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Thread: Questions of life-roast beef

  1. #1
    z z Guest

    Default Questions of life-roast beef

    What exactly is that green iridescent sheen on slices of roast beef?
    I've seen it a million times at the work cafeteria and I dont buy their
    beef anymore because it is repugnant to me, though apparently considered
    edible. This wkend it was on the slices of roast beef bought at our
    "premium" grocery store meat counter.


  2. #2
    spamtrap1888 Guest

    Default Re: Questions of life-roast beef

    On Jul 22, 7:52*pm, angie-...@webtv.net (z z) wrote:
    > What exactly is that green iridescent sheen on slices of roast beef?
    > I've seen it a million times at the work cafeteria and I dont buy their
    > beef anymore because it is repugnant to me, though apparently considered
    > edible. This wkend it was on the slices of roast beef bought at our
    > "premium" grocery store meat counter.


    Your tax dollars at work:

    9. What causes iridescent colors on meats?
    Meat contains iron, fat, and other compounds. When light hits a slice
    of meat, it splits into colors like a rainbow. There are various
    pigments in meat compounds that can give it an iridescent or greenish
    cast when exposed to heat and processing. Wrapping the meat in
    airtight packages and storing it away from light will help prevent
    this situation. Iridescence does not represent decreased quality or
    safety of the meat.

  3. #3
    Julie Bove Guest

    Default Re: Questions of life-roast beef


    "z z" <[email protected]> wrote in message
    news:[email protected]..
    > What exactly is that green iridescent sheen on slices of roast beef?
    > I've seen it a million times at the work cafeteria and I dont buy their
    > beef anymore because it is repugnant to me, though apparently considered
    > edible. This wkend it was on the slices of roast beef bought at our
    > "premium" grocery store meat counter.


    Good question. I have seen it on very expensive organic beef but didn't
    know what it was.



  4. #4
    Sqwertz Guest

    Default Re: Questions of life-roast beef

    On Sun, 22 Jul 2012 20:37:10 -0700 (PDT), spamtrap1888 wrote:

    > 9. What causes iridescent colors on meats?
    > Meat contains iron, fat, and other compounds. When light hits a slice
    > of meat, it splits into colors like a rainbow. There are various
    > pigments in meat compounds that can give it an iridescent or greenish
    > cast when exposed to heat and processing. Wrapping the meat in
    > airtight packages and storing it away from light will help prevent
    > this situation. Iridescence does not represent decreased quality or
    > safety of the meat.


    Any time I see that iridescent sheen it always means it's past it's
    prime. Especially in sliced deli meats - the smoother the surface the
    more apparent it is, but it doesn't show up for a few days - has been
    my experience with buying deli roast beef (although rare).

    -sw

  5. #5
    Janet Bostwick Guest

    Default Re: Questions of life-roast beef

    On Sun, 22 Jul 2012 21:52:40 -0500, [email protected] (z z) wrote:

    >What exactly is that green iridescent sheen on slices of roast beef?
    >I've seen it a million times at the work cafeteria and I dont buy their
    >beef anymore because it is repugnant to me, though apparently considered
    >edible. This wkend it was on the slices of roast beef bought at our
    >"premium" grocery store meat counter.


    It's light refraction of various compounds in the meat fluids. (I want
    to say blood, but am trying to be sensitive to the ick factor in some
    people) It does not mean the meat is spoiled.
    Janet US

  6. #6
    Brooklyn1 Guest

    Default Re: Questions of life-roast beef

    On Sun, 22 Jul 2012 21:52:40 -0500, [email protected] (z z) wrote:

    >What exactly is that green iridescent sheen on slices of roast beef?
    >I've seen it a million times at the work cafeteria and I dont buy their
    >beef anymore because it is repugnant to me, though apparently considered
    >edible. This wkend it was on the slices of roast beef bought at our
    >"premium" grocery store meat counter.


    That irridescent rainbow effect is caused by the type of lighting
    used, delis and meat departments typically illuminate meat with a lamp
    of a particular spectrum that enhances the appearence of meat,
    typically more red... meats actually fall into the grey scale, it's
    only lighting that gives it that attractive red color by a prismatic
    effect, just like fish scale and bird feather coloration is prismatic
    so are cell walls of flesh, not due to pigmentation. As the surface
    of meats dry the prismatic effect is more pronounced, same as wet
    birds look dull but once dry their color appears more pronounced.
    Anyone who has a home aquarium knows that their fish exhibit no color
    until the tank is lit. The coloration of objects is determined by
    what our eyes transmit to our brains, everyone sees color differently.

  7. #7
    gloria p Guest

    Default Re: Questions of life-roast beef

    On 7/22/2012 8:52 PM, z z wrote:
    > What exactly is that green iridescent sheen on slices of roast beef?
    > I've seen it a million times at the work cafeteria and I dont buy their
    > beef anymore because it is repugnant to me, though apparently considered
    > edible. This wkend it was on the slices of roast beef bought at our
    > "premium" grocery store meat counter.
    >



    A reply from Google/Yahoo from 2006:

    "It means nothing. Its totally normal and its called birefringence.

    Here's the deal. The cut surface of meat is pretty smooth. But, if you
    look closely, you'll see it's actually a vast landscape of parallel
    fibers. When cut, the reduced surface pressure coaxes microscopic beads
    of moisture to the surface, each one of which acts as an independent
    prism. When viewed in concert, they look like a rainbow."



    gloria p

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