Antioxidant dispersions in emulsified olive oils

In this paper water droplets dispersed in olive oils were used as containers of l-ascorbic acid and its inhibitory effect on lipid oxidation was studied. In detail, olive oil samples were emulsified by adding a certain quantity of vitamin C aqueous solutions and then oxidized by UV light. Data collected from sample analysis by optical microscopy were used to calculate the average droplets parameters and to characterize the droplet size distribution function. The results revealed a strong correlation between the initial rate of hydroperoxide formation and the specific surface area of aqueous dispersed phase. Such correlation has been explained as the consequence of a synergistic interaction between the ascorbic acid contained in the droplets and the natural tocopherols present in olive oil. A key role is played by the water–olive oil interface which is the boundary where the synergisms take place.