Multivariate data analysis for the development of multiple emulsions based on cold plasma treated sunflower oil

The properties of vegetable oils can be improved by initiating their polymerization, in order to increase their viscosity, their thermal stability and their drying capacity. A process based on cold plasma treatment represents mild and ecofriendly conditions to get pre-polymerized vegetable oils. A pre-polymerized sunflower vegetable oil was chosen to prepare water-in-oil-in-water emulsions, using an association of biobased surfactants. Emulsification conditions were optimized using central composite design (CCD) and principal component analysis (PCA) based on temperature (25–50 °C), casein content (1.5–3.5% w/w), and alkylpolyglucoside (APG) concentration (1.5–3.5% w/w). Evaluated responses were the onset of destabilization (OOD), creaming index (CI), and droplet sizes. CCD results suggest an optimum at temperature of 35 °C using 3.0% of APG and 1.8–3.9% of casein, yielding lower water droplet diameters ensuring emulsion stability. Furthermore, PCA results highlighted a positive correlation between ODD and the total amount of surfactant (Pearson correlation coefficient = 0.67), and a negative correlation between CI and the total amount of surfactant (Pearson correlation coefficient = -0.62). Casein rate and temperature of emulsification are the factors which control the inner water droplet sizes of the studied system, while total amount of surfactant impacts the ODD and CI.