Abstract: By comparing the nutrient contents of broccoli and purple potato after cooking, the effects of different cooking methods on food nutrients were studied. The study found that under the best technological conditions of different cooking methods, open flame steamer and microwave have the highest retention of vitamin C and polyphenols in broccoli, followed by electric steam box, stir fry and poaching, the worst is baking; Steamers, electric steamers and microwaves have the highest retention of polyphenols and total anthocyanins in purple sweet potatoes, followed by baking and frying, and the worst is poaching. In summary, the lower temperature electric steamer, open flame steamer cooking method and shorter time microwave cooking method can retain nutrients in food, which provides theoretical basis and practical support for the healthy cooking of household appliances.

Key words: Cooking methods, Food, Nutrients