Will orange juice keep apples from turning brown?

No, orange juice will not keep apples from turning brown. Apples turn brown due to oxidation, a chemical reaction between the fruit's polyphenol compounds and oxygen in the air. Orange juice contains vitamin C, which is an antioxidant, but not enough to prevent apples from browning. To prevent apples from browning, they can be stored in an airtight container or covered with a plastic wrap to prevent contact with the air, or dipped in a solution of water and lemon juice.