Sweet potato flour is made from dried sweet potatoes and crushed into powder. It is also called sweet potato starch. Sweet potato starch is one of the main products of sweet potato processing. Sweet potato starch can be divided into two types: fresh sweet potato and dried sweet potato. However, because the quality of fresh sweet potato starch is better than that of dried sweet potato starch, fresh potato starch is mostly processed. Since cutting sweet potatoes is troublesome, few people use dried sweet potatoes to process starch.

The sweet potato in sweet potato starch contains a variety of nutrients needed by the human body. Each 500 grams of sweet potato can produce approximately 635 kcal of heat energy, containing 11.5 grams of protein (protein food), 14.5 grams of sugar, 1 gram of fat, 100 mg of phosphorus, 90 mg of calcium, 2 grams of iron (iron food), and 0.5 mg of carotene. It also contains vitamins B1, B2, C, niacin, linoleic acid, etc. Among them, the contents of vitamin B1 and B2 are 6 times and 3 times higher than that of rice respectively. In particular, sweet potatoes are rich in lysine, while rice and flour lack lysine. But many people haven't realized it yet.