Fall Food Science: Apple Edition


September just screams apples to me. As soon as the temperature drops low enough for crisp mornings and pumpkin-spiced-anything, I’m ready to head to the nearest orchard for some classic fall fun!

If you’re anything like me, you’re really in it for the baked goods. (Apple cider donuts anyone?) But for those more inclined to actually take some apples home, read on for some fall food science tips to preserve and prepare your prized pickings.

Culinary Question: How Do You Stop Apple Slices From Turning Brown?


It’s the age-old story. You slice up a delightfully crisp apple only to return later and find the golden fruit has turned brown and mushy. Ever wonder why that happens?

When the apple is cut, the flesh is exposed to oxygen in the air. When this happens, enzymes called polyphenol oxidase (PPO) in the apple’s chloroplast cells rapidly oxidize compounds in the apple’s tissue and create o-quinones. These o-quinones then react with the apple’s amino acids and proteins, creating the brown-colored by-product. Long story short, the oxygen did it.

To limit the browning, you need to limit the oxygen. Coating fresh apples in sugar syrup reduces oxygen diffusion and slows the browning process. Brushing apple slices with acidic juices like lemon and pineapple will lower the pH level and slow down the PPO enzyme, as well.

Heat will also do the trick. Blanche the apple slices by immersing them in boiling water for 60 seconds before transferring to an ice bath. Cooking the apples will affect the texture somewhat, but at least they’ll stay pretty!

Culinary Question: How Do You Bake The Perfect Apple Pie?


Last July, I wrote an entire post about the food science behind the perfect apple pie. (Again, I’m in it for the baked goods.) While there are lots of food science tips to help you perfect this classic recipe, the foundation is really set by which apples you pick in the first place. Long story short: Start with tart.

Ever heard of pectin? This complex carbohydrate and a soluble fiber, found in the walls of plant cells, is basically the glue that holds an apple together. When apples are cooked, pectin breaks down and causes the apple to become mushy. When an apple has lower pH levels, as it does in tart varieties like Granny Smith, Honeycrisp or Cortland, pectin doesn’t break down as quickly. The result? A perfect bite.

For an awesome review of which apples make the best pie, check out this article from The Food Lab at Serious Eats.


This fall, wherever your apple picking paths may lead, I hope these food science tips help you further enjoy the fruits of your labor. (See what I did there?) If you end up going home with just a bag of apple cider donuts, no judgment here.

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