`Researchers Extract Olive Oil Pigments to Detect Frauds - Olive Oil Times

Researchers Extract Olive Oil Pigments to Detect Frauds

By Luciana Squadrilli
Nov. 3, 2014 13:36 UTC

Last year, the University of Calabria pre­sented a method to detect olive oil frauds based on mag­netic res­o­nance test­ing. The method, devised by researchers Giuseppina De Luca and Loredana Maiuolo, is con­sid­ered highly reli­able for the detec­tion of fresh­ness and ori­gin, but it is quite expen­sive.

Now, fel­low Italian researchers Donatella Ancora, Mario Cifelli, Carlo Alberto Veracini and Maurizio Zandomeneghi at the Industrial Chemistry Department at Pisa University, coor­di­nated by Valentina Domenici, cre­ated a new, cheaper and faster way to test the organolep­tic qual­i­ties of the olive oil and to expose pos­si­ble frauds.

In devel­op­ing the research, the team worked with Andrea Serani, qual­ity man­ager at SALOV, a huge olive oil com­pany in Tuscany that was recently sold by its Italian own­ers to the Chinese group Bright Food, a multi­na­tional food and bev­er­ages man­u­fac­tur­ing com­pany head­quar­tered in Shanghai.

The research project lasted four years, and its out­come was recently pub­lished in the Journal of Agricultural and Food Chemistry under the title of Extraction of Pigment Information from Near-UV Vis Absorption Spectra of Extra Virgin Olive Oils.

The team looked at the the process by which olive oil ages and the effect of heat. They used oil pig­ments” that dom­i­nate the light absorp­tion, to extract chem­i­cal infor­ma­tion in less than a minute. Even if these pig­ments rep­re­sent only 2 per­cent of the total com­pounds in olive oil, they are essen­tial to test and ver­ify its organolep­tic qual­i­ties and to detect fraud and adul­ter­ation.

Our method, Valentina Domenici explained, allows us to quan­tify, through a math­e­matic process of decon­vo­lu­tion of the UV – vis absorp­tion spec­trum, the con­cen­tra­tion of four main oil pig­ments:” lutein, pheophytin‑a, pheophytin‑b and β‑carotene. With a few, sim­ple pro­ce­dures the oil is inserted into a small quartz cell. We then obtain the spec­trum which takes a dis­tinc­tive shape and which allows us to under­stand imme­di­ately whether the oil has been adul­ter­ated or not.”

Thanks to this method it will be eas­ier and cheaper to unmask the most com­mon frauds olive oil can be affected by: heat-treat­ments com­monly used to erase unpleas­ant smell and taste, bad stor­ing con­di­tions and expo­sure to light or oxy­gen, or mix­ing with dif­fer­ent veg­etable oils.

In all such cases,” Domenici said, the spec­trum curve that is obtained sub­stan­tially changes and it becomes a clue to unveil the fraud. It only takes a few minute to have the response while other, more expen­sive meth­ods that are the only ones approved by EU reg­u­la­tions at the moment, need one or two days in spe­cial­ized labs.”


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