Fruits may be ripened on tree or vine for maximum quality, but if so, they may not survive shipping over large distances. To improve matters, the farmer may grow varieties developed specifically with shipping in mind, however that alone may not suffice to assure success. Fruits may have to be shipped ‘green’ to avoid spoilage.
Ripening after picking
Some fruits do well even if they have being picked green. Bananas may arrive at the local grocery partly green, yet in a day or two, they are yellow and ready to eat with little loss of flavor and texture. Not all produce does as well.
Green tomatoes take considerable time to ripen. In fact, they may spoil before changing color. To avoid this and to hasten ripening, tomatoes and other fruits may be ‘gas ripened’. Gas-ripened tomatoes are not as desirable as vine-ripened tomatoes are, but it is not the gas itself that is to blame. It is the premature picking.
Ethylene gas, chemical formula H₂C=CH₂, is part of the natural ripening process of many fruits. Ethylene gas acts as a hormone. One way to hasten the ripening of fruits is to place them in an airtight plastic bag, which traps ethylene gas naturally produced. Some fruits do not respond much to the influence of ethylene gas. These include blueberries, strawberries, grapes, pineapples and cherries.
Ethylene gas stimulates the conversion of starches into sugars in such fruits as apples, apricots, cantaloupes, figs, pears and plums.