ABSTRACT
Fructans have been dened as “any compound where one or more fructosylfructose linkages constitutes a majority of linkages … fructan is used to name molecules that have a majority of fructose residues, whatever the number is” (Roberfroid, 2005a). Fructans therefore represent a heterogeneous group, and as such, many different possible chemical entities exist. Fructans can vary with respect to the following (Roberfroid, 2005a):
Source-Plant, bacteria, and fungi• Chain composition-All fructose or mostly fructose• Linkages-2,1 and 2,6• Degree of polymerization (DP)—Plant fructans do not exceed DP of 200; however, • bacterial fructans can have a DP as high as 100,000 Architecture-Linear, branched, or cyclic• Functionality-Physiology and food science•
Because of the heterogeneity of the fructan family, subclass classications have evolved with their own set of chemical and physiological properties. Figure 2.1 represents different classes of linear fructans, categorized according to chain length. The subclass called inulin represents a higher-molecular-weight group, with DP < 200. In contrast, the subclass called oligofructose has a lower molecular weight, with DP < 10 (Roberfroid, 2005a). The oligofructose subgroup can be further subdivided into the group called short-chain fructo-oligosaccharides (scFOS).
