Celebrity-branded extra virgin olive oil, dangerous due to mineral oil contamination and otherwise defective, outlawed. The burning dossier-published in the May 2019 issue of the German trade journal Ökotest-deserves careful analysis, offered below.
Extra virgin oils, dangers and legal violations revealed in tests
19 of the 20 products tested were found to be contaminated with mineral oil hydrocarbons(MOH) or plasticizers. These include both some Italian brands – Monini, Bertolli, De Cecco, Primoli, La Selva – and Italian oils used in blends with different brands, including Lidl’sItalian sounding ‘Primadonna‘ (see Appendix). The only bottle to be saved from contamination is that of Rapunzel, an organic product made in Crete. Thus, a widespread chemical safety risk of food emerges.
‘For contaminant means any substance not intentionally added to food products, but present in them as a residue from the production (including treatments applied to crops and livestock and in the practice of veterinary medicine), manufacture, processing, preparation, treatment, packaging, transport or storage of such products, or as a result of contamination due to the environment‘ (EC Reg. 315/93, as amended, Article 1).
9 of the 20 oils tested were then found to be outlawed due to defects-such as rancidity and unpleasant odors-that European regulations strictly prohibit in olive oils designated as ‘extra virgin. (1) Chemical analysis was entrusted by Ökotest to an accredited laboratory, organoleptic analysis to a panel recognized by the International Olive Council.
Mineral oils in food, health hazards
The mineral oils at the center of the investigation, MOH(Mineral Oil Hydrocarbons), belong to the hydrocarbon family. A very heterogeneous group of substances consisting of chains of carbon and hydrogen atoms (classified according to the C number of the carbon atoms). Predominantly derived from crude oil, MOHs can also be derived from the synthesis of natural gas, coal and biomass. The contaminants present in almost all of the extra virgin olive oils examined belong to several categories:
– MOSH(Mineral Oil Saturated Hydrocarbons), saturated hydrocarbons, both linear and branched,
– MOAH(Mineral Oil Aromatic Hydrocarbons), aromatic hydrocarbons, consisting of one or more benzene rings with hydrocarbon chains and
– POSH(Polyolefin Oligomeric Saturated Hydrocarbons), polyolefin oligomeric saturated hydrocarbons consisting of short and long branched chain molecules.
The sources of mineral oils in foods are varied and diverse. To name a few, exhaust and flue gases in the atmosphere, lubricants used for machinery and instrumentation in the food industry. But also MOCAs (food contact materials, e.g., plastic packaging, inks, oiled jute bags, etc.), processing aids and food additives, pesticides. POSHs, similar to MOSHs in chemical structure, are derived mainly from polyethylene (PE) and polypropylene (PP).
The human health hazards of consuming MOH in food are serious. MOAHs are classified as genotoxic carcinogens (i.e., they can cause cancer development as a result of induction of genetic mutations). Instead, MOSHs can accumulate and cause damage to various tissues and organs (liver and spleen, lymph nodes). However, risk characterization is still difficult, partly because of the difficulty of analyzing the exact composition of many compounds.
Mineral oils in food, an unsolved problem
Contamination of food by mineral oils is nothing new. A serious and unresolved risk, rather. At the international level, the JECFA(Joint FAO/WHO Committee on Food Additives), back in 2002, had agreed on anAcceptable Daily Intake (ADI) of 0.01 mg/kg body weight). However, this approach was found to be unsuitable for characterizing risk, according to subsequentEuropean Food Safety Authority (EFSA) analyses.
EFSA, the European Food Safety Authority, has repeatedly evaluated the impact of different groups of mineral oils in foods. Already following early reports in 2008 of widespread contamination of ‘sunfloweroil’ from outside the EU by hydrocarbons. (2) The EFSA Panel of Experts on Contaminants in the Food Chain (CONTAM)-in confirming the human health hazards of dietary exposure to MOH-highlighted the difficulties of quantitative risk characterization. Moreover, an estimated 30-35% MOAH (potentially mutagenic and carcinogenic) in residual MOH in food is estimated to be a serious concern, particularly for infants and children. With emphasis on vegetable oils, eggs, bread and rice, recycled paper packaging.
The European Commission intervened only in 2017, asking member states to carry out a monitoring activity on the presence of MOH(Mineral Oil Hydrocarbons) in food during 2017-2018. (3) Without, however, defining maximum permissible contamination thresholds or prescribing corrective actions-which, on the other hand, are necessary to ensure the chemical safety of food-if they are exceeded. Brussels has indeed limited itself to defining ‘reference values,’ which have no binding force. Mild and ineffective measures, in this case as in that of another seriously hazardous contaminant, acrylamide. An unsolved problem.
Contamination of olive oils with mineral oils, the causes
Olive oil, including extra virgin, is exposed to the risk of contamination at every stage of the production chain, from the ripening of the drupes on the tree to the storage of the finished product. Ökotest experts reiterate that ‘every second olive oil is contaminated,’ unless appropriate measures are taken.
Environmental pollution in the growing area affects oil quality by increasing exposure to sources of contamination. The areas most at risk are those located near highways and busy roads, incinerators and industries, and non-electrified railways. In fact, atmospheric contaminants can settle on the surface of the fruit and penetrate by diffusion into the pulp.
During harvesting, the risk of pollution is mainly related to the use of diesel-powered handling equipment, whose emissions can be deposited on olives. To dripping facilitator lubricants and handling olives with gloves soiled with mineral oils (e.g., lubricants).
During transport, contamination may be related to the use of jute bags or containers previously used for high-risk materials. Defective covering of olives during transport can also be a cause of contamination, derived from vehicle emissions.
The storage of olives on paved yards, to which agricultural vehicles used for handling and unloading have access, is another critical point. Which becomes particularly important if storage times exceed 24 hours. Washing olives is therefore also necessary to remove contaminants potentially accumulated on the outer surface of the drupe.
Extraction with pressure equipment is itself a delicate phase. In the face of the high risk of oil contact with lubricants, used for maintenance, which also entrain metal residues released from mechanical surfaces. Conversely, continuous flow extraction plants reduce contamination risks through the use of steel structures and considerable process automation.
In the storage phase, the greatest dangers are associated with the use of non-airtight containers, as extra virgin olive oil absorbs contaminants, often lipophilic, in the air.
Ökotest, the hot dossier
Ökotest tested 20 extra virgin olive oils in 500 ml bottles, with prices ranging from €2.39 to €13.20. The products were purchased from supermarkets, discount stores, and organic stores. It is emphasized that all products tested–by virtue of the EVOO(Extra-Virgin Olive Oil) designation–should be free of any defects. As prescribed by the relevant EU regulations. (4) Not so, however (see Appendix).
Contaminants abound, in quantity and variety. Two Tunisian oils-branded Rapunzel Alnatura (€3.99, ‘unsatisfactory,’ thus outlawed because rancid) and Byodo (€6.66, also because rancid)-revealed the presence of traces of dibutylphthalate (DBP). A plasticizer used in the manufacture of pipes and conveyor belts, the use of which in MOCAs is banned in the EU as toxic to reproduction. Naturata’s Spanish oil, 7.33€, is also found to contain DBP (in addition to MOSH/POSH). Mani Bläuel, on the other hand, exceeds the allowable threshold for diethylhexylphthalate (DEHP), a family of phthalates, a plasticizer with harmful effects on reproductive capacity.
Organoleptically, the evaluation was negative for 9 out of 20 products:
– 3 ‘rancid‘ oils (Alnatura, Byodo and Naturata). Rancidity, a symptom of oxidation, can result from processing olives harvested late or from poor storage of the finished product,
– 1 oil with ‘musty smell‘ (De Cecco, €4.99, ‘EU origin’ unspecified. A musty odor is symptomatic of a fermentation process and implies, like rancidity, a failure to meet the legal requirements prescribed for extra virgin olive oil. The four oils were therefore rated as ‘unsatisfactory‘ and ‘defective‘,
– 5 ‘insufficient‘, though not defective,
– 7 ‘sufficient‘,
– 2 ‘satisfactory‘,
– Only 2 products, among the 20 samples analyzed, received an overall favorable rating. ‘Good‘ the Cretan Rapunzel Kreta (€9.99), 2018/2019 collection, which is also the only one free of traces of MOH and other contaminants. ‘Very good‘ the Italian Primoli I.G.P. Toscano (€12.99), 2018/2019 collection, which, however, contains MOSH, POSH and chlorinated compounds.
As for the origin of the olives, the magazine states, no producer lied. After all, the wording ‘European Union‘-used by Monini-Bios and De Cecco-allows ample freedom in the choice of oils to be blended.
Ökotest, first reactions and possible solutions
The producers surveyed tried to justify the contaminations by attributing their cause to environmental pollution alone. This hypothesis has been decisively refuted by laboratory analysts, who instead point out that separation of the chemical components demonstrated precisely the presence of MOH.
Two of the producers under investigation, Gaea and Reichhold Feinkost, assured that they had taken specific corrective measures immediately. By substituting plant-based lubricants and using agricultural implements with lower pollutant emissions. The situation remains critical for all, given that MOH contamination levels exceed ‘reference values’ in 17 products of the 20 tested.
Possible solutions lie in revising self-control plans (good agricultural and processing practices, HACCP). Experts surveyed by Ökotest indicate a number of steps to take, depending on the case. For example, equipping the olive grove with windbreaks (so as to block, at least in part, environmental pollution factors), not using jute bags (which release mineral or polycyclic aromatic hydrocarbons) or transporting olives in bulk without cover during transport or on trailers where containers of plant protection products are present. Avoid the movement of diesel vehicles in olive storage yards, always wash drupes before milling, do not mix oil from the starter milling with extra virgin (as the former can be contaminated by lubricants from machinery used to preserve the mechanical parts of the plant during idle periods). Avoid alternative uses of mill premises during idle periods, take care of maintenance and cleanliness of plant and machinery.
Dario Dongo and Marina De Nobili
ANNEX – The Ökotest dossier on EVOOs.
Notes
(1) See reg. EC 29/12 as amended, ‘on marketing standards for olive oil’, Art. 4. V. Also reg. EC 1234/07, Annex XVI, point 1, letters ‘a’ and ‘b’
(2) Cf. EFSA Journal 2009;7(11):1387. http://www.efsa.europa.eu/it/efsajournal/doc/1387.pdf, EFSA Journal 2013;11(1):3073. http://www.efsa.europa.eu/it/efsajournal/doc/3073.pdf
(3) See Recommendation (EU) no. 2017/84
(4) See Note 1
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
Graduated in law in Trento, she follows a master's degree in food law at Roma Tre. She is passionate about food and wine, she is between culture and tradition.
