The case of the health claim for “polyphenols” of virgin olive oil
In the European Union, health and nutrition claims related to foods are adopted under the strict procedure in accordance with EC Regulation 1924/2006. This procedure includes a scientific assessment of EFSA at the request of the interested parties.
In this context, the EFSA has approved a health claim related to the consumption of olive oil with health, and particularly with the protection of LDL from oxidation.
Τhis health claim is included in the Commission Regulation (EC) No 432/2012 of 16 May 2012 ‘on establishing a list of permitted health claims made on foods, other than those referring to the reduction of disease risk and to children’s development and health’
The health 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.
For a product, in order to bear the health 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 health claim was the only one approved among the 16 applications for olive oil polyphenols.
According to the EU regulation, the health claim concerns only olive oil by excluding the cases of enrichment of other vegetable oils (seed oils, margarines) with polyphenol content from olive mill wastewaters or other similar methods
Phenolic compounds (simple and complex forms) are accumulated as defense mechanism of the olive tree against pathogens and herbivores
The main forms of phenolic compounds and related ones present in olive fruit (comprise 1-3% of the flesh + epidermis as it is) are oleuropein, verbascoside, ligstroside, elenolic acid, oleoside, hydroxytyrosol & tyrosol. During oil extraction some transformations of the original phenolic compounds are observed. The major forms of phenolic compounds present in fresh high quality virgin olive oils are bound forms of hydroxytyrosol and tyrosol whereas free hydroxytyrosol and tyrosol are present in lower amounts.
For an olive oil processor, in order to add information on the label that his product meets the requirements of the health claim, he should contact an analytical laboratory which, by applying an appropriate analytical method, will certify the possibility of such information without misleading the consumer. The compounds that should be measured are more than 30. For this reason, in the frame of the OLEUM project, the research team of Professor Maria Tsimidou (AUTH University, Greece) worked to simplify the analytical procedure in a way that phenols can be measured in any laboratory with availability of an UHPLC system equipped with a UV detector.
The method is based on the extraction of the polar fraction according to the method proposed by the International Olive Oil Council and the determination of the target compounds in this fraction before and after hydrolysis under which more complex forms of hydroxytyrosol and tyrosol hydrolyzed into free forms. The flow diagram of the analytiscal procedure is illustrated in the following figure.
The method, was published in an international open access journal (doi: 10.3390/molecules24061044), it was presented at the Spring Summit of IOC olive oil experts by the Coordinator Prof. Tullia Gallina Toschi in May 2008 in Madrid, and then the Consortium decided to organize an interlaboratory study. The initiation of such a trial is estimated in January 2020.
OLEUM consortium addresses an invitation to those laboratories, which have the appropriate instrumentation and are interested in this method to contact with Maria Tsimidou (tsimidou@chem.auth.gr) and Tasso Koidis (t.koidis@qub.ac.uk) for further details.
Maria Z. Tsimidou, professor, Laboratory of Food Chemistry and Tecgnology, School of Chemistry, Aristotle University of Thessaloniki, tsimidou@chem.auth.gr