Fresh produce like fruit often ends up in the trash soon than expected after it starts to brown and the texture begins to soften: the fruit has ripened. Part of the problem may be the way in which they are stored and the main culprit is a gas called ethylene. This organic chemical compound is produced by fruits like apples, pears, melons, and bananas as they mature, since they continue the process post-harvest. When stored near fruits that emit this gas, other ethylene-sensitive fruits (like watermelon and nectarines) also spoil sooner. The article explains how ethylene affects the ripening of fruits and how fruits should be stored for better preservation.
What makes fruit ripen? Why are some fruits stored in the refrigerator and others at room temperature? The answer is ethylene, an aging hormone that causes fruit to ripen. The more damaged a fruit is, the more ethylene gas it produces and, therefore, there is more risk of it causing damage to other fruits nearby. The quality of the fruit is also affected and its shelf life reduced due to premature ripening. Understanding how ethylene effects fresh produce like fruits and how the ripening process works can help you keep your fruits fresher for longer at home.
Ethylene and the fruit ripening process
Ethylene is a natural gas, although it can also be produced as a result of combustion and other processes. Invisible and colorless, it is considered an aging hormone in plants. Ethylene is responsible for the changes in texture, softening, color, and other processes involved in ripening. Ethylene effects also include loss of chlorophyll and stem shortening. Some fruits like apples and pears produce ethylene when they start ripening. In contrast, others like cherries or blueberries do not produce much ethylene.
As they ripen, fruits like apples and pears produce ethylene, a gas that causes the fruit to change
The fruit’s cells use this type of plant hormone to send signals between them. At a certain point, the fruits begin to produce ethylene and nearby fruit that detects the gas also begin to ripen. This effect occurs both at room temperature and in cold storage (although the process is slower).
But not all fruits are the same and not all react to ethylene the same way. To that end, it’s necessary to distinguish between climacteric and non-climacteric fruits. Climacteric fruits continue to ripen after harvest, associated with ethylene production. These are apples, bananas, melons, avocados, apricots, figs, nectarines, peaches, plums, and pears.
Non-climacteric fruits, on the other hand, ripen only while on the plant and stop ripening after harvest (examples are cherries, grapes, oranges, and pineapples). Therefore, their shelf life is reduced if they are harvested at the maximum point of ripeness.
How to store fruit
To ensure that fruit is eaten in the most optimal condition possible, it is important to pay close attention at key moments, like purchase. Check that the fruit is undamaged and has no bruises, and it is better to buy small quantities of both fruits and vegetables and eat them quickly.
At home, proper storage is essential to ensure both quality and safety of fruit. Store fruit separately, depending on the degree of ripeness, to avoid premature ripening from ethylene.
The shelf life ranges from two to seven days, depending on the fruit. Strawberries and cherries can be stored for two to three days; bananas, peaches, and pears keep in good condition for up to five days; and melon and oranges can be stored for a week.
The following are recommendations for different fruits:
- Store the fruit that goes in the fridge in the drawer, at about 4ºC.
- Both apples and pears keep better at room temperature.
- Bananas turn black in the fridge; they ripen quickly at room temperature. They can be peeled and put in a container in the fridge. They can also be preserved by wrapping the stem and storing them in the drawer.
- Fruits that are purchased peeled and cut must be refrigerated.
- Fruits that are consumed raw in most cases should be stored separately from other foods like meat, poultry, and fish.
- Parts that are damaged or bruised should be cut out and discarded.
Fruits can also be frozen. The process is similar to that of refrigeration: you have to clean, wash, and cut the fruit before freezing, and cutting the fruit into pieces and storing them in trays in the freezer is recommended. Certain fruits such as blackberries, strawberries, cherries, and peaches can be kept frozen for about twelve months.