Researchers from the Department of Physical Chemistry at the University of Jaen have revealed that olive oil can be preserved for longer with the help of microalgae extracts, which are rich in carotenoids. These molecules have an antioxidant effect and protect the oil against deterioration once it has contact with air. By slowing down this process, the useful life of the oil is prolonged.

According to the experts, olive oil can keep for longer than the usual twelve months or so with the help of extra antioxidants. The increased resistance to oxidation also generates better resistance to light and heat, slowing down the degradation process when it is heated, for instance. This means that the oil will conserve its healthy properties for longer, even at high temperatures.

Ruperto Bermejo, a researcher at the university and the principal author of the study, explained that the increase in oxidative stability is related to the composition of the microalgae extracts, known as scenedesmus almeriensis, which were used in the study. This type is especially rich in betacarotenes and lutein, both recognised antioxidant compounds.

To obtain these results, the microorganisms were subjected to various processes until they were converted into freeze-dried biomass. This resulted in a dehydrated green powder, from which the researchers obtained an extract composed of betacarotenes and lutein, the principal carotenoids in the algae.

The effects of the introduction of these elements on various types of olive oil were then analysed. In fact, olive oil protects these elements very well. It has been proven that in other solvents, carotenoids degrade and lose their properties. However, in olive oil they remain stable. This is because, depending on the olive variety and where it was grown, olives tend to contain traces of carotenoids. Consequently, when they are enriched with the same elements, they do not react negatively.

The experts indicate that carotenoid deficiency lowers the body´s protection against diseases associated with a lack of antioxidants, such as skin cancer. Having verified the positive effects that such antioxidants have on olive oil, the researchers are now focused on determining the optimum quantity to add in order to ensure the maximum benefit to the consumer.