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Is microwave cooking safe?

by Si14
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russ_watters
#19
Oct29-09, 08:14 PM
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Quote Quote by Moonbear View Post
It's not like a radioactive isotope that would contaminate something and linger.
Not that I want to create an additional fear, but this was the fear that people had about irradiation sterilization of food. Irradiated food is exposed to high energy radiation from a radioactive source. But it does not become/stay radioactive and eating irradiated food does not expose the consumer to that radiation. I have gotten the impression from past discussions that these fears/issues tend to bleed together.

http://en.wikipedia.org/wiki/Food_irradiation
Pythagorean
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Oct29-09, 10:25 PM
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Quote Quote by russ_watters View Post
Not that I want to create an additional fear, but this was the fear that people had about irradiation sterilization of food. Irradiated food is exposed to high energy radiation from a radioactive source. But it does not become/stay radioactive and eating irradiated food does not expose the consumer to that radiation. I have gotten the impression from past discussions that these fears/issues tend to bleed together.

http://en.wikipedia.org/wiki/Food_irradiation
What kind of materials can store radiation, and then release it as radiation anyway?
chroot
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Oct30-09, 01:55 AM
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Quote Quote by Pythagorean View Post
What kind of materials can store radiation, and then release it as radiation anyway?
Depending upon what you mean by "radiation," the answer might be any material. If you bombard just about anything with protons or neutrons, it'll end up radioactive.

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Pythagorean
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Oct30-09, 03:41 AM
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Quote Quote by chroot View Post
Depending upon what you mean by "radiation," the answer might be any material. If you bombard just about anything with protons or neutrons, it'll end up radioactive.

- Warren
I suppose I was referring to electromagnetic radiation, specifically microwaves in this case. Is there even a material that you could stick in the microwave oven and "charge up" and then it would release microwaves after it's taken out of the microwave oven?
Moonbear
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Oct30-09, 07:43 AM
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Quote Quote by russ_watters View Post
Not that I want to create an additional fear, but this was the fear that people had about irradiation sterilization of food. Irradiated food is exposed to high energy radiation from a radioactive source. But it does not become/stay radioactive and eating irradiated food does not expose the consumer to that radiation. I have gotten the impression from past discussions that these fears/issues tend to bleed together.

http://en.wikipedia.org/wiki/Food_irradiation
Yes, they're generally the same question, because people simply don't understand enough about radiation vs. radioactive materials to know the difference. I thought we'd answered that question here before. It's a pretty common fear due to ignorance issue.
chroot
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Oct30-09, 01:26 PM
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Quote Quote by Pythagorean View Post
I suppose I was referring to electromagnetic radiation, specifically microwaves in this case. Is there even a material that you could stick in the microwave oven and "charge up" and then it would release microwaves after it's taken out of the microwave oven?
One could probably invent a device with an antenna and a battery that could do the job, but no ordinary, simple materials -- certainly not foods -- would do this.

- Warren
Pythagorean
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Oct30-09, 06:11 PM
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thank you for your input, russ and chroot.
Jasongreat
#26
Nov8-09, 02:50 PM
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What is the purpose of the shield in a microwave? Isnt it to keep the dangerous microwaves inside the oven? Since microwaves are not good for organic material outside the oven wouldnt it be not good to the organic material inside? Granted the organic matter outside is alive and the organic matter inside is dead and that could be the reason microwaves are dangerous to us but not to the food we are cooking, but I am not so sure. I am probably over reacting but I try not to use the microwave for anything if at all feasible.
D H
#27
Nov8-09, 03:18 PM
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False analogy.

The heat of your oven or range is not all that great for living tissue, either. One of the key reasons we cook food is precisely because heat is not all that great for living tissue. That heat kills all of (or at least most of) those nasty microbes that grow on our food. Moonbear in post #16 did raise one issue regarding microwave ovens: The short cooking time might not be hostile enough to living tissue.
mgb_phys
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Nov8-09, 03:39 PM
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Quote Quote by Pythagorean
Is there even a material that you could stick in the microwave oven and "charge up" and then it would release microwaves after it's taken out of the microwave oven?
Any material above absolute zero should manage to do that
Jasongreat
#29
Nov8-09, 05:55 PM
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=D H;2432070]

The heat of your oven or range is not all that great for living tissue, either.
Agreed, however I havent noticed a shield around my conventional oven to keep the microwave radiation in. I dont think that it is just about heat, but how that heat is made. I am probably wrong and over reacting like I said before, but when it comes to radiation I am very conservative, I try not to eat irradiated foods either.


One of the key reasons we cook food is precisely because heat is not all that great for living tissue. That heat kills all of (or at least most of) those nasty microbes that grow on our food.
I agree, but do we use heat because it is the best/only way or is it just the the easiest way? When governments started to mandate cooking milk to kill the microbes it was far easier and less expensive than making the dairies clean up, atleast from what ive read on that subject. Or the fact that it is pretty much impossible to order a hamburger less than well done, we can get away with a far dirtier food supply if we just accept the fact that everything needs to be cooked until it has been killed twice. Like today it is far easier to irradiate food than to clean up the food supply. I could be wrong and am probably so, but it only takes a little longer and the food tastes better when cooked conventionally imo, so I will continue not cooking in the microwave.


Moonbear in post #16 did raise one issue regarding microwave ovens: The short cooking time might not be hostile enough to living tissue.
Isnt it the heat value that kills microbes and not the length of time? On cooking shows they say you need to cook to a certain temp, not that you need to hold at that temp for a certain amount of time. Moonbear is far smarter than me though so I will accept that opinion and I have one more reason not to use a microwave.
mgb_phys
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Nov8-09, 06:40 PM
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Quote Quote by Jasongreat View Post
but when it comes to radiation I am very conservative, I try not to eat irradiated foods either.
Microwave radiation is only radiation in the electro-magnetic sense, your regular stove uses infrared radiation, a light bulb uses visible radiation

but do we use heat because it is the best/only way or is it just the the easiest way?
It also breaks down tissue to make it easier to eat - it's a lot easier to eat chicken casserole than raw chicken.

When governments started to mandate cooking milk to kill the microbes it was far easier and less expensive than making the dairies clean up,...impossible to order a hamburger less than well done, we can get away with a far dirtier food supply
Sometimes the bacteria are in the source however clean the processing. Milk inside the cow can contain dangerous bacteria. You can get a variety of diseases straight form the teat, just as you could 100 years ago.
Pasteurizing is a cheap and easy way of partially cleaning milk - at least enough for it to be safe for two weeks. If you want it to last longer you can heat it more to kill more bacteria but you destroy more milk proteins and end up with nasty sterilized milk.

You can eat (almost) raw steak because unless the animal is badly diseased there are no bacteria in the meat, there is only a risk of contmination on the surface. The problem with hamburger is that you take surface and mix it right through the meat. If you start with steak and mince it (in a clena kitchen) just before serving it's safe = steak tartare.

Isnt it the heat value that kills microbes and not the length of time? On cooking
It's the energy that the microbes absorbs - which is a combination of heat and time. The danger of a microwave is that the food might not have time to heat up fully all the way through and so the centre might not get hot enough for long enough to kill the microbe.
Jasongreat
#31
Nov8-09, 08:16 PM
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mgb_phys;2432361]Microwave radiation is only radiation in the electro-magnetic sense, your regular stove uses infrared radiation, a light bulb uses visible radiation
I was wondering about that after I made my post, the fact that all heat is a form of radiation. I think it was Moonbear who stated in an earlier post that laymen get confused when it comes to radiation vs radioactive. However I havent read of any dangers associated with infared or visible radiation but lately there seems to be lots of studies showing or atleast claiming the dangers of electro-magnetic radiation such as all the cell phones causing cancer claims or that living under power lines is dangerous. I am not saying they are true or false but they do raise questions in my mind.


It also breaks down tissue to make it easier to eat - it's a lot easier to eat chicken casserole than raw chicken.
The example you give about made me toss my cookies, raw chicken, although I did see a show on the travel channel where there is a place in japan where they eat raw chicken, however they are raised in the guys backyard and dont have to travel through the food supply picking up microbes along the way. Local supplies seem to be far less dangerous than a supply that travels a long way. Fermentation, brining, and other methods will also break down meat and veggies making them easier to eat and as far as fermenting goes it is my understanding that it increases enzymes and the solubility of the vitamins and minerals making the food better for you, whereas cooking reduces those and makes them not as good for you but a lot safer.

Sometimes the bacteria are in the source however clean the processing. Milk inside the cow can contain dangerous bacteria. You can get a variety of diseases straight form the teat, just as you could 100 years ago.
Pasteurizing is a cheap and easy way of partially cleaning milk - at least enough for it to be safe for two weeks. If you want it to last longer you can heat it more to kill more bacteria but you destroy more milk proteins and end up with nasty sterilized milk.
The cleaner you keep the dairy the less chance of bacteria in the milk, although I agree that it is still possible, if we kept cows out in pasture there would be less chance than if they were kept in a feed yard since the pasture is far more steril than a garbagety coral. I worked on a dairy about 12 yrs ago and IMO there is nothing better than fresh raw milk, most of the dairy farmers I know drink their milk raw and I dont know of one that has ever gotten sick, but here again I think that might have a lot to do with local supply since imo it would be harder to contaminate milk if you produce it yourself, but if milk in california has to travel to new york to be consumed there would be a far greater chance of contamination. Your last sentence above makes me ask if the original cooking(pasteurization) doesnt destroy some proteins, enzymes and such as well as the bacteria? According to the raw milk supporters lactose intollerant people can drink raw milk since it still has the enzymes to allow them to make use of the lactose where pasteurized milk has those enzymes destroyed. Is there any truth to this or is it just propaganda to support their cause?


It's the energy that the microbes absorbs - which is a combination of heat and time. The danger of a microwave is that the food might not have time to heat up fully all the way through and so the centre might not get hot enough for long enough to kill the microbe.
I thought that microwaves cooked from the inside out but it wouldnt be the first nor the last time(i'm sure) i have found out i am wrong in this forum. Although that really wouldnt change your point since if they do cook from the inside out, that would still mean the outer edge might not get hot enough for long enough and since all/most bacteria is on the surface unless it has been ground and mixed we could still be in danger.
mgb_phys
#32
Nov8-09, 08:40 PM
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Quote Quote by Jasongreat View Post
Ibut lately there seems to be lots of studies showing or atleast claiming the dangers of electro-magnetic radiation
Electromagnetic radiation is dangerous, but due to it's heating effect (at > visible wavelengths) if you stand in front of a powerful enough microwave transmitter for long enough you will be damaged. It's unlikely that a 1W cell phone outside your head could do much heating.

The example you give about made me toss my cookies, raw chicken, although I did see a show on the travel channel where there is a place in japan where they eat raw chicken,
You eat raw fish! The danger with chicken is that they are generally raised in less than sanitary conditions so the disease risk is rather high.
The point remains that we cook food both for texture/taste and safety.

The cleaner you keep the dairy the less chance of bacteria in the milk,
True but there is still a chance of mastitus/bovine TB/ etc. There is probably less risk in hand reared hand milked cows simply because the farmer would notice any illness and there is less chance of transferring contamination through milking machines.

You are also going to consume the milk immediately, like anything else it's a time/growth thing. If you want milk to last 1 month you need to kill off more bacteria than if it only needs to last 1 week. The standards for the allowable level of bacteria in Eu milk are much lower than in the US and milk in Europe definitely lasts longer than in the US.

Your last sentence above makes me ask if the original cooking(pasteurization) doesnt destroy some proteins, enzymes and such as well as the bacteria?
Probably too low a temperature to destroy milk protein.

According to the raw milk supporters lactose intollerant people can drink raw milk since it still has the enzymes to allow them to make use of the lactose where pasteurized milk has those enzymes destroyed.
Not sure, lactose does depend on the amount of fat so there might be a differnet reaction to full fat milk than 2% supermarket milk.

I thought that microwaves cooked from the inside out
Common urban myth. In fact because of the short cooking time and poor thermal conductivity you can end up with the inside much less cooked than in a stove.

since all/most bacteria is on the surface unless it has been ground and mixed we could still be in danger.
True of steak, not true of hamburger - once you mince it you mix 'surface' all through the meat.
russ_watters
#33
Nov8-09, 09:17 PM
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Quote Quote by Jasongreat View Post
What is the purpose of the shield in a microwave? Isnt it to keep the dangerous microwaves inside the oven?
Yes.
Since microwaves are not good for organic material outside the oven wouldnt it be not good to the organic material inside? Granted the organic matter outside is alive and the organic matter inside is dead and that could be the reason microwaves are dangerous to us but not to the food we are cooking, but I am not so sure.
Yes, the reason microwaves are bad for us is because we are alive: it is dangerous to cook a person while they are alive!
Agreed, however I havent noticed a shield around my conventional oven to keep the microwave radiation in.
Your microwave has a shield to prevent microwaves from escaping and cooking you. Similarly, your normal oven has a shield to keep heat (hot air) from escaping and cooking you.
Jasongreat
#34
Nov8-09, 10:11 PM
P: 75
=mgb_phys;2432549]Electromagnetic radiation is dangerous, but due to it's heating effect (at > visible wavelengths) if you stand in front of a powerful enough microwave transmitter for long enough you will be damaged. It's unlikely that a 1W cell phone outside your head could do much heating.
The only danger of emf waves is the heating caused? EMFs dont cause any other damage to the molecular structure? If the answers are yes and no respectively, i guess i have been over reacting as far as the danger of microwaves.


The point remains that we cook food both for texture/taste and safety.
I agree but we eat food for the nutrition, if the way we are cooking could be damaging the nutritional value of the food, I would consider that harmful even if it is safer.


Probably too low a temperature to destroy milk protein.
I'm sorry I mis-spoke, does the temperature damage the milk protein?
This part of our discussion has strayed way off topic so I will not be continuing any further, unless of course I decide to start a new thread on raw vs cooked food.


Common urban myth. In fact because of the short cooking time and poor thermal conductivity you can end up with the inside much less cooked than in a stove.
Thanks for correcting me. Thats what I love about this forum, I learn something new quite often.
Jasongreat
#35
Nov8-09, 10:28 PM
P: 75
russ_watters;2432616] Yes, the reason microwaves are bad for us is because we are alive: it is dangerous to cook a person while they are alive!
The part I wasnt sure about wasnt that its dangerous to cook a living thing, but that the microwaves dont cause other changes to the thing getting cooked other than just heating it up.

Your microwave has a shield to prevent microwaves from escaping and cooking you. Similarly, your normal oven has a shield to keep heat (hot air) from escaping and cooking you
.

Oh, I thought the door on my normal oven was to keep the heat from escaping so I can cook at the temperature of my choosing.
mgb_phys
#36
Nov8-09, 10:39 PM
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Quote Quote by Jasongreat View Post
EMFs dont cause any other damage to the molecular structure?
Not at microwave energies - these are much lower energy than any of the molecular bonds and so don't cause any chemical changes other than heat. The same isn't true of UV that can do chemical damage without heating.

I agree but we eat food for the nutrition, if the way we are cooking could be damaging the nutritional value of the food, I would consider that harmful even if it is safer.
For meat, heating is probably a benefit - it breaks down muscle fibre and makes it more digestible. It denutures some proteins but you don't use protein directly you break it down into amino acids. For vegatables heating is more a loss, a lot of vitamins are destroyed by heating, especially cooking in water.


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