Nutritional Benefits of Dairy Ingredients: Whey
Whey is a derivative of cheese production, and is therefore available in most cheese-producing countries. Whey ingredients are available in a variety of forms including the following:
- Dried Sweet Dairy Whey (DSW) obtained by drying liquid whey, a co-product from the manufacture of cheeses (such as cheddar or mozzarella); typically contains 11% to 14.5% protein.
- Whey Protein Concentrates have higher protein levels compared to sweet whey. The most common forms contain protein levels of 34% or 80% (WPC34 and WPC80 respectively). Concentrations of 50%, 60%, 75% and 85% protein are also available, but on a more limited basis.
- Whey Protein Isolate (WPI) has a protein content of 90% or greater.
Whey Protein Quality
Whey ingredients are considered to be a high quality source of protein, whether measured by Protein Digestibility (PD), the proportion of protein that is absorbed by the body, Biological Value (BV),the proportion of absorbed protein that is retained for growth and maintenance, Protein Efficiency Ratio (PER), the gain in body weight per unit (g) of protein consumed, or Protein Digestibility Corrected Amino Acid Score (PDCAAS), which compares the amino acid profile to the amino acid requirements for a child between ages two and five, adjusting for digestibility. To view a graphic comparison of whey with other proteins, click here.
Whey contains all the essential amino acids in the proper proportions, making it an excellent source of nutrition for both therapeutic and supplementary foods. Most amino acid levels in whey exceed Food and Agriculture Organization/World Health Organization (FAO/WHO) nutritional intake recommendations, both for children aged 2 to 5 and for adults. Whey contains among the highest concentration of branched-chain amino acids (BCAAs) available from any natural food protein source. To view the complete nutritional profile of DSW, WPC34, WPC80 or WPI, click here.
Whey protein is comprised of a number of individual bioactive components, or fractions, which include alpha-lactalbumin, beta-lactoglobulin, serum proteins, lactoferrin and a series of immunoglobulins. Individually, these fractions are known to be immune-system enhancing. In addition, they support a wide range of bioactive functions, such as iron binding, tissue repair, maintenance of intestinal integrity, resistance to pathogens and elimination of toxins. For more on the physiological effects of whey protein fractions, click here.
Whey proteins are easily digested and work well in products designed to quickly provide nutrients to the body. They are often the preferred choice in ingredients where digestibility is a critical factor.
Dry sweet whey (DSW) is a powder obtained from drying pasteurized, fresh, natural whey made from certain types of cheeses, such as cheddar and mozzarella. It is also referred to as sweet dairy whey (SDW). The protein content is less than what is available in a whey protein concentrate or isolate and ranges from 11.0-14.5%. The protein is the same as in other whey ingredients and is of high quality and high biological value. DSW provides a source of essential and BCAAs, just at lower levels than the more concentrated whey ingredients.
DSW has a mild, pleasant dairy flavor and disperses well in dry mixes. It provides a cost efficient source of dairy solids, mostly in the form of lactose, and protein for many food applications. Lactose has been shown to have beneficial digestive benefits by stimulating the growth of acid forming lactobacilli in the intestinal tract to help combat intestinal disorders.
From a nutritional viewpoint, DSW naturally contains higher levels of important minerals and vitamins than any other whey ingredient. It is sometimes used to replace SMP in food applications where an ingredient with less protein and higher levels of lactose is acceptable. DSW is an excellent source of natural dairy calcium and a 100 g serving provides approximately 150% of the recommended daily intake for adult males based on WHO guidelines. The lactose in DSW has added value and helps increase calcium absorption and retention.
In addition to DSW, the following types of lower protein whey powders are available:
- Acid whey powder: this type of whey powder is obtained from the manufacture of cottage cheese. It is an alternative when higher levels of bio-available calcium are desired.
- Reduced lactose whey: the lactose content may not exceed 60%.
- Demineralized (or reduced mineral) whey: a portion of the minerals have been removed from pasteurized whey. Typical levels of demineralization are 25%, 50% and 90%.
Whey protein concentrate 34% (WPC34) is made by removing a specific amount of non-protein constituents from whey to create a finished product with a minimum of 34% protein and up to a level of 36% protein. This cost efficient source of dairy solids and dairy protein is similar in lactose, protein and total amino acid content to skim milk powder (SMP).
The main difference between WPC34 and SMP is the composition of the protein as a result of the manufacturing process. Whey protein is a co-product of the cheese making process. The casein portion of the milk protein remains in the cheese while the more soluble whey protein is removed as part of the liquid whey stream. This differs from SMP which is a combination of both casein and whey protein.
WPC34 may be used for a variety of food applications due to its combination of high quality protein, lactose and milk minerals. It is well-suited in products where higher levels of carbohydrate and some amount of fat are acceptable, if not desired. The lactose and milk fat provide a source of energy and important nutrients. WPC34 also serves as a source of vitamins including A, C, thiamin, riboflavin and niacin. WPC34 provides bioactive calcium and contains only slightly less amounts than DSW.
WPC34 is available in both food and feed grade versions. Only food grade products are suitable for use in food applications.
Whey Protein Concentrate 80%
Whey protein concentrate 80% (WPC80) is made by removing a specific amount of non-protein constituents from whey so that the finished product has a minimum of 80% protein. The protein content will vary between 80-82%, depending upon the supplier.
WPC80 is a highly concentrated form of whey protein with a much reduced level of lactose compared to WPC34. It also has the lowest sodium content of all the dairy ingredients. WPC80 is beneficial in products where the focus is providing a high quality source of protein with lower or reduced carbohydrate levels.
Due to its higher protein level, WPC80 contains over twice the amount of BCAAs than WPC34. This is beneficial when the goal is to prevent muscle loss and build new lean muscle tissue. It is also important in the development of products with immune enhancing properties. The bioactive components in whey are known to enhance immune health and higher concentrations of protein are often preferred in this type of application. The combination of high BCAA content and easy-to-digest protein makes WPC80 an ideal ingredient from a nutritional perspective.
WPC80 performs well in many applications as an egg replacement from both a functional and nutritional perspective. The finished product will contain the desired level of high quality protein and the need for traditional emulsifiers, such as egg yolk powder, may be eliminated. In some situations this may yield a safer product as it avoids any potential contamination associated with eggs.
WPC80 is available in both a standard form and a hydrolyzed form. In the latter, the amino acids have been broken down into smaller, more easily digestible peptide components. A hydrolyzed dairy ingredient is frequently used in products where allergic reactions are of concern, or when special dietary requirements exist.
Whey protein isolate (WPI) is the purest and most concentrated form of whey protein available. WPI must contain a minimum of 90% protein and most often, the protein content will range between 90-92%. If the protein level falls below 90% the product must be labeled as a concentrate and not an isolate. This same rule also applies to milk protein ingredients.
In terms of nutrition, WPI is a superior protein given its highly concentrated form. WPI contains all the essential and branched-chain amino acids (BCAAs) found in other whey ingredients, but in the most highly concentrated form available. Even though WPI has been highly purified, it is still a source of important nutrients, such as calcium. It is not, however, as good of a source of vitamins as some of the less concentrated types of whey protein.
WPI contains little to no fat or lactose and is often selected for lactose-free products. It is also a preferred ingredient for higher protein products that do not require the nutritional or functional benefits of lactose.
As with WPC80, WPI is available in both a standard form and a hydrolyzed form. In the latter, the amino acids have been broken down into smaller, more easily digestible peptide components. A hydrolyzed dairy ingredient is frequently used in products where allergic reactions are of concern or in products targeted to individuals with special dietary requirements.
WPI may be produced using either membrane separation or ion exchange technology. The finished WPI contains slightly different amounts of individual bioactive peptides depending on the process used. In general, either process will produce a very high quality dairy-based protein powder. When sourcing WPI from potential ingredient suppliers it is recommended to always request a product specification sheet.
Whey permeate comes from the liquid residual that remains after the majority of the whey proteins have been removed from liquid whey. The main component of whey permeate is lactose. Whey permeate is primarily used to directly replace dairy solids in food applications and is also referred to as Dairy Products Solids (DPS).
Please note that whey permeate contains only trace amounts of protein. Commercial specifications, however, typically list protein content around 3.5% to 5%. The discrepancy is due to dairy industry testing for total nitrogen, a number that is then automatically multiplied by 6.38. The nitrogen found by testing is largely non-protein nitrogen (NPN), rather than true protein. Examples of NPN compounds found in milk and whey include urea, creatine, creatinine, uric acid, orotic acid and ammonia. Whey permeate is not suitable for products that require higher levels of protein.
Whey permeate offers numerous functional benefits to food manufacturers. It may be used to reduce the level of sweeteners in breads and other bakery-type products while helping the product to develop a brown crust. The protein and lactose content will determine how well the product will function. Whey permeate also contain sodium which may be sufficient to replace any added sodium in a formulation. This may help lower ingredients costs and reduce the sodium content listed on the nutrition label. Whey permeate is not suitable for products that require higher levels of protein.
Whey permeate is available in both a food-grade and feed-grade form. If whey permeate is the dairy ingredient best suited to your needs, care should be taken to only use food-grade whey permeate in the formulation of food products. In addition, local standards for protein content need to be taken into consideration. There are some countries, such as China, that require protein levels higher than 8% for a product to be considered food-grade.