With the improvement of people's living standard, the application of functional food additives is more and more extensive. fructooligosaccharides has been widely used in food and other fields because of its excellent and active physiology and function of benefiting health . As a health food ingredient, it can be added to almost all beverages and foods with sweet taste, thus improving the value of the original food. There are many patents that report the application of fructooligosaccharides in food and medicine, such as Salmonella inhibitors, low calorie foods and beverages, anemia improvers, etc.

The results also showed that fructooligosaccharide has totally different digestive process and metabolic pathway from common sugar, and has many physiological functions.

Ⅰ. Digestive and metabolic characteristics

After fructooligosaccharides enters the human digestive system through the mouth, it cannot be decomposed by various digestive enzymes, so it can not be absorbed through the stomach and small intestine, and goes into the large intestine without being affected. Fructooligosaccharides can be selected and used by bifidobacteria and lactobacillus in the large intestine, which makes them reproduce rapidly and in large quantities.

Fructooligosaccharides has the following two characteristics in the digestion process:

1. It is a kind of sugar which is hard to digest and has the same characteristics as water-soluble dietary fiber.

2. In the large intestine, it can promote the reproduction and growth of a few beneficial bacteria, such as bifidobacteria, and significantly inhibit the reproduction of harmful bacteria, and realize the biphasic regulation of human micro ecology.

Ⅱ. Physiological function

Fructooligosaccharides, as a representative of prebiotics, has the physiological function of "whole intestine" which can regulate the microecological balance in two phases.

1. Improve the function of intestinal bacterial flora

2. Low sweetness and low heat

3. Lower blood lipid

4. Smooth intestines and relax bowel

5. Enhance immunity

6. Anti caries

7. Promote mineral absorption

Fructooligosaccharides have functional properties that are beneficial to human body as described above. As a health food or food ingredient, the safety of human body is also a key factor that it can be accepted and widely used.