Food additives are substances added to food to enhance its flavor, texture, color, or shelf life. DYE is a three-letter food additive that is used to give food a vibrant color. AGAR is a four-letter food additive that is derived from seaweed and is used as a thickening agent in many foods. MSG is a three-letter food additive that is used to enhance the flavor of food. SAUCE is a five-letter food additive that is used to add flavor and moisture to food.