An emulsifier is a food additive that helps mix two substances that typically separate when they are combined, such as oil and water. Emulsifiers have one end that is compatible with oil and another end that is compatible with water, allowing them to link with both and create a stable, homogeneous mixture called an emulsion. Emulsifiers can be derived from plants, animals, or made synthetically. They are used extensively in food manufacturing to prevent the separation of oil and water components in processed foods like mayonnaise, margarine, meats, ice cream, salad dressings, chocolate, peanut butter, cookies, creamy sauces, breads, baked products, and more. Emulsifiers also give these foods a smooth texture and increase their shelf life. Some common examples of emulsifiers include lecithin, which is derived from foods that contain fats such as eggs, soybeans, meat, and sunflower seeds, and hydrocolloids, which are naturally derived emulsifiers that serve as thickening agents and support the structure, texture, flavor, and shelf life of various food products.