Does Frying Affect Vitamin C Content?

Vitamin C is one of the most unstable of all essential vitamins. Your body cannot store it, so getting an adequate supply through the foods you eat is essential. The unstable nature of vitamin C means cooking can easily degrade or destroy it. The only way to fully preserve the vitamin C content in fruits and vegetables is by eating them raw, but this is not always possible or desirable. In some cases, cooking foods that contain vitamin C, even by frying, enhances their nutritional value.

Facts

Frying does affect vitamin C, although not in the way you might expect. Because vitamin C is a water-soluble vitamin, it is time and temperature, rather than cooking oil, that carries the potential to degrade vitamin C. While this excludes deep frying, and in most cases pan frying, from cooking methods appropriate for foods that contain vitamin C, stir-frying is acceptable. Stir-frying works because although vitamin C starts to degrade at temperatures over 70 degrees Fahrenheit, cooking time is short enough to counter its effect.

Procedures

To preserve vitamin C during frying, start by cutting vegetables into uniform, bite-size pieces to speed up frying time. Preheat your skillet or wok over high heat, then add vegetables in order of cooking time. Add broccoli, carrots, cauliflower, celery and onions first, as these take the longest to cook, about 4 minutes. Next, add cabbage, green beans and red or green bell peppers, and continue frying for another minute. At this point, reduce heat to medium to stop frying, add 2 to 3 tsp. of soy sauce and finish cooking vegetables via steaming.

Benefits

Although heat generally works to degrade vitamin C, it can also help activate or release certain types of antioxidants, including lycopene and beta carotene, from foods such as tomatoes, carrots and sweet potatoes. Antioxidants are important in controlling free radicals, or damaged molecules that occur during metabolism or because of lifestyle factors such as smoking. Free radicals not only contribute to the aging process but may also increase your chance of developing cancer, heart disease and arthritis. Foods especially high in antioxidants include spinach, carrots, cabbage and peppers.

Requirements

Vitamin C requirements increase with age. Gender and lifestyle, however, also play a role. Adolescent girls age 14 to 18 years require 65 mg of vitamin C per day, while boys of the same age require 75 mg. Females age 19 and over require 75 mg of vitamin C per day, and males require 95 mg each day. Regardless of age, if you smoke or live or work in an environment where you consistently experience secondhand smoke, you need an extra 35 mg of vitamin C every day.