Baked sweet potatoes are considered to be carcinogenic, on the one hand, because baking is high-temperature cooking, and the general temperature can reach 160℃- 170℃, and the charcoal baking temperature can reach 350℃. Starch food heated above 140℃ will produce acrylamide, protein paste will produce heterocyclic amines, and fat will produce carcinogens such as benzopyrene at high temperature. However, not all baked goods are unhealthy. Although acrylamide is a carcinogen, it is a class 2A carcinogen and a potential carcinogen. The evidence of carcinogenesis to animals is clear, but the evidence of carcinogenesis to people is limited, so eating it does not cause cancer. And sweet potatoes have almost no fat, and there are few in protein. Most vendors bake sweet potatoes indirectly with charcoal fire, and the temperature they can reach is limited. Normal baking of sweet potato is not easy to produce a large number of heterocyclic amines and benzopyrene carcinogens.
On the other hand, some people think that the brown and black spots on the surface of baked sweet potatoes will cause cancer. This black spot is because Maillard reaction will occur during sweet potato baking, which will produce harmful substances, such as reducing ketones and aldehydes. However, Maillard reaction only occurs on the surface of food. Sweet potato is baked with skin, and harmful substances are concentrated in the skin. Just peel off the skin before eating. Compared with the roasted part, there are dry black spots, and the surface of roasted sweet potato has brown sticky substances. This is because the sugar in sweet potato is concentrated at high temperature, resulting in caramelization reaction. The higher the temperature, the darker the color, and finally it turns black and carbonized. It is not a carcinogen of baked sweet potatoes and has no toxicity.