Ascorbic acid (or vitamin C) is found naturally in many fruits and vegetables, such as citrus fruits and green and red peppers and is also used as an antioxidant and preservative.
Ascorbic acid prevents oxidation and rancidity, especially in fats, and can help preserve the flavor, color, and aroma of the foods.
Ascorbic acid is added to cured meats to help prevent the formation of nitrosamines from nitrites.