Lemon Juice

• Lemon juice is perhaps the simplest, most readily available method to prevent apples from browning. When you purchase apples, add a few lemons to your shopping cart. Squeeze the juice from the lemons (or purchase bottled lemon juice) and brush any exposed areas on your apples with the juice. If you don't have an appropriate brush, toss the cut apples in a large bowl with lemon juice. The juice will impart a slight citrus flavor to your apples and keep them white long enough to serve and eat.
  
  

Vinegar

• Vinegar can impart an unpleasant flavor to cut apples, so you must take special precautions to prevent it from ruining the taste of your fruit. Combine 1/4 cup of apple cider vinegar with 4 cups of cold water. Submerge the apple slices in the solution and allow them to soak for 10 minutes. Drain the apples, then pat them dry before eating.
  
  

Ascorbic Acid

• Ascorbic acid, more commonly known as vitamin C, prevents apples from browning. Pure ascorbic acid is highly concentrated, however, making it six times more effective in halting browning than lemon juice. Purchase pure crystalline ascorbic acid or ascorbic acid tablets at natural food and drugstores. Dissolve 2 teaspoons of pure crystalline ascorbic acid or 400 milligrams of crushed ascorbic acid tablets in 4 cups of cold water and soak the apples for 10 minutes. Drain the apples, then pat them dry before serving. Make a fresh batch of the ascorbic acid solution for every new group of apples for the best results.
  
  

Commercial Options

• There are several products on the market specially designed to stop fruit from browning. Available in most grocery stores, you can find these products stocked near the fruit pectin, canning jars and other food preserving materials. In addition to ascorbic acid, most brands contain citric acid, which is less potent, although still effective, in preserving the apple's white flesh. Sugar is often used as a base, thanks to its pleasant flavor. Whichever brand you choose, read the label to make sure there are high levels of ascorbic acid in the product. Although they dissolve nicely, these products can be pricey to use since they are significantly less concentrated than pure ascorbic acid. Your chosen product should include measurements for diluting it in water based on your needs, whether it be serving, drying, canning or freezing.