Characterization of alcohol-containing dairy emulsions: Pseudo-ternary phase diagrams of sodium caseinate solution-oil-ethanol systems

- Complete phase diagrams mapped for alcoholic dairy emulsions (canola and coconut).
- Limits of Instability defined by sodium caseinate concentration and ethanol content.
- Rheology and droplet size in stable region characterized for both types of emulsion.

The physical properties and the stability of alcohol containing emulsions made with sodium caseinate using two types of oil (canola and coconut) were investigated. The region of emulsion stability was presented on ternary phase diagrams. This region was limited to emulsion compositions in the range of sodium caseinate solutions between 32-68 wt.%, oil contents between 10 and 53 wt.% and ethanol concentrations from 8 to 32 wt.% The type of oil had a minor effect on emulsion stability, but stability was sensitive to ethanol content and casein/oil ratio. Emulsions within the region of emulsion stability behaved as Newtonian fluids with high ethanol content (> 22 wt.%) emulsions being low viscosity and those of low ethanol (< 22 wt.%) being of high viscosity. Ethanol affected the average droplet size. By establishing the boundaries of emulsion stability for the full phase space in cream liqueurs, formulation strategies for specific product properties can be planned.