If you’re wondering how a crunchy white apple can suddenly turn brown minutes after you’ve cut it, we break down why and the best way to stop it so you can continue to get more fiber and fruit into your diet this fall.
Undoubtedly, apples will probably be a staple on your holiday fruit and cheese platters this season, or even as a key ingredient in your kids’ lunch boxes. And while we love putting the spotlight on crisp, ripe apples during fall, the fruit (unfortunately) has one cosmetic flaw: enzymatic browning.
There’s nothing worse than cutting an apple into slices to enjoy as a snack, only for those same slices to turn brown before lunch. It certainly doesn’t look or sound appealing—which begs the question, are brown apples safe to eat? Furthermore, is there anything you can do about apples turning an ugly shade of tan? The answer to both questions is yes. Here's why they’re perfectly fine to munch on, in spite of the color, and what you can do to slow down the browning process.
Why Does It Happen?
Dying to know the science behind the cause of the browning? Well, apples contain an enzyme called polyphenol oxidase, which means it acts as an oxidizing agent for the polyphenol molecules that give apples their color or pigmentation. Normally, the enzyme and the polyphenols are stored in separate areas of the apple’s cells. But when sliced, dropped, or bitten into, the cells become damaged and the enzyme connects with those polyphenol molecules.
When you add oxygen into the mix with the damaged cells, a chemical reaction occurs that changes the polyphenols and produces a brown pigment. Whew! Got all that? To put it simply, apples brown when the flesh of the fruit is exposed to oxygen, altering its color, flavor, scent, and in some cases, nutritional value. The longer a cut apple is exposed to air, the more brown it becomes.
What Can You Do About It?
Okay, that’s all the complex, not-so-appealing stuff. The good news is that you don’t have to resort to buying the USDA-approved genetically-modified (GMO) apple that never browns when cut, because these home solutions could help to slow the browning and preserve the flavor of every sweet bite:
- Lemon or Citrus Juice - Any liquid containing citric acid will stop the enzyme and prevent browning because it brings the apple’s pH levels down. Just squeeze whatever citrus fruit you prefer directly onto the surface of the cut apple. However, be mindful that whatever fruit you use will change the apple’s flavor profile. If lemons, lime juice, or vinegar are too tart for your taste, try soaking the apple slices in pineapple juice to savor the sweet flavor.
- Plain Water - Immersing cut apple slices in plain water is the easiest method, and certainly, one of the most helpful in limiting the oxygen that reaches the apple's cells. Not only that, but water doesn’t alter the taste of the fruit. For the best results since apples are floaters, put slices or half a cut apple into a Ziploc bag with the air pressed out before submerging into water.
- Antioxidants - There’s a reason why those pre-packaged apple slices from McDonald’s stay fresh (and white) for so long, and it’s because of a chemical antioxidant known as calcium ascorbate, or most commonly, vitamin C. You can do this at home with the aid of your medicine cabinet. Try dissolving a vitamin C tablet and a calcium supplement in water along with your slices. The vitamin C and calcium work together to keep the apple’s cell walls intact when cut.
Bonus Tip: Don’t ever put apple slices near copper or iron because these metals speed up the browning process. If you’re thinking, when would I ever have apples near iron or copper, it can be as simple as serving apples in a bowl made of these metals or cutting apples with a knife made of copper or iron. Lastly, and most importantly, always remember to refrigerate any cut fruits or vegetables.
Even if you’re the most picky or sluggish eater, we hope you find solace in the fact that you can absolutely eat brown apples. One less apple wasted a day...and well, you know the rest.