`Hydrocarbon Fingerprinting Helps E.U. Researchers Verify Olive Oil Provenance - Olive Oil Times

Hydrocarbon Fingerprinting Helps E.U. Researchers Verify Olive Oil Provenance

By Paolo DeAndreis
Feb. 9, 2022 08:17 UTC

Researchers from Spanish and Italian uni­ver­si­ties have iden­ti­fied a sim­pler and cheaper method to authen­ti­cate extra vir­gin olive oil’s geo­graph­i­cal ori­gin.

In their newly pub­lished study, the sci­en­tists said they have devised and val­i­dated a clas­si­fi­ca­tion model capa­ble of ver­i­fy­ing when an extra vir­gin olive oil sam­ple was pro­duced in the European Union or if it has a non‑E.U. ori­gin.

The European Union financed the research through the ongo­ing Oleum project, which is specif­i­cally aimed at devel­op­ing solu­tions to assess olive oil authen­tic­ity and qual­ity.

See Also:Research News

According to the last report from the European Union Food Fraud Network, olive oil tops the list of the most noti­fied prod­ucts,” the study authors wrote. Current E.U. reg­u­la­tion states geo­graph­i­cal ori­gin as manda­tory for vir­gin olive oils, even though an offi­cial ana­lyt­i­cal method is still lack­ing.”

Verifying the com­pli­ance of label-declared E.U. oils should be addressed with the high­est pri­or­ity level,” the authors added.

The sci­en­tists explained that the new instru­men­tal meth­ods allow a reli­able geo­graph­i­cal authen­ti­ca­tion of vir­gin and extra vir­gin olive oils pro­duced in spe­cific and homo­ge­neous areas, as well as in wider regions with higher het­ero­gene­ity in terms of tra­di­tional cul­ti­vars and pedo­cli­matic con­di­tions.

To develop the new mod­els, researchers focused on sesquiter­pene hydro­car­bons. Found in many plants, marine organ­isms and fungi, sesquiter­pene hydro­car­bon fin­ger­print­ing in vir­gin olive oils offers a vast amount of infor­ma­tion, help­ful in iden­ti­fy­ing spe­cific olive tree cul­ti­vars and geo­graph­i­cal areas.

To fur­ther refine the inves­ti­ga­tion, the sci­en­tists applied a par­tial least-squares dis­crim­i­nant analy­sis to the involved olive oils, a well-known chemo­met­rics tool.

The research team used 400 vir­gin olive oils’ sesquiter­pene hydro­car­bons obtained through head­space solid-phase micro-extrac­tion cou­pled to gas chro­matog­ra­phy-mass spec­trom­e­try.

Nearly 250 sam­ples were selected from six olive oil-pro­duc­ing coun­tries within the European Union (Spain, Italy, Greece, Portugal, Slovenia and Croatia), while 154 came from Tunisia, Turkey, Morocco and Argentina.

All sam­ples came from dif­fer­ent har­vest sea­sons, and all had met the cri­te­ria to be graded as vir­gin’ or extra vir­gin’ through a panel test assess­ment.

See Also:Using Isotopic Footprints to Authenticate Olive Oil, Combat Fraud

To test the reli­a­bil­ity of the new meth­ods, researchers used a large dataset with great diver­sity, includ­ing dif­fer­ent pro­duc­tive regions, olive cul­ti­vars, crop years and even ana­lyt­i­cal batches, in order to eval­u­ate the per­for­mance of the authen­ti­ca­tion approach in a more real­is­tic sce­nario where the nat­ural vari­abil­ity is highly rep­re­sented.”

Those sam­ples made it pos­si­ble to dis­crim­i­nate between E.U. and non‑E.U. prod­ucts with an 89.6 per­cent degree of cor­rect clas­si­fi­ca­tion.

Thanks to the sub­se­quent devel­op­ment and val­i­da­tion of multi-class dis­crim­i­na­tion mod­els for E.U. and non‑E.U. coun­tries, researchers cor­rectly iden­ti­fied E.U. coun­tries in 92.2 per­cent of instances, a value ris­ing to 96.0 per­cent when iden­ti­fy­ing non‑E.U. coun­tries.

The best results were obtained in iden­ti­fy­ing sesquiter­pene hydro­car­bons from Italy, Spain and Greece, with 99.6 per­cent accu­racy. The slightly lower scores found for other coun­tries were mainly due to fewer col­lected sam­ples.

It is remark­able that these high per­cent­ages of cor­rect assign­ments were obtained with a data set that con­sid­ered a high vir­gin olive oil nat­ural het­ero­gene­ity and ana­lyt­i­cal vari­abil­ity as it included sam­ples from the main cul­ti­vars for each pro­duc­tion area, from dif­fer­ent crop-years and they were ana­lyzed in sev­eral ana­lyt­i­cal batches,” wrote the researchers.

According to the researchers, the new method comes on the heels of sev­eral pre­vi­ous lab­o­ra­tory meth­ods to iden­tify olive oil ori­gin, but it now reduces instru­men­ta­tion needs and oper­a­tional costs.

Based on the results obtained with the lat­est research, the sci­en­tist also stressed that the same approach could be scaled down to authen­ti­cate the ori­gin of oils obtained from smaller regions.

The paper’s authors said that the same method could also be used to authen­ti­cate high-qual­ity extra vir­gin olive oils within the European Union, those cer­ti­fied with a Protected Designation of Origin or Protected Geographical Indication.


Related Articles