The antioxidant capacity and oxidative stability of virgin olive oil enriched with phospholipids

Virgin olive oil (VOO) enriched with phospholipids (soy lecithin) up to the levels present in seed oils (from 2.5 to 10.0 g/kg) was studied as a potential functional food. Lecithin addition slightly increased the concentration of tocopherols and considerably increased K270 values. In the fatty acid composition, an increase of linoleic and a slight decrease of oleic acid were observed, as the decrease of monounsaturated/polyunsaturated fatty acid ratio. The radical-scavenging activity was evaluated by two methods: electron spin resonance spectroscopy using galvinoxyl free radical and VIS spectroscopy measurement of the disappearance of 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical. Results indicate that lecithin addition retards the scavenging activity of VOO that is ascribed to the bipolar character of lecithin and its ability to entrap hydrophilic antioxidants. The effect of lecithin addition on the oxidative stability of VOO was evaluated by the Rancimat method, and a positive linear correlation (r = 0.9849) with induction time was found.