Which degree of heat would destroy vitamin c in any food?

Answer 1

Normally, boiling water at 100°C is not hot enough to cause any significant destruction of the Vitamin C, which only decomposes at 190°C. However, pressure cooking, roasting, frying and grilling food is more likely to reach the decomposition temperature of vitamin C. Longer cooking times also add to this effect, as will copper food vessels, which catalyse the decomposition.

Answer 2

I think when you fry the food it lose vital amines or they turn toxic and change form as frying requires more than 100 degree centigrade. In steamed food it will be intact almost. Don't throw water left out after steaming vegetables. that is the essence for consuming vita amines. Eating raw food is also not recommended.