Abstract

The effects and interactions of emulsion components namely refined soybean oil content (1.87 to 4.12%, w/w), polyglycerol polyricinoleate (PGPR) content (0.89 to 1.93%, w/w) and mango seed kernel extract (MSKE) content (0.00 to 0.24%, w/w) on water–oil–water (W/O/W) emulsion characteristics were studied using response surface methodology. The emulsion properties studied as response variables were droplet size distribution, centrifugation stability, apparent viscosity and encapsulation efficiency. Results indicate that the response surface models were significantly (p<0.05) fitted for stability and viscosity. The effects of PGPR and MSKE were significant (p<0.05) variables affecting all responses, hence the concentration of PGPR and MSKE should be considered as critical variables for the formulation of W/O/W emulsions in terms of the emulsion characteristics studied. The overall optimum region resulting in a desirable double emulsion was predicted to be obtained at 2.33% (w/w) refined soybean oil, 1.68% (w/w) PGPR and 0.16% (w/w) MSKE. No significant (p>0.05) difference was however found between the experimental and predicted values, thus ensuring the adequacy of the response surface models employed for describing the changes in physicochemical properties as a function of the main emulsion components.

Key words: Optimization, W/O/W emulsion, phenolic, mango seed.