In addition to anticancer components, sweet potato skin also contains a lot of alkaloids, which will cause gastrointestinal discomfort if eaten too much. The sweet potato skin with brown and dark brown spots is infected by "black spot pathogen", which can produce "sweet potato ketone" and "sweet potato ketone alcohol", which will damage the liver and cause poisoning.
Medicinal efficacy
According to the ancient documents such as Compendium of Materia Medica and Addendum to Compendium of Materia Medica, sweet potato has the effects of "tonifying deficiency and benefiting qi, strengthening spleen and stomach, and strengthening kidney yin", which makes people "live longer and have fewer diseases" and also "tonify the middle energizer, promote blood circulation, warm the stomach and nourish the five internal organs". The Manual of Sweet Potato says that it has six medicinal values: treating dysentery and diarrhea; Treat wine accumulation and heat diarrhea; Treating damp-heat jaundice; Treating nocturnal emission with white turbidity; Treating blood deficiency and menstrual disorder; Treat infantile malnutrition. It can be seen that sweet potato is not only a healthy food, but also a good medicine for treating diseases.
1. Nourish liver and kidney and help the body recover. Sweet potato can improve the function of digestive organs, nourish liver and kidney, restore physical weakness, and effectively treat hepatitis and jaundice.
2. Sweet potato has anticancer effect. The most anticancer nutrients in the diet are β -carotene (the precursor of vitamin A), vitamin C and folic acid, and the contents of the three are rich in sweet potatoes. Rich lysine and carotene can promote the normal maturation of epithelial cells, inhibit the abnormal differentiation of epithelial cells, eliminate carcinogenic oxygen free radicals, prevent carcinogens from combining with protein in the nucleus, and promote the enhancement of human immunity.
3. Sweet potato is good for the heart. Sweet potato is rich in potassium, beta-carotene, folic acid, vitamin C and vitamin B6, all of which help to prevent cardiovascular diseases. Potassium contributes to the balance of liquid and electrolyte in human cells and maintains normal blood pressure and heart function; β -carotene and vitamin C have the effects of anti-fat oxidation and prevention of atherosclerosis. Folic acid and vitamin B6 are helpful to reduce the content of homocysteine in blood, avoid damaging arterial blood vessels and eliminate the risk factors of cardiovascular diseases.
4. laxatives. Sweet potato contains a lot of cellulose and pectin that are not easily destroyed by digestive enzymes, which can stimulate the secretion of digestive juice and gastrointestinal peristalsis, thus playing a laxative role.
5. Enhance resistance, promote sexual desire and delay aging. Sweet potato contains vitamins C and E with special properties, that is, only vitamins C and E contained in sweet potato will have special properties and will not be destroyed at high temperature. Among them, vitamin C can obviously enhance the body's resistance to several viruses such as colds, while vitamin E can promote sexual desire and delay aging.
Lose weight. Sweet potato is also an ideal diet food. It contains less calories, only one-third of the calories produced by the same weight of rice, and contains no fat. Therefore, eating sweet potatoes often is beneficial to human health and has a certain weight loss effect.
Edible method
There are many ways to eat sweet potatoes, which can be boiled directly or made into dry food. The most common ways to eat sweet potatoes are steamed sweet potatoes, baked sweet potatoes and sweet potato porridge.
Dissolving sweet potato powder in milk or soybean milk is a way suitable for the elderly and children.
It is also important to eat sweet potatoes correctly. First, it should be steamed and cooked thoroughly, because the cell membrane of starch in sweet potato is difficult to digest without being destroyed by high temperature. Moreover, the "gasification enzyme" in sweet potato will not be destroyed by high temperature, and it will cause discomfort after eating. Second, sweet potatoes should be eaten together with the skin, because the skin of sweet potatoes contains enzymes that decompose starch, which can make sweet potatoes easier to digest, thus reducing the generation of waste gas and alleviating the discomfort caused by eating sweet potatoes, such as abdominal distension, heartburn, burping, pantothenic acid and exhaust.
Edible taboo
1. Eating cold sweet potatoes is easy to cause gastrointestinal discomfort. Sweet potato produces acid in the stomach, and patients with gastric ulcer and hyperacidity should not eat it.
2. Rotten sweet potatoes (sweet potatoes with dark spots) and germinated sweet potatoes can make people toxic and inedible. If the storage time of sweet potato is too long, or the storage place is too wet, the skin will appear brown, black spots or dry depressions, and the potato heart will become hard and bitter, indicating that sweet potato has been attacked by black spot disease.
This toxic substance is toxic to the liver, and even if it is boiled, steamed or roasted, it cannot destroy this toxin. Therefore, if you eat raw or cooked sweet potato with black spot or black spot disease, it will cause sweet potato food poisoning.
Poisoning symptoms mostly occur within a few hours to a few days after eating sweet potatoes. The main symptoms are stomach upset, nausea, vomiting, abdominal pain and diarrhea. In severe cases, there may be high fever, headache, asthma, hematemesis, unconsciousness, convulsions and coma, and even death.
3. The rhizome of sweet potato contains a lot of starch, which can be processed into vermicelli, but alum is often added in the production process. If you eat too much, aluminum will accumulate in your body, which is not good for your health.
4. Excessive or unreasonable consumption of sweet potato will cause abdominal distension, heartburn, pantothenic acid and stomachache. This is because sweet potato contains "gasification enzyme", but as long as you don't eat too much at a time, you can eat it with rice flour, pickles or soup to avoid this phenomenon.
5. Those diagnosed by TCM as dampness blocking the spleen and stomach, qi stagnation and blood stasis should be carefully eaten.