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.
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.)
Does the filtration method matter?
Liquid whey, whether obtained as a by-product of cheesemaking or directly from milk, contains more than just protein. Filtration is required to remove unwanted components such as bacteria, fat, lactose (milk sugar), and residual casein (the other protein in milk). Sweet whey, the most common type of liquid whey, is 5.14% carbs (lactose), 0.85% protein (mostly whey), and 0.36% fat.
The most common method used in making whey protein powders is ultrafiltration, sometimes paired with microfiltration. Both methods involve pushing liquid whey through a membrane without the use of heat or chemicals; the whey protein passes through non denatured, while unwanted components do not pass at all.
Some companies may advertise the use of crossflow filtration. With this method, water gets run across the membrane rather than directly onto it, thus removing built-up gunk. This results in increased throughput, which only benefits the manufacturer.
Ion exchange is another method of isolating protein: liquid whey is run through special resins that chemically bind the protein. Alas, the chemicals alter the pH of the liquid whey and denature the whey protein. Mixed-matrix-membrane ion exchange, a novel ion-exchange method developed as part of a PhD thesis back in 2003, does without harsh chemicals and can thus yield non denatured whey protein, but it has received little attention; it doesn’t seem promising enough to be favored over the membrane filtration methods.
Microfiltration and ultrafiltration do not denature whey protein, whereas ion exchange does.
Is spray drying a concern?
Spray drying is the method most widely used in the dairy industry to convert the whey protein solution into a powder. This process can take on many forms, some of which denature whey protein. Conventional methods, which maximize production speed, denature 30–40% of the protein, even at what would be considered low temperatures for spray drying: 60–80°C (140–176°F). At those low temperatures, lower-throughput spray drying does not denature whey protein. To avoid the issue of heat denaturation entirely, some manufacturers use vacuum drying (below room temperature) and/or freeze drying. Such processes, which are used notably in the making of a patented non denatured whey protein, take much longer (15–18 hours, usually) and so are not a prime choice for the mass production of whey protein powders.
Freeze drying and vacuum drying do not denature whey protein. Spray drying can, but steps can be taken so it won’t.
Whey protein concentrates and isolates
Whey protein powders can be divided into three main categories: concentrates, isolates, and hydrolysates. Here, we focus on concentrates and isolates.
Whey protein concentrates and isolates differ mostly in their protein, lactose, and fat contents. Isolates are at least 90% protein by weight; therefore, they contain with very little lactose and fat. Concentrates, the most widely used form of whey protein in food manufacturing, contain 29–89% of protein by weight. The most common types of concentrate in the US, used notably for food aid, are WPC34 (34% protein) and WPC80 (80% protein). WPC80 is the protein powder most commonly used by the supplement industry.
WPC80 and whey protein isolates are very similar. The former contains a little less protein and a little more lactose and fat, but that’s it. Since isolates are significantly more expensive, a decent concentrate will usually be your better choice, unless you are very sensitive to lactose.
Whey protein hydrolysates
Whey protein hydrolysates are concentrates or isolates that have been “predigested”, meaning that the protein has been broken down into peptides (hydrolysates), primarily through enzymatic means.
Hydrolyzation denatured whey protein, but whether this denaturation results in higher or lower bioavailability of the bioactive peptides depends on the type and amount of enzymes used, as well as on the incubation temperature, pH, and time.
From a practical standpoint, hydrolyzed whey protein is often promoted as being better for building muscle because it is absorbed faster than other forms of whey protein. But that isn’t so. In several studies, hydrolysates increased serum concentrations of amino acids faster than did concentrates, but to a similar or even lower extent than did isolates.More to the point, two separate studies reported that concentrates and hydrolysates, coupled with resistance training, led to similar increases in strength and muscle mass.
What if I’m allergic to whey?
First, make sure it isn’t the lactose you’re sensitive to by trying a whey protein isolate.
If you do find that you are sensitive to (or even allergic to) whey protein, then the cause is probably β-lactoglobulin,the main whey protein subfraction in cow’s milk. That’s because this protein is absent from human milk. Other whey protein subfractions can be responsible for the allergy or sensitivity, but it is less likely. Milk from buffalo, sheep, goats, horses, and donkeys also contains β-lactoglobulin, and cross-reactivity between species is common (so if you are sensitive to cow’s milk, don’t be surprised if you are also sensitive to goat’s milk). Camel milk lacks β-lactoglobulin, but finding a whey protein powder sourced from camel milk may prove ... challenging.
Hope the above helps you.