New Industrial Procedures for Achieving a Nutritional Added Value of the Olive Oil. The NUTRAOLEUM Study

The Mediterranean diet, in which olive oil is the main source of fat, has shown to be protective for chronic degenerative diseases. These diseases, such as cardiovascular, cancer, and neurodegenerative, and even the aging process, are linked to oxidative stress and inflammation. Recently, the Prevention through Mediterranean Diet Study has provided for first time evidence of the benefits of the Mediterranean diet on the primary prevention of cardiovascular disease. In human, randomized, controlled studies olive oil, and particularly the virgin one rich in phenolic compounds, have been shown to provide benefits on oxidative damage, inflammation, and on the generation of cell adhesion molecules, a key process for atherosclerosis development.

Olive oil, besides its high content of a healthy fat, the monounsaturated (MUFA) one: the oleic acid, has minor components with bioactive properties. The minor components of virgin olive oil are classified into two types: the unsaponifiable fraction, defined as the fraction extracted with solvents after the saponification of the oil, and the soluble fraction which includes the phenolic compounds. The content of the phenolic compounds (polyphenols) of an olive oil depends of the variety of the olive fruit, the cultivar, the climate, the ripeness of the olive, and the type of processing. Virgin olive oils obtained from the first press of centrifugation of the olives are those with high phenolic content. On November 2011, the European Food Safety Authority (EFSA, 2011) released a claim concerning the benefits of the daily ingestion of olive oil rich in phenolic compounds, such as the virgin olive oil. The Panel considers that in order to bear the claim, 5 mg of hydroxytyrosol and its derivatives (e.g. oleuropein complex and tyrosol) in olive oil should be consumed daily. These quantities, if provided by moderate amounts of olive oil, can be easily consumed in the context of a balanced diet (EFSA, 2011). The conditions for the use of the claim in the bottles, are regulated in the Commission Regulation (EU).Nº 432/2012 of 16 May 2012 (Official Journal of the European Union , L136/1. 25, 5, 2012). According to this regulation: "The claim may be used only for olive oil which contains at least 5 mg of hydroxytyrosol and its derivatives (e.g. oleuropein complex and tyrosol) per 20 g of olive oil. In order to bear the claim, information shall be given to the consumer that the beneficial effect is obtained with a daily intake of 20 g of olive oil". This implies that only high phenolic content olive oils can bear the claim. Due to this, the need to optimize the olive oil processing in order to obtain high phenolic content olive oils is one of the current goals in terms of increasing the nutritional value of an olive oil. To obtain an optimized olive oil with high phenolic content (OHPCO) has been one of the achievements within the frame of the NUTRAOLEOUM Project. In this sense we must point out that, among minor olive oil components, not only polyphenols, but components of the unsaponifiable fraction such as the triterpenes have also shown to have potential for providing benefits for health. The seeds and the skin of the olives, used to produce pomace olive oil, are very rich in triterpenes. Pomace olive oil and triterpenes, such as oleanolic and maslinic acids, have shown anti-inflammatory, antioxidant, and vasodilatation properties in cellular and animal models. Due to this, the enrichment of an OHPCO with olive triterpenes, by joining the healthy properties of virgin and pomace olive oil, will result in a Functional Olive Oil (FOO) with a high bioactive potential for health. This FOO has also been developed in the frame of the NUTRAOLEUM Project. Consumers are every day asking for an "added value" in the nutritional properties of the food to be purchased and responses from the Olive Oil Industry are needed.

However, the healthy properties of the new olive oils (OHPCO and FOO), according to the Evidence Based Medicine must be tested in proper clinical randomized trials. New olive oil products need to be tested in front of the parental ones (i.e. virgin olive oil obtained by common procedures) in order to ensure that their healthy properties are highlighted. This is the purpose of the NUTRAOLEUM Study. In order to be able to obtain future health claims from EFSA or FDA, for the products, we will also examine the bioavailability in humans of the active principles (phenolic compounds and triterpenes) of the olive oils, as well as possible basic mechanisms involved in the potential health benefits of the olive oils tested.