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Jul 15, 2010 01:44 PM

Extra-Virgin Olive Oil Fraud: Whole Foods, Rachel Ray, Safeway, Newman's Own, Colavita, Bertolli

UC-Davis has just published an extensive report on the fraudulent labeling of extra-virgin olive oil. Imported olive oil has been known to often have fraudulent or misleading labels, now certain US brands have been found to be mislabeling their olive oil as well.

"More than two-thirds of common brands of extra-virgin olive oil found in California grocery stores aren't what they claim to be, according to a report by researchers at UC Davis, " said the Los Angeles Times in the story linked to below.

Scroll down to page 10 of the UC-Davis report here for the chart of the various brands.

The tests to determine extra-vrigin oil (acidity, peroxide level, etc.) are listed and described.

"Lab tests cast doubt on olive oil's virginity"
Los Angeles Times

Found to have be fraudulently labeled as Extra-Virgin:
Whole Foods
Rachel Ray
Newman's Own
Filippo Berio

Found to be accurately labeled as Extra-Virgin:
Kirkland Organic
Corto Olive
California Olive Ranch
McEvoy Ranch Organic

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  1. i am anxious to read through the whole report. i was interested to read that corto and also the california olive ranch financially supported this research. that doesn't mean necessarily that it is biased, but it does require a keener look at their methodology.

    but, at first blush, this is shocking news of widespread fraud. do the perpetrators use a bulk importer, then re-bottle? (i guess i should read the report before asking too many questions).

    thanks for linking this here, maria lorraine.

    5 Replies
      1. re: junescook

        LOL! all of them!

        newman's own! for shame!

        1. re: alkapal

          Funny, junescook.
          Boy oh boy are the RR EVOO Rachel Ray jokes going to rip.

          alkapal, I was surprised/saddened also by Newman's Own.

        2. re: junescook

          Or maybe E V Oh No! . . . sorry . . .

        3. Oh great. My husband just brought home a bottle of WF EVOO this weekend. He said it was cheaper than the other options. I guess there's a reason why.


          32 Replies
          1. re: The Dairy Queen

            This was a relatively small study funded by the California olive industry. I'm not going to run over to the cupboard and throw out my extra v grown and pressed in the ancient Stop and Shop family olive groves. Actually, it probably comes from China so I'm likely safe.

            1. re: junescook

              Well, two things, I wouldn't throw it out, but I might return it, just on principle. (Although, of course, they will just throw it out.) But, also, I had sent my husband to the grocery store for evoo because I was making a vinaigrette for a salad I was bringing to a friend's house for a potluck. I was really disappointed by the olive oil--very generic and bland. I ended up calling her at the last minute and asking if she could whip up her own vinaigrette (not enough time to make a SECOND last minute trip to the grocery store.) It wasn't good enough to use in my salad dressing. Just in cooking at low temps.


              1. re: The Dairy Queen


                Hell, with my "sophisticated" palate, I am lucky that I can tell it's olive oil and not peanut oil, I wouldn't know there was any difference in any olive oil I use, except the price. I probably represent the greatest majority of the consuming public in this, so understand the temptation by bottlers to "creatively" label.

                Back in the stone age when I was a full time student and part time rent-a-cop one of the places I worked was a major label packing plant, they churned out jams, jellies, fruit preserves, ketchups, tomato sauces and related products. The raw materials came in via huge gondolas mounted on flat bed trailers or railroad cars, the processed materials left in cans and bottles that were labeled with that day's production run brand name, but it all came out of the same production line.

                1. re: ChinoWayne

                  That is funny: same product, different label. And, probably, different price.

                  I can't claim to be able to be able to distinguish a good olive oil from a great one, but what I can say is that in this vinaigrette recipe, where the flavor of the olive oil was really prominent, this particular olive oil was a disappointment. :(.


              2. re: junescook

                Seconding alkapal, I'm interested to read deeper. But when results are accurate and rigorous, they don't become less so because someone with a competing product funded the study.

                UC Davis has one of the leading US food-science departments, with high visibility and some excellent past work.

                1. re: eatzalot

                  Looks like the tests were quite rigorous. Excellent scientific panel, as well.

                  1. re: maria lorraine


                    Can you tell me why the tests are rigorous and why this an excellent scientific panel? Shoemarker is the only full professor in the team.

                    1. re: Chemicalkinetics

                      A research team headed up by a full professor is the norm in academic research. No red flag there and certainly nothing unusual.

                      On edit: The lead author on this report, Edwin Frankel, is so well known in food oil quality research that there is an award given annually in his honor for the best paper in the field: " Edwin Frankel Award for Best Paper in Lipid Oxidation and Quality". I'd guess the guy knows what he's doing.

                      1. re: Gustavo Glenmorangie


                        Thanks. As you put it "No red flag there and certainly nothing unusual". That is my point: nothing unusual.

                        Shoemarker is the full professor, but he does not head this investigation. Frankel is an adjunct professor. The rest of team are just normal, right? Selina Wang is a postdoc. Dan Flynn heads a very small group. Yes, I know he has an executive director title, but it is an inflated title. It is a group of one executive director, two assistant directors and intern. Think of an army with one general, two lieutenants and one soldier.


                        There is nothing really wrong with this team, but it seems like a normal team to me. I can randomly grab a paper out of an peer-reviewed journal, and a good% of the time, it will be authored by two professors, a postdoc and a staff.

                        Many review-articles are coauthored by 4-7 infamous professors in their respective fields, right? I am not sure if there is this "Wow" factor to this particular panel. Now, I am not saying that this makes their works any less. It does not, but the author list just does not jump out at me as impressive.

                        1. re: Chemicalkinetics

                          I cannot agree. If you're looking for Wow factor, I think it's here. A bit of googling tells me that Shoemaker was the chairman of UC Davis's Food Science program (which is among the best in the world). Frankel looks to me like a fairly big fish in the food oil chemistry pond (see above). Mailer, the guy from Oz, certainly appears to have excellent credentials: "He heads the laboratory’s edible oil research program,which plays a leading role in national olive industry research, and is the Australian representative on the International Standards Organization (ISO) for Fats and Oils." And Wang, the postdoc, almost certainly did most of the lab work.

                          Ok, there's not a single Nobel Laureate in the bunch, but not too many of that bunch does food chemistry. In the world of food science, I think you would have a difficult time finding fault with the credibility of this group.

                          If I were to raise an issue it would be that it doesn't look like it's been peer reviewed. I would certainly feel better about it if it were.

                          1. re: Gustavo Glenmorangie

                            I am aware that Shoemarker is the chairman. Chairman does not mean anything in this case. You should know chairman has a lot more to do with politics than academic. The person who get selected to the the Chemistry departmental chair or Physic departmental chair is the person who has to deal with daily affairs and business in the department, which can include overhead fee, lab space, graduate student rotation, availability of TA.... It really does not mean he is the most awesome researcher in the department.

                            It is like having the Dean of College in the paper. It is nice from a political point of view, but not necessary one way or the other from an academic angle. Mailer's CV does not impress me. I think there is a lot of inflated words, like Flynn.

                            Like I said, I can grab any review paper, and I will find 4-7 full professors who are renounced in their respective field. I just don't know if I am going to "Wow" every single time I come across a review article or a featured article. Otherwise, I have to "wow" a few times for every typical journal I read, and I probably have to burst into tears when I read something like Nature or Science.

                            Look, at the end, we just have to agree to disagree. I don't want to bad mouth any of them. I am sure they are fine people. You are very impressed with the author list. Me, not so much. You are not going to convince me, and I am not going to convince you.

                            1. re: Chemicalkinetics

                              4 of the 5 specialize in olive oil chemistry. Here are the bios. Decide for yourself.

                              Dr. Edwin N. Frankel, Scientific Advisor. Dr. Frankel is among the world’s leading
                              authorities on lipid oxidation. An adjunct professor at the UC Davis Department of Food
                              Science and Technology, he ranked in 2003-04 as the world’s most-cited author of agricultural
                              research by the Institute for Scientific Information. Most recently he has authored “Chemistry
                              of Extra Virgin Olive Oil: Adulteration, Oxidative Stability, and Antioxidants,” Journal of
                              Agricultural and Food Chemistry, 2010, 58, 5991-6006.

                              Dr. Rodney J. Mailer, Co-Investigator. Dr. Mailer has been involved in olive
                              research since 1996, and is the principal research scientist at the Australian Oils Research
                              Laboratory in Wagga Wagga, NSW. He heads the laboratory’s edible oil research program,
                              which plays a leading role in national olive industry research, and is the
                              Australian representative on the International Standards Organization (ISO)
                              for Fats and Oils.

                              Dr. Charles F. Shoemaker, Co-Investigator. Dr. Shoemaker is the co-chairman of the UC
                              Davis Olive Center and a professor in the UC Davis Department of Food Science and
                              Technology. He supervises the UC Davis Olive Oil Chemistry Laboratory. Dr. Shoemaker is
                              a specialist in food emulsions, micelles, microemulsions, and food separations.

                              Dr. Selina C. Wang, Co-Investigator. Dr. Wang received her Ph.D. in Chemistry from UC
                              Davis in 2008. She has since lectured for the UC Davis Department of Food
                              Science and Technology and is a research associate at the UC Davis Olive Oil
                              Chemistry Laboratory.

                              Dan Flynn, Consultant. Mr. Flynn is the executive director of the UC Davis
                              Olive Center, the only center of its kind in North America. He leads the
                              center’s efforts to promote research and education.

                              1. re: maria lorraine


                                I have seen this list before. It is not too different from the author description in the report. Almost every single journal article is published by people who specialized it in. You read a particle physic review article. It will be written by a particle physicist. You read a mass spectrometry article and it will be written by a mass spectrometrist. What is so special that an olive oil article which is written by people who do olive oil. It does not make it impressive.

                                If that is the definition of impressive, then every single article is very impressive.

                                1. re: Chemicalkinetics

                                  Er, I think the point you make is that this study, like other studies in other fields, was done by people who work in the specific field. That doesn't seem like alarming. Do you just not like the results? What's the point?

                                  1. re: c oliver


                                    Yes, pretty much.

                                    The results seem fine overall. There a few points which I thought raise some questions. Maybe I will take a closer look, but when I first skimmed at it, I could not find QC (quality control) curves. It would be nice if QC curves are done.

                              2. re: Chemicalkinetics

                                You’ve been very critical of this study, Chemical Kinetics. Design a better one.

                                List the specifics. Put together your dream scientific panel, and the tests that will be used.
                                List the equipment and methods – if not gas chromatography, then what?
                                What do you propose?

                                A healthy skepticism, I respect. But all you’ve done is curmudgeonly point out holes.

                                Tell us what you’d do to detect non-extra virgin olive oil labeled as extra virgin.

                                1. re: maria lorraine

                                  I don't know what is the rationale that I have to design a better experiment to show there are issues with using a GC in this experiment. Even the authors themselves have acknowledged this. So they can point this out and I cannot? Scientific proofs are inevitably based on null hypothesis:


                                  The burden is always on the person who want to prove against the null hypothesis, not the other way around. If a person says eating fish causes cancer, the burden of proof is on that person. Other people do not have to prove fish is not carcinogen. In other words, the burden is not on me.

                                  GC/UV detection were done at a high temperature. These compounds decompose at high temperature. Isn't that an issue? The fact that I can come up a better or not better experiment, does not change the fact that high temperature GC introduces problems.

                                  Since you said "the tests were quite rigorous", can you explain how you come to this conclusion?

                                  My first impression would led me to do it on LC/MS/MS. Nevertheless, the fact that I can come to this conclusion or not, makes no difference in their conclusion. The reliability of their method (or any method) stands on its own. If their data are right, then they are correct no matter what other methods I can come up with. If their data are wrong, then they are wrong even if I cannot think of an alternative.

                                  1. re: Chemicalkinetics

                                    Actually, the burden of proof IS on you. You need to back up your statements and accusations with facts and critical analysis.

                                    You’ve stated this team of scientific experts does not have adequate scientific understanding to make the determinations they have. You’ve cited a lack of professorships, but not all chemists work in academia. You've provided no examination of their scientific credentials. Point out the holes in their scientific credentials and scientific knowledge that proves your statement. Otherwise, you're just saying they're not qualified to write this scientific paper but not why.

                                    You’ve also implied that the heat used in gas chromatography renders the test results unscientific.

                                    Prove it.

                                    Does heat skew the result in every single one of the lab tests?

                                    How many of compounds analyzed are heat stable and thus unaffected by heat? (Take a close look.)

                                    If there is a difference in lab result because of heat, is that difference clinically significant?

                                    Asked anoher way, is the difference big enough to render the test result invalid?

                                    Are the test results for non extra-virgin olive oil so close in value to those for extra-virgin olive oil
                                    that, when correcting for GC heat, the results would then be normal?

                                    Are the organoleptic/sensory (human) analyses affected by heat?

                                    Analyze the numbers for us, showing us where -- in your considered opinion --
                                    the scientists reached their inaccurate conclusions.

                                    Until you do so, until you back up your own statements with facts and critical analysis,
                                    you're sounding like a dentist looking for cavities.

                                    1. re: maria lorraine

                                      "Actually, the burden of proof IS on you"

                                      Not true in my experience when my papers get reviewed or when I reviewed others' manuscripts. Since high temperature GC promotes degradations, it is the responsibility of the authors to ease my doubts, not my responsibility to prove they are wrong. It is never the responsibility of a reviewer to conduct an experiment for the authors. Are you telling me that the next time I submit my paper that if a reviewer raises a question about my experiment design, I can just reply "Prove me wrong"?

                                      “You’ve stated this team of scientific experts does not have adequate scientific understanding to make the determinations they have”

                                      When did I actually say this team does not have adequate scientific understanding? I said it is not a particularly impressive team, no different than an average author list I have seen. That does not translate into your accusation. “Not impressive” is far from being “not qualified”. If I say a car is not particularly impressive, does that mean it is not drivable?

                                      This is not a Phase I or Phase II study. I have no idea what clinically significant has anything to do with this. So, yes, it is not clinically significant.

                                      I didn't say the heat in this study makes the data unscientific. I believe I said it raises questions. Those are different.

                                      Do you know when two people read the same article that they can come out with different conclusions? I am not in a crusade to try to purse you. It appears that the fact that I have the slightest doubt bothers you. If you think there is nothing wrong with this article, fine with me. You just have to understand that other people can have their questions.

                                      1. re: Chemicalkinetics

                                        This is obfuscation. We're talking about your statements. You said that heat raises questions. OK, for which tests? Did heat skew the result of only one test? What about the other nine or so? What's the confidence level of the test results? If the scientists' credentials are not impressive, what makes them not so, apart from their lack of professor status? What credentials would be impressive? Back up your statements. Give specifics.

                                        In short, subject your statements to the scientific rigor you demand of others.

                                        1. re: maria lorraine

                                          Like I said, if you like the paper, you like the paper. If this is an impressive author list which you have never seen, good for you. Why do you care that I am unimpressed? Did I tell you that you have to unimpressed? Why do you try to force me to say the list is impressive? I said it over and over. I just don't see the list any more impressive than most author lists I have seen in other papers.

                                          You just have to respect other people drawing a different conclusion. It is not my responsbility to do their experiments for them. Those questions you have are for authors not for readers (me).

                                          Have you ever written a peer-reviewed scientific manuscript?

                                          1. re: Chemicalkinetics

                                            Just explain *your* statement that heat raises questions on the ten lab results. You've said several times you're not impressed by the authors' credentials. OK, I get that. Why not? What would impressive credentials be in olive oil chemistry?

                                    2. re: Chemicalkinetics


                                      An absolutely key point here is that the tests used are precisely the tests that are required for olive oils to be certified as extra virgin by the keepers of the international standards. I have no doubt that a knowledgeable chemist could come up with better, more sophisticated methods of analysis, but that wouldn't tell us anything about the extra virginity of the oil.

                                      The facts here are: 1. the study tested oils using the international standards for extra virgin olive oil. 2. two thirds of the imported oils tested failed those tests despite their being labeled extra virgin. 3. nine tenths of the domestic oils tested checked out as being legitimately extra virgin.

                                      The interesting thing is that the US has no official criteria for allowing the label designation "extra virgin". Near as I can tell any olive oil can be labeled extra virgin in the US. The only rule is that it must contain olive oil and not be adulterated with some other food oil (which is often done if one believes several credible reports going back to that New Yorker article a few years ago). The USDA is on the edge of adopting the international standards for labeling olive oil. That would be a big step forward except for one reason: It's voluntary.

                                      At the end of the day, you have to trust your supplier. This report certainly leads me to consider our domestic oil producers as being a damn sight more deserving of that trust than the bulk oil importers.

                                      I wish that many more oils were tested. I would expect (based on my own personal taste tests) that a lot of imported oils would pass handily. But those oils would certainly not be the cheapest on the shelf as some of the failures in this group are.

                                      1. re: Gustavo Glenmorangie


                                        Thanks. My original points are two. First, the author list does not jump out at me as extra impressive. It seems normal for any scientific journal article. Remember that you wrote that “No red flag there and certainly nothing unusual” and I agreed but focused on “nothing usual”. I also wrote "There is nothing really wrong with this team, but it seems like a normal team to me." Just because I don’t think the list is very impressive, it does not mean I think the list is horrible. It just looks average to me, like most scientific journal. It is not a put-down. If I have to say this is an impressive list, then I will have to say that for 70-80% of the journal articles I read, which inflate the meaning of “impressive”. If I have to rank the impressiveness of this author list, I rank it about 5-6 out of 10 (7 at the best). Maybe you give it a 9 or 10 among what you read. I don't know, but it is a personal thing.

                                        My second point is that this study is not what I consider as very rigorous, and certainly not what I consider an elegant study. Then again, I don’t think most journal articles are elegant. I also don’t believe a single of my own publications is elegant. Haven’t you ever gone to conference session, the speaker covered point to point very clearly and the experiments were well-controlled? At the end of the seminar, you said to yourself “Wow, I wish I can do that” and the rest of the audience gave a long clap. This study does not come across to me like that. It is unpolished with rough spots here and there.

                                        Think of it like movies. There are some real impressive movies and there are some really horrible ones. Majority are average and in between. I think when I said it is not impressive, it does not mean it is horrible.

                                        1. re: Gustavo Glenmorangie

                                          The new USDA standards for olive oil go into effect this fall. They're the same standards that the California Olive Oil Council (COOC) and International Olive Council (IOC) use.

                                  2. re: Gustavo Glenmorangie

                                    <<If I were to raise an issue it would be that it doesn't look like it's been peer reviewed. I would certainly feel better about it if it were.>>

                                    The study of the brands in the UC-Davis was an outgrowth of this peer-reviewed article in the May, 2010, The Journal of Agricultural and Food Chemistry:

                                    “Chemistry of Extra Virgin Olive Oil: Adulteration, Oxidative Stability, and Antioxidants”
                                    Edwin N. Frankel
                                    Department of Food Science and Technology, University of California, Davis, California 95616
                                    J. Agric. Food Chem., 2010, 58 (10), pp 5991–6006
                                    DOI: 10.1021/jf1007677
                                    Publication Date (Web): April 30, 2010

                                    What we’ve been discussing is the “magazine article” or the news version of the story.
                                    The language is less scientific and technical, and there is far less detail on the methodology and results.

                                    Report: Tests indicate that imported “extra virgin” olive oil
                                    often fails international and USDA standards”

                                    1. re: maria lorraine


                                      The J. Agric Food Chem article appears to be a nice article. However, it is a perspective article or review article. It summarizes what other experts have done in the field. In this case, Frankel mentioned various avaliable analytical methods, from RP-HPLC, to APCI-MS. Frankel argues for two major points. First, many people focus too much on statistical methods and not enough on analytical methods. Second, too much literature is based on sensory tests which are highly variable and subjective.

                                      This perspective article is independent of the magazine article.

                                  3. re: Chemicalkinetics

                                    "4-7 infamous professors"

                                    INFAMOUS -- ??

                                    Infamous: Well known for some bad quality or deed,Wicked; abominable: "infamous misconduct"

                            2. re: eatzalot

                              >>>But when results are accurate and rigorous, they don't become less so because someone with a competing product funded the study.<<<
                              absolutely correct.

                              1. re: alkapal

                                Corollary: Judge the researchers by the ultimate quality of their results, not the results by the researchers.

                                Chemicalkinetics raised some good technical points (though I couldn't tell whether Chemicalkinetics knows this particular specialty -- its literature, procedural conventions, related work). But that first comment about the team containing just one full professor (albeit in context of "scientific panel") raised a flag to me. Mary-Claire van Leunen in her _Handbook for Scholars_ (about 1979) wrote that in scholarly circles it's widely understood that the work's quality gauges the author's credentials, not vice versa. Maybe some specialties have protocols about certain occupational titles authoring papers. But in many years refereeing formal technical papers I've always focused on the work itself.

                                Advertising an author's formal rank or credentials, as if that measured the quality of his/her conclusions (rather than vice versa), is a practice I associate more with pop culture, like TV documentaries or mail-order psychics.

                                  1. re: c oliver

                                    Olive oil (unlike, say, quasars or classical philology) is an intensely practical, commercial topic. In such situations, the best science may even come from industry workers without academic position, who merely know the subject best. Contrast the discussion above about whether the author list is "impressive" (measured, please note, by academic titles or labels, without even reference to the authors' peer standing, past body of work, citation in other work, etc.).

                                    Also, researchers with dramatic results do, obviously, bear a burden of proof to their field. They bear NO responsibility to satisfy casual Internet critics who (standing on one foot?) show uncertain familiarity with the specialty, and acknowledge just skimming the work. (Casual critics have been the curse of other Internet consumer-science discussions for the decades I've been reading them.)

                        2. Yes, I've heard about this for quite some time now. Thanks for including the report. Someone I know has said that the highest figure he has found was 50% of extra virgin olive oil was canola. He didn't mention the brand.

                          12 Replies
                          1. re: Miss Needle

                            The amount of fraud on packaged goods labels is staggering. For kicks, I occasionally read the list of FDA lawsuits for fraudulent claims -- most of this stuff never gets in the news. The few manufacturers the FDA actually sues is just a small portion of who could be sued. And, of course, the FDA is no paragon of virtue either. Oh my, I'm sounding cynical.

                              1. re: coney with everything

                                I don't know what that means, but with the new USDA standards in place this fall, that means olive oil companies will be much more vigilant regarding storage issues even after the oil is pressed. They'll have to make sure that storage issues don't cause the extra virgin oil to degrade into virgin oil, and that the consumer actually gets what s/he pays for. This is good news, especially when a bottle of good extra virgin olive oil can cost anywhere from $13 to $30.

                                1. re: maria lorraine

                                  while an extra virgin oil can degrade from heat (i get that), isn't a first-pressed ("extra virgin") oil *always* a first-pressed oil? i guess you're referring to its acidity?
                                  for regulatory purposes, it is in the range of "virgin" oils, but in reality it is "extra-virgin" (first press) in origin. that fact doesn't change, though, regardless of the acidity level or regulatory criteria.

                                  am i confused about extra virgin vs. virgin, maria?

                                  1. re: alkapal

                                    Cold pressing is only part of the equation, and it's the easy part. A bigger issue is the freshness of the olives. Olives have to be pressed within 24 (12 is better) hours of harvest. They start to deteriorate as soon as they are picked. With time, free acidity starts to go up and they become rancid and moldy. This is especially a problem in traditional, low-tech areas. One advantage California has is that everything is new and designed to get the olives from the trees and through the press quickly. Many millions of dollars have been invested in building some of the largest capacity oil mills in the world.

                                    Of course, there are lots of new, highly efficient oil mills in Europe too. But there are still many, many old and inefficient ones there. And lots of small scale orchards where farmers hold their olives for days to accumulate enough to take to the mill. A lot of the supermarket oils coming from Europe try to position themselves as being Italian, but if you read the small print, you'll see that they are simply blended and bottled in Italy. The oil itself may be from anywhere. A lot of it is from Tunisia which produces a tremendous amount of olive oil but is especially problematic in terms of quality control.

                                    1. re: Gustavo Glenmorangie

                                      Easy part? Almost NO olive oil anymore is actually cold pressed....Its such a blatant lie. ...I've visited 13 olive mills all over Italy and Greece, and they all laugh when you mention cold press.....cold press is what they do when they turn out a few hundred liters for their own personal use...Almost everything on the shelves uses hot water during the washing process.

                                    2. re: alkapal

                                      Re: alkapal

                                      When extra virgin olive oil is stored on store shelves for too long, or stored improperly (at too high a heat) or exposed to light, it is no longer an extra virgin oil and won't taste like one.

                                      That's where the many brands on store shelves fall short, and how consumers are deceived. The bottles are labeled extra virgin, but the contents are not. This is why it is important for manufacturer reps to swap out stock on store shelves. This will become law this October, 2010.

                                      Certain chemical changes take place in old or improperly stored EVOO. The polyphenols decrease, which means a decrease in aroma and flavor. Oxidation increases, and this is measured both as a peroxide value and as the number of conjugated dienes and trienes (the unconjugated bonds become conjugated with oxidation). "Acidity" in olive oil is a bit of misnomer, since pH doesn't apply to oils. What "acidity" refers to is free fatty acids (FFA), which break off the main fat molecule triacylglycerols (TGA), if the olives have a long lag time between picking and pressing, if the olives are damaged in processing, or if heat or solvents are used in processing. Acidity doesn't increase with age.

                                      The standard rule still applies: A consumer should never buy an extra virgin olive oil that is not from the latest harvest. Some brands are clearly date-stamped, but most brands have a date-code somewhere on the bottle that one needs to decipher. In that case, the year is fairly easy to detect, something as simple as 10 for 2010. The manufacturer's customer service hotline can help you decipher the date code if you're concerned you've purchased old oil.

                                      1. re: maria lorraine

                                        maria, how old is too old? And would that mean it should be tossed? I'm kinda miserly with the "better" stuff so maybe this is the perfect excuse not to be? TIA.

                                        1. re: c oliver

                                          Wish I could tell you that this number of months was OK and this number was not. But we are talking months, not a full year, and the age of the oil when purchased from the store will have a great bearing on how long it can be held at home. Like Bob96 said, taste will tell you. I buy fresh a quart or half-gallon of EVOO from a nearby producer, and because I'm so concerned it's going to go bad, I store the bottle in the refrigerator and take out a small quantity every week or so.

                                          The first sign of age for me is that oil doesn't smell as fruity or aromatic, and the taste is no longer as alive and vibrant, as it once was. From that point forward, there's a steady decrease in aromatics and flavor, and a steady increase of subtle rancid aromas and flavors. Were I you, after I'd noticed a dropoff in aromas and flavors, I'd no longer use the oil as a finishing oil or in vinaigrettes/dressings, but might use it for frying. Sorry I can't be more helpful that merely to say: Remember the smell and taste of the fresh extra virgin olive oil, and compare each subsequent taste of the oil against that.

                                          1. re: maria lorraine

                                            Maria, much of this applies also to food oils in general.

                                            Not only do desirable flavors change, but oxidation greatly accelerates when a bottle is opened periodically, letting fresh air in. Writers on food science have cautioned consumers for years to become sensitive to rancidity smells, and refrigerate oils (retarding degradation processes in general), because oxidized oils are considered particularly unhealthy (however much Russ Parsons may write that they are catalytic in French frying). I notice rancidity smells developing in my (refrigerated) olive oils within a few months of opening, so I buy only moderate amounts at a time, and mark the date when I get them.

                                            1. re: maria lorraine

                                              Maria, the point you make about time speaks loudly to me. I used to buy a large (maybe 1 1/2 - 2 liter) bottle of Colavita in BJ's thinking I was saving money. By the time I got to the second half of the bottle, it started to smell off, then rancid to me. Now I'll buy a pint of whatever looks nice and is fairly reasonable in the market and at least have not have not had any rancidity issues.

                                            2. re: c oliver

                                              Try to use it within a year of harvest date. If you have Fall 2009 - Winter 2010 oil in the cupboard, plan to use it up by the time the 2010-11 oils start hitting the shelves.

                                              A lot of producers are getting into the Italian tradition of Olio Nuevo, ultrafresh oil that is usually avaiable in November. Sort of like Beaugolais Nouveau except that it's the very best quality, not a gimmick.

                                2. ML,

                                  I find the use of the word "fraud" a little strong here. Fraud means intentional deceit. The report itself only uses the word fraud in reference to "media reports of fraud" where olive oils have been adulterated with less expensive oils or refined olive oil. This study did not find any conclusive evidence of adulteration.

                                  The most commonly failed chemical tests may be due to oxidative damage to the oil after it left the producer, say during shipping across an ocean, as opposed to being trucked fewer than a couple hundred miles across CA. I think the observation that different samples of the same brand tested differently supports this notion.

                                  While I don't question the motives of the scientists who produced this report or the veracity of their results, I don't think one can hang a claim of widespread fraud based on this evidence.

                                  4 Replies
                                  1. re: kmcarr

                                    Also looks like they are all LC or GC/UV methods for most of the analytical methods, which can have interference measurements due to the relatively nonspecific of UV absorption. Unfortunately, that may be the limitation here which they are dealt with. GC is also a fairly questionable method to use here because GC is done at high temperature, so the analytes of interest will be unstable and undergo decomposition. It is a problem when the goal of the study is to look at decomposition while the analytical technique also promotes decomposition. At least the authors mentioned that. It is unfortunately, nevertheless.

                                    In addition, standard calibration curves can be off. That is one common error. Afterall, all the quantitation numbers are based on the integrity of those curves. Finally, I see standard curves, but I don't see QC curves. Maybe I missed it, but it would be a poor experimental design without quality control curves.

                                    1. re: kmcarr

                                      <<I find the use of the word "fraud" a little strong here.>>

                                      I thought about the word before I used it. False advertising and false billing are considered fraud.

                                      "Our laboratory tests found that samples of imported olive oil labeled as “extra virgin” and sold at retail
                                      locations in California often did not meet international and US standards."

                                      The study said that "chemical testing indicated that the samples failed extra virgin
                                      standards for reasons that include one or more of the following:
                                      • oxidation by exposure to elevated temperatures, light, and/or aging;
                                      • adulteration with cheaper refined olive oil;
                                      • poor quality oil made from damaged and overripe olives, processing flaws, and/or improper oil storage"

                                      Manufacturers had to have been aware that their oils were oxidized, had been diluted with cheaper oil, or were made from less than quality fruit sources. If they were not aware, then that lack of oversight and quality control is the problem.

                                      1. re: maria lorraine

                                        Sorry, I'm still not seeing fraud here. There are too many sample to sample variations to make me comfortable with such a condemnation. Look, for example at the Safeway select brand. Two of the samples pass all objective chemical tests, while one fails significantly on four of the tests. This leads me to wonder whether that one sample was somehow mishandled by someone other than the producer or if the testing methods have a wide degree of variability. I also am not comfortable tacking a fraud label on someone strictly based on sensory tests. All three of the Filipo Berio samples passed all objective tests but two of the three were labeled "virgin" by the sensory panel. I'm not going to accuse someone of a crime based on that evidence.

                                        1. re: kmcarr

                                          I responded to this below. Appreciate your concern.

                                    2. If it were a private lab doing the test, I would be more wary of the connection between the lab and the CA Olive Council. However, this is a university where funding lives and dies based upon their reputation. UC Davis is a very credible university with a well known food science program.

                                      Also, I'm always skeptical of "imported" goods so I guess I'm not surprised by the results.