Improperly prepared food can lead to the growth and survival of spoilage and pathogenic microorganisms. Spoilage microorganisms can affect food by causing undesirable changes in appearance, texture, taste, and smell. Pathogenic microorganisms, however, can cause foodborne illness in humans while also being undetected in food, as they do not cause physical changes in foods (like spoilage organisms do). Reducing the ability of pathogenic microorganisms to grow in the food is an important way to keep food safety risks low.