Stability of Fluid Food Emulsions. I. Effects of Emulsifiers, Electrolytes and Sodium Caseinate

Abstract

The purpose was to develop stable dairy-type fluid foods containing balanced electrolytes. This report deals with the effects of the Hydrophilic-Lipophilic-Balance (HLB) of emulsifiers, electrolytes and sodium caseinate on the emulsion stability of oil-in-water emulsions. The stability of emulsions containing 4% coconut oil varied with the HLB of the emulsifiers. A mixture of mono-, diglycerides and polyoxyethylene sorbitan monostearate at 0.5% of the system, provided maximum stability when ratios of emulsifiers were 2:1 to 1:1, corresponding to an HLB range 7 to 9. Calcium, citrate and phosphate had varying effects on emulsion stability. Calcium had limited positive effect up to 5 mM/liter, beyond which it became negative. Citrate supported emulsion stability up to 10 mM/liter at which maximum stability was obtained. Phosphate had no significant influence.The emulsifying properties of sodium caseinate were concentration dependent. Without other conventional emulsifiers, sodium caseinate showed optimum emulsification at 0.2 to 0.4%. In the presence of the emulsifiers mentioned, maximum stability was with sodium caseinate at 0.5%. At higher concentrations, in both cases, sodium caseinate destabilized emulsions, indicated primarily by creaming. Addition of calcium to sodium caseinate emulsions had a positive effect on emulsion stability which increased with increasing calcium. Increased emulsion stability coincided with increased caseinate precipitation by calcium.