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Author Topic: Why Do Eggs Harden ?  (Read 9406 times)

Offline neilep

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Why Do Eggs Harden ?
« on: 07/02/2007 16:12:13 »
As I boiled an egg this morning for my son ..It dawned on me as to why the application of heat makes them go hard ?
I can't think of anything else that when cooked...starts of slimy and gooey and then becomes rigid when cooked.

You know how extreme cold also burns ?...could an egg be cooked like this too ?..I don't mean frozen but cooked ?


 

Offline science_guy

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Why Do Eggs Harden ?
« Reply #1 on: 07/02/2007 16:29:08 »
I have also wondered about this but never though to ask about it.  Another question:  why does the application of heat turn egg "white" white?  I do know that the clear liquid is of little nutrition and made to hold the yolk at the center of the egg, and that might be why the fibrous properties would melt and mold with the application of heat.

If Im wrong, someone stop me before I become too sure of myself.

edit: the sensation of burning is when skin cells are dying ahead of themselves.  Skin dies in hot, and skin dies in cold.  I do not believe it is the same for normal matter, which lack brain cells and pain receptors.
« Last Edit: 07/02/2007 16:31:13 by science_guy »
 

Offline elegantlywasted

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Why Do Eggs Harden ?
« Reply #2 on: 07/02/2007 17:22:16 »
From cooking I understand that its the albumen(sp?). I don't know how it works or why but im sure thats the stuff, that makes them eggcellent.... hah, im so not funny.
 

Offline DrN

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Why Do Eggs Harden ?
« Reply #3 on: 07/02/2007 17:38:24 »
Ii know its something to do with altering the structure of the protein - heat denatures protein, so the tertiary (3-D) structure will basically fall apart - and I suppose this must have something to do with it going from clear and gooey to opaque and hard, but I don't know the specifics.
 

Offline neilep

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Why Do Eggs Harden ?
« Reply #4 on: 07/02/2007 18:59:03 »
I have also wondered about this but never though to ask about it.  Another question:  why does the application of heat turn egg "white" white?  I do know that the clear liquid is of little nutrition and made to hold the yolk at the center of the egg, and that might be why the fibrous properties would melt and mold with the application of heat.

If Im wrong, someone stop me before I become too sure of myself.

edit: the sensation of burning is when skin cells are dying ahead of themselves.  Skin dies in hot, and skin dies in cold.  I do not believe it is the same for normal matter, which lack brain cells and pain receptors.

Great minds think alike......and you're only a yoof too !!...Nice !!!
 

Offline neilep

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Why Do Eggs Harden ?
« Reply #5 on: 07/02/2007 19:01:12 »
From cooking I understand that its the albumen(sp?). I don't know how it works or why but im sure thats the stuff, that makes them eggcellent.... hah, im so not funny.

LOL....this made me laff out loud !!!...cos it's silly !!


I wonder if I should ahve written to one of my favourite musical artists for the answer ?...cos me has got all their  ' Albumens '.......!!..LOL............*groan...that is sooooo bad*
 

Offline neilep

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Why Do Eggs Harden ?
« Reply #6 on: 07/02/2007 19:02:38 »
Ii know its something to do with altering the structure of the protein - heat denatures protein, so the tertiary (3-D) structure will basically fall apart - and I suppose this must have something to do with it going from clear and gooey to opaque and hard, but I don't know the specifics.

YAYYYYYYYYYYY !!..Hugs the Fishytails.....

me is glad ewe not know the specifics cos your explanation is about my level...YAY.

TAHNK EWE Lindsay !
 

Offline DrN

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Why Do Eggs Harden ?
« Reply #7 on: 07/02/2007 19:05:42 »
Glad to be of assistance   ;D
 

Offline Hadrian

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Why Do Eggs Harden ?
« Reply #8 on: 08/02/2007 17:09:50 »
Why Do Eggs Harden?

Because they carry the yoke of life and the fear of being separated.    [^] [^] ;D [^] [^]


 

Offline lightarrow

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Why Do Eggs Harden ?
« Reply #9 on: 09/02/2007 18:05:41 »
As I boiled an egg this morning for my son ..It dawned on me as to why the application of heat makes them go hard ?
Proteins (especially Albumin) are dissolved or disperded in water. Heating make them loose their water and also change their shape making them packed together (protein's irreversible denaturation).
I sincerely don't know if extreme cold can denaturate irreversibly a protein solution; it could be.
 

Offline lightarrow

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Why Do Eggs Harden ?
« Reply #10 on: 09/02/2007 18:14:16 »
Another question:  why does the application of heat turn egg "white" white?
Proteins become packed together. This makes light reflect off the surface, as most of solid substances. The colour is white because those proteins (mostly Albumine) don't absorb electromagnetic radiation in the visible spectrum, so they reflect all wavelenghts (all colours).
It's not bright as a polished metal surface, because the surface is not as smooth; so light is reflected off to all directions, instead of one precise direction, as in the first case.
« Last Edit: 09/02/2007 18:18:00 by lightarrow »
 

Offline neilep

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Why Do Eggs Harden ?
« Reply #11 on: 09/02/2007 23:49:06 »
As I boiled an egg this morning for my son ..It dawned on me as to why the application of heat makes them go hard ?
Proteins (especially Albumin) are dissolved or disperded in water. Heating make them loose their water and also change their shape making them packed together (protein's irreversible denaturation).
I sincerely don't know if extreme cold can denaturate irreversibly a protein solution; it could be.


EXCELLENT...THANK YOU ALBERTO !!..YAYYYYYYYYYYYYYYYY !!!
 

jolly

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Why Do Eggs Harden ?
« Reply #12 on: 24/02/2007 23:36:34 »
deleted as inapproprate   
« Last Edit: 06/03/2007 01:05:38 by jolly »
 

Offline MayoFlyFarmer

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Why Do Eggs Harden ?
« Reply #13 on: 02/04/2008 05:51:28 »
you could not "cook" an egg with extreme cold.  it would get hard, but this would simply be a freezing process and would reverse itself as the egg warmed back up (ie it would "thaw")  Protein denaturation on the other hand (which as has been pointed out here is the process which causes an egg to become hard/white when it is cooked) is an irreversible process, which is why your egg stays hard boiled when it cools off.

also, eating a frozen egg would be little safer from a bacterial stand point than eating a raw egg.  The reason bacteria are killed during the boiling process is because all of their proteins are irreversably denatured.  most bacteria, however can survive a freezing process (no matter how cold) and revive when thawed.  As a matter of fact the bacteria are preserved better at the colder temperature.
 

Offline Carol-A

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Why Do Eggs Harden ?
« Reply #14 on: 02/04/2008 11:51:54 »
Each protein is a long chain of amino acids, which fold up in a particular way to give them their distinct characteristics, and these proteins are held together by various interactions between the individual amino acids. When heated up, these internal bonds break, and they are then able to re-bond with other amino acids, from within their own chain or from others. Imagine a whole lot of neatly rolled balls of wool, direct from the manufacturer... add heat (a cute kitten for example) and imagine the unravellable mess you would get! Thats what happens to your proteins!
 

Offline Seany

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Why Do Eggs Harden ?
« Reply #15 on: 02/04/2008 12:14:43 »
As I boiled an egg this morning for my son ..It dawned on me as to why the application of heat makes them go hard ?
I can't think of anything else that when cooked...starts of slimy and gooey and then becomes rigid when cooked.

You know how extreme cold also burns ?...could an egg be cooked like this too ?..I don't mean frozen but cooked ?

Excellent question Neily!

I also want to know why it turns white. And whether it cooks in extreme cold.
If it is cooked in extreme cold, would you need to eat it at that temperature, or could you heat it back up to room temperature again (when an egg would usually be all slimey) and it would still be hard and edible?
 

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Why Do Eggs Harden ?
« Reply #15 on: 02/04/2008 12:14:43 »

 

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