Fresh yam is rich in water, about 80%. In addition, yam is rich in carbohydrates, about 12%, and less than 2% of protein, trace vitamins and minerals, such as carotene, vitamin C, vitamin E, nicotinic acid and other minerals, as well as calcium, iron, phosphorus, potassium, zinc and other minerals, among which potassium content is high. There are many varieties of yam, and the nutritional components are slightly different, and the nutritional components in different producing areas are also slightly different.