Abstract:

Oil-in-water emulsion formulations often contain vegetable oil such as soybean oil as the core component. In the current study, oil derived from harp seals, rich in ω-3 long chain fatty acids, was used. The effect of different polyet hleneglycols (PEGs) coated on hydrogenated castor oils as emulsifying agents on the physical stability of seal oil-in-water emulsions was studied. It was fou nd that 2.5% PEG-40 coated hydrogenated castor oil (Croda-RX40, HLB 13) formed the most stable 10% of seal with diameter of 240-270 nm. The effe ct of surface charge on the physical stability of seal oil emulsions was also st udied by adding different amounts of either negatively charged surfactant (Croda,sinic LS-30) or positively charged surfactant (Incroqal Behenyl TMS). The neg atively charged Croda,sinic LS-30 had very little effects on the particle sizes. For the positively charged surfactant such as Incroquat Behenyl TMS, there w ere big fluctuations of particle sizes, especially in the concentrations of 0.25 % and 0.5%. pH values of 10% of seal oil emulsions were found to decrease over the time because of the hydrolysis of triacylglycerides into free fatty acids. The current studies demonstrated that the stable emulsion systems could be form ed when the absolute Zeta-potential value exceeds ^*20 mV^*, regardless of the po sitive or negative charges on the surface of emulsions.