September 28, 2011

Old Apples.

Apples are available year-round in most grocery stores, even though apples come into season once a year. In the United States, apples are ripe and ready for picking in the late summer and throughout the fall depending on where you get your apples. So how is it that you can buy apples in the spring and summer, before even the bees have had their way with apple blossoms? Cold storage!

Apples naturally produce ethylene, a plant hormone that stimulates and regulates the ripening of fruit. In the world of post harvest technology, ethylene is a wonder gas because of this feature - one can manipulate when a fruit ripens by introducing ethylene gases or hindering natural ethylene production. When it comes to apples, the fruit will continue to ripen off of the tree through natural ethylene production, so this process must be stopped in order to store apples for long periods of time. Because apples produce such little ethylene compared to bananas or citrus, this isn’t that difficult to do. Apples can be stored for up to a year depending on the variety in carefully controlled storage facilities. These facilities use high concentrations of carbon dioxide, nitrogen and oxygen gases to reduce the build up of ethylene, and thus stop the apples from ripening.

What does this do to the fruit? Growers like to believe that it does little other than provide a year-round supply of apples. But have you ever eaten an apple and found the inner texture slightly grainy? Or even seen slightly browned flesh next to the core without evidence of bruising on the outside? These are ‘diseases symptoms’ of long-term apple storage, and science is doing what it can to try to prevent these ‘problems’ from occurring. In this case, growing organic apples is not the answer because organic and conventionally farmed apples alike will exhibit the same symptoms.

Apples are fantastic because they do last a long time off the tree. If placed in cold storage, they’re bound to last several weeks. We’ve eaten apples for centuries because we learned to store them properly, and there is no reason we shouldn’t continue to keep apples around as long as possible. The problem occurs when we expect to have perfectly luscious apples many, many months after harvest. Now, if you don’t mind a grainy, flavorless apple any time of year then don’t worry about it. But if you do want a better apple, keep in mind that fruits and vegetables always taste best when they’re in season. Apples are in season now – not in the spring – so enjoy them while they’re tasty. Even better, purchase apples from local growers at the farmers market - they’re much less likely to have been stored and saved from last years harvest this way.

1 comment:

  1. I'd never heard of cold storage for apples. That explains a lot.