From: hank@well.sf.ca.us (Hank Roberts)
Subject: Re: dangers of microwaving
Organization: Whole Earth 'Lectronic Link
Date: Tue, 29 Sep 1992 23:48:46 GMT

In <16643@pitt.UUCP> geb@cs.pitt.edu (Gordon Banks) writes:

>In article <1992Sep23.232222.1@kean.ucs.mun.ca> mgomes@kean.ucs.mun.ca writes:
>>
>>
>>    Long ago I came across this controversy about the possibility
>>that microwaving food would change some organic molecules in such a
>>way that they might become cancer promoters.

>Any kind of charring or burning can do this, but I'm not familiar
>about microwaving making any difference.  Sounds crackpot to me.
>-- 
>----------------------------------------------------------------------------
>Gordon Banks  N3JXP      | "I have given you an argument; I am not obliged
>geb@cadre.dsl.pitt.edu   |  to supply you with an understanding." -S.Johnson
>----------------------------------------------------------------------------

Here are two tidbits I archived on our local system a while back; these
are _my_ paraphrases and brief quotes from published articles, so please
refer to the actual articles for reliable info.  This is just my understanding
of what the writers were getting at:

WSJournal, Tuesday 10-22-91 at page A9A (the page following 'A9')
Quoting and paraphrasing an article by Sonia Nazario of the WSJ staff:
...
"The two-year study, published yesterday by the International Journal of
Cancer, says that apart from the amount of meat consumed or its fat
content, the way it is prepared can significantly increase the rate of
colon and rectal cancers in humans ....
...
The study in the Journal, an independent publication based in Switzerland
...
indicated that ... meat that has been browned by frying,...meats boiled or
served with meat gravy, can boost risks of cancer...."This study shows
that cooking methods are very important in preventing cancer," says Maria
Gerhardsson de Verdier, a visiting research scholar at the University of
Southern California (Preventive Medicine)...author of the study.
 
"This really is the first study that has done a comprehensive job of
looking at how people prepare meat and the risks of colon cancer," says
James F.  Felton, a group leader for molecular toxicology at the
University of California's Lawrence Livermore National Laboratory and
another leading researcher in the area....
 
Dr. Gerhardsson ... speculates that the problem with highly browned meats
is the formation of at least 10 heterocyclic amines ...which ...form in
meat crust at high cooking temperatures\... formation of the chemicals
"goes up logarithmically" at temperatures higher than 300 degrees F. ...
 
The study looked at 559 patients with colon or rectal cancer and a control
group of 505 individuals, and compared their cooking methods.
 
"Dr. Felton noted that his studies have found that some cancer-causing
chemicals formed in cooked meats can be reduced 20 to 30 times by
microwaving meats for one minute and removing the juices formed before
cooking the meat with any other chosen method."

 =====================

Looks like there are distinct differences between
heat and microwaves in cooking foods:
 
New Scientist 18 Jan. 1992, at 20
Why Microwave Cooking Fails the Taste Test by Julie Johnson
 
quoted and paraphrased (hank)
 
...acccording to two American chemists, Helen Yeo and Takayuki
Shibamoto of the University of California, microwave irradiation
does not provide the right conditions for the chemical reactions
which help a full flavour to develop.
 
CITE: Trends in Food Science and Technology; Dec. 1991, p. 329
 
Desirable flavours:              Undesirable flavours:
 
   _N    Thiazole                 _N      Oxyazole
 //  \\  meaty                  //  \\    Fishy
   \ /   like popcorn            \  /     like green vegs.
    S                              O
 
   _      Furan                    _      Thiophen
 //  \\   sweet                  //  \\   onions
  \  /    like caramel            \  /    sulfurous, burnt, rubbery
    O     nutty/buttery             S
 
 
    N     Pyrazine                __      Pyrrole
  //  \   sweet                 //  \\    pungent
  |   ||  nutty                  \  /     like boiled corn
  \\  /   roasted                  N      like hay
    N     like bell peppers        H      
 
================ Claimer: my paraphrases
Newsgroups: sci.med