Study of grinding mechanisms of yellow pea grains: influence of roller mill settings on powder characteristics

Companies face challenges in transforming pulse grains into powders. The current practice of pulse millers remains largely empirical and scientific expertise in pulse grinding is required. This study investigates the impact of cylinder configuration, rotation speed and speed ratio settings on the properties of pea powder, using a laboratory roller mill. The aim is to provide a comprehensive description of the effects of the grinding process parameters on the granulometric characteristics, damaged starch content and hydration behavior of pea powders. The present study proposes an original approach to describe particle sizes distribution curves for pea powders, taking into account the systematic presence of 3 different particle populations of particles that differ in size and composition. Experimental design and response surface methodology were used to manage the approach and to analyze the results. Different pea powders of similar composition were produced by modifying the grinding conditions. The findings indicated that the use of splined cylinders improves the fragmentation mechanisms and the release of subcellular components, increasing the proportions of fine and very fine particles in pea powders. In addition, the contribution of particle populations on pea powder hydration behavior is dependent on the degree of hydration. • The griding of peas systematically generates the presence of specific particle populations within the powders. • The type of the cylinders used in roller milling is the main factor influencing the granulometric characteristics of pea powders. • The content of damaged starch in powders depends mainly on the speed ratio in a roller mill. • The use of splined cylinders in roller milling improves the fragmentation mechanisms and the release of cellular components. • Grinding conditions influence the hydration properties of pea powders.