ABSTRACT
Inulin is a polymer of fructans with a degree of polymerization of 2 to 60. It consists principally of linear chains of fructosyl units linked by β(2-1) bonds ended by a glucosyl unit. Due to this structure, both inulin and oligofructose resist hydrolysis by human digestive enzymes but are fermented by the caecocolonic microflora. Thus, they have quite the same physiological action as dietary fiber. Finally, as the term dietary fiber doesn’t cover a single entity, in the point of view of food analysis, it is more practical to analyze inulin or oligofructose with a specific method which involves enzymic hydrolysis followed by high performance liquid chromatography (HPLC) (done by CERIA, Belgium) or by high performance anion exchange chromatography (HPAEC) (done by INRA, France). In conclusion, a modification of the AOAC method is proposed to include these fructans in the determination of the soluble dietary fiber fraction.
