Explain the Fructo Oligosaccharides (FOS)?

FOS are polymers of fructose, usually attached to an initial glucose molecule. The total number of fructose units range from 2 to 8 and are linked by (2 → 1) linkages. They are naturally present in certain foods like onion, banana, leak, wheat, garlic, chicory root and artichoke. FOS can also be obtained commercially by an enzymatic action on sucrose. Like other non-digestible oligosaccharides, they resist hydrolysis by human digestive enzymes.

They enter the cecum without significant changes, where they are fermented by the resident microflora into short chain fatty acids, lactic acid, carbon dioxide and hydrogen. They enhance the growth of intestinal flora especially growth of bifidobacteria. Thus, like dietary fibre and resistant starch they exert many health benefits. FOS are low-energy bulk ingredients that have a taste profile similar to that of sucrose. Also their physical and chemical properties match precisely those of sucrose. Thus, they can replace sucrose and have been successfully used in food industry, especially bakery industry.