Arabinoxylan and AXOS
Cereal-derived arabinoxylan fibres and their shorter-chain oligosaccharides, with distinct hydration, viscosity and formulation profiles.
Ingredient overview
Arabinoxylans are plant cell-wall polysaccharides built from a xylose backbone with arabinose side groups. They occur in cereal tissues, including bran and endosperm cell walls. Extraction separates arabinoxylan-rich fractions from the surrounding grain matrix.
Arabinoxylan oligosaccharides, or AXOS, are shorter fragments produced through controlled breakdown of arabinoxylan. The distinction is functional: longer soluble chains contribute more strongly to solution viscosity, while shorter fragments generally have a lower thickening effect. The family therefore spans structural cereal fibres and more readily soluble oligosaccharide preparations.
Functional characteristics
| Characteristic | Technical profile |
|---|---|
| Molecular structure | Chain length and arabinose substitution influence solubility and chain interactions. |
| Water behaviour | Preparations range from water-unextractable material to soluble extracts and oligosaccharides. |
| Viscosity | Soluble longer-chain fractions contribute more viscosity than extensively hydrolysed fractions at comparable conditions. |
| Matrix contribution | Residual cereal proteins, starch and insoluble material influence colour and dispersion. |
| Processing response | Enzymatic cleavage changes molecular size and therefore functional behaviour. |
Applications
| Application | Ingredient role | Contribution to the product |
|---|---|---|
| Bread and cereal products | Cereal-derived fibre enrichment | Changes to dough water distribution and consistency. |
| Nutrition powders | Inclusion of soluble AX or AXOS fractions | Fibre delivery within a reconstituted formulation. |
| Bars | Fibre-rich cereal solids or soluble fractions | Different contributions to the dry matrix and binder phase. |
| Beverage formulations | Soluble, lower-viscosity fractions | Dissolved fibre with a profile governed by extraction and hydrolysis. |
Formulation behaviour
In dough systems, arabinoxylan shares the water phase with starch and proteins. Water-extractable and water-unextractable fractions behave differently: one contributes dissolved polymer, while the other remains part of a hydrated particulate matrix. Their balance affects dough consistency and crumb development.
Xylanase activity changes the distribution of molecular sizes during processing. Hydrolysis can first release soluble material and then shorten it further. The effect on viscosity therefore reflects both solubilisation and chain breakdown. AXOS preparations already contain shorter chains and occupy a different formulation position from high-molecular-weight arabinoxylan extracts.
Material forms
Material forms include cereal fibre fractions enriched in arabinoxylan, extracted soluble arabinoxylan and hydrolysed AXOS preparations. These names describe different compositions rather than equivalent concentrations of one substance. Extraction route and purification determine how much of the original cereal matrix remains alongside the target carbohydrate.
Comparison with related ingredients
XOS consists of short xylose-based chains, while AXOS retains arabinose substitution on those chains. Oat and barley beta-glucans are glucose-based cereal polymers with a different linkage structure. Wheat fibre concentrates dominated by insoluble cellulose contribute particle structure rather than the same dissolved-polymer behaviour.