T Nation

Protein Denaturation


#1

I was talking to a friend the other day about using protein powder when cooking and then I remembered my Bio-Chem class and that we learned that heat causes a denaturation of proteins and basically ruining them.

So my question is, does anybody know if the protein in protein powders can be damaged by heat, such as when cooking the protein cookies that were listed on the Cool tips this week. And for reference I use 100% Whey Protein.

Thanks


#2

Heh, no offense, but this is asked every couple of weeks.

Think about this...

Do you cook meat? Is milk used in recipies? Is there any protein that people don't cook and then eat?


#3

The search function, what a concept. Found good articles thanks.


#4

Just because a protein is denatured does not mean that it is not protein anymore. But like cooked fish or eggs or meat, they can no longer serve the purpose that they were initially meant for once denatured via heat to the extreme we cook things. When egg albumin turns from clear and liquid to white and solid this is an example of denaturation. Acid can also have the same effect on food and foods bathed with acid are often considered cooked for this reason, though there are some parasites and bacteria that the acid most likely does not kill so doing this to poultry would be unadvisable.

And FYI I didnt know a thing about this until you asked the question. Just a combination of common sense and google. But thanks for bringing it up.


#5

I do believe that denaturing egg whites greatly increases their bioavailability

just cause denatured sounds bad it doesnt mean it is bad


#6

your body denatures all proteins you ingest anyway(through just throwing the protein in a harsh environment, acidity for example). that is how you digest a protein.
basically denature just means to unfold the protein.

the proteins you ingest will not retain their catalytic activity, so it does not matter. You eat protein to get the amino acids to build new proteins.

Basically this is why taking enzyme supplements is useless, because the enzymes just get digested, unless they are active in very low pH's(which is pretty rare).


#7

www.library.uu.nl/digiarchief/dip/diss/2003-0113-110350/inhoud.htm

milk proteins- whey and casein - are damged by heat and the damage done does not look good. casein is more durable than whey and though post-exposure a casein micelle may be technically intact, it's "hairy brush " structure means it will likely become clogged w/ particulate and merely pass rather than be digested. that's how i read it.


#8

Almost all protein you ingest orally is denatured during digestion.


#9

Your body needs amino acids.

You should be more worried bout whether the amino acids get morphed or destroyed in the cooking process.

The proteins that you ingest from meat are broken down and made into new proteins that your body uses. Otherwise, if the protein were merelt absorbed by your body there would be all sorts of health complications from the antibodies (protein), hormones (also protein) and other substances found in the respective organism's body that yould affect your bodily functions.

That's why all those things have to be digested and broken down. Your body does nto know which are good and usable and shich are bad... so break 'em all and remake them again.


#10

Well dahhh. What about milk?

J/K, being a smartass. Not that you can't relate, heh?


#11

Pasteurization?


#12

Ok, so the concensus seems to be that yes cooking may cause a denaturation of the protein, but that does not mean that it is effected in such away that makes it unusable by the body.


#13

Yes, considering we cook almost everything that we eat, and we have for centuries, let's hope that is the case.


#14

I'd say this is a safe assumption. Of course, raw foodists would argue that cooking damages food.

Basically, some foods are better cooked, some are better raw, some have different benefits if they're cooked and raw. For example, cooking tomatoes destroys some of their vitamin C, but increases the bioavailability of lycopene, a very powerful antioxidant known for preventing prostate cancer.

High quality protein powders are cold-filtered for a reason - heat does damage them. But that doesn't mean the denatured protein is useless, it's just perhaps not quite as useful - less bang for the buck so to speak. Don't stress over it.