Should you refrigerate a peach?
Definitely not, reader Sally. Refrigeration makes peach flesh mealy. Why? Mainly because cold temperatures inhibit the degradation of pectin in the fruit. Most of us think of fruit pectin as a thickener. However its purpose in nature is rather different. Essentially, it’s the glue that holds fruit cells together. Lots of pectin keeps the rows of cells in the fruit’s flesh strong and rigid, which helps keep the flesh in its entirely to stay firm.
When fruit begins to ripen various genes turn on that are responsible for enzyme production. Enzymes are basically non-living molecules that do specific chemical jobs. Where fruit is concerned you have enzymes designed to do things like break starch into sugar (which makes the fruit sweet), break green chlorophyl down into different pigments (which changes the fruit’s color), neutralize acids (which reduces the fruit’s tart taste), and break big organic molecules down into smaller aromatic molecules (which give fruit a lovely smell). Still others — pectinases — go to work on the pectins, breaking them down and basically ungluing the molecules in the flesh from one another. The effect of course is that the flesh softens dramatically.
Cold temperatures put the hammer down on this pectin-slicing process, though I confess I’m not sure exactly how, whether it slows enzyme production or inhibits the ability of the enzymes to function. In any case the effect is that the fruit only partially softens and that creates the sensation of “mealiness” in the mouth. All of which translates to: leave the peaches out on the counter. Thanks for the question, Sally!
Request for a list of all fruits/veggies this fridge=mealy equation. We’d love to print and hang that on the fridge 😉
The key to that question is: which fruits continue to ripen after they’re picked? Any of those should be left out of the refrigerator. Fully ripe ones will only degrade at room temperature. Here’s a handy guide: http://www.stilltasty.com/articles/view/10
Regarding vegetables, there aren’t many of those that don’t need to be refrigerated. In general it’s a good idea to observe where you found them in the grocery store and act accordingly. Alliums like onions and garlic should not be refrigerated, nor should tomatoes (actually a fruit of course) or potatoes and squashes.
Another important point is to avoid storing fruits and vegetables together. The reason: because fruits give off a lot of ethylene gas, which in plants acts as a hormone that triggers the enzyme-producing genes I mentioned above. Ethylene can cause a lot of degradation in vegetables if they’re stored in the same refrigerator bin around ethylene producers.
Hopes that helps, C!
– Joe
More on peaches — mmmmmmmmm. The best fruit ever, IMHO, but only worth eating in season. In addition to mealiness, refrigeration kills the balance in their taste between sweet, acidic and juicy. It’s so much better to buy peaches in small batches and eat them as they are ripe, than to try to refrigerate them.
Yes that’s very true, Maura…cold interferes with all those processes. Fruit flies are the only down side to keeping them on the counter. Those things drive me nuts!
– Joe