Sourcing a whey protein

Does organic or grass-fed matter?

First, let’s deal with that organic certification you might see on a whey protein powder. It means that the cow was given neither hormones or antibiotics, and that its pasture or feed was itself organic. Does that make your powder healthier? Maybe, maybe not: while there is some evidence that organic produce might be safer, whey protein is very different from a salad. All we can tell is that there doesn’t appear to be any difference in the whey protein composition of the milk produced by two farms, one certified organic and the other not, that have similar farming practices.

But what about when the farming practices differ?

An increasing number of companies advertise that they source their whey from cows raised on pasture or fed grass rather than grain. There are important environmental and ethical arguments to be made about either practice, but our focus here will be on its effect on the nutritional value of whey protein.

This effect is, at best, minimal. An early study reported that greater access to pasture resulted in small increases in some whey bioactive peptides, but small decreases in others, whereas a later study found no meaningful differences.

There is little nutritional difference between whey protein sourced from the milk of cows raised conventionally and whey protein sourced from the milk of cows pastured or grass fed. Also, an organic certification has no impact on whey protein composition.

Does pasteurization denature whey?

The FDA requires that all milk intended for human consumption be pasteurized, including any used to make whey protein powders. So all whey protein powders are pasteurized at least once, meaning there is no such thing as raw whey protein powder.

The most common type of pasteurization in the dairy industry is high-temperature, short- time (HTST) pasteurization, in which milk is heated at 72C (161F) for 15 seconds and then cooled rapidly. Basically, milk is run through millimeter-wide, superheated tubes for 15 seconds, then through supercooled tubes to end the pasteurization process nearly instantly. HTST pasteurization does not denature whey protein,which is why it is used notably in the production of a patented, non-denatured whey protein powder.

A less common form of pasteurization, called vat or low-heat pasteurization, involves heating large batches of milk to 63C (145F) and holding them at that temperature for 30 minutes. Some companies may advertise the use of this type of pasteurization because it uses lower temperatures than HTST pasteurization. Over time, however, this “low” heat is still high enough to denature several whey protein subfractions, especially when we consider that the exposure time is not just the 30-minute holding temperature but also the time it takes to heat and cool the vat of milk. Some studies have reported that 10–20% of whey proteins are denatured during vat pasteurization.

In fact, this is the primary reason why many cheesemaking plants turn away batches of vat-pasteurized milk: denatured whey protein sticks to the casein, negatively affecting cheese quality.

Cheese whey vs. native whey

When whey is a byproduct of cheesemaking, it is called cheese whey. When it is extracted directly from milk, it is called native whey. Most supplement companies use cheese whey; those that use native whey claim that it is superior because it has more leucine and because the heat and chemical processes used to make cheese can denature the whey protein.

They aren’t technically wrong.

Native whey does contain marginally more leucine than does cheese whey: 2.7 versus 2.2 grams per 20 grams of protein. But one study comparing the two types of whey protein found similar increases in anabolic signaling, MPS, and strength recovery in resistance-trained young adults, while another found similar rates of anabolic signaling and MPS in elderly adults.

And yes, cheesemaking can denature whey protein.

Whey can be obtained from different types of cheeses. To produce acidic cheeses (cottage cheese, cream cheese, etc.), the milk is exposed to high temperatures and its acidity is altered chemically. Since both processes can denature whey protein, you should avoid using powders made from acid whey. Thankfully, most cheese whey comes from the production of natural, rennet-produced, cultured cheeses (Cheddar, mozzarella, etc.). Milk is allowed to ripen for a mere 60 minutes after being mixed with lactic acid bacteria, at which point the enzyme rennet is added to the mixture for another 60 minutes before the liquid whey, called sweet whey, is drained. Both exposures are too brief, and take place at about half the temperature required to denature whey protein. A patented non-denatured whey protein powder is made from sweet whey.

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.