Antioxidant activity and sensory properties of an artisanal ice-cream functionalised using extra virgin olive oil

Ice cream is one of the most consumed dairy products in the world, even if it is generally poor in functional ingredients such as polyphenols and vitamin E. This research aimed to improve the nutritional attributes of ice-cream using extra virgin olive oil (EVOO) as a functional ingredient providing known added health benefits (unsaturated fatty acids, biophenolic antioxidants, tocopherols, squalene, phytosterols) and characteristic sensory notes. For this purpose, we investigated the chemical-physical and sensory properties of an artisanal ice-cream made by adding an EVOO characterised by high content of biophenols (420 mg kg-1) and an herbaceous flavour with a moderate bitter taste. A sorbet, where milk is missing, was also produced as a control, to study the possible binding effect of milk proteins toward the natural EVOO phenolic and aroma compounds. The extractability of phenolic compounds and the antioxidant activity of the EVOO-ice-cream was lower compared to the sorbet, suggesting an interaction of polar antioxidants with milk proteins and also some trapping effects of the ice-cream emulsion. The antioxidant activity of the EVOO-ice-cream was 0.8 mmol Trolox L-1, which was lower than that of EVOO (51 mmol L-1). However, the use of EVOO in the ice-cream allowed obtaining an antioxidant activity 5 times higher than a regular ice-cream (~0.2 mmol L-1). The sensory analysis also indicated an attenuation effect of the EVOO bitter-pungent note and herbaceous aroma in ice-cream compared to the sorbet. These findings could lead to the formulation of ice-creams in which EVOO can be used to partially replace the milk fat, so that their nutritional profile is improved and new flavours can be created, without the addition of artificial flavouring agents. However, when EVOO aroma is not desired in ice cream, it can be masked using other ingredients (hazelnut, chocolate, fruits) as natural aromas.