The vivid yellow color normally associated with supermarket bananas is in fact a side-effect of the artificial ripening process. Flavor and texture are also affected by ripening temperature. Bananas are refrigerated to between 13.5 and 15 °C (56 and 59 °F) during transport. At lower temperatures, ripening permanently stalls, and turns the bananas gray as cell walls break down. The skin of ripe bananas quickly blackens in the 4 °C (39 °F) environment of a domestic refrigerator, although the fruit inside remains unaffected.
Cavendish bananas have a greenish-yellow appearance which changes to a brownish-yellow as they ripen further. Although both flavor and texture of tree-ripened bananas is generally regarded as superior to any type of green-picked fruit, this reduces shelf life to only 7–10 days, making commercial distribution impractical. For most people the only practical means of obtaining such fruit is to grow it themselves, however this is also problematic, because the bunch tend to ripen together and spoil quickly.
Bananas can be ordered by the retailer and may show up at the supermarket fully green. While such bananas ripen more slowly, the flavor is notably richer[citation needed], and the banana peel can be allowed to reach a yellow/brown speckled phase, continuing to protect firm flesh within, and extending shelf life.
Storage and transport Banana storage room, 1913 Transfer of boxes from refrigerated truck in cold chainBananas must be transported over long distances from the tropics to world markets. To obtain maximum shelf life, harvest comes before the fruit is mature. The fruit requires carefully handling, rapid transport to ports, cooling, and refrigerated shipping. The goal is to prevent the bananas from producing their natural ripening agent, ethylene. This technology allows storage and transport for 3–4 weeks at 13 °C (55 °F). On arrival, bananas are held at about 17 °C (63 °F) and treated with a low concentration of ethylene. After a few days, the fruit begins to ripen and is distributed for final sale. Unripe bananas can not be held in home refrigerators because they suffer from the cold. Ripe bananas can be held for a few days at home. They can be stored indefinitely frozen, then eaten like an ice pop or cooked as a banana mush.
