Extend the life of your fruits and vegetables by learning how to select and store your produce.
Don’t let your produce spoil your health or your budget. Fresh fruits and vegetables are full of nutrients, fiber and antioxidants. They are living, breathing organisms that will go to waste if not used in time, and their nutritional value diminishes as they begin to spoil.
Understanding how produce spoils, what to look for and what you can do to slow down the spoilage process pays dividends for your body and your wallet.
Most fruits and vegetables go bad because of damage caused by microorganisms such as bacteria and mold, enzymatic processes or bruising.
Microorganisms speed produce deterioration through structural decay. Microorganisms such as bacteria and molds release their own enzymes as they grow, speeding up the spoiling process.
Enzymes, which occur naturally in live fruits and vegetables, are part of the natural aging process. Enzymatic browning leads to discoloration and later, spoilage. Bruising physically alters the exterior of your fruits and vegetables, which trigger enzymatic reactions.
How you store your fruits and vegetables has a significant impact on their lifespan. Cold temperatures are best for slowing down respiration — but do not store produce inside airtight containers, because the total lack of respiration will speed decay. Exceptions are onions, garlic and potatoes, which are best stored outside of your refrigerator in a cool, dry and dark space.
Fruits emit ethylene gas, which speeds ripening, and some vegetables are more sensitive than others. Incompatible combinations include apples and apricots stored with spinach, lettuce or other leafy greens.
The Effects of Refrigeration on Fruit
Margaret Barth, author of “Microbiological Spoilage of Fruits and Vegetables,” estimates that of all the product that is grown in the United States, 20% will be lost to spoilage. One of the chief means of reducing this spoilage is refrigeration. Some fruit benefits from refrigeration. Some, however, is spoiled if you put it in the refrigerator too soon.
Some fruits ripen after they are picked. Strawberries, cherries and grapes ripen on the plant. Once you pick them, they may get softer due to the natural deterioration of plant matter, but they will never get any sweeter. Once picked, these fruits are as ripe as they will ever get. Fruits that don’t ripen after picking should be refrigerated immediately. Other fruits that fall into this category are apples, blueberries, raspberries, tangerines, oranges, limes and blackberries.
Ripening after Picking
Other fruits continue to ripen after picking. If the fruit is left on the plant long enough, the plant will send the signal. But the signal can also be triggered by a wound to the plant. The wound made when the fruit is cut from the plant can actually trigger ripening. These kinds of fruits--avocados, bananas, mangoes, pears, plums and tomatoes--will stop ripening if you put them in the refrigerator. For best quality, ripen them at room temperature in a brown paper bag. When the fruit is fully ripe, you can store it in the refrigerator to stop it from over-ripening or spoiling.
Refrigeration and Spoilage
All fruit can spoil. Ripe fruit spoils more quickly than unripe fruit. One of the reasons fruit spoils is bacteria, mold and fungus. If you have ever forgotten about a peach only to find it covered in blue or green mold, you are familiar with this kind of spoilage. Refrigeration slows the growth of these microbes. In doing so it buys you a little bit of time between the time your fruit is fully ripe and the time it starts to deteriorate.
Fresh cut fruit always requires refrigeration. Whether the fruit was cut before you bought it or whether you cut it up, that fruit needs to be refrigerated. Soft fruits that have been cut up, fruits like mangoes or melons, typically have a shelf life of two days or less even if they are refrigerated. Fruits containing more acid or harder fruits have a slightly longer shelf life. Anytime you cut open a fruit, you accelerate the ripening process and expose that fruit to bacteria, mold and fungus. For both food safety reasons and food quality reasons, keep cut fruit in the refrigerator.
Ethylene: The Ripening Hormone
Ethylene is a small hydrocarbon gas. It is naturally occurring, but it can also occur as a result of combustion and other processes. You can’t see or smell it. Some fruit will produce ethylene as ripening begins. Mangoes, apples and pears are examples of fruit that produce ethylene with ripening. Ethylene is responsible for the changes in texture, softening, color, and other processes involved in ripening. Fruits such as cherries and blueberries do not produce much ethylene and it doesn’t influence their ripening.
Ethylene is thought of as the aging hormone in plants. In addition to causing fruit to ripen, it can cause plants to die. It can be produced when plants are injured, either mechanically or by disease.