Air classification of flour.

摘要

Air-classification of flours with a particle size of 5-160 mu m is best performed on flours that are remilled at least once to give a remilled flour with an x-50 of less than 40 mu m. The remilling, preferably being carried out by using a jet air mill, a Retsch mill or an extruder. In this way a higher yield of a fraction, enriched in protein (up to 40% protein) and a higher yield of a starch fraction with a low protein content (even less than 3 wt%) can be obtained. Wetting of the remilled flour, prior to remilling and drying of the remilled flour, prior to air classification lead to improved results.