Emulsifier properties of saturated acyl l-ascorbates for preparation of O/W emulsions

Oil-in-water emulsions, the oil phases of which were soybean oil, were prepared using acyl l-ascorbates with even acyl carbon numbers of 8–16. The median diameters of oil droplets in the emulsions and the stability of the emulsions were examined. Caproyl and lauroyl l-ascorbates were adequate for the preparation of fine and stable emulsions. The emulsions were more stable at higher concentrations of the emulsifiers. The emulsions were prepared using citrate buffers with various pH values as an aqueous phase. The stability of the emulsions was higher at higher pH values of the aqueous phase. The high stability was ascribed to the largely negative surface-charge of oil droplets in the emulsions.