Potato is the fourth largest food crop in the world and has been planted in China for more than 400 years. Although the Netherlands, Britain and other western countries have long regarded potato as one of the four staple foods, and its various benefits are widely known, the road to becoming a staple food in China has been slow. Except for some places in the west of China, the dining table of China people has been occupied by three staple foods: rice, wheat and corn. Although whole grains and sweet potatoes are also staple foods, potatoes have long been classified as vegetables and non-staple foods. 20 1 may/February1day, the No.1 document of the Central Committee clearly put forward that potato should be listed as the fourth staple crop besides rice, wheat and corn.
Potatoes (potatoes) have high nutritional value in protein. Protein content in potato tuber is about 2%, and protein content in dried potato is 8% ~ 9%. According to research, the protein nutritional value of potatoes is very high, its quality is equivalent to the protein of eggs, and it is easy to digest and absorb, which is better than protein of other crops. Moreover, the protein of potato contains 18 kinds of amino acids, including various essential amino acids that cannot be synthesized by human body. A high evaluation of the nutritional value of potatoes is inseparable from the existence of high-quality protein and essential amino acids such as lysine, tryptophan, histidine, arginine, phenylalanine, valine, leucine, isoleucine and methionine.
1, potatoes have unique nutrition compared with other staple foods.
For a long time, people's impression of potatoes mostly stays in the impression that "high starch content is easy to lead to obesity". The data show that 100g fresh potatoes contain 17.2g carbohydrates, 100g steamed rice contains 25.9g carbohydrates, and 100g steamed bread contains 47g carbohydrates ... In fact, the carbohydrates in potatoes are lower than those in rice, steamed bread, bread and other foods. According to the same starch content, 1 kg of dry rice is equivalent to about 4 kg of potatoes; 1 kg of cooked rice is approximately equivalent to 1.5 kg of cooked potatoes.
In addition, the vitamins and minerals in potatoes are also well received by nutrition experts. Fan Zhihong, an associate professor in the Department of Nutrition and Food Safety, College of Food Science, China Agricultural University, said in his blog: "All kinds of potatoes not only contain vitamin C which is completely absent in cereals, but also are rich in various B vitamins which are insufficient in rice. For example, the content of vitamin C in potatoes is equivalent to that of tomatoes. Because of the protection of starch, the cooking loss of vitamin C is relatively small. "
2, potatoes as a staple food or have positive significance for controlling blood sugar and weight.
Whether obese or diabetic, controlling postprandial blood glucose fluctuation and inhibiting rapid and large insulin secretion are important factors to control weight and diabetes, and reasonable diet is an important means. Although both rice and potatoes contain starch, it is easy to cause blood sugar to rise after meals, but potatoes, as a staple food, have a slower rate of blood sugar rise than rice noodles. Domestic blood sugar test data prove that the blood sugar reaction of potatoes and sweet potatoes is higher than that of oats and buckwheat, but lower than that of rice, steamed bread and bread. This is because the dietary fiber and resistant starch contained in potatoes lead to slow digestion and slow rise of blood sugar, which makes it easier to control postprandial blood sugar. Coupled with the characteristics that potatoes are easy to be full and slow to digest, it is difficult for people to feel hungry, which can reduce their food intake and help them lose weight.
"If you can replace some potatoes such as potatoes, it will not only help prevent obesity, but also help control blood pressure and have no adverse effects on preventing diabetes. At the same time, the intake of various vitamins will be greatly improved, and there will be more fibers and minerals, which is really good for improving the nutritional quality of a day. "
3. Pay special attention to supplementing protein with potatoes as staple food.
Although potatoes have many advantages, from a nutritional point of view, they also have an irreparable disadvantage, that is, they almost do not contain protein. The data showed that each 100g steamed bread contained 7g protein, each 100g japonica rice contained 7g protein, and each 100g fresh potato contained 2g protein. Ma Guansheng, deputy director of the Institute of Nutrition and Food Safety of China Center for Disease Control and Prevention, pointed out: "Potatoes are rich in nutrition. Dietary Guidelines for Residents in China suggest increasing the intake of potatoes appropriately, about five times a week, with an intake of 50 ~ 100g each time. However, due to the low content of protein in potatoes, long-term excessive consumption by children will be detrimental to their growth and development. " Therefore, when potatoes are the staple food, it is necessary to increase protein's intake in a targeted way. Potatoes can be mixed with beans and rice as the staple food, or a small amount of high-quality animals such as lean meat, liver, fish and shellfish can be added every day. In addition, when you are not used to eating potatoes as the staple food, it is best not to change the staple food into whole potatoes immediately, especially in families with old people and children at home. You can gradually increase the proportion and frequency of potatoes as the staple food, while paying attention to maintaining a balanced diet.
Disadvantages of potatoes:
Solanine is contained in potato, and its toxic component is solanine (C45H73O 15N), also known as potato toxin, but its content is extremely low (0.005%-0.0 1%), which is not enough to cause poisoning. However, after potato germinates, the content of solanine in bud and bud eye can be as high as 0.3%-0.5%. Normal people can cause acute sprouting potato poisoning by eating 0.2-0.4 grams of solanine once.
Poisoning of sprouted potatoes occurred 2-4 hours after eating. The manifestations are as follows: first, there is itching or burning sensation in the throat, burning sensation or pain in the upper abdomen, and then there are symptoms of gastroenteritis such as nausea, vomiting and diarrhea; Those who are deeply poisoned may suffer from dehydration, electrolyte disorder and blood pressure drop due to severe vomiting and diarrhea; In addition, it is often accompanied by dizziness, headache and mild disturbance of consciousness. In severe cases, coma, convulsions, and finally death due to heart failure and respiratory center paralysis.
For potatoes with a little germination, go deep into the germination part and around the bud eye, then soak for more than half an hour, pour out the soaking water, add water and cook before eating. Because solanine is easy to decompose when it meets vinegar, you can add some vinegar when cooking to accelerate the destruction of solanine and become non-toxic.
Pregnant women often eat potatoes with high alkaloid content, which may lead to fetal malformation if accumulated in the body. Of course, there are considerable individual differences between people, and not everyone will be abnormal after eating potatoes. However, it is best for pregnant women not to eat or eat less potatoes, especially potatoes that have been stored and germinated for a long time, which is especially important for women in the early pregnancy.
The stems and leaves of potato plants are poisonous, and even the potato itself is poisonous. If you have carefully observed potatoes, you may find that some potatoes are slightly green, which is caused by the toxicity of glycoside alkaloids. In the past, there were also cases of death due to potato poisoning. Although few, most of them are due to drinking potato leaves or eating green potatoes. The fatal incident is not sudden, and the parties are often weak at first and fall into a coma after eating. Don't worry about the occasional green potato chips, but be sure to throw away the potatoes with green shoots or skins, don't cook them any more, and pay special attention not to give them to children.
Wild potatoes are highly toxic, and solanine poisoning can lead to headache, diarrhea, convulsions, coma and even death. However, the toxicity of common cultivated potatoes is very low, and there are few potato poisoning incidents. Generally, cultivated potatoes contain less than 0.2 mg/g of alkaloids, and generally more than 200 mg will lead to poisoning, which is equivalent to eating 1.4 kg of raw potatoes at one time. If potatoes are exposed to light during storage, they will turn green and toxic substances will increase; The purple eyes of germinated potatoes can also cause the accumulation of toxic substances, which is prone to poisoning incidents. Pay special attention when eating.
1. Poisoning cause
Potato (potato) can produce highly toxic alkaloid solanine after germination, which can cause poisoning after eating. The general content of Solanum nigrum in potato is 2 ~ 10 mg/ 100 g, and it can reach 35 ~ 40 mg/ 100 g after germination and skin turning green, which can cause poisoning. The buds and buds of Solanum nigrum are the most abundant. Serious poisoning can occur when 0.2~0.4g solanine is ingested. The main causes of poisoning of sprouted potatoes are due to improper storage, potato sprouting or partially turning black and green, solanine can not be removed or destroyed during cooking, and poisoning occurs after eating.
2. Poisoning symptoms
The incubation period is 10 minutes to several hours, and symptoms such as itchy tongue and throat, heartburn and gastroenteritis appear. Symptoms such as dilated pupils and tinnitus; Seriously ill people twitch, lose consciousness and even die.
3. Preventive measures
(1) Potatoes should be stored in a dry and cool place or irradiated to prevent germination.
(2) Those that germinate a lot or whose pulp turns black and green cannot be eaten. If there is not much germination, the buds and their parts can be removed, peeled, soaked in clear water for 30 ~ 60 min, and some vinegar can be added during cooking to destroy the residual toxins.