Depending on the stage of breast milk production, the protein in human milk is 80% to 50% whey. By contrast, the protein in cow’s milk is 20% whey (and 80% casein). Whey protein from cow’s milk makes for more than 80% of the protein powder market.
Online sales of protein powders
Comparison of various foods’ protein quality
Whey is high in EAAs, notably leucine (the most anabolic amino acid). Whey protein is 52% EAAs and 13.6% leucine. By contrast, protein from other animal sources is roughly 40–45% EAAs and 7–8% leucine, while protein from plant sources is even lower.
Further, whey protein is rapidly digested and absorbed, and so is an ideal companion to resistance training, since rapid increases in serum EAAs lead to greater MPS compared with slower, more steady rises. (Unsurprisingly, consuming whey protein away from training sessions lessens its benefits.)
EAA content of plant- and animal-based proteins
Leucine content of plant- and animal-based proteins
Bioactive peptides
Proteins are a source of amino acids, but also of peptides, small chains of amino acids that aren’t completely broken down by your digestive enzymes. Some of those peptides, called bioactive peptides, have physiological effects.
A peptide can become bioactive only after being freed from a larger protein strand (a protein subfragment) by your digestive enzymes. It can act locally in the gut or be absorbed into the bloodstream, from where it has a variety of effects on tissues throughout the body.
Whey protein is a rich source of bioactive peptides that benefit the cardiovascular and immune systems. These peptides may partly explain why breastfed infants have a lower risk of developing obesity, diabetes, and cardiovascular disease than formula-fed infants: infant formulas are not always made with dairy (soy is a popular alternative), but even when they are, cow’s milk has less whey than human milk, and what whey it does have may have been denatured during processing.
Bioactive peptides from whey protein
Whey protein contains bioactive peptides that are released during digestion. These peptides can act locally in the gut or be absorbed into the bloodstream. Some appear to benefit the cardiovascular and immune systems.
Whey processing and denaturation
The overall process of making whey protein powders is rather simple, yet with each step there can be differences in manufacturing. Some techniques can denature the protein, preventing the formation of bioactive peptides when the protein is digested.
Denaturation: Denaturation is the alteration of a native structure. Protein denaturation can be caused by heat, chemicals,
acids, or physical treatments. It changes the way the protein functions and interacts with your body.
Denaturation is an important part of our evolutionary history. It was our ability to harness heat to denature the physical structures of food that allowed us to obtain more calories from what we ate. For example, cooking an egg denatures its proteins in such a way as to increase their bioavailability from roughly 50% to 90%.
As discussed earlier, however, the digestion of whey protein leads to the production of bioactive peptides that can benefit notably your immune system. The denaturation of whey protein can interfere with the production of those peptides because a change in the protein’s structure means that our digestive enzymes will act on it differently.
Denaturation of whey protein may explain, at least in part, why observational studies have found that infants drinking milk that has been aggressively heated are at higher risk of allergic diseases and respiratory infections than infants drinking raw milk or milk that has not been aggressively heated. Raw milk can also protect mice against the development of asthma, while heated milk cannot.
If your goal is exclusively to get protein, then this may not matter. But since bioactive peptides may benefit your health, then why not opt for a whey protein that supplies them? It’s like icing on the cake.
The first step in making a whey protein powder is securing a source of milk. There are many companies now advertising whey protein obtained from pastured cows fed an ecologically appropriate diet, and whether the cattle’s diet and life conditions affect whey quality will be discussed later.
From milk, the liquid whey can be extracted. It is most often a byproduct of cheesemaking, although an increasing number of companies are extracting their whey directly from milk. The differences between the two types of liquid whey, cheese whey and native whey, are used as advertising arguments by manufacturers.
Both types of liquid whey need to be filtered to separate the whey protein from the lactose, fat, bacteria, and other unwanted components. There are several methods for accomplishing this.
Finally, the whey extract is dried into a powder and sold as whey protein concentrate (29–89% protein) or whey protein isolate (at least 90% protein). Further processing with enzymes that “predigest” the protein produce whey protein hydrolysate. These three forms of whey protein will also be discussed.
From milk to whey protein powders
Whey protein powders are created through the filtration, concentration, and drying of liq- uid whey obtained either as a by-product of cheesemaking or directly from milk. At each step in production, differences in manufacturing practices can denature the protein and thus prevent your digestive enzymes from forming bioactive peptides out of it.
On the next blog we will dig deeper into whey protein powder
Hope the above helps you.
Coach HB