dehydrate the fruit and accelerate its own internal enzymatic action, causing the fruit to spoil prematurely, even without the presence of bacterial or fungal colonies.
Keep in mind that oranges must be left in their intact form with the peel unbroken in order to allow them to last for up to one week, as even small dents or cuts in the orange’s skin will expose them to microbial life which will cause the oranges to go bad.
What is the Ideal Temperature for Oranges?
Like most forms of organic fruit and vegetable, oranges must be stored at or near their ideal temperature in order to preserve them at their best quality. While long-term storage likely will require lower temperatures than that of the ideal temperature, it is a fact that exposing the oranges to temperatures this low for purposes of long-term storage will decay their quality.
The ideal temperature for oranges to be kept at their best quality is between the range of 38°F to 48°F, or around that of the average commercially available refrigerator, of which is usually at an average temperature of 40°F.
Considering the fact that the average range of room temperature is between 68°F to 72°F, this makes simply storing oranges in the pantry or on the kitchen table an unsuitable method of preservation, as this will cause an acceleration of the orange’s spoilage, or, at the least, cause it to lose its best quality sooner than needed.
What is the Ideal Humidity for Oranges?
Just as oranges must be stored at a certain range of temperatures in order to ensure their top quality is retained, the ideal humidity environment for the storage of oranges must also be controlled for if one wishes to keep their oranges as excellent as possible.
The relative humidity range of 90% to 95% is considered the best possible environmental circumstance for preserving oranges in their best state, as ambient air humidity levels lower than this may cause the fruit to dry out and desiccate, and relative humidity percentages higher than this may accelerate the development of microbiological life.
An excellent way for home chefs and farmers to preserve their oranges at the ideal humidity levels without the need for expensive equipment is to place it in the crisper drawer of their refrigerator, of which maintains a carefully controlled 95% relative humidity, or the upper end of the ideal humidity range for oranges.
Can You Refrigerate Oranges?
In the event that you have chosen to store the oranges in another method other than simply leaving them at room temperature, refrigerating oranges is an excellent alternative way to extend their shelf-life.
As an added bonus, oranges stored in the proper way within the refrigerator will retain their top quality for a longer period of time than that of oranges stored in any other method, though this will require a few simple steps be taken in order to insulate the oranges appropriately.
In order to refrigerate whole oranges that have not had their peels compromised in any way, simply leave them in the crisper uncovered. Care should be taken that the oranges are not stored in the same air space as anything with a particularly strong odor or flavor, as the orange may absorb these characteristics.
However, if you are storing orange wedges or other forms of cut orange, you must first completely swaddle the pieces in plastic cling wrap so as to insulate the delicate flesh from the open air, which will cause it to spoil prematurely.
The primary reasoning behind why oranges last longer in the refrigerator at their top quality than anywhere else is because of the inhibition of the internal ripening enzymes present within the orange.
These compounds are produced by the oranges’ plant cells in order to cause it to decompose more quickly, releasing its payload of seeds into the soil and continuing the orange plant’s reproduction cycle.
The low temperatures of the refrigerator help inhibit or entirely stop these compounds, while at the same time being sufficiently warm enough to not form ice crystals at a cellular level within the orange, preserving them at their current quality for as long as possible.
How to Freeze Oranges
Choosing to instead freeze oranges is an excellent option so long as you are aware of the drawbacks associated with this method of preservation. On the positive side of things, however, oranges last their longest when frozen, so long as the proper methods are used.
To begin, first choose oranges that are suitable candidates for freezing. Generally, the ideal oranges for freezing are the ones at their prime and free of any visible signs of spoilage such as dents or cuts in the peel or off-color blemishes.
Once you have selected the appropriate oranges for freezing, wash their surfaces thoroughly by running the fruit under a cold tap and brushing lightly with your fingertips. Pat the oranges dry with a cloth towel, ensuring that as little moisture remains on the oranges as possible.
This is done to ensure that the oranges do not fuse together when stored, as ice crystals will form after a short length of time in the freezer.
Now cleaned and dry, simply place the oranges into a freezer bag or resealable plastic pouch and leave in the deepest part of your freezer for up to twelve months. Keep the bag of oranges away from anywhere that other objects stored in the freezer may puncture the bag or deal mechanical damage to the fruit, as rupturing the peels will cause the oranges to spoil prematurely.
How to Thaw Oranges
All that is required to thaw oranges is to simply leave them in the refrigerator overnight. Otherwise, should you require the oranges to thaw more quickly, you may leave the bag of fruit in a bowl of room temperature water, changing out the water every twenty minutes.
References
1. Xu, Q; Chen, LL; Ruan, X; Chen, D; Zhu, A; Chen, C; Bertrand, D; Jiao, WB; et. al(Jan 2013). “The draft genome of sweet orange (Citrus sinensis)”. Nature Genetics.
2. Morton, J (1987). “Orange, Citrus sinensis. In: Fruits of Warm Climates”. NewCROP, New Crop Resource Online Program, Center for New Crops & Plant Products, Purdue University
