2003/01/30, 07:35 PM
Letter I wrote to t-mag and following answer:
Denatured Proteins
Recently I've read a lot about the denaturing of protein. I haven't yet been able to gather enough information to satisfy my curiosity, but so far I've learned that a number of conditions (temperatures over 140, pH of chemicals and blending) can denature a protein.
I understand what this means for the protein (the amino chains unfold and reform bonds), but what does this mean for me? Do I lose value from the protein under these conditions? Is the protein I put in my oatmeal actually rendered unusable? How about when I throw a shake in the blender?
And how about eggs? I know that the cooking process denatures the protein, but does it lose its BV?
Mack ----
Mack, T-mag contributor John Berardi has written about this topic extensively in the newsstand edition of the magazine (issue #6) but we'll sum up a few of his ideas here.
Denaturing isn't as evil as many make it out to be. Basically, it doesn't mean that the protein is "destroyed" or made totally useless. In fact, cooking some protein foods, like eggs, fish, and meat, is a good thing. For example, the body is only able to utilize about half the protein in raw eggs. If you want to "get" all the protein in eggs, you gotta' cook'em.
Protein supplements in the form of whey and casein are a little different. If you cook your protein powders you don't totally destroy them but the denaturing process does alter their unique digestive profiles. In other words, whey may not digest as quickly if cooked. No big deal really, but sometimes you want whey to be digested quickly, like right after training.
Whey and casein are also thought to have unique and bioactive sub-fractions. Heat denaturation may lead to altered "folding" and metabolism of the protein in the GI, so once they're digested the unique peptide components may be altered and rendered useless. The protein isn't useless, but it loses some of its "specialness."
Finally, cooking casein and whey could make them a little less digestible.
So, blending protein in shakes is fine, as is adding it to already cooked oatmeal. Just don't add it in before you cook it.
By the way, about the only time you'll run into this problem with protein supplements is with those ready-to-drink cans of protein. While the protein inside isn't totally useless, it did have to be cooked first. So any protein that comes premixed in a can is sub-quality stuff compared to powders. (For more info, checkout TC's Protein Insider article.)
Hope all that helps!
---------------------------- "Don't follow leaders and watch your parking meters!" -- Bob Dylan
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