As a weak organic acid, this compound is regularly used as a preservative and flavor enhancer in both home cooking and food manufacturing. Often confused with ascorbic acid, or vitamin C, citric acid is actually what gives certain fruits and foods their sourness. If you don't have access to fresh lemon juice year round, you may benefit from using powdered citric acid, which is available in many grocery stores.
Substitute a ½ teaspoon of powder citric acid for 2 tablespoons of lemon juice in every quart of canned goods. The citric acid helps to keep the food firm and regulate the pH level to prevent bacteria proliferation.
Add a pinch of citric acid powder to fondue sauce if the cheese starts to thicken. The citric acid helps to prevent the function of casein -- the milk protein responsible for the coagulation.
Apply 1 teaspoon of citric acid powder to fresh cut or peeled fruits before you can them. The citric acid content inhibits oxidation, which causes the flesh to turn brown. Fruits particularly prone to this are pears and apples.
Replace salt with citric acid when baking sour-tasting breads, such as rye or sourdough. This will help to reduce your sodium intake without affecting the taste. Usually, bread recipes need no more than 1 tablespoon.
Use a small amount of citric acid in any dishes you want to have a slightly sour taste. Do not overdo it, however, as the powder can overpower your dish.
"On Food and Cooking"; Harold McGee; 2004
National Center for Home Food Preservation: Selecting, Preparing and Canning Tomatoes
"Keys to Good Cooking"; Harold McGee; 2010