Hot or cold water for dissolving protein?

I have heard that if you dissolve protein shake powder in
warm or hot water, it "denatures" protein, thus making
the protein shake less effective. Is this true?

I also have heard that it does not matter whether you
dissolve it hot or cold water, because
our digestive tract denatures the protein anyways.

Right? Wrong? Anyone care?

 

There are different types of denaturing.

In Biochemistry, we term a protein denatured when it can no longer do the function it was designed for, or permanently changing the protein structure. For example, egg white. Frying an egg will denature the egg white, and there's nothing you can do to make it liquid again.

This type of denaturing is fine, because our body just stirs up the protein with a bunch of acid to digest it anyway. In fact, I've heard rumors that cooking an egg makes the protein more accessible (though I can't figure out why).

The other type of denaturing is actually changing the protein so it's not longer protein. Eg. Changing the H-N-C group into a C-N=O group (for example). This type is BAD. Luckily, this would need heat plus chemical reagents to get get these chemical changes.

This is the type of denaturing that processed meats undergo when you fry them. Some of the protein is being converted to unusable, even poisonous, forms.

Putting protein in warm water, even "hot" (not boiling) shouldn't do anything more than ruin the protein's structure. I can't imagine it being too bad - this is nothing worse than cooking an egg or putting the whey in your belly. Plus, I've noticed that whey dissolves in warm water better.

However, I'd still store the protein shake in cool temperatures to avoid bacterial/fungal growth (ie. don't let the food rot).

 

Thanks El.