Description of a micromill with instrumentation for measuring grinding characteristics of wheat grain

A new method for characterizing the grinding characteristics of wheat grain is described. A micromill was designed for this purpose and equipped with on-line torque transducers to obtain accurate measurements of mechanical en ergy consumption during milling. This micromill can be used for testing the milling performance of small quantities of grain (100 g). It can distingui sh between different types of wheat grain (soft wheat, hard wheat, durum wh eat) on the basis of total specific energy during milling. Wheat characteri zation can be enhanced by taking particle sizes of the milled products into account. A milling index based on energy consumption and particle size red uction was developed to characterize wheat behavior during milling. This in dex had a high discriminatory potential, ranging from 100 kJ/kg for soft wh eat flour to 600 kJ/kg for durum wheat flour This micromill directly measur es the grinding resistance of wheat kernels as a function of both the kerne l hardness and vitreousness, contrary to standard kernel hardness measureme nts obtained by particle size index and near-infrared reflectance analysis techniques that only reflect the fracture mode (fine particle reduction pot ential).