NSP content differs from a vegetal to another. Wheat contains 9.5% of NSP. Among those NSP, arabinoxylans represent 63%. Corn contains in average between 8% and 9% of NSP. Among those NSP, arabinoxylans represent almost 50%.
|
|
For wheat, NSP are mainly located in the cell walls of endosperm and pericarp.
In the wheat endosperm, cell walls are mainly formed of Arabinoxylans and Mixed-Beta-Glucan. Both are partly water soluble and are the origin of viscosity of water extract. As arabinoxylan is the main component, it has been identified as the main source of problems in food and feed applications.
In the wheat pericarp, the main polysaccharides are also arabinoxylans but they are more complex and thus are named heteroxylans.
The content in cellulose is higher and the cell walls are also lignified, inducing the hydrophobic feature of these walls.
In wheat, 30% of the arabinoxylansare soluble in water. Wheat NSP mostly possess mono-substitutions of xylose. The arabinose:xylose (A:X) ratio is lower than 1.
In corn, arabinoxylans are highly substituted with complex ramifications. The A:X ratio is more than 1.
Due to its structural complexity, arabinoxylans require a broad range of enzyme activities to be completely degraded, each enzyme targeting a specific link.
