Effect of some chelating agents, emulsifiers and salts on functional characteristics of skim milk powder

Physical and functional properties of the milk powder play an important role in the formulation of various food products. In this study, the effects of adding Lecithin (1%) and Tween 80 (0.1%) as emulsifiers, di sodium EDTA and sodium citrate dihydrat (SCD) each one 5 mM as chelating agents, NaCl (0.08%) and CaCl2 (0.01%) as salts in improving Physical and functional characteristics of skim milk powder  (thermal stability, bulk density and particle size distribution) were investigated. These compounds were added to skim milk prior to spray drying. The results showed that chelating agents and salts had different effects on the heat stability of milk powders when compared with the emulsifiers. The heat stability of milk powder enhanced when SCD and NaCl used simultaneously, while it was reduced significantly, with using EDTA and NaCl and consequently, the higher heat stability was found for powders produced by tween80, SCD and NaCl.  The best particle size distribution and bulk density were observed for samples treated  with Tween 80 and the milk powder produced by adding of Tween 80, EDTA and CaCl2 led to better particle size distribution. In general, the results of this study showed that simultaneous use of Tween 80, SCD and NaCl resulted in improved functional characteristics of non-fat milk powder.