slow digesting protein powder

stevie

New Member
Whole egg is relatively slow digesting protein. But if you have 100% egg powder derived from egg white only, does that not then become a fast digesting powder just like whey, soy etc?
I guess the same question goes for casein. If its in powder from, surely it gets digested very quickly?
After all, there is no fat around and there is huge surface area.....i would have thought that these powders would also be 'fast' proteins...but it seems that they are not.
Is there something about the composition of these proteins that makes it harder for the various proteases to cleave peptide bonds?
 
Dear stevie,

The surface area of the protein is but one factor in its digestion. The protein's quarternary and tertiary structure also play a great part in its digestion.

For example, casein (the primary protein in milk) forms a curd in one's stomach resulting in a slow-digesting protein gel.

Whey does not form a curd and thus is assimilated much faster than casein despite casein and whey being both liquid in form when initially ingested.

Such a digestion disparity is due to differences in the protein's 3D shape and also, the physical/chemical properties it assumes within the human gut.

From memory, in ascending order of digestion speed: casein, cheese, animal protein, eggs, whey.

Vegetable protein is somewhere between cheese and animal protein I think.

The only time to worry about protein digestion speed is prior to the workout. The pre-workout meal should consist of fast proteins (whey in water is best for this) in order for hyperaminoacidaemia to occur. Post-workout, take another shake but with milk instead of water. And if solid food is available post-workout, then ignore the post-workout shake altogether and indulge in real food instead.

Godspeed, and happy HSTing :)
 
[b said:
Quote[/b] (Dianabol @ May 28 2003,1:24)]From memory, in ascending order of digestion speed: casein, cheese, animal protein, eggs, whey.
At best, this is just a guess, as there hasnt been research on anything other than casein/whey.
 
In reality what are the digestive rates of casein versus whey? It can't be any greater than say 10-15 minutes and does that make a huge difference?
 
[b said:
Quote[/b] ]In reality what are the digestive rates of casein versus whey? It can't be any greater than say 10-15 minutes and does that make a huge difference?

well according to the primer/driver articles (and the one very famous study published in Nature!), there is a very dramatic difference between the times that whey and caesin amino acids get into and remain in the blood.
 
Whey isolate peaks in blood after about 30mins, free form aminos (basically protein hydrolysates) will peak after about 15mins.
Casein peaks after about an hour, but its peak is lower than whey, because of the 'drip feeding' effect.
Taking a small amount of whey every 20mins or so has a similar effect to taking casein.
 
You can see a handy graph of the blood levels in response to whey and casein on the Driver/Primer info page: HST Products. The charts are representative of a whey product (Primer) and a casein product (Driver); they assume the Primer is taken pre-workout, and the Driver immediately post.
 
I stick with whey due to cost and make poor man's casein with cottage cheese and milk in my post-WO meal. I think that has me more than covered. ;)
 
[b said:
Quote[/b] (Cliner9er @ May 28 2003,5:59)]I stick with whey due to cost and make poor man's casein with cottage cheese and milk in my post-WO meal. I think that has me more than covered. ;)
except that cottage chesse + milk is more expensive gram for gram of protein than casein...at least in the UK!
 
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