Fructooligosaccharides (FOS) is a common name for fructose oligomers in which fructosyl units (F) are bound at the Beta-(2-1)position of sucrose(GF). Its structure can be expressed as GFn, (n=1-9). FOS usually is a mixture mainly composed of kestose(GF2), nystose(GF3) and 1F-fructofuran osylnystose(GF4) .
Fructooligosaccharides naturally presents in quantities of plants and fruits, such as Jerusalem artichoke, chicory, asparagus, onions, garlic, banana and bee honey.
The commercial FOS products can be available by extracting from plant directly or by enzymetic means. Sanhao™； FOS is produced by leading enzymetic method.