Whey protein has long been considered the gold standard in dairy protein. But with more consumers seeking varied, high-performance protein options – there’s one often overlooked nutrient that has huge potential to power your next innovation: casein protein. But what is it exactly? And what benefits does it offer? Keep reading to find out.
Casein protein makes up around 80% of the total protein found in cow’s milk, with the remaining 20% coming from whey protein.
Hoffman, J.R. and Falvo, M.J. (2004). Protein – Which is Best? Journal of Sports Science & Medicine, [online] 3(3), p.118. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC3905294/.
In its natural form, the protein exists as micelles
Huppertz, T., Gazi, I., Luyten, H., Nieuwenhuijse, H., Alting, A. and Schokker, E. (2017). Hydration of casein micelles and caseinates: Implications for casein micelle structure. International Dairy Journal, 74, pp.1–11. doi:https://doi.org/10.1016/j.idairyj.2017.03.006.
– clusters of protein molecules – giving it a unique structure and set of benefits compared to other proteins.
The most striking difference lies in casein protein’s structure. Its micelle structure is less prone to denaturation – or unfolding – when exposed to heat. This micelle structure helps casein protein maintain its functional properties and nutritional quality – even at higher temperatures.
Holt, C., Carver, J.A., Ecroyd, H. and Thorn, D.C. (2013). Invited review: Caseins and the casein micelle: Their biological functions, structures, and behavior in foods. Journal of Dairy Science, 96(10), pp.6127–6146. doi:https://doi.org/10.3168/jds.2013-6831.
Another key difference? Casein protein isn’t acid soluble.
Kim, J. (2020). Pre-sleep casein protein ingestion: new paradigm in post-exercise recovery nutrition. Physical Activity and Nutrition, 24(2), pp.6–10. doi:https://doi.org/10.20463/pan.2020.0009
In acidic conditions, it precipitates, which is why it separates so effectively during the refinement process. On the other hand, whey proteins aren’t heat-stable; when exposed to heat, they aggregate and form a gel-like texture.
Wijayanti, H.B., Bansal, N. and Deeth, H.C. (2014). Stability of Whey Proteins during Thermal Processing: A Review. Comprehensive Reviews in Food Science and Food Safety, 13(6), pp.1235–1251. doi:https://doi.org/10.1111/1541-4337.12105.
This makes whey protein trickier to use in ambient-stable, high-protein ready-to-drink (RTD) applications.
When it comes to extracting casein protein from milk, there are three main methods, each taking advantage of the unique properties of casein and whey proteins. These processes – acidification (for caseinate production) and filtration (to isolate micellar casein protein) – give each casein protein its distinct form and properties.
Hamouda, M.E.A. and Salunke, P. (2024). Changes in Milk Protein Functionality at Low Temperatures and Rennet Concentrations. Foods, [online] 13(3), p.447. doi:https://doi.org/10.3390/foods13030447.
Casein protein is a high-quality protein, which means it contains all nine essential amino acids needed to make proteins found in the human body.
Lopez, M.J. and Mohiuddin, S.S. (2022). Biochemistry, Essential Amino Acids. [online] PubMed. Available at: https://pubmed.ncbi.nlm.nih.gov/32496725/.
Essential amino acids (EAAs), also known as indispensable amino acids, cannot be synthesised from metabolic intermediates by humans. These amino acids must therefore be supplied from our external diet.
van Vliet, S., Burd, N.A. and van Loon, L.J. (2015). The Skeletal Muscle Anabolic Response to Plant- versus Animal-Based Protein Consumption. The Journal of Nutrition, [online] 145(9), pp.1981–1991. doi:https://doi.org/10.3945/jn.114.204305.
For muscle protein synthesis to occur, sufficient levels of all EAAs must be present.
Wolfe, R.R. (2017). Branched-chain amino acids and muscle protein synthesis in humans: myth or reality? Journal of the International Society of Sports Nutrition, [online] 14(1). doi:https://doi.org/10.1186/s12970-017-0184-9.
When one essential amino acid is limited or not available, new tissue cannot be completely built.
Processing and storage can also impact the bioavailability of essential amino acids, particularly lysine.
Hurrell, R.F. and Finot, P.-A. (1983). Food Processing and Storage as a Determinant of Protein and Amino Acid Availability. Experientia Supplementum, 44, pp.135–156. doi:https://doi.org/10.1007/978-3-0348-6540-1_9.
In fact, some high-protein products available today experience protein glycation during processing and storage.
José Ángel Rufián-Henares, Delgado-Andrade, C., Salvio Jiménez-Pérez and Morales, F.J. (2007). Assessing nutritional quality of milk-based sport supplements as determined by furosine. 101(2), pp.573–578. doi:https://doi.org/10.1016/j.foodchem.2006.02.016.
This impacts the availability of essential amino acids, such as lysine, for protein synthesis – an important factor in many nutritional products aimed at muscle development and maintenance.
Krause, R., Knoll, K. and Henle, T. (2003). Studies on the formation of furosine and pyridosine during acid hydrolysis of different Amadori products of lysine. European Food Research and Technology, 216(4), pp.277–283. doi:https://doi.org/10.1007/s00217-002-0649-0
Pahm, A.A., Pedersen, C. and Stein, H.H. (2008). Application of the Reactive Lysine Procedure To Estimate Lysine Digestibility in Distillers Dried Grains with Solubles Fed to Growing Pigs. Journal of Agricultural and Food Chemistry, 56(20), pp.9441–9446. doi:https://doi.org/10.1021/jf801618g.
Xiao, C.-W., Hendry, A., Kenney, L. and Bertinato, J. (2023). l-Lysine supplementation affects dietary protein quality and growth and serum amino acid concentrations in rats. Scientific Reports, 13(1). doi:https://doi.org/10.1038/s41598-023-47321-3.
Curious about casein protein? We’ve got the answers you need. Click here to dive into the world of casein protein and explore its powerful benefits.
Why use casein protein in your next performance and active nutrition innovation?
Read moreFrieslandCampina Ingredients launches Nutri Whey™ ProHeat for the performance and active nutrition market
Read moreProtein shakes go plant-based: your questions, answered
Read moreFor more than a century we’ve been creating quality ingredients delivered with passion. Whether we’re inspiring ideas from drinks to bars, or supporting how to manufacture products in better ways, our customers can count on us to deliver, time and time again.
Subscribe"*" indicates required fields
Notifications