Common potatoes are sweet potatoes (also known as sweet potatoes, sweet potatoes, sweet potatoes, sweet potatoes and so on. ), potatoes (also known as potatoes, potatoes) and cassava (also known as tree potatoes and wood sweet potatoes). Potatoes are rich in starch. Besides cassava, potatoes and sweet potatoes are also rich in vitamins and minerals. Potato contains starch 17%, and is also rich in vitamin C and minerals, which can be used as both staple food and vegetables. The protein content of sweet potato is generally 1.5%, and the carbohydrate content is as high as 25%. The content of carotene, vitamin C and nicotinic acid in sweet potato is higher than that in cereals. Sweet potatoes are also rich in mucin, and some sweet potatoes (such as purple sweet potatoes) contain anthocyanins, which can protect the elasticity of human cardiovascular wall and improve human immunity. Sweet potato leaves have become vegetables on the dining table, and the contents of protein, fat, sugar, calcium, phosphorus and iron are higher than those of some leafy vegetables. Cassava contains more starch, but protein and other nutrients are low, so it is an excellent raw material for starch production. The starch content in dried potato can reach about 80%, while the protein content is only about 5% and the fat content is only 0.5%.