Pasteurized orange juice is juice squeezed from oranges that has undergone pasteurization, which is a process in which the juice is heated in order to kill bacteria. Developed by Louis Pasteur, pasteurization is a process that typically used to kill bacteria in milk, but it can also be used to remove bacteria from food items like juices and eggs.
Although pasteurization may damage some nutrients in juice, it does not completely deactivate the vitamins and minerals that are present in orange juice. Orange juice contains a high level of vitamin C even after pasteurization. The process of pasteurization may affect the color and flavor of orange juice, but most orange juice that is commercially available goes through the process to ensure it is safe to drink.