Text 6254, 100 rader
Skriven 2006-10-06 19:49:46 av Barbara McNay (1:382/48)
   Kommentar till text 6101 av JOAN MACDIARMID (1:123/140)
Ärende: shrimp etc. 289
=======================
 >  Hi, Barbara,

 >>  BM> Would you explain what you mean by "a persistent toxin comparable to
 >>  BM> botulin", please?  I have sort of been under the impression that one
 >>  BM> could eat botulin spores with no problem; that it was only the toxin
 >>  BM> from improperly processed foods that caused the problem.

 >>  Botulin is the toxin made by botulinium bacteria.
 >>  They are anaerobic bacteria, able to thrive in
 >>  oxygen-free environments, and might even be
 >>  unable to thrive in O2-rich environments, so
 >>  the spores stay dormant on our plates and in
 >>  our system. But if they are not killed off
 >>  as a food is being canned, they can activate
 >>  and live happily in the sealed cans and jars,
 >>  eating our soup and vegetables and creating
 >>  botulin toxin, which builds up to a dangerous
 >>  dose. Cooking kills off any live bacteria but
 >>  that toxin is apparently heat-stable (thus I
 >>  used the term persistent) and isn't degraded
 >>  by any amount of normal cooking.

 >>  Again, I am not an expert, I could be wrong
 >>  on some details, but I remember this from
 >>  general reading on stuff like this.

 >  BM> It has been many years since I've canned, so I don't have my
 >  BM> references available, but my recollection is that we are advised to
 >  BM> boil home-canned food for ten minutes or so to destroy any toxin.  If
 >  BM> the bacteria themselves didn't harm, there would be no point in
 >  BM> boiling.  I also seem to remember an article about a picnic at which a
 >  BM> canned three-bean salad made its eaters sick--all except one, who came
 >  BM> late, thought the beans were supposed to be hot, so heated them first
 >  BM> and didn't get sick.  Perhaps somebody with more recent canning
 >  BM> experience and references can help us out.

 >  Well, there are more bacteria than botulinium to
 > worry
 >  about. Salmonella is a more constant worry. But safe
 >  cooking seems to defuse that and any toxins it
 > produces.
 >  Botulism scares us because it isn't prevented by our
 >  safe cooking procedures. We must trust our canners.

Well, according to the canning manuals as I remember, yes, we must trust our
canners, but only if we check the gauge annually and boil the canned goods
before eating. Home canning, I guess, has problems with faulty equipment and
faulty usage.  My MIL had a canner with a badly frosted glass over the gauge,
and it was all right, she said, because she knew "about where it (the indicator
and pressure marking) was supposed to be." There are a lot of variables in home
canning that can make the results unsafe, although spoilage certainly happens
in commercially canned products, too, and for probably the same reason:  human
variability.

 >  Note added later: I just ran across a news article
 >  dealing with some of this stuff. For those who
 >  didn't see this AP article in their papers,

 >  "Germs in food make 76 million Americans sick, send
 >  323,000 to hospitals and kill 5000 each year, the
 >  CDC estimates. But the situation greatly improved
 >  over the last decade, according to illness statistics
 >  the agency reported Friday at a conference of the
 >  American Society for Microbiology. In 2005, compared
 >  with the 1996-98 period when the CDC's FoodNet
 > tracking
 >  system began, illnesses were down for virtually every
 >  major germ.

 >  CDC estimates the declines as follows: yersinia, 49%;
 >  shigella, 43%; listeria, 32%; campylobacter, so%;
 >  the dangerous O157 strain of E. coli, 29%; and
 >  salmonella, 9%. Only vibrio, a germ spread through
 >  raw oysters, rose significantly - 41%.

 >  Campylobacter and salmonella sicken the most
 >  people, usually through raw or undercooked poultry
 >  or eggs. Yersinia can taint raw meats, seafood and
 >  dairy products. Listeria causes problems in
 >  lunchmeats and soft cheeses. E. coli outbreaks
 >  typically have involved undercooked ground meat.
 >  But in recent years, the germ has increasingly
 >  been linked to produce, as has a certain strain
 >  of salmonella."

 >  Excerpted from article by Marilynn Marchione, AP.

I don't know whether any of these infect canned products, but botulism is not
the only thing that can go wrong with canned goods.  When I was younger and
living with another family, I perceived a difference in taste between two
bottles of catsup, and I wouldn't take from the emptier bottle, but only from
the new, and was criticized for it.  A week or so later, one of the family came
and apologized to me, saying that there was mold in that catsup bottle.  I was
astounded, and didn't believe it, so asked to see the bottle.  And there it
was, greenish and in plain sight, growing on the glass, not loose, and nobody
had seen it before.  I guess it wasn't poisonous, as they had been eating it,
but it sure didn't taste good.

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 * Origin: T E X A S ! (1:382/48)