Special flours differ from normal flour, which consists solely of wheat, either due to their composition or their intended use. Powdery products with a special character are also included in the area of bakery products.
These can be either
- Micronized flours,
- Flours with particular finenesses with a steep particle size distribution,
- Specially dried flours and/or powders with a reduction of the residual moisture in the product to below 5 %,
- Flours or powders with an improved microbiological stability or
- Flours with modified protein structures.
As well as dietary fiber, minerals and digestible carbohydrates, plant-based materials used for feeding humans or animals also contain proteins. The aim of the process of protein shifting is to gain a protein-rich fraction in which the amount of protein is considerably higher than in the original product by grinding and separating.
In this process the large difference between the size of the protein- and starch particles (starch: 30 µm to 40 µm, protein < 17 µm) is exploited, as well as the fact that starch can only be ground by means of dry impact grinding with a high energy input.
Using the NETZSCH classifier mill type CSM to fine-grind commercial wheat flour, protein- and starch particles in the flour are separated to a large degree. As the starch particles are difficult to grind due to their flexible structure, the protein particles are ground significantly more finely. By subsequent classifying with the NETZSCH Fine Classifier CFS or the NETZSCH High-Efficiency Fine Classifier CFS HD-S or the InlineStar, fractions with different protein- and starch contents can be obtained.