Food additives are substances that become part of a food product when added (intentionally or unintentionally) during the processing or production of that food.

Common food additives include:

• Monosodium glutamate (MSG)
• Artificial sweeteners such as Aspartame, saccharine, and sodium cyclamate
• Antioxidants in oily or fatty foods
• Benzoic acid in fruit juices
• Sulfites in beer, wine, and packaged vegetables
• Nitrates and nitrites in hot dogs and other meat products
• Antibiotics given to food producing animals
• Lecithin, gelatins, corn starch, waxes, gums, propylene glycol in food stabilizers and emulsifiers
• A number of different coloring agents

Food additives serve five main functions:

1. Maintain product consistency

Substances called emulsifiers provide a consistent texture and prevent products from separating. Stabilizers and thickeners provide an even texture. Anticaking agents allow substances to flow freely.

2. Improve or preserve the nutrient value

Many foods and drinks are fortified and enriched to improve the nutritional status of the United States population. For example, vitamins and minerals are added to many foods including flour, cereal, margarine, and milk. This helps to make up for vitamins or minerals that may be low or completely lacking in a person's diet. All products that contain added nutrients must be labeled.

3. Maintain the wholesomeness of foods

Contamination from bacteria can allow foodborne illnesses to occur. Preservatives reduce the spoilage that air, fungi, bacteria, or yeast can cause. Certain preservatives help preserve the flavor in baked goods by preventing the fats and oils from going bad. They also keep fresh fruits from turning brown when exposed to the air.

4. Control the acidity and alkalinity and provide leavening

Specific additives help change the acid-base balance of foods to obtain a desired taste, color, or flavor. Leavening agents that release acids when they are heated react with baking soda to help biscuits, cakes, and other baked goods rise.

5. Provide color and enhance flavor

Certain colors improve the appearance of foods. There are many spices and natural and synthetic flavors that bring out the best in the flavor of food.