Ripening Room

• Like most fruit, bananas give off ethylene gas, which speeds up the ripening process. Banana wholesalers use a ripening room to ripen the bananas before sale to stores. The ripening room keeps the temperature and humidity constant and promotes the circulation of air around the fruit, circulating the ethylene. Some wholesalers also pump additional ethylene into the ripening room to speed up and control the process. Circulating ethylene in this way helps ensure that all the bananas on a bunch will be at the same degree of ripeness.
  
  

Ripening Process

• As the banana is exposed to ethylene, starches in the fruit are converted into sugars such as glucose, fructose and sucrose. These sugars are what give the banana its sweet taste. As they ripen, the bananas also begin to take on first a lighter green, and then a yellow color. At the same time, the pectin starch in the fruit begins to break down, giving the fruit a softer texture.
  
  

Sale

• Wholesalers use a scale of one to seven to gauge when it is time to ship the bananas to stores for sale to the public. One is the least ripe and seven is almost overripe for sale, with the fruit sporting a deep yellow color with some brown spots. Bananas are generally moved from the ripening room to the store shelves when they are between stage three to five and are either a uniform light green or light yellow.
  
  

Ripening at Home

• You can easily ripen green bananas at home by placing the green bananas in a paper bag. The bananas will naturally give off ethylene, which in an enclosed environment will accelerate the ripening process. Bananas are ready to eat when they are yellow, but are at their sweetest when the skin is dotted with brown spots or flecks. Once the bananas are ripe, remove them from the bag to slow ripening. You can arrest the ripening process by placing the bananas in the refrigerator, although this will cause the skin to turn brown.