Jet milling conditions impact on wheat flour particle size

Abstract

Jet milling is an emerging, size reduction technique for producing superfine powders in one-step process. The aim of the present article was the research about the efficiency of jet milling process on the wheat flour micronization. A mathematical power model is proposed to describe the effect of feed rate and air pressure on the final flour particle size and energy consumption. A sample of soft wheat flour was grοund using a jet mill at different feed rate (FR) and air pressure (AP) (2–18 kg/h at 4 and 8 bar, respectively). Τhe decrease in FR and further increase in AP resulted in finer flour reaching the lowest value of 10.62 μm. The energy-size reduction equations revealed that the particle size, as well as the energy consumption, were mainly influenced by FR and to a lower extent by AP. FR of 70% was the limit for energy efficient grinding. Α short grinding at high FR and AP is also preferable as damaged starch content was lower.