XYLANASES IN WHEAT SEPARATION

Hemicellulases used in the wheat separation process have resulted in b etter separation, purer fractions, increased plant capacity, reduced p rocessing time etc. In order to further improve enzyme-treatment in th e 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 prep aration used for wheat separation) between viscosity of the wheat flou r slurry and the sludge/supernatant ratio after centrifugation of the slurry. A xylanase (Novozyme 867) with excellent performance in the wh eat 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 sol ubilized material this was not was found to contribute negatively to t he enzymes' performance. The pH and temperature conditions in the whea t 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.