Dietary fiber (DF) is the sum of nonstarch polysaccharides and lignins in food. DF is a kind of essential carbohydrate which is not digested easily by digestive enzyme and beneficial to health. Because intake of dietary fiber may be associated with a number of diseases such as constipation, obesity, high blood fat, diabetes etc, it is called seventh nutrient by many nutritionists.
Dietary fiber includes soluble dietary fiber and insoluble dietary fiber. Health protection function of s...