Sciencemadness Discussion Board - Microwave/nutrition?

Microwave/nutrition?

Nixie - 5-5-2007 at 02:29

So, I still don't understand, is there any nutritional impact from cooking with microwaves, compared to conventional methods (steam/bake/boil/broil/grill/fry)?

I see conflicting information. For example, this:
http://md1.csa.com/partners/viewrecord.php?requester=gs&...
On the other hand, I think they actually used water when microwaving the broccoli, so it's not clear if the loss is just due to leaching in the water, or compounds were actually destroyed differently than regular heating would have done.

roamingnome - 5-5-2007 at 09:37

i could see complex health related compounds being broke down from local super heating and vibrations...

since "cooking" is a type of chemistry, the microwave is only an arrow in the quiver
i.e. i dont toast my bread in the nuke

Nixie - 5-5-2007 at 13:47

Quote:

Originally posted by roamingnome
vibrations

The question is, is there any difference in said 'vibrations' over those due to plain heat.

roamingnome - 5-5-2007 at 15:26

i would say this is regular heat

http://en.wikipedia.org/wiki/Brownian_motion

http://galileo.phys.virginia.edu/classes/109N/more_stuff/App...

whereas microwaves flip flop back and forth creating friction at 2.45 GHz

gotta run, but its somethig like that

12AX7 - 5-5-2007 at 16:20

There are no chemical reactions that take place at 2.45GHz any more than at the blackbody spectrum of infrared heat. The only possible effects are from the way the heat is applied, which since excess water is generally not used and charring is hard to produce, I would be inclined to say most foods contain more vitamins and fewer degredation products than otherwise!

Please leave your conspiracy theories elsewhere.

Tim

The_Davster - 5-5-2007 at 17:04

Could go either way. I am doing some microwave assisted polymerizations at work currently, reactions which take less time and effort when done in the microwave than any other way. Microwaves seem to heat polar solvents more readily than nonpolar solvents, so it cannot just be inducing brownian motion.
I would not rule out the idea that microwaves do destroy good parts of food, but even other types of cooking destroy nutritious value(Eskimos eat raw meat, and get vitamin C from that, no vitC in cooked meat). It would be relative to other cooking methods anyway.

I think I read somewhere that food is most nutritious when cooked on an open fire, either best for nutrition, or best for tase. I can't remember which.

EDIT: http://en.wikipedia.org/wiki/Microwave_chemistry

[Edited on 5-5-2007 by The_Davster]

Organikum - 6-5-2007 at 05:55

Microwave ovens are just great and I am thankful that the household machines industry provides me for very cheap with them.

Microwaves are also completely non-intuitive and have some strange effects. Why does yeast which is treated with low powered microwaves perform considerably better in certain biotransformations then untreated yeast? Hmm.

So microwave ovens are great. And cheap and abundant. I have one. Or three. I wouldnt cook my daily food in them though, no problem to warm a coffee up or defrost something once or twice a month, but every or almost every day? Nada.

I dont mind the war between the microwave haters and the lovers, I just see what microwaves do and a lot is pretty unexpected. Better save then sorry.

Nixie - 6-5-2007 at 20:33

Quote:

Originally posted by Organikum
Why does yeast which is treated with low powered microwaves perform considerably better in certain biotransformations then untreated yeast?

Why do supposedly educated people fail to differentiate 'than' from 'then'?

Quote:

warm a coffee up

You would drink coffee that has been rewarmed? Either you have really poor taste, or you've never had properly prepared fresh coffee.

[Edited on 6-5-2007 by Nixie]

12AX7 - 6-5-2007 at 21:23

= Nothing to say then, eh?

Not too suprising.

alancj - 29-5-2007 at 23:24

Quote:

Originally posted by Organikum
I wouldnt cook my daily food in them though,

Then what do you eat? Salad? I have at least one meal come out of the microwave a day.

Seriously though, I think people confuse microwave radiation with the “bad” ionizing radiation. If it was the latter then I wouldn’t eat it if you paid me.

I would guess that since microwaves can achieve heating faster than other means then that could mean less heat caused degradation of foods.

I read somewhere about a university project to reduce home heating bills by just heating the people, and nothing else, with microwaves. They did a test with an 800 watt magnetron in the room and the test subjects said they felt a little warmer. I would imagine you would need to where metal mesh glasses to keep your eyes from getting fried. Apparently these researchers weren't to concerned about RF energy being harmful. (in stark contrast to worries about cell phones causing brain tumors, with a couple watts next to your skull, but these guys suggest to heat yourself with it!)

-Alan

[Edited on 29-5-2007 by alancj]

Drone - 30-5-2007 at 01:35

In my experience microwave radiation feels really rather pleasant.

Standing next to a reasonable sized microwaves transmission horn gives rise to a similar sensation to standing in front of a small fire.

I wonder in that study how they avoided frying the participant's corneas. From what I have heard even relativly low doses of energy can cause cataracts fairly quickly.

12AX7 - 30-5-2007 at 13:23

Quote:

Originally posted by alancj
Seriously though, I think people confuse microwave radiation with the “bad” ionizing radiation. If it was the latter then I wouldn’t eat it if you paid me.

Maybe high energy gamma (GeV range), and certainly neutrons and other transmutational bric-a-brak, but absolutely anything else -- alpha, beta and electromagnetic -- has no permanent result.

Freezing is dramatically more destructive to food than nuclear radiation is.

Quote:

I read somewhere about a university project to reduce home heating bills by just heating the people, and nothing else, with microwaves.

That would be pretty effective, sensitive areas aside (you definetly want the emitters diffuse and not at crotch or eye level!). If such a house were built, it would certainly settle once and for all whether UHF to microwave radiation causes long term health issues.

Tim

alancj - 30-5-2007 at 13:49

Quote:

Originally posted by 12AX7
Maybe high energy gamma (GeV range), and certainly neutrons and other transmutational bric-a-brak, but absolutely anything else -- alpha, beta and electromagnetic -- has no permanent result.

Freezing is dramatically more destructive to food than nuclear radiation is.

Tim

I guess I was thinking in terms of it making the food radioactive. But my nuclear chemistry is pretty rusty then again.

I would think if you had goggles on that were little faraday cages, then your eyes should be safe, since the rest of your scull should absorb radiation from other directions.

-Alan

Pyridinium - 30-5-2007 at 14:28

Quote:

I'm not sure what gave you this idea, unless by "permanent" you mean actual nuclear transformation.

Visible light can facilitate certain chemical reactions, and its energy is a mere few electron volts (generally less than 4 eV).

Covalent bond dissociation energies are down in the range of 0-10 eV per molecule. Of all the organic molecules, only the CC triple bond of acetylene actually needs 10.0 eV / molecule. Even the H-H bond is only 4.5 eV / molecule.

Alpha and beta particles can be up in the range of MeV. Are you trying to say this is not enough energy to facilitate chemical reactions that would otherwise not have happened? I guess nuclear chemistry is a waste of time, then.

Why, as soon as someone claims that a microwave oven is capable of altering nutrients, did you fly in a "you must be a conspiracy theorist" attack? That doesn't make any sense to me. So what if microwaves cook things differently? So what if they make different reactions happen? Is that a political issue?

Everyone knows food cooked in a microwave just doesn't taste the same as traditionally cooked food. What basis do you have to claim the chemistry of the two cooking methods is identical?

It's quite obvious that certain reactions can be made to happen with microwaves, when they are impractical to carry out with ordinary heating. Even though this probably has more to do with the penetrating nature of the microwaves, as opposed to having enough eV to ionize substrates (which it doesn't), it still makes a difference.

If all chemical bonds need high-energy gamma to be made or broken, how are you able to bring about reactions on a hot plate? Did they hide a strong gamma emitter somewhere in there?

Assuming that only "ionizing radiation" can play any role in chemical bond formation or dissociation, we're all inert blocks of matter and just don't know it yet.

We can stop eating now, because the chemical reactions that require food aren't really happening.

Nixie - 31-5-2007 at 08:54

Quote:

Originally posted by Pyridinium
Is that a political issue?

His behavior is typical of skeptic crusaders that overreact so strongly that not only do they discount actual pseudoscience, but claim certainty on issues where it is not yet justified. I've seen the same thing in audio, where if something doesn't show up on a THD measurement, it doesn't exist--and they turned out to be wrong; thermal memory distortion for example doesn't affect THD, yet is very real and there are papers on it.

Quote:

If all chemical bonds need high-energy gamma to be made or broken, how are you able to bring about reactions on a hot plate? Did they hide a strong gamma emitter somewhere in there?

Ahahah, pwn3d!

One thing I've been wondering about is microwave solvent extractions. From all the material I've seen it doesn't seem convincing that the increased effectiveness can simply be explained by the faster heating of the sample. Someone correct me if I'm wrong.

[Edited on 31-5-2007 by Nixie]

12AX7 - 31-5-2007 at 14:34

Obviously you didn't think about what I was actually saying.

I was responding to the question of nuclear radiation. Therefore, I was responding to the notion that the food might contain residual radioactivity, and what from.

This has fuck all to do with chemistry, which obviously is changed 1. just sitting there, 2. sitting in the 'fridge, 3. by freezing, or 4. by heating (by any method).

As far as "nuclear chemistry", the term itself is apparently bullshit, because nuclei do not undergo chemistry; the electrons in their potential well do. The only possible application of the term would be transmutation, where you might change most of a sample into something else (obviously, a very intensive process involving 10^20ths of neutrons or high-energy protons).

Reactions as a result of, say, ionization, which just so happens to be from a nuclear source, are ionic or free radical interactions and themselves have nothing at all to do with nuclear reactions. "Nuclear chemistry" is a convienient term, but misleading at best.

Check and mate, pwn yourself.

Tim

P.S. And I get the feeling neither Maxwell, Fermi nor Boltzmann would appreciate you saying "there are no gamma rays from a hot plate". The high-energy tail of the thermal spectrum is just really FUCKING low propability. It's still possible that my cup of coffee sends off a nuclear-sized thermal photon.

Nixie - 31-5-2007 at 15:07

Huh? I never was worried about nuclear radiation, from the starting of this thread and all the way through it. Someone else brought that into the discussion and I consider it off topic, and you're just continuing on that tangent that was never a concern in the first place.

12AX7 - 31-5-2007 at 15:21

Yes, and I was addressing that concern. So GFY, as you are so prone to doing.

We now return you to your regularly scheduled thread.

Tim

Pyridinium - 1-6-2007 at 10:18

@12AX7, you were the one who made the following statement:

"absolutely anything else -- alpha, beta and electromagnetic -- has no permanent result."

That is what I was addressing. So desist with the "check and mate" nonsense.

Then you invoke Maxwell, Fermi, and Boltzmann to justify your misreading of my own statement. I said strong gamma emitter in reference to a hot plate. Did you not see that part? You can throw around statistically aberrant gamma rays all you want-- we all know even your left-over dinner throws off the odd one every so often-- but you know I wasn't talking about that.

I wouldn't have jumped on you in the first place if you hadn't come off as being so authoritative while making plainly wrong statements.

Someone asked whether microwave ovens could have different effects on nutrients, and right away you became almost hostile. If anyone else tried that, an apology would be the next step in the progression.

In case you missed it, I realize you were arguing two different lines of thought at the same time-- apples and oranges, as it were. It's just that you were not expressing them very clearly (or correctly). Sure, so you're an expert in quantum mechanics and nuclear chemistry (radiation chemistry, if you prefer-- we both realize that the nucleus itself undergoes no chemical reactions). It's just that this expertise wasn't showing, because you were too busy trashing someone else's ideas.

Now, if you want to get back on track to the science... let's talk about radical formation. Yes, heating alone can produce free radicals. Microwaves cause heating of certain substrates. The heat is a more penetrating, rapid type than traditional cooking. The logical conclusion is that the reactions might be different in type or quantity.

Photodissociation can also bring about radical formation. As I mentioned, visible light does so, but it doesn't penetrate very well. So microwaves might have some effect on that score as well.

Nixie - 1-6-2007 at 11:02

Quote:

Originally posted by Pyridiniuman apology would be the next step in the progression.

I'm sure extracting an apology from him is even harder than getting one from me

I don't know why he's like that on public forums; when I ask him something by email he seems quite reasonable. Must be a vanity issue. ;P

12AX7 - 1-6-2007 at 14:39

Quote:

Originally posted by Pyridinium
@12AX7, you were the one who made the following statement:

"absolutely anything else -- alpha, beta and electromagnetic -- has no permanent result."

Again, from a nuclear standpoint, which was what I was addressing. Re-read my previous post.

Tim

12AX7 - 1-6-2007 at 14:41

Quote:

Originally posted by Nixie

Quote:

Originally posted by Pyridiniuman apology would be the next step in the progression.

I'm sure extracting an apology from him is even harder than getting one from me

I don't know why he's like that on public forums; when I ask him something by email he seems quite reasonable. Must be a vanity issue. ;P

The only thing you'll get from me is that I may not have clearly indicated that I was taking about the nuclear reactions. Anything else I'm not going to apologize about because I AM right about it

(mind that there may be some misunderstanding in communication).

Tim

Nixie - 1-6-2007 at 14:42

This thread is made of FAIL

Rosco Bodine - 1-6-2007 at 17:39

And now , for a diagrammatical expression .....