Hello Teeming Millions!
A friend of my wife said that she doesn’t microwave her food because microwaves “disturb the molecular structure of nutrients redering them unrecognizable to the digestive system and are therefore not absorbed.”
I say that’s a load of dingo’s kidneys, and am looking for evidence or a technical explanation to prove her wrong.
Can anyone at least explain how a microwave oven works?
(I have to plead ignorance here) If there is a good explanation for how it works, maybe I could use that to explain why her assertion is bogus.
Well, all cooking “disturbs the molecular structure” of your food - that’s why we cook it! (Well, one of the reasons.) For instance, proteins get denatured, in other words the arrangement of the molecules is greatly altered (hence the big difference in texture between cooked and uncooked meat and eggs), cellulose crosslinks get broken down etc etc. But I don’t see any reason why microwaves should do it any more than a regular oven, as it’s still just heating the food. Maybe your wife’s friend is getting confused with food irradiation, which was experimented with as a means of preserving it. I don;t think it’s done any more, at least not in the UK.
First, a peeve about people’s understanding of microwaves. Lots of people refer to microwaving food as “nuking it”, which I assume is because they have some sort of notion that radiation is involved.
Well, yes it is radiation, but not in the plutonium sense. Microwaves are part of the electromagnetic wave spectrum, just the same as radio waves (which are very long wavelength, say 100 metres) and light (very short wavelength, say one millionth of a metre). Microwaves fall somewhere in the middle, with a wavelength of about a millimetre.
Basically, microwaves heat food by making the water molecules in it vibrate rapidly. The water molecules absorb the energy from the microwaves and so get hot, which in turn heats the rest of the food. For a more in-depth explanation, see How Stuff Works.
The conviction that microwaves compromise the nutritional integrity of food has a historical basis, but it’s not applicable to consumer microwave ovens–
Many years ago, there was an incident in which babies were found to be languishing in a hospital nursery – the longer they stayed in the nursery, the worse they fared. Eventually, it was discovered that the problem was a large microwave warming device in which both baby formula and pumped breast milk was kept continually at body temperature. Constant exposure to the magnatron was found to be breaking down the protein-chains in the milk. The device was scrapped, and the hospital went back to heating the milk on an “as-needed” basis, (also with a microwave.)
So, in a nutshell, microwaves are safe for your food-- unless you use microwaves to keep your food continually at a “ready-to-eat” temperature, all day… which I imagine is pretty uncommon scenario.
Personally, I find that sometimes heating food in a microwave makes it unpalatable, however, I am confident that it is nutritionally equivalent to the same food heated in a convection oven or on the stovetop.
I’m sorry, I can’t find a cite for that. It’s an explanation that I read many years ago for the belief that microwave-heated food is somehow harmful. If I recall correctly, the incident occured in the 1950’s and was limited to one hospital.
Food irradiation has been done to eliminate bacteria. The consumer public has been scared of by the word “irradiation” and due to bad press by health food store newsletters and other periodicals of the same ilk. As a result, there hasn’t been a good market in the USA for this, although it is completely safe and does not destroy many nutrients. Microwaving is the best way to cook foods as far as preserving nutrients goes, with the possible exception of steaming.
I, without a cite, contend that boiling would be the worst method for preserving nutrients. It’s the only method of cooking where the medium itself can leech matter from the food.
Robert Wolke’s web site is an excellent source of hard scientific facts related to food and cooking. I believe he addressed a similar issue in a regular column he has in the Washington Post. He is a professor emeritus of chemistry at the University of Pittsburgh. This topic is not found on his web site but is treated in his book, What Einstein Told His Cook: Kitchen Science Explained.
His position is essentially as described by r_k. Microwaves don’t cause any chemical changes not caused by other forms of cooking. Of course, there’s a fad afoot to eat only raw foods, the wisdom of which is unsubstantiated by any actual facts (also a subject treated by Dr. Wolke).
Yes, but you can consume the medium and thus absorb nutrients from it.
P.s- I was told about boiling through my survival instructor so I’m not just being a smartass by saying you can drink the water. According to him, boiling would keep everything together in the water so you could have a sort of stew.
Microwave ovens operate at 2.45 GHz, so the wavelength is about 100 mm, or 4 inches. Above about 25 GHz, the term “millimeter wave” is used instead of microwave, I guess because the wavelength gets below one centimeter. I don’t know of much work being done above about 110 GHz, so we still have some work to do before “millimeter wave” won’t cut it anymore (250 GHz).