Re: Bichromate Sausages
But this is the same idea as the sausage casings in the 1870
campaign; the dichromate is used as an crosslinking agent to seal
the sausage casing; either way one would not be ingesting hexavalent
dichromate, as the unused hexavalent dichromate would be washed out
and the reduced (to whatever extent) chromium would be fixed in the
insoluble gel, and not dangerous. That's the difference between the
idea of using dichromate for an oxidizing agent to seal sausage
casings and the idea that dichromates were used as an ingredient in
the sausage. It seems a small difference, but it's actually a big
difference. But I do appreciate the irony you intended.
kt
On Jan 9, 2007, at 10:28 AM, Tom Sobota wrote:
Ah, but sausages seem to have a strange affinity for dichromates
and I'm not sure if this should be taken as funny or rather
dramatic :-)
Citing US Patent 6797015 (from http://www.freepatentsonline.com/
6797015.html)
"Method for producing transparent, colored cellulose sleeves.
Abstract: Process for producing dyed, tubular food wrappings from
non-woven fabric coated with regenerated cellulose, characterized
in that an alkaline dye liquor containing at least one dye which
has been previously converted into an alkali-soluble form by
chemical reduction and which can be converted into its insoluble
form by oxidation is admixed to the viscose solution used for the
production of the layer of regenerated cellulose, a tubular non-
woven fabric is coated with the mixture of viscose solution and dye
liquor, the viscose is coagulated and regenerated to form cellulose
hydrate gel and the dye distributed in the viscose is reconverted
into its insoluble form by oxidation; tubular food wrappings
produced by this process and their use as synthetic casings for
sausages..."
Later on, the patent explains that "...After the material has been
rinsed, the oxidation is carried out and the original water-
insoluble dye, which adheres well to the cellulose material, is
again formed from the leuco form. Examples of suitable oxidising
agents are atmospheric oxygen, hydrogen peroxide, sodium perborate
and potassium dichromate."
This is probably OT, but I couldn't resist...
Tom Sobota
Madrid, Spain
Liam Lawless wrote:
Just for fun, here's the passage referred to, from Vogel's 'The
Chemistry of
Light and Photography in their Application to Art, Science, and
Industry'
(mine is 6th, ed., 1892):
Section XII. - THE CHEMICAL ACTION OF LIGHT, AND THE PEA-SAUSAGE.*
In the campaign of 1870, the well-known pea-sausage was one of the
most
important articles of food for the army, and was prepared daily by
thousands. The fabrication of the interior portion caused little
difficulty, but the obtaining so many skins created much
difficulty. As the
supply fell short, a substitute was sought in vegetable
parchment. This
paper, which is produced by dipping blotting-paper in sulphuric
acid for
about a second, then washing and drying, is distinguished by its
skin-like
properties of resistance. It is impenetrable to water, and
difficult to
tear. It is therefore used for the production of bank-notes. It was
attempted to make sausage skins of this paper, by doubling a skin
cylindrically and pasting it together. No glue or gum can however
resist
the effect of the boiling water in which the sausage has to be
cooked, and
so the artificial sausage skin fell asunder. Dr. Jacobson solved the
problem by producing an adhesive substance, with the help of the
chemical
action of light, which could resist boiling water. He mixed the glue
intended for the sausage skin with bichromate of potash, and
exposed the
glued parts to the light. This made the glue insoluble, and now the
artificial skin endured boiling water thoroughly well. The number of
sausage skins prepared in this way, by the chemical action of light,
amounted to many hundred thousands.
* Erbswurst.
Liam
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