High pressure jet spray drying of condensed skim milk results in powders with enhanced interfacial properties

Condensed skim milk was processed through a continuous, custom-made high pressure jet spray dryer system (HPJ-SD) at 100–500 MPa. The resulting skim milk powders (SMPs) were evaluated for physiochemical and structural properties. The 500 MPa SMP exhibited increased particle density (1.48 g/cm³) compared to the ≤300 MPa SMP (1.33 g/cm³), but particle size analysis reflected no significant differences between these samples with D[4,3] values of 10.8 μ (100 SMP) and 12.2 μ (500 SMP). The 500 MPa SMP also had a reduced solubility and increased protein surface coverage compared to the 100 MPa SMP. The viscosity of the reconstituted HPJ-SD SMPs (9% w/w) increased from 2.3 mPa s (100 MPa) to 6.0 mPa s (500 MPa). The foam stability of the 500 MPa reconstituted SMP was exceptional with a foam head that remained stationary for 8 h (FVSI of 100%), while the foam in the 100 MPa reconstituted SMP diminished almost entirely in 2 h (FVSI of 21.3%). Evaluation of emulsification ability for reconstituted SMPs (1:9 oil in 2% diluted reconstitute w/w) revealed a 1.6-fold reduction in destabilization rate for the 500 MPa SMP compared to the 100 MPa SMP. HPJ-SD powders have physiochemical properties that can be utilized in a variety of clean label applications including ice cream or specialty beverages (e.g., cappuccino coffee).