Efficient protein separation
Combined milling and sieving of raw materials may be an energy efficient alternative for air classification to separate animal feed ingredients into different fractions. The Buhler MLU-202 laboratory mill - a roller mill with six different passages - offers this possibility. After milling, the material is sieved to obtain fractions with varying particle sizes. Fractions can be recycled into the milling process to obtain finer flour fractions.
Raw material fractions
Fractionating raw materials yields components (bran, fodder meal, flours) with different particle sizes and protein contents. These fractions enable the nutritionist to formulate diets fulfilling specific needs with respect to particle size and protein content. Fractionated raw materials increase the flexibility in feed formulation.
Ilse Klein Wolterink, a student at Van Hall Larenstein University of Applied Sciences, investigated the perspectives during her internship at Zetadec.
Ilse tested the Buhler lab mill with corn, wheat, field beans, barley, sunflower meal and rapeseed meal. She found distinct differences in weight distribution of the fractions between the materials tested. Both raw material and roller settings had a significant effect on energy use (SME, KWh/ton). In this study, rapeseed meal and wheat had the lowest energy consumption in both roller settings.
Protein
The protein content varied between fractions: For both field beans and rapeseed meal, the bran and fodder meal did not have a high concentration of protein compared to the other fractions. In the wheat samples, however, the highest protein content was found in the bran and fodder meal fractions. Ilse concluded that it is possible to obtain raw material fractions with different particle sizes and protein contents, by using the Buhler MLU-202 laboratory mill.
the highest achieved protein separation efficiency was 0.38, and this efficiency may be further improved by optimization of the settings of the Buhler mill for various raw materials, and for the desired fractions.