According to records, sweet potato has a variety of health effects. The Compendium of Materia Medica describes that sweet potato has the effect of "replenishing deficiency, benefiting vitality, strengthening the spleen and stomach, and strengthening kidney yin". Modern scientific research also confirms that sweet potatoes can help reduce weight, laxative, inhibit cholesterol, etc., thus helping to health and delay aging.
The purple sweet potato is a new variety of sweet potato with purple-black skin and purple-red flesh, which was introduced from abroad in the 1980s. At present, China's purple potato varieties have been introduced from abroad, there are also domestic hybrid cultivation. On the market, the price of purple potatoes is higher than ordinary sweet potatoes, we analyze whether it is value for money?
Purple potato basically contains sweet potato all the nutrients, rich in protein, dietary fiber, vitamins and trace elements. After Japan bred purple potato, compared the difference between purple potato and common sweet potato, found that lysine, copper, manganese, potassium, zinc in purple potato is 3-5 times of common sweet potato, especially iodine and selenium content, is 20 times of common varieties.
According to the analysis of the U.S. Agricultural Products Center, the nutritional value of purple potatoes produced in the U.S. mainland is also much higher than that of other potatoes, in which lysine, potassium, manganese, zinc is higher than that of the general sweet potatoes by a factor of 5-8, while the content of iodine and selenium is higher than that of the other sweet potatoes by a factor of 20 or more. For the rice, noodle-based diet of our residents, purple potatoes in the rich lysine can be supplemented rice, noodle lysine in the lack of, therefore, purple potatoes and rice, noodle with food can achieve the role of protein complementary.
The reason why purple potatoes have a purplish red color is because they are rich in anthocyanins, which are not comparable to ordinary sweet potatoes. Anthocyanin is also a powerful antioxidant, and its ability to scavenge free radicals is stronger than vitamin C and vitamin E. It can not only scavenge excessive free radicals through the indirect effect of increasing the activity of animal antioxidant enzymes, but its phenolic hydrocarbon group can also release electrons to replenish free radicals through redox, thus scavenging free radicals directly.
The benefits of anthocyanins go beyond that, as more and more studies have shown that anthocyanins in purple potatoes can help constrain the development of certain cancers and serious vascular diseases and reduce their incidence. In addition, anthocyanins have the ability to enhance memory, prevent aging, prevent diabetes and obesity, and improve the optic nerve. Another thing that makes purple potatoes particularly superior to regular sweet potatoes is that they are rich in selenium. Selenium is a component of glutathione peroxidase, which has a special contribution to scavenging free radicals in the body; selenium is also an important contributor to the prevention of and fight against cancer.
From the nutritional composition, purple potatoes are indeed richer than ordinary sweet potatoes, but compared to the market price is much higher than ordinary sweet potatoes, its cost-effective or debatable, after all, our body needs nutrients is not just eat a certain kind of food to supplement. And purple potatoes and ordinary sweet potatoes, containing oxidative enzymes easily in the human gastrointestinal tract to produce a large amount of carbon dioxide gas, so that people bloating, uh, gas, once a large number of food will also stimulate a large amount of secretion of gastric acid and thus produce a "heartburn" feeling. Therefore, even if the purple potatoes are nutritious can not eat too much!
Author introduction: Ma Guansheng, Ph.D., Professor, Department of Nutrition and Food Hygiene, School of Public **** Health, Peking University, Ph.D. Supervisor, Chief Science Communication Specialist of the China Association for Science and Technology, has been engaged in nutrition and health research for 27 years. He is currently a member of the National Advisory Committee on Food and Nutrition, an expert on women and children in the Working Committee on Women and Children under the State Council, a member of the Expert Committee of the National Nutrition Improvement Program for Rural Compulsory Education Students, the head of the Expert Group of the Pilot Project on Nutrition Improvement for Children in Poverty-stricken Areas, and the deputy director of the Chinese Nutrition Society. In 2012, he was awarded the "Science Communication Person of the Year" by the first Science Communication Award Ceremony, the "Healthy China 2012 Top Ten People of the Year Award" by the People's Daily Health Times, and the first prize of the nutrition popularization work of the Chinese Nutrition Society for the years from 2008 to 2010.
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