What is Whey Protein Concentrate?
Whey protein concentrate is made from fluid whey, a by-product of cheese making. While similarly named, fluid whey is not same as whey protein (to make sense of the difference, read this post).
Why is Whey Protein Concentrate Added to Infant Formulas?
While there is a wide range of proteins in mammalian milks, two classes predominate: caseins and whey. In human milk, the proportion of casein to whey changes as the infant grows. Early milk is 70-80% whey and decreases to 50-60% within a few weeks. Mature cow milk that is used to make dairy ingredients is about 18-20% whey. Thus, manufacturers add whey to balance out the ratio of casein to whey in order to mimic that of human milk. Given that the percentages change as the infant grows, age-specific formulas (e.g. newborn, Stage 1) have higher percentages of whey.
While the proportional differences of whey to casein between human and cow milk have been long known, technical improvements allowing in-depth analysis of specific proteins in each class has renewed the focus on understanding casein and whey in human milk. For example, newer analysis methods suggest that casein levels in human milk may be lower than previously believed. Also variation between women may be greater than previously understood. One study found that 37 out of 166 common proteins in human milk differed between women of different ethnicities over the course of lactation. These technological improvements are exciting, as they progress scientific knowledge of infant nutritional needs.
Whey protein concentrate is similar to, but not the same as, the following ingredients:
Whey powder (partially demineralized)
Is Whey “Easier” to Digest?
Higher levels of whey, up to 100%, are promoted by some companies in their solution formulas. Indeed, casein is frequently described as being “harder” to digest, implying that casein is metabolically more difficult or taxing on an infant. However, this portrayal a mental short-cut and isn’t technically correct, especially for healthy infants.
Clinicians have long believed that casein is much slower to leave the stomach than whey, an effect called delayed gastric emptying time. While early research showed this to be the case, more recent work throws a wrench in this assumption for healthy infants without GI conditions.
How Is Whey Protein Concentrate Made?
Fluid whey contains protein, lactose, fat, and minerals. Dairy processors make whey protein concentrate from fluid whey by removing part of the fat and carbohydrate, and then drying it. According to the American Dairy Products Institute, whey protein concentrate powder has at least 25% protein by weight. In contrast, regular dry whey has half this amount with a minimum 11% protein.
Regulations and Safety
Whey protein concentrate is generally recognized as safe (GRAS) by US FDA. Manufacturers can buy several standard concentrations from dairy processors such as 30% and 80% whey protein. Some forms include vitamin A (fortified in the original cow milk), which influences how much vitamin A manufacturers must add to meet government requirements.
Manufacturers can also buy a version where the minerals like calcium and phosphorus have been partially removed, in which case it is commonly listed as demineralized whey protein concentrate or whey protein concentrate (partially demineralized).
Dietary Considerations
Whey protein concentrate is not appropriate for vegans since it comes from fluid cow milk. It is acceptable for vegetarians who drink milk (lactovegetarians). The OU (Orthodox Union) Kosher considers many whey-containing infant formulas as OU-D (kosher dairy) but not Kosher for Passover. Since whey concentrate is derived from fluid milk, it is not Cholov Yisroel unless specifically certified as such. For reference, see the Orthodox Union Kosher Dairy Primer.