Food powder characteristics important to nonelectrostatic and electrostatic coating and dustiness

Corn starch, maltodextrin, powdered sugar, cellulose, soy flour, corn flour, wheat flour, cocoa, nonfat dry milk, and salt were coated at 0, 19, and 25 kV using corona particle charging. Particle size, powder charge, density, and flow characteristics (flow index, cohesiveness, angle of repose, Hausner ratio) were correlated to coating efficiency and dustiness. Nonelectrostatic coating efficiency improved with large particle size, small powder charge, and low cohesiveness. Electrostatic coating at 25 kV improved with small particle size, low flow index, and high particle density. Dustiness decreased with large particle size-particle density interaction, high flow index, and low cohesiveness. Electrostatics improved coating efficiency 68% and decreased dustiness 65% (excluding largest salt).