Impact of spray‐drying conditions on flow properties of skim dromedary and cow's milk powders using the FT4 powder rheometer

Two sets of spray-drying conditions were applied on skim dromedary and cow's milks to determine the effect of air outlet temperature (75 and 85°C) and milk type on proximate composition, particle-size distribution, and flow properties of spray-dried powders. The particle-size distribution was more influenced by the chemical composition than the spray-drying conditions. The air outlet temperature impacted on dromedary milk powder flowability, as the basic flowability energy was significantly increased from 620 to 1,018 mJ when the outlet air temperature was increased from 75 to 85°C, respectively. Specific energy, associated with the flow performance of a powder in a low-stress environment, was significantly higher for dromedary milk powder at the higher air outlet temperature. However, spray-drying conditions had no significant effect on specific energy values of cow's milk powder. Dromedary milk powders had better flow behavior than cow's milk powders. Shear tests confirmed that powders spray-dried at 75°C had better flowability than powders spray-dried at 85°C.