Fructooligosaccharides are produced either by enzymatic transfructosylation of sucrose using fungal β-fructosidase, or by partial hydrolysis of inulin from chicory root.
The resulting product contains kestose (GF2), nystose (GF3) and fructofuranosyl-nystose (GF4) at ≥95% purity. FOS provides 30–60% sucrose sweetness with only 2 kcal/g, zero glycaemic response, and clinically proven prebiotic effect.