title: Effect of surface composition on the flowability of industrial spray-dried dairy powders.
abstract: The surface composition of four industrial spray-dried dairy powders (skim milk powder, whole milk powder, cream powder and whey protein concentrate) was estimated by electron spectroscopy for chemical analysis (ESCA), and its influence on powder flowability was studied. It was found that skim milk powder flows well compared to the other powders because the surface is made of lactose and protein with a small amount of fat, whereas the high surface fat composition inhibits the flow of whole milk, cream and whey protein powders. However, the poor flowability of the powders with high surface fat coverage was drastically improved by removal of fat present on the surface through a brief wash with petroleum ether. The results obtained indicate that, although there are several parameters including particle size, which influence the flowability of powders, the flowability of powders is strongly influenced by the surface composition of powders, particularly for fat-containing powders.
authors.affiliation: Food and Bioproducts Processing Cluster, Department of Chemical & Materials Engineering, The University of Auckland, Private Bag 92019, Auckland, New Zealand.
authors.forename: Esther H-J
authors.initials: EH
authors.lastname: Kim
authors.forename: Xiao Dong
authors.initials: XD
authors.lastname: Chen
authors.forename: David
authors.initials: D
authors.lastname: Pearce
mesh_terms: D003611:Dairy Products; D005223:Fats; D007221:Industry; D011208:Powders; D013057:Spectrum Analysis / Q000379:methods; D013499:Surface Properties
chemical_list: D005223:Fats; D011208:Powders