Produce Storage 101

What's Ethylene?

The natural question is what is ethylene gas, how it is used and is it safe for humans. Ethylene is a hydrocarbon gas, flammable, odorless, harmless and tasteless.

Effect of Ethylene on Fruit Ripening

You may be interested to know how does the presence of ethylene affect fruit ripening. The effect of ethylene (senescence hormone) is to promote ripening of fruits to make them softer and sweeter. The ethylene, therefore, is a natural ripening agent.

Here are examples of what ethylene gas does to fruits and vegetables over time:

  1. Apples lose crunchiness
  2. Fresh produce and flower decay, wilt
  3. Leafy vegetables and eggplants spotting

Both fruits and vegetables release ethylene gas, however, fruits produce more ethylene than vegetables do. While some fruits and vegetables are high ethylene producers, others are more sensitive to it.

What You REALLY Need to Know

You'll speed up the ripening process of an unripe fruit by putting an ethylene producing food near it -- for example, by putting an unripe avocado with an apple in a bag. This is why leafy greens and other ethylene sensitive produce should be stored in sealed containers, not in our famous mesh produce bags.

  1. The action of ethylene slows down at lower temperatures, so the fruit does not respond well to externally supplied ethylene. that is why you can store your fruits in fridge to slow down their ripening process.
  2. Some fruits and vegetables are sensitive to the ethylene gas, so keep such produce away from ethylene producers as they deteriorate quickly and decay prematurely in high- ethylene environment. The degree of damage depends upon the concentration of ethylene, the temperature and duration of exposure.
  3. High ethylene producing fruits should be kept away from other fruits and vegetables. Store fruits and vegetables separately, because fruits release more ethylene gas than vegetables, which can spoil the veggies. Keep leafy vegetables and lettuce away from fruits. Therefore, store ethylene emitting produce such as apples, avocados, bananas, melons, peaches, pears, tomatoes, etc. separately from broccoli, cabbage, cauliflower, leafy greens, lettuce, etc. as these are ethylene sensitive.
  4. Do not store spinach, kale or similar leafy vegetables near apples, bananas or peaches, otherwise they will turn yellow quickly and limp. 
  5. Keep away your ripe foods from ethylene-producing foods to last longer.
  6. Storing potatoes with apples naturally inhibit sprouting in potatoes. The potato industry introduce trace amounts of ethylene into potato storage boxes to delay the sprouting process significantly [5].
  7. Keep Onions & Potatoes Separated as both can release moisture that will cause each other to spoil faster. Store them separately in a dry, cool and airy place. Many people have given ethylene as the reason for storing onions and potatoes separately, but that is not true; both potatoes and onions do not produce ethylene gas, only potato is sensitive to this gas.
  8. Remove and discard the older rotten fruits so that your other fruits and vegetables last longer with full nutritional benefits.
  9. Citrus fruits do not ripen further after they are picked so they have long self-life.
  10. Note that tomatoes are not artificially reddened by ethylene. The normal tomato ripening process can be accelerated by externally applied ethylene.