- Protein powders can be made from whey, casein, egg, soy, pea, or rice. This article focuses on whey protein powders.
- The protein in whey protein powder is derived from liquid whey, a byproduct of the cheese-making process.
- Whey protein is a “complete protein,” meaning it contains all nine essential amino acids that the body must obtain through food or drink.
- There have been no confirmed foodborne illness outbreaks linked to whey protein powder, although there have been precautionary recalls – one due to Clostridium botulinum and three due to Salmonella.
Protein powders are commonly marketed as a dietary supplement for those looking to increase protein intake. Among the most common proteins used in these products are whey, casein, egg, soy, rice, hemp, and pea proteins, accompanied by additives such as creatine, glutamine, sugar, artificial sweeteners, or herbal sweeteners. This article examines whey protein powders, the most popular among American consumers.
Whey is a byproduct of the cheese making process. Whey protein, derived from whey, is touted as an easily-digestible, complete protein because it contains all of the nine essential amino acids (EAAs) that the body cannot synthesize itself. Specifically, whey protein is composed of approximately 50% Beta-lactoglobulin proteins, 20% Alpha-lactalbumin proteins, 10% Bovine serum albumin proteins, lactoferrin, and immunoglobulins. Depending on the cheese-making process, either sweet whey or acid whey will be produced. Each of these has varying nutrient compositions and chemical characteristics. Sweet whey is more commonly used in whey products, as it is produced in far larger quantities within the United States compared to acid whey (95 billion pounds of sweet whey compared to four billion pounds of acid whey were produced during 2011). Sweet whey has a pH of 5.6 or higher and is a byproduct from manufacturing cheddar, mozzarella, or Swiss cheeses. Acid whey has a pH lower than 5.1 and is a byproduct from manufacturing cottage or ricotta cheeses. (More information on the differences between these whey variations is presented in the above table.)
There are three main types of whey protein powder products: whey protein concentrate (WPC), whey protein isolate (WPI), and whey protein hydrolysate (WPH). Whey product labels include the type as well as the percent of whey protein the dry powder contains. For example, “WPC80” indicates a whey protein concentrate powder that is made up of 80% whey protein.
The three types of whey are often mixed along with added flavors and other ingredients to enhance nutritional value and palatability. Whey products include protein powders, baked goods, meats, processed cheeses, yogurts, and frozen desserts. The affordability and nutritional benefits of these whey proteins have contributed to their rise in popularity.
Whey Protein Concentrate (WPC):
Whey protein concentrate (WPC) has undergone various processes so that the final product contains low levels of fats and carbohydrates, yielding a whey protein concentration of approximately 30–90%. This variation tends to be cheaper than WPI or WPH because it undergoes less processing.
Whey Protein Isolate (WPI):
Whey protein isolate (WPI) is processed further so that all fat and lactose is removed, producing a whey protein concentration over 90%. The removal of all fat and lactose makes this an appealing option for those looking to reduce their carbohydrate intake.
Whey Protein Hydrolysate (WPH):
Whey protein hydrolysate (WPH) is considered by dietitians to be the “predigested” form of whey protein that has already undergone partial hydrolysis. Initial studies have indicated that consuming WPH may lead to faster and easier absorption of the proteins, although more research is needed. This process of partial hydrolysis breaks down the whey’s amino acids into smaller, simpler units called peptides. Peptides are much less likely to cause allergic reactions, making WPH a great, hypoallergenic alternative for individuals with milk allergies.
Although there have been no confirmed foodborne illness outbreaks linked to whey protein powder, from 2011 to 2014, there was one international voluntary recall involving potential Clostridium botulinum contamination and three voluntary recalls due to potential Salmonella contamination within the United States. Furthermore, in July 2018 a precautionary recall was placed on a dry whey powder (a closely related product to WPC, WPI, and WPH) product from Minnesota, due to potential Salmonella contamination.
In 2014, there was an outbreak scare of Clostridium botulinum in a 3.78-ton batch of whey protein concentrate produced by the New Zealand dairy company, Fonterra. This outbreak scare originated in February 2012 when broken flashlight fragments were found in a batch of whey protein concentrate 80 (WPC80). While the fragments were eventually removed, the process used to rework the product was poorly planned and executed, resulting in further contamination of the batch. Specifically, the factory workers ran the WPC80 through improperly cleaned pipes, and they failed to disperse the reworked WPC80 among new, standard product up to a maximum of 10% reworked product. Dispersal of reworked product is an important safety step within the dairy industry that ensures if contamination does remain, the contaminated product (as well as the risks it may pose to consumers) are diluted to acceptable levels. When the suspected batch underwent routine testing during production of Danone’s nutritional powder, the results indicated the possible presence of Clostridium botulinum. In June 2013, a Fonterra manager approved testing for Clostridium botulinum by AgResearch, an independent agricultural research organization that did not have the required accreditation to conduct these tests. In August 2013, three months after approving these tests, Fonterra notified New Zealand’s Ministry of Primary Industries of AgResearch’s test results, which claimed that the presence of Clostridium botulinum was “likely” but not “confirmed,” setting off the coordinated tracing and recall efforts by Fonterra and the Ministry. It was later determined by two United States government laboratories that the WPC80 batch was contaminated with the non-toxic Clostridium sporogenes (associated with food spoilage), instead of Clostridium botulinum.
In 2011, a Minnesota supplier implemented a voluntary recall of WPI due to concerns of Salmonella contamination. An independent laboratory conducted tests for Salmonella, which all came back negative, eliminating concerns of a potential outbreak.
In 2018, Salmonella was found in 25kg and 50kg bags of dry whey powder during routine testing at a production facility. Although the specific cause of this precautionary recall has not been publicly reported as of July 2018, there are a several ways whey protein products can be contaminated by Salmonella. The introduction of moisture into the processing area produces an environment conducive to Salmonella growth, which could either directly contaminate or indirectly contaminate whey protein products via workers, equipment, or pests
In recent years, heavy metal contamination (e.g. arsenic, cadmium, lead, and mercury) has also been a concern with whey protein products. Heavy metals are sparse, naturally occurring elements that can be found in extremely high quantities due to human industrial activities such as mining/smelting, coal burning, agricultural use of heavy metals, or paper processing. These heavy metals, often found in soil, can be absorbed by plants and concentrate in grazing ruminants, like the dairy cows that supply the milk for whey protein production. The vast majority of whey protein products contain safe levels of these metals, but there are a few brands, including Muscle Milk Chocolate powder, Muscle Milk Vanilla Crème powder, and the ready-to-drink liquid EAS Myoplex Original Rich Dark Chocolate Shake, that may expose individuals to unsafe levels of heavy metal contamination if they are consuming three or more servings a day. Consumers may be unaware of this, as this information is not usually included on the nutritional labels of protein powders, except in certain states (such as in California) where toxic substance reporting is mandated.
The first steps of whey protein production coincide with commercial cheese making, as whey is often harvested as a byproduct of these processes. Please see our article on cheese-making here.
Milk arrives at the dairy processor where it is tested for purity, quality, fat content, and proper storage temperature to ensure the milk is free from harmful bacteria.
Milk Standardization and Pasteurization
Standardization includes determining the ratio of protein to fat in the milk or standardizing the solids and then weighing the milk. Various technologies, including ultrafiltration, are common in large cheese or dairy processing operations to ensure milk is cleared of debris and spores that could survive pasteurization. A specially designed centrifuge, called a Bactofuge, is often used to separate bacterial spores, which have a higher density than the milk. Unless raw milk cheese is being produced, pasteurization is carried out at this point in the process.
Coagulation is the process of denaturing the milk proteins to form a gel network that facilitates the separation of milk solids (casein curds) from liquid (whey). However, coagulation itself does not separate curds and whey. Bacterial cultures are added to the milk before coagulation and after pasteurization. Streptococcus, Lactobacillus, and Lactococcus lactis are commonly used starter cultures that convert the lactose in milk to lactic acid via fermentation. A bovine-derived enzyme called rennet is added, which coagulates the milk protein, casein, forming a custard-like mass.
Whey Draining and Pasteurization
After separation, the whey is drained from the curds and then stored and transported to a protein manufacturing facility. After draining, the liquid whey is pasteurized again at 161 degrees Fahrenheit for at least five seconds to further ensure that the whey is free of harmful pathogens.
The liquid whey then undergoes filtration using a variety of methods, such as membrane filtration or ion exchange, which allow the whey proteins and other nutrients to selectively pass through while filtering out suspended solids (such as fine casein curd particles that remain from the draining step). In order to raise the concentration of whey protein (to 90% or higher) relative to all other dry matter, the liquid whey may undergo diafiltration, a process that adds water to the liquid whey during filtration to wash out lactose and minerals. Filtration steps may be repeated as necessary to reach the desired whey protein concentration. All the proteins and nutrients that pass through the filtration process are known as permeate. The permeate is then deposited in concentrated permeate storage to await the evaporation step.
Evaporation and Crystallization
Next, the permeate enters the evaporators, which siphon off more liquid in the whey product, further concentrating the whey proteins and nutrients.
After evaporation, the whey is flash cooled to 85 to 105 degrees Fahrenheit to facilitate the formation and growth of lactose crystals, a process known as nucleation. The whey is then held within the crystallizers for four to eight hours to achieve a uniform distribution of lactose crystals, a characteristic that prevents the final product from absorbing or attracting moisture from the air.
The whey is then transported to a post-crystallization spray dryer where any remaining water in the whey concentrate is evaporated off and the product is milled into a powdered or flake form. Spray drying prevents the growth of microorganisms in order to protect the consumer and to better preserve the food product. The most widely-used method is drum-spray drying, by which the whey product is run over high-capacity, steam-heated, rotating drums to facilitate the grinding of the whey concentrate and siphoning of the whey’s excess liquid in the form of a vapor.
After drying, the powdered concentrate is transferred to Permeate Powder Storage, where the powdered whey protein product is then bagged, typically in approximately 25 kg, plastic-lined, industrial bags.
Packaging, Transportation, and Storage
It is important that both consumer and producer understand the biggest risks associated with whey protein powder and how to mitigate those risks to protect consumer safety. After production, the whey protein powder should be properly sealed to prevent contamination from the outside environment. Whey protein powders should be packaged, shipped, and stored in cool, dry environments with temperatures and relative humidity not to exceed 80℉ and 65%, respectively. It is recommended that whey protein products be consumed within nine months to a year of production.
Spore-forming bacteria (such as Clostridium botulinum) can withstand stresses, such as UV radiation, drying, or high temperatures, that kill other pathogens. Bacterial spores can be present in the environment as biofilms on the surfaces of processing plant equipment or even on the udders of dairy cows (cleaning the udders may reduce the spore count in milk). In addition, if the product is rehydrated and kept at room temperature in anaerobic conditions, dormant Clostridium botulinum bacteria could be stimulated to produce the harmful neurotoxin that causes botulism illness in humans. Other non-spore forming bacteria, such as Salmonella, Escherichia coli, or Listeria monocytogenes, can also contaminate whey products at different stages of production. Pasteurization can effectively eliminate most, but not all pathogens of concern. However, contamination can still occur later in production during transportation and retail storage or in the consumer’s home.
Allergies and Sensitivities
Individuals that are lactose intolerant are advised to avoid consuming protein powders that contain WPC and, instead, consume protein powders containing WPI because it has much lower lactose content. Those with milk allergies are recommended to use protein powders with WPH, as they are less likely to cause allergic reactions.
Whey protein powder is used in a wide variety of products, such as infant formula, emergency food rations, bakery items, cereal products, and sports nutrition products. As of 2015, whey protein had been used in over 6,000 products launched globally, and this number is expected to continue rising given the 4% annual increase in sales of whey protein powder every year from 2009 to 2016.
Whey protein powder contains all nine essential amino acids that individuals need to obtain from their diet and can easily be incorporated and mixed into virtually any food or drink. Protein powders made from WPC, WPI, and WPH vary in the amounts of lactose, minerals, and other nutritional additives they contain, but they are all composed of basic whey proteins (beta-lactoglobulins, alpha-lactalbumins, bovine serum albumins, lactoferrins, and immunoglobulins). For some individuals, whey protein powders may play a key role in supplementing or substituting food-based protein to follow the National Institute of Health’s recommended protein consumption guidelines of 0.8 grams of protein per kg of body weight.
Furthermore, many individuals elect to exceed these guidelines in order to increase muscle mass and strength. Whey protein has a high concentration of proteins and amino acids and can increase the release of hormones that facilitate muscle growth. High protein diets also have a high satiety value and have been shown to aid individuals in weight loss by boosting their metabolic rate and decreasing appetite. Beyond these two primary uses of whey protein powder, recent studies have identified associations between whey protein intake and various health outcomes such as lowered blood pressure, moderation of blood sugar in type II diabetics, inflammation reduction, improved mood and serotonin levels, boosting of the body’s immune system as well as anti-tumor and anticarcinogenic effects, although more research on the health benefits of protein powders is needed.
In recent years, the American Heart Association’s Nutrition Committee has claimed that high protein diets, such as those supplemented by whey protein products, put consumers at risk of bone, kidney, and liver problems. However, there is no consensus on the health effects of these products, with some studies indicating that high protein diets may be beneficial to these same aspects of human health. Individuals with current kidney or liver conditions have traditionally been advised to consult with a healthcare provider before including whey protein powder into their diet. Limiting dietary protein has been standard practice to avoid further complications among these patients, though recent studies have called this practice into question. Lastly, some individuals consuming too much whey protein powder may experience nausea, cramping, flatulence, or diarrhea.
- Albert Salehi, Ulrika Gunnerud, Sarheed J. Muhammed, Elin Ostman, Jens J Holst, Inger Bjorck, et al. The insulinogenic effect of whey protein is partially mediated by a direct effect of amino acids and GIP on β-cells. Nutrition & Metabolism [Internet]. 2018 Jul 27;9(48). Available from: https://col.st/imfUw
- Anders H Frid, Mikael Nilsson, Jens Juul Holst, Inger ME Björck. Effect of whey on blood glucose and insulin responses to composite breakfast and lunch meals in type 2 diabetic subjects. The American Journal of Clinical Nutrition. 2005 Jul 1;82(1):69–75.
- Anssi H Manninen. High-Protein Weight Loss Diets and Purported Adverse Effects: Where is the Evidence? Journal of the International Society of Sports Nutrition [Internet]. 2004 May 10;1(1). Available from: https://col.st/Yoyw6
- Anssi H Manninen. Protein hydrolysates in sports nutrition. Nutrition & Metabolism [Internet]. 2009;6(38). Available from: https://col.st/kayzk
- Atli Arnarson. 10 Evidence-Based Health Benefits of Whey Protein [Internet]. HealthLine. 2017. Available from: https://col.st/ju57e
- C Rob Markus, Berend Olivier, Geert EM Panhuysen, Jan Van der Gugten, Martin S. Alles, Adriaan Tuiten, et al. The bovine protein α-lactalbumin increases the plasma ratio of tryptophan to the other large neutral amino acids, and in vulnerable subjects raises brain serotonin activity, reduces cortisol concentration, and improves mood under stress. The American Journal of Clinical Nutrition. 2000 Jun 1;71(6):1536–44.
- EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the substantiation of health claims related to whey protein and increase in satiety leading to a reduction in energy intake (ID 425), contribution to the maintenance or achievement of a normal body weight (ID 1683), growth or maintenance of muscle mass (ID 418, 419, 423, 426, 427, 429, 4307), increase in lean body mass during energy restriction and resistance training (ID 421), reduction of body fat mass during energy restriction and resistance training (ID 420, 421), increase in muscle strength (ID 422, 429), increase in endurance capacity during the subsequent exercise bout after strenuous exercise (ID 428), skeletal muscle tissue repair (ID 428) and faster recovery from muscle fatigue after exercise (ID 423, 428, 431), pursuant to Article 13(1) of Regulation (EC) No 1924/2006. European Food Safety Administration Journal [Internet]. 8(10). Available from: https://col.st/Ijv68
- Elding C. THE DETAILED GUIDE TO WHEY PROTEIN [Internet]. Health Cloud. 2016. Available from: https://col.st/hXCVv
- Government Inquiry into the Whey Protein Concentrate Contamination Incident. The WPC80 incident: causes and responses Government Inquiry into the Whey Protein Concentrate Contamination Incident [Internet]. Wellington, New Zealand: the Ministry for Primary Industries; 2014 Nov. Available from: https://col.st/R0LEy
- Gregory D. Miller, Judith K. Jarvis, Lois D. McBean. Handbook of Dairy Foods and Nutrition, Third Edition [Internet]. Third Edition. National Dairy Council; 2006. Available from: https://col.st/yuAwF
- Gustavo Bounous. Whey Protein Concentrate (WPC) and Glutathione Modulation in Cancer Treatment. Anticancer Research. 2000 Jul 4;20(6):4785–92.
- Joseph N. What are the benefits and risks of whey protein? [Internet]. Medical News Today. 2017. Available from: https://col.st/B9v96
- Kimberlee (K.J.) Burrington. Technical Report: Sensory Properties of Whey Ingredients [Internet]. Dairy Research Institute & U.S. Dairy Export Council; Report No.: 1. Available from: https://col.st/h3V3b
- Kris Gunnars. Whey Protein 101: The Ultimate Beginner’s Guide [Internet]. HealthLine. 2018. Available from: https://col.st/o3rXs
- Ling-Mei Zhou, Jia-Ying Xu, Chun-Ping Rao, Shufen Han, Zhongxiao Wan. Effect of Whey Supplementation on Circulating C-Reactive Protein: A Meta-Analysis of Randomized Controlled Trials. Nutrients. 7(2):1131–43.
- M. Ellin Doyle, Kathleen Glass. Spores of Clostridium botulinum in Dried Dairy Products. University of Wisconsin-Madison, Food Research Institute Science News Alert [Internet]. 2013 Aug 28; Available from: https://col.st/4y3wQ
- Margriet S. Westerterp-Plantenga. Protein intake and energy balance. Regulatory Peptides. 2008 Aug;149(1–3):67–9.
- Marjorie Geiser. The Wonders of Whey Protein. National Strength and Conditioning Association’s Performance Training Journal [Internet]. 2(5). Available from: https://col.st/mqH6o
- Mark O’Keefe. Three Global Consumer Groups Driving Demand for Whey Protein [Internet]. The U.S. Dairy Exporter Blog (U.S. Dairy Export Council). 2017. Available from: https://col.st/tamTP
- Michael D, U.S. Food & Drug Administration. WARNING LETTER (to Bluegrass Proteins, Inc.) [Internet]. Available from: https://col.st/5Iw4B
- O. P, A. H, P. J. Human insulinotropic response to oral ingestion of native and hydrolysed whey protein. Amino Acids. 2009 Jul;37(1):333–9.
- Sachiko T. St. Jeor, Barbara V. Howard, T. Elaine Prewitt, Vicki Bovee, Terry Bazzarre, Robert H. Eckel. Dietary Protein and Weight Reduction. Circulation. 2018 Mar 22;104(15):1869–74.
- Sarah Schmidt. AMPI Recalls Limited Amount of Dry Whey Powder Because of Possible Health Risk [Internet]. U.S. Food & Drug Administration. 2018. Available from: https://col.st/a6lXh
- Scott R. Kimball, Leonard S. Jefferson. Signaling Pathways and Molecular Mechanisms through which Branched-Chain Amino Acids Mediate Translational Control of Protein Synthesis. Oxford Academic: The Journal of Nutrition. 2006 Jan;136(1):227S–231S.
- Sharon K. Gerdes. U. S. WHEY INGREDIENTS AND WEIGHT MANAGEMENT [Internet]. U.S. Dairy Export Council. 2003. Available from: https://col.st/RacZH
- Smith D. The Ultimate Guide to Protein Supplements [Internet]. Greatist. 2015. Available from: https://col.st/3L2nz
- Spritzler F. The 7 Best Types of Protein Powder [Internet]. HealthLine. 2016. Available from: https://col.st/PAlYK
- Susan M. Fluegel, Terry D. Shultz, Joseph R. Powers, Stephanie Clark, Celestina Barbosa-Leiker, Bruce R. Wright, et al. Whey beverages decrease blood pressure in prehypertensive and hypertensive young men and women. International Dairy Journal. 2010 Nov;20(11):753–60.
- Tchounwou PB, Yedjou CG, Patlolla AK, Sutton DJ. Heavy Metals Toxicity and the Environment. 2012; Available from: https://col.st/ZiEYN
- Tetra Pak. Evaporators. In: Dairy Processing Handbook [Internet]. Tetra Pak; Available from: https://col.st/KvYwG
- The Editors of Encyclopaedia Britannica. Nucleation (Crystallography). In: Encyclopedia Britannica [Internet]. Available from: https://col.st/lPuef
- U.S. Food & Drug Administration. The Dangers of Raw Milk: Unpasteurized Milk Can Pose a Serious Health Risk [Internet]. U.S. Food & Drug Administration. Available from: https://col.st/dq71v
- V. Burke, J. Hodgson, J. Beilin, N. Giangiuloi, P. Rogers, B Puddey. Dietary protein and soluble fiber reduce ambulatory blood pressure in treated hypertensives. Hypertension. 2018 Apr 1;38(4):821–6.
- Health risks of protein drinks You don’t need the extra protein or the heavy metals our tests found [Internet]. Consumer Reports. 2010. Available from: https://col.st/82bGq
- Dietary Reference Intakes (DRIs): Recommended Dietary Allowances and Adequate Intakes, Total Water and Macronutrients [Internet]. Food and Nutrition Board, Institute of Medicine, National Academies; 2011. Available from: https://col.st/71fH1
- Recall: Possible Salmonella in Whey Protein Powder. Food Safety News [Internet]. 2011 Mar 12; Available from: https://col.st/HUKVD
- Whey Protein Recall Now Nationwide. Food Safety News [Internet]. 2011 Mar 22; Available from: https://col.st/9SjNC
- More Whey Protein Powder Recalled. Food Safety News [Internet]. 2011 Mar 31; Available from: https://col.st/cj5TR
- Concentrations of toxic heavy metals and trace elements in raw milk of Simmental and Holstein-Friesian cows from organic farm. Environmental Monitoring and Assesment. 2013 Apr 10;185(10):8383–92.
- Usefulness of testing for Clostridium botulinum in powdered infant formula and dairy-based ingredients for infant formula [Internet]. International Commission on Microbiological Specifications for Food; 2014 Jan. Available from: https://col.st/kyULQ
- How Whey Protein Is Made | Step-By-Step [Internet]. MyProtein. 2016. Available from: https://col.st/pERkG
- CHAPTER 17 MILK AND WHEY POWDER. In: Dairy Processing Handbook [Internet]. Tetra Pak; Available from: https://col.st/j2cjC
- Dairy Processing [Internet]. Food Science, University of Guelph. Available from: https://col.st/X7pfa
- Historical Export Trade Data [Internet]. U.S. Dairy Export Council. Available from: https://col.st/WXQn8
- Introduction to Membrane Science and Technology [Internet]. Separation Processes. Available from: https://col.st/sQmJY
- Whey Processing. In: Dairy Processing Handboom [Internet]. Available from: https://col.st/dEAkN
- Whey Protein (Powder and Concentrate) Market: Global Industry Trends, Share, Size, Growth, Opportunity and Forecast 2017-2022 [Internet]. Market Research Group: IMARC Firm; Available from: https://col.st/7Iwm2
- Whey Protein Concentrate (WPC) Standard [Internet]. American Dairy Products Institute; Available from: https://col.st/rqSGd
- WHEY PROTEIN CONCENTRATE COMMODITY FACT SHEET [Internet]. USAID.gov. Available from: https://col.st/rLkop
- Whey Protein Isolate (WPI) Standard [Internet]. American Dairy Products Institute; Available from: https://col.st/KXCVm
- Whey Protein Powder: Complete A-Z Guide For All Types Of Whey Supplements [Internet]. Muscle and Strength. Available from: https://col.st/0bIfV