Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site redwood.UUCP Path: utzoo!watmath!clyde!bonnie!akgua!gatech!seismo!lll-crg!qantel!hplabs!fortune!redwood!rpw3 From: rpw3@redwood.UUCP (Rob Warnock) Newsgroups: net.med,net.physics,net.cooks Subject: Re: sterilizing food with radiation Message-ID: <225@redwood.UUCP> Date: Thu, 14-Nov-85 21:35:03 EST Article-I.D.: redwood.225 Posted: Thu Nov 14 21:35:03 1985 Date-Received: Sat, 23-Nov-85 00:10:55 EST References: <6202@amdcad.UUCP> Organization: [Consultant], San Mateo, CA Lines: 84 Xref: watmath net.med:2791 net.physics:3612 net.cooks:5445 Phil Ngai writes: +--------------- | I understand that preliminary tests are being done on the use of | radiation to sterilize food. The food is exposed to a source of | radiation... Afterwards, the food is not radioactive and is supposed to | be edible. My question is, are the results of breaking large molecules | at random places likely to be completely innocuous?... +--------------- Actually, as I understand it, the technique is *old*, as such things go. It was first tried by the U.S. miltitary some 20 years ago(?), with great success. The idea was to have a cheap way to store large quantities of "normal" (not frozen or dehydrated) foods, for the usual military and civil-defense reasons. They use only ionizing radiation, such as gamma or electron-beam, not neutrons or alphas, thus no secondary radiation is even possible. From newspaper reports at the time (I mean, really *years* ago), the processed food looked, smelled, and tasted just like what went in, with one difference -- you could leave it on the shelf at room temperature for decades and it wouldn't spoil (if the package were intact). Of course, some people prefer to chill such things as milk just before consuming them, but I saw a picture of a guy drinking a carton of warm milk that had been on the shelf for a couple of years. (Yecchh! ;-} ) The machines to do it aren't (weren't?) particularly cheap, since they have to have large heavily shielded areas (much like cancer-therapy treatment rooms), and no one seems to have taken on the task of making them cheap (i.e., in volume). Freeze drying since became popular among campers, etc., so irradiation didn't catch on in the general public (which is to say, with those who MARKET to the general public). This seems to be changing recently. I don't know the social or economic driving functions. I think the new E-beam machines may be cheaper. I do know that in the years since the technique was first tried, our general cultural paranoia of anything with the word "radiation" in it has added a new cost element to the process -- the necessity to educate the public at each and every proposed processing plant site that such irradiators are NOT in any way related to nuclear weapons, power plants, or waste sites, and are NOT going to poison them and destroy the local environment! Hmmm... there is one point of commonality: Since some versions of food irradiators DID contain lethal quantities of radioactive substances inside their lead shields (such as Co-60), you have the usual problems of transportation (while building the plant), disposal (tearing it down), and security (don't want some terrorist stealing this 20-tonne gamma source and driving down the street pointing it at people! ;-} ). But the articles I've been reading lately imply that the cost-effective versions will probably employ electron-beam techniques, which have NO transportation hazards. (ANYTHING has a terrorist hazard, but I dare say you could steal some ion-implant machines fromm Silicon Valley, tear them open, and point them at people as easily as you could do anything with modern E-beam food processors. Heard anybody in the Valley screaming about "radiation" in the semicon plants?... Oops! Me and my big mouth! ;-} ) As far as long-reaching effects from the molecular disruption, I have no new info. They certainly weren't as sensitive to those issues back when the technique was first developed. The main (intended) disruption was to the enzymes that cause decomposition of other proteins, and only secondarily the sterilization.( You can kill bacteria with other techniques, but the natural catabolic enzymes continue to tear down the food.) As with any other risk assessment, one has to look that whether the one-time damage to the food due to the irradiation is better or worse than the continued damage caused by the slow spoilage of the food inherent in other techniques. Such slow spoilage or rancidity has itself been implicated in cancer-promoting mechanisms. Ideally, one should eat fresh foods. But if one HAS to eat preserved or stored foods, I would prefer not to eat nitrites and other chemical preservatives, or food which is on its way to being rancid. Thus it may be that proper irradiation techniques may have a valid, useful place in the world, ESPECIALLY for foods intended for emergency or disaster relief use. Certainly the safety studies should be done, but the results should be compared with the available alternatives, and not judged by an overly-idealistic absolute standard. Rob Warnock Systems Architecture Consultant UUCP: {ihnp4,ucbvax!dual}!fortune!redwood!rpw3 DDD: (415)572-2607 USPS: 627 26th Ave, San Mateo, CA 94403