Cooking Eggs (Bioavailabilty vs Protein Content)

[RebelDogg]

Okay, not trying to get into a raw vs. cooked debate here. Just wondering about this: I know cooking eggs is supposed to make them more bioavailable than eating them raw. But, I also know (well, let's say "think") that high heat denatures proteins. So when I cook eggs, I never cook them long. I don't flip 'em, don't break the yokes and leave em just a little runny. When I boil 'em, I soft boil 'em. Now I prefer my eggs this way, anyway. However, does fully cooking eggs, say for an omelet or scrambled eggs, lose you any protein-y goodness? If so, to what extent?

Just curious 'cause I was gonna scramble my eggs tomorrow morning for a change of pace. But if it's healthier to not, then I don't really need to.

[Sean S]

Remember that you are eating eggs and other proteins for the amino acid content, not for any function of the intact proteins. Denaturing the proteins changes the secondary and tertiary structure of the protein, but the amino acid content is still intact. The digestive system is going to cleave the protein into small polypeptide chains to be absorbed anyway, so the protein structure is essentially destroyed in the GI tract. Cook the eggs any way you like, it's not going to make a difference.

[RebelDogg]

Okay, thanks, Sean. I didn't know that. I thought "denaturing" somehow destroyed the protein or rendered it useless. Okay... going get me some eggs now...

[Mercuryblade]

Remember that you are eating eggs and other proteins for the amino acid content, not for any function of the intact proteins. Denaturing the proteins changes the secondary and tertiary structure of the protein, but the amino acid content is still intact. The digestive system is going to cleave the protein into small polypeptide chains to be absorbed anyway, so the protein structure is essentially destroyed in the GI tract. Cook the eggs any way you like, it's not going to make a difference.

Nailed it, nice explanation.

[soclydeza]

Remember that you are eating eggs and other proteins for the amino acid content, not for any function of the intact proteins. Denaturing the proteins changes the secondary and tertiary structure of the protein, but the amino acid content is still intact. The digestive system is going to cleave the protein into small polypeptide chains to be absorbed anyway, so the protein structure is essentially destroyed in the GI tract. Cook the eggs any way you like, it's not going to make a difference.

yup, right on the money. denaturing essentially means that the proteins unfold. there are a lot of "nutrition" articles out there that fail to use that word and instead say something like "cooking food kills the nutrients" (usually from some hardcore holistic source trying to push some product or ideal), which is inaccurate unless you burn your food to a blackened crisp. and in turn a lot of ppl become skeptical of how they cook their food. good explanation sean

[Mercuryblade]

yup, right on the money. denaturing essentially means that the proteins unfold. there are a lot of "nutrition" articles out there that fail to use that word and instead say something like "cooking food kills the nutrients" (usually from some hardcore holistic source trying to push some product or ideal), which is inaccurate unless you burn your food to a blackened crisp. and in turn a lot of ppl become skeptical of how they cook their food. good explanation sean

It's a fact that cooking foods will denature certain enzymes, either destroying their function entirely or partially.
But whether or not certain enzymes are beneficial, useless, or harmful depends entirely on the enzyme. Since enzymes are just catalysts in metabolic pathways, it's likely that the "ZOMG DESTROYED ENZYMES" broken down in cooking probably do jack-squat in the human body anyway if they were left intact.

Just goes to show how easy it is to push an agenda by using broad biochemistry terms.

[J.C.]

Just a theoretical question, but if cooking eggs and denaturing the proteins renders them more digestible - which I've read numerous times - does that also mean that a steak well-done will be more bio-available than a steak done medium rare? Because you'd have a hard time convincing me that a well done steak is "better" than a medium rare steak.

[Sean S]

The denaturing doesn't necessarily make the protein more or less digestible, just changes the conformation. Thus it likely makes very little difference in how the steak is cooked, provided you don't scorch it into a charcoal block.