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Primary Protein In Milk

milk protein is primarily whey correct… or does it also have casein… also if it is both does anyone know the typical percentages of each?

Milk has no whey in it. It must be aged and processed to produce whey. Read up on the process of making the stuff, it’s actually really interesting and pretty wild.

I’ve read that milk is 80% casein and 20% whey.

whey is extracted from milk when it is homogenized (it’s the stuff at the top of the milk vats on farms and bottling factories). also, whey is the “watery substance” on top of natural yogurts. I don’t know what the hell casein is precisely, but I’m pretty sure it comes from milk.

[quote]Digity wrote:
I’ve read that milk is 80% casein and 20% whey.[/quote]

this is correct. in cow milk, the protein ratio is roughly 80% casein proteins and 20% whey proteins.

products such as cheese and cottage cheese are usually whey free (curds for the cottage cheese, not the ‘wet’ version sold commonly which has a little whey left). originally this was a source of surplus whey.

yogurt is often made with whey included and sometimes you can find ones with added whey.

high end protein blends like Metabolic Drive are roughly half casein and half whey as this ratio is closer to that of human milk and seems to provided better benefits that either milk protein or whey alone. most of the casein in such products is micellar casein which has an extended release profile due to superior gelling profile in the stomach vs. other more processed caseins.

Milk protein isolates and concentrates are simply the proteins from milk and are found in the same ratio, with varying amounts of the carb and fat content of milk removed and differing in the denaturing of the proteins and protein fractions contained.

[quote]Padilla7921 wrote:
whey is extracted from milk when it is homogenized (it’s the stuff at the top of the milk vats on farms and bottling factories).[/quote]

no it isn’t. that is fat globules held together by very few of the total whey proteins. homogenization is when the milk is forced through pipes with turbulence so the globules of different types separate and form a new more consistent type of globule leading to a more uniform consistency.

you can read more under creaming and homogenization of milk at wikipedia:

[quote]Padilla7921 wrote:
also, whey is the “watery substance” on top of natural yogurts.[/quote]

actually, that is product of the bacterial fermentation and water runoff. the whey remains mixed into the product unlike cottage cheese where the watery substance does include some whey, but by no means most of the original. dry curd cottage cheese is free of this (though i am sure traces linger).

you can find support for this on page 5 of:

http://www.yogurtforever.org/download/yogforevuk.pdf

[quote]Padilla7921 wrote:
I don’t know what the hell casein is precisely, but I’m pretty sure it comes from milk.[/quote]

good guess, it is 80% the protein in milk, check the link above.

thanks for the info guys