Whether it's a strength trainer who sweats at the gym or a runner who is keen on endurance sports, high protein intake has become an integral part of their daily diet.
In the field of sports nutrition, whey protein has long been dominant due to its properties of rapidly promoting muscle synthesis.
But did you know that casein, as a high-quality protein source, can also bring unique nutritional value and application advantages to sports nutrition products?
What is casein?
Casein and whey protein are parallel in the field of protein supplementation, but their physical and chemical properties are quite different.
Casein occurs as a natural micelle and accounts for about 80% of the total milk protein, with the remaining milk protein group divided into whey protein (20%).
Properties of casein
Form: Casein Micelle
Structure: non-spherical structure
Thermal stability: High, suitable for UHT treatment
Acid solubility: insoluble in acid, precipitation under acidic conditions
Application: Neutral RTD beverage, protein bar, protein powder, etc
Extraction technology of casein
Casein extraction depends on its different chemical properties from whey protein, and there are usually three main methods.
Among them, caseinate is produced by separating and extracting casein through acidification step.
During acidification, casein micelles break down into their natural protein building blocks:
Caseinate, thereby enhancing its solubility and functional properties.
This means that caseinate not only retains its original nutritional value, but can also be used in a wider range of food and beverage formulations.
Nutritional value of casein
Complete supply of essential amino acids
Casein is a quality protein rich in all 9 essential amino acids the body needs, which are essential for muscle growth, repair, and overall health.
The body cannot synthesize these amino acids on its own and must consume them through diet, and casein provides a balanced and sufficient source of amino acids.
Protein processing and storage also affect the bioavailability of amino acids, especially lysine.
The Maillard reaction occurs in certain high-protein products during storage, resulting in a decrease in the digestibility of key amino acids such as lysine, which in turn affects muscle synthesis.
The Excellion® caseinate range of Frieslandcampina Food Ingredients has a lower lactose content and a lower risk of glycosylation, which better protects protein activity and ensures a high quality nutrient supply.
Application of casein in sports nutrition
In the sports nutrition market, the core goals of protein supplementation are to promote muscle recovery, increase muscle mass and enhance athletic performance.
Different proteins are metabolized in different ways and are suitable for different application scenarios.
Whey protein dominates the sports nutrition market due to its fast absorption properties, which can rapidly increase the rate of muscle protein synthesis in a short time after exercise.
In recent years, consumers have become increasingly concerned about protein sources that slowly release amino acids over a long period of time.
Casein, as a representative of slow-release protein, has shown unique advantages in nighttime muscle recovery and long-term energy supply.
Slow release digestion, continuous energy supply
The rate of protein digestion affects the supply rhythm of amino acids, and there are significant differences between casein and whey protein metabolism in human body.
Whey protein (quick absorption) :
An acidic soluble protein that can be quickly digested and absorbed after entering the intestine, causing amino acid levels in the blood to rise rapidly and peak in a short period of time
Casein (slow release digestion) :
once inside the stomach, casein forms a curdy structure due to pepsin (and stomach acid), which slows the emptying of the stomach, making the release of amino acids slower and more stable, and providing a continuous feeling of fullness.
Figure 1: Whey protein is absorbed faster, while casein is more durable
Night Recovery: Gold Window
Protein sources that consistently release amino acids are receiving increasing attention, especially when it comes to nighttime muscle recovery, where casein presents a unique advantage.
Studies have shown that reasonable adjustment of nutritional strategies can not only prolong the nighttime muscle repair time, but also effectively maintain muscle mass.
Data show that during sleep, the rate of muscle protein synthesis decreases, while protein breakdown continues, and this time period can become a "protein replenishment opportunity."
Figure 2: Diagram of Muscle Protein Synthesis (MPS) and Muscle Protein Breakdown (MPB) throughout the day.
Long-term energy supply, shape and muscle building
Studies have shown that ingestion of casein alone over several weeks of resistance training is more associated with fat-free weight gain than a combination of casein and whey protein, which may be related to its more durable amino acid release properties.
Combining calcium caseinate intake with endurance training can significantly improve exercise capacity and reduce body fat.
