The Role of Orange Juice

• Orange juice in an apple cake serves several purposes. First, the juice adds a slightly sweet, slightly tart flavor that complements the apples nicely. Orange juice also helps add moisture without extra fat. If the recipe calls for baking soda, the acid in the orange juice causes the chemical reaction needed to develop carbon dioxide bubbles and cause the cake to raise. Without an acidic ingredient, baking soda doesn't work as well, and it can give a bitter, soapy flavor to the cake.

Adding Flavor

• To add flavor to your cake, use a bit of orange extract or orange flavored liquor. You can also use lemon juice and zest. Even without any of these additions, the cake will still taste delicious, especially if it contains other flavorful ingredients, such as vanilla, cinnamon, ginger or cardamom.

Keep It Moist

• To help preserve moistness in an apple cake, substitute apple juice for the orange juice in equal proportions. You can also add a few tablespoons of yogurt, sour cream, applesauce or buttermilk, or even a bit more oil or butter. Apple cakes are naturally dense, moist cakes because of the apples, but a few simple ingredients give you extra insurance.

Positive Reactions

• Baking soda, or sodium bicarbonate, is a highly alkaline substance that creates carbon dioxide bubbles when it combines with moisture and acidity. If using baking soda, you must include an acidic ingredient to cause the necessary chemical reaction. Substitute apple juice, applesauce, yogurt or buttermilk for the orange juice. Use the same amount of apple juice as you would orange juice, but limit the addition of other ingredients to 3 or 4 tablespoons. Another option would be to use baking powder instead. Baking powder already contains an acid and doesn't need an additional acidic ingredient to work. Baking powder isn't as potent as baking soda. Use it at a rate of 1 teaspoon for each cup of flour.