what happens to protein when it denatures?

[stabmaster]

say you cook your whey protein at 300 degrees for, say, a few minutes, until 50% of it is denatured.

Are all of the calories still there? If so, then how would your body metabolize these calories? If not, than can you actually cook calories out of other food? Confused.

[oddball182]

In my chemisty class we bruned peanuts until there was nothing but burnt crap left.

We concluded that since we lit it on fire, it used the energy (calories) of the peanut to keep the fire lit, therefor once it was turned into ash, it had 0 calories left.

[pduke1]

Bascially when protein denatures, it changes form. The tertiary structure of a protein unfolds.

As to baking whey, heres some info straight from ON:

"Q: I heard that high temperatures "break down" protein. Will the cooking/baking process have a negative effect on the protein?

A: While it's true that proteins can be denatured by heat, unless the protein structure is particularly delicate or exposed to extremely high temperatures for extended periods of time, any denaturation that takes place is likely to be minimal. It is also important to keep in mind that denatured DOES NOT equal non-nutritious or unavailable - denaturation simply refers to a situation where the physical or chemical structure of a protein is rearranged. In some cases the denaturation process is temporary (e.g. whipping egg whites into a foam); in others, such as when you fry an egg, the denaturation is permanent. In both situations, the egg contains the same amino acid makeup and is equally nutritious. In fact, the fried egg is actually slightly more nutritious when cooked because cooking inactivates a component that binds the essential B-vitamin biotin.

That said, while denaturation does not alter the nutritive value of proteins, excessive heat can reduce or destroy delicate peptides (i.e. microfractions) within a protein. For this reason, it is best to limit the exposure of 100% ANY WHEY Protein to high heat, and cook with lower temperatures whenever possible. In other words, add 100% ANY WHEY Protein at the end of the cooking cycle whenever possible, and choose lower temperature cooking like microwaving and baking over higher heat methods like pan or deep-frying."

[tweeter37]

Proteins are in tight bundles, almost like a peice of string all bundled together. When you heat this protein passed a certain temperature, the bundle unfolds and starts to straighten out. Your body does not know what to do with this, and therefore will try to get rid of it.

[user34566548717114]

Originally posted by pduke1
Bascially when protein denatures, it changes form. The tertiary structure of a protein unfolds.

As to baking whey, heres some info straight from ON:

"Q: I heard that high temperatures "break down" protein. Will the cooking/baking process have a negative effect on the protein?

A: While it's true that proteins can be denatured by heat, unless the protein structure is particularly delicate or exposed to extremely high temperatures for extended periods of time, any denaturation that takes place is likely to be minimal. It is also important to keep in mind that denatured DOES NOT equal non-nutritious or unavailable - denaturation simply refers to a situation where the physical or chemical structure of a protein is rearranged. In some cases the denaturation process is temporary (e.g. whipping egg whites into a foam); in others, such as when you fry an egg, the denaturation is permanent. In both situations, the egg contains the same amino acid makeup and is equally nutritious. In fact, the fried egg is actually slightly more nutritious when cooked because cooking inactivates a component that binds the essential B-vitamin biotin.

That said, while denaturation does not alter the nutritive value of proteins, excessive heat can reduce or destroy delicate peptides (i.e. microfractions) within a protein. For this reason, it is best to limit the exposure of 100% ANY WHEY Protein to high heat, and cook with lower temperatures whenever possible. In other words, add 100% ANY WHEY Protein at the end of the cooking cycle whenever possible, and choose lower temperature cooking like microwaving and baking over higher heat methods like pan or deep-frying."

BUMP!!!!! you are correct the tertiary form of the protien unfolds and the weak hydrogen bonds are broken quickly and the covalent bonds will be destroyed in the temperature increases too much.....also in some protiens they have a fourth stage (hemagloben for example) where it is multy strings of protiens, i think four in hemagloben......so that form can also be broken down as well

[stabmaster]

Yeah I kindof feel stupid asking this question because I'm a biochemical engineer, and I work primarily with proteins and model protein denaturation. On the other hand, I work with microbes, so I was just curious as to what bodybuilders would say about the utilization in humans. We tend to prefer more complex media than, say, saccharomyces.

In speaking of casein in particular, i believe there is a sufficient denaturation at what 170C? Oven baking some cookies made of casein instead of flour would cause a high percentage of protein denaturation. In this case, the casein would not effectively coagulate in your stomach and the release of amino acids into the bloodstream would be quicker than the desired anticatabolic 6-8 hours (sleepytime).

In speaking of quarternary structures; well i suppose you can take that into account because coagulation results in quarternary structure (albeit no functional site involved). Furthermore, I've read that whey and casein coagulate to a good extent in your stomach, so a 50/50 casein/whey powder before bed is going to be nearly as slow as a 100% casein powder (the 50/50 that i use tastes soo very good).

But what's to stop us from baking whey protein? I suppose a loss in peptides could be an issue. Maybe this will tilt the AA profile unfavorably. On the other hand, who needs to bake whey? its only purpose is fast absorption, and when mixed and in solid form it's rather worthless. Interesting thread though. I've found that you can use protein powder in place of flour if you use some clever baking tricks.. Any thoughts are appreciated.

[user34566548717114]

hmmm good question not sure what happens if the calories go away or not.....if your body can still access the remains of the protien then I would imagine they would still be there, I will ask my bio-chem teacher when I get a chance