My sliced apples are rusting!

October 30, 2008 8:00 PM

How do Subway/McDonald's keep apple slices from oxidizing?

I noticed that a few fast food places have, at one point or another, sold apple slices in little plastic bags. However, when I slice an apple up and don't eat it immediately, the fruit's flesh oxidizes quite quickly (a matter of minutes).

How can one avoid this oxidization? Are these fast food joints spraying the fruits with nasty chemicals?

posted by TheyCallItPeace to food & drink (12 comments total)

Some ideas.
posted by Fuzzy Skinner at 8:03 PM on October 30, 2008

They're treated with vitamin C. You can avoid oxidation by putting more vitamin C on them, such as with lemon or orange juice.
posted by Cool Papa Bell at 8:06 PM on October 30, 2008

Calcium ascorbate
posted by TedW at 8:16 PM on October 30, 2008

Dilute lemon juice works, but I don't know if that's what they're using.
posted by Class Goat at 8:28 PM on October 30, 2008

TedW (and in essence Cool Papa Bell) are correct - from the horse's mouth, search down the page for "apple dippers." You can easily buy calcium ascorbate as a nutritional supplement. As chemicals go it's a perfectly edible one.
posted by nanojath at 8:52 PM on October 30, 2008

My mother has long used lemon juice for this purpose. It makes them taste good, too (which cannot always be said for whatever the fast food places use).
posted by MadamM at 9:24 PM on October 30, 2008

I worked in a potato peeling factory for a bit, years ago, and I'm pretty sure we used magnesium chloride solution to keep them from browning. But then I've blocked out a lot of stuff from that time. Point is, something similar might be used for apple slices.
posted by turgid dahlia at 10:10 PM on October 30, 2008

Yes - cut slices, roll around in bowl with some lemon juice to coat them; then a bit of sugar if the lemon juice makes them too tart.
posted by LobsterMitten at 11:37 PM on October 30, 2008

It's quite possible that they're "packaged in a protective atmosphere" which basically means replacing the oxygen with something like nitrogen or carbon dioxide. No oxygen, no oxidation.
posted by alby at 12:51 AM on October 31, 2008

There was a big article in the Times magazine about this a few years ago.

"As soon as you slice into an apple, the apple mobilizes against you, swiftly and on many fronts."
posted by thejoshu at 1:05 AM on October 31, 2008 [3 favorites has favorites]

Receont cooking sites say you can use Sprite also. Haven't tried it, though.
posted by raisingsand at 9:30 AM on October 31, 2008

Some varieties of apples naturally brown more slowly. The Granny Smiths from my back yard brown quickly; for whatever reason, the gala apples I buy at Safeway remain un-brown even after I cut them, put them in the kids' lunch and have them brought home again presumably because someone else shared a cookie with my kids.
posted by GuyZero at 9:59 AM on October 31, 2008