olive oil is there a chemist there?

Discussion in 'Food and nutrition' started by Nick, Dec 24, 2003.

  1. Nick

    Nick Guest

    Is there a DIY test to see if the olive oil I was given in a bottle whilst on holiday is really
    olive oil? A test I can do in my kitchen using typical kitchen equipment. The oil might be diluted
    with some other oil, which is not unusal, and no attempt would have been made by the adulteres to
    make testing difficult enough to require a lab.

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  2. "nick" <[email protected]> wrote in message
    news:[email protected]...
    > Is there a DIY test to see if the olive oil I was given in a bottle whilst on holiday is really
    > olive oil? A test I can do in my kitchen using
    typical
    > kitchen equipment. The oil might be diluted with some other oil, which is not unusal, and no
    > attempt would have been made by the adulteres to make testing difficult enough to require a lab.

    Try crossposting to one or two of the chemistry related forums. I'd bet Uncle Al might just rise to
    the challenge. I'll suggest that since adulterate oils would contain more polyunsaturated, the
    temperature at which the oil turns into a soft solid would be lower in the adulterated oil. I'd
    suspect "mild" adulteration would be done with rapeseed oil as it contains a fair large percentage
    of monounstaturated fatty acids. Still it contains more polyunsatururated fatty acids than olive oil
    if I recall correctly. You would have to work your own standards based on good olive oil, a sample
    of rapeseed oil, a sample sunflower seed oil, and soy oil. Of course the adulerator may have also
    used a bleached palm oil, in addition to rapeseed oil with result the solid point might be quite
    similiar to the real thing.

    Costco sells a pretty good dark virgin olive oil. It isn't cheap, I think is about 10 dollars a
    liter. It is in a dark bottle which help slow the oil from degrading. Olive oil in clear bottles is
    a bad idea as even a day under fluorescent lights will result in taste changes.

    A color change induced by some chemical change at unsaturated bond might work though a device to
    quantify the color change might be needed.

    OK I recall now it is an "unsaturation test", (I refreshed myself with a book) I did this one "back
    in the day". You need test tubes, some potassium permanganate, an accurate scales $$, methylene
    chloride, bromine solution (damned nasty stuff that HBr solution). Any intro to organic lab
    techniques textbook would complete the discussion of how to. You need a decent lab if simple lab for
    this one. Plus you need the antidote for HBr contact..........as I recall

    Heres another test the Baeyer test, you may need some solvents possible "just" ethanol or isopropyl
    alcohol, a 1% solution of potassium permanganate. Problem is that it will detect all double bonds
    and hence your oils will make a lot of brown ppt. It would take a fair bit of fussing and accurate
    screwing around to get a technique that would yeild some hints. You need to measure the weight of
    brown ppt from each standard oil and your assay oil.

    No longer "back in the day"............ ...........................William A. Noyes
     
  3. On Wed, 24 Dec 2003 13:39:50 +0000 (UTC), "nick" <[email protected]>
    wrote:

    >Is there a DIY test to see if the olive oil I was given in a bottle whilst on holiday is really
    >olive oil? A test I can do in my kitchen using typical kitchen equipment. The oil might be diluted
    >with some other oil, which is

    Perhaps buying a used gas chromatograph or HPLC. Could be a nice ktichen aid :)

    But otherwise, no.
     
  4. Amanda

    Amanda Guest

    Alf Christophersen <[email protected]> wrote in message news:<[email protected]>...
    > On Wed, 24 Dec 2003 13:39:50 +0000 (UTC), "nick" <[email protected]> wrote:
    >
    > >Is there a DIY test to see if the olive oil I was given in a bottle whilst on holiday is really
    > >olive oil? A test I can do in my kitchen using typical kitchen equipment. The oil might be
    > >diluted with some other oil, which is
    >
    > Perhaps buying a used gas chromatograph or HPLC. Could be a nice ktichen aid :)
    >
    > But otherwise, no.

    In that case, take it to the Chem Dept at a nera by University and talk to a Chem professor who has
    that instrument. He might just give it to one of his grad student as EXTRA workload.
     
  5. Amanda

    Amanda Guest

    "nick" <[email protected]> wrote in message news:<[email protected]>...
    > Is there a DIY test to see if the olive oil I was given in a bottle whilst on holiday is really
    > olive oil? A test I can do in my kitchen using typical kitchen equipment. The oil might be diluted
    > with some other oil, which is not unusal, and no attempt would have been made by the adulteres to
    > make testing difficult enough to require a lab.
    >
    >
    > ---
    > Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com).
    > Version: 6.0.554 / Virus Database: 346 - Release Date: 20/12/03

    GO TO sci.chem. I bet someone can guide you where to go get that oil tested.
     
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