Xylanases in wheat separation

Hemicellulases used in the wheat separation process have resulted in better separation, purer fractions, increased plant capacity, reduced processing time etc. In order to further improve enzyme-treatment in the wheat separation process, monocomponent xylanases were evaluated. A laboratory viscosity model has been set up to evaluate the xylanases. The model showed good correlation (for a commercial hemicellulase preparation used for wheat separation) between viscosity of the wheat flour slurry and the sludge/supernatant ratio after centrifugation of the slurry. A xylanase (Novozyme 867) with excellent performance in the wheat separation process has been found. The xylanase has high activity towards soluble arabinoxylan and gives a rapid viscosity reduction of wheat flour slurries. The enzyme also has a moderate activity towards insoluble arabinoxylan, but due to the low molecular weight of the solubilized material this was not was found to contribute negatively to the enzymes' performance. The pH and temperature conditions in the wheat separation process were well within the active range of the enzyme. A pilot plant experiment showed improved yield of gluten and A-starch, with no apparent negative effect on the gluten quality.