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The Chemistry Expert Group of the International Olive Council responded to a report from the UC Davis Olive Centre quesÂtionÂing the qualÂity of extra virÂgin olive oil imported into the United States. The Expert Group clarÂiÂfied that the UC Davis study was not staÂtisÂtiÂcally sigÂnifÂiÂcant, lacked inforÂmaÂtion on storÂage conÂdiÂtions, and did not folÂlow offiÂcial IOC testÂing methÂods, leadÂing to unreÂliÂable conÂcluÂsions about the qualÂity and purity of the olive oil. The IOC Chemistry Expert Group emphaÂsized the imporÂtance of using offiÂcial testÂing methÂods and expressed readiÂness to disÂcuss any new input to ensure the authenÂticÂity of olive oil.
STATEMENT ISSUED BY THE CHEMISTRY EXPERT GROUP OF THE INTERNATIONAL OLIVE COUNCIL ON THE REPORT PRODUCED BY THE UC DAVIS OLIVE CENTRE
A report issued by the UC Davis labÂoÂraÂtory quesÂtionÂing the trueÂness-to-grade of extra virÂgin olive oil imported into the United States has been pubÂlished recently in varÂiÂous news media. The IOC Chemistry Expert Group have disÂcussed this subÂject at their latÂest meetÂing.
The Group is made up of expert chemists from almost all the IOC memÂber and non-memÂber counÂtries (Australia, Canada and the United States) and interÂnaÂtional organÂiÂsaÂtions (AOCS, CODEX and ISO). The main aim of the group is to study testÂing methÂods and revise them when necÂesÂsary to deterÂmine the qualÂity and conÂtrol the purity of olive oils and olive-pomace oils. Methods are conÂstantly being improved to adapt them to indusÂtry needs and techÂnoÂlogÂiÂcal develÂopÂments.
IOC stanÂdards are revised in the light of sciÂenÂtific advances that help to make testÂing methÂods more accuÂrate, or of techÂnoÂlogÂiÂcal and comÂmerÂcial develÂopÂments. Their aims are to enhance and conÂtrol qualÂity, as well as to ensure transÂparency on the interÂnaÂtional marÂket for olive oils, olive-pomace oils and table olives, and to proÂmote their conÂsumpÂtion.
Considering the report pubÂlished by UC Davis, there are sevÂeral points this Expert Group wishes to clarÂify.
The results reported are for only 52 samÂples of 19 brands. This is not staÂtisÂtiÂcally sigÂnifÂiÂcant of the olive oil imported into the USA, because samÂples traded in three cities of California are not repÂreÂsenÂtaÂtive of the whole olive oil marÂket in the USA; thereÂfore, the claim quesÂtionÂing the trueÂness-to-grade of the extra virÂgin olive oil imported into the USA is not realÂisÂtic.
There are no details of storÂage conÂdiÂtions durÂing shipÂping or time of testÂing. Without this inforÂmaÂtion it is imposÂsiÂble to conÂsider the results to be reliÂable. In addiÂtion, the recÂomÂmenÂdaÂtions stated on the prodÂuct labels indiÂcate that the oils must be kept in a cool dry place and must not be exposed to direct light in order to comÂply with their assigned grade clasÂsiÂfiÂcaÂtion durÂing their shelf life. We do not know if the non-comÂpliÂance with the stanÂdards was due to the origÂiÂnal charÂacÂterÂisÂtics of the oils or to the storÂage conÂdiÂtions durÂing tradÂing.
The IOC trade stanÂdard is under conÂstant superÂviÂsion by the IOC Chemistry Expert Group and conÂtains all the necÂesÂsary methÂods to assess the qualÂity and purity of olive oil. Hence, it was not necÂesÂsary to apply the non-offiÂcial methÂods cited in the report.
Most of the samÂples were misÂclasÂsiÂfied by the senÂsory analyÂsis. The offiÂcial method of the IOC was used, but was not applied accordÂing to the stanÂdardÂised proÂceÂdure described in the method. When the grade assigned by the senÂsory analyÂsis does not match the grade stated on the label clasÂsiÂfiÂcaÂtion, the proÂceÂdure requires a secÂond analyÂsis to be perÂformed by another IOC recogÂnised panel. This was not done in the UC Davis study.
The UC Davis study places parÂticÂuÂlar emphaÂsis on the appliÂcaÂtion of non-offiÂcial methÂods and gives the impresÂsion that the IOC methÂods are not sufÂfiÂcient to assess the qualÂity and purity of olive oil. We would like to stress that some of the methÂods used in this study are not IOC methÂods, even though IOC methÂods are availÂable (polypheÂnols and TAG) to assess the same paraÂmeÂters.
It is also imporÂtant to point out that the IOC does have an offiÂcial method to detect low qualÂity oils or the addiÂtion of soft refined oils obtained from low qualÂity oils (alkyl esters of fatty acids). Instead, the study used non-offiÂcial methÂods, – DAGs ‑and pyropheoÂphyÂtine – that had already been studÂied by the IOC Chemistry Expert Group, which conÂcluded that the scope of these methÂods could not include the assessÂment of the qualÂity and purity of olive oil because these comÂpounds change dynamÂiÂcally durÂing the shelf life of the oil.
In this conÂtext, the UC Davis report claims that cheap refined oil was added to the oils; howÂever, all the paraÂmeÂters (stigÂmasÂtaÂdiÂenes and sterol comÂpoÂsiÂtion) that detect the addiÂtion of this type of oil were within the limÂits. Consequently, they canÂnot conÂclude that refined oils were added.
As the IOC Chemistry Expert Group, we are very conÂcerned about the final recÂomÂmenÂdaÂtions of the study advoÂcatÂing the impleÂmenÂtaÂtion of methÂods that have not been proven to have any relaÂtionÂship with the qualÂity or purity of olive oils.
The Group wishes to end by sayÂing it is ready and willÂing to disÂcuss any new input to ensure the qualÂity and authenÂticÂity of olive oil.
Madrid (Spain), 8 October 2010