Cow’s milk contains about 3.5% protein, as well as 4% fat, about 4.6% lactose, 0.7% minerals, and 87% water (see Figure 1). Of the protein, whey is about 20% and casein makes up the remaining 80%. During cheese production, curds and whey are the main products. In the past the liquid whey was thrown away, but today it is the raw material for purified whey that athletes can use to build muscle. B To end up with highly purified whey used in supplements, the raw material must be processed to remove fat, minerals, lactose and water.
Figure 1. Highlights that whey protein only constitutes 0.7% of milk, and yet, when whey protein is removed and concentrated, it becomes a most useful nutrient for athletes and others
It takes about 100 grams of whey liquid to get 1 gram of whey protein. The process of separating the whey protein from the other constituents in the liquid whey results in the formation of a more concentrated product. Depending on the processes undertaken, the ‘separated’ whey protein becomes a whey protein concentrate (WPC), a whey protein isolate (WPI), or a whey protein hydrolysate (WPH). During the processing, fat and lactose (the milk carbohydrate) are filtered out to make a lower fat, lower carbohydrate and higher protein powder. The final protein content in a whey product can range from 30% to 95% depending on the filtering process used. The higher the protein content, on a gram per gram basis, the more processing (filtering) is needed. When a whey protein concentration is greater than 85% protein, it is considered to be WPI. Less than 85% and it is considered to be WPC.
As the name suggests, micro-filtration involves filtering through a membrane with many microscopic holes. These holes let through most of the ‘impurities’ while capturing the larger whey proteins. The resulting whey is then dried to produce what is commonly known as Whey Protein Concentrate (WPC). Micro-filtered whey (or WPC) typically contains between 75 – 85% protein, about 1 – 2 % fat, and 5 – 10% lactose.
To produce an even more pure form of whey protein, it is possible to use even finer filtration, known as Ultra-filtration. This process removes more lactose, fat and minerals to produce what is commonly referred to as Whey Protein Isolate (WPI). WPI manufactured using ultra-filtration usually contains about 86 – 88% protein, 0.5% fat, 1 – 2 % lactose and about 0.3% minerals.
other terms related to whey protein filtration:
Cross Filtered Whey – a filtration method that describes the process of passing the whey liquid to be filtered continuously across the filter membrane. This method is standard in virtually all milk processing and so is more a marketing term than a ‘new technology’ in filtration.
Reverse Osmosis – a membrane separation process, driven by a pressure gradient, in which the membrane separates the water from other components of milk.
Diafiltration – a specialised type of ultrafiltration in which the concentrated whey solution is diluted with water and re-ultrafiltered. This type of filtration is often used in the production of WPI.
Ion Exchange Isolation – a method of purifying whey which is often used in conjunction with filtration methods already mentioned to provide very pure forms of WPI with virtually no fat or lactose. Typically, ion exchange WPI has a protein content greater than 90%. The way in which ion exchange isolation works is due to the fact that all proteins (such as milk proteins) exhibit positive or negative charges if they are exposed to an acid or an alkaline. The solution is then exposed to a charged resin material that binds specific whey proteins while letting all other material such as lactose, minerals and fat to flow past. The resin effectively collects all of the desired whey proteins while the other components remain in solution and are washed away. By changing the pH, the whey proteins can then be released from the resin and provide a solution containing very pure whey protein. Filtration techniques such as reverse osmosis, micro-filtration or ultra-filtration are then used to concentrate the whey before it is dried using traditional methods.
A brief comparison of the main components of micro-filtered WPC, ultra-filtered WPI, and Ion Exchange WPI can be seen in Table 1 below.
|Component||Ultra-filtered WPI||Ion Exchange WPI||WPC|
Table 1: main Components of Whey Protein Concentrate, Ultra-filtered Whey Protein Isolate and Ion Exchange Whey Protein Isolate.
Hydrolysed whey protein isolate or whey protein hydrolysate (WPH) is usually a WPI that has had some of its protein constituents broken down. The reason for the production of WPH is that it is thought to aid better absorption in the intestine. However, WPH is not popular because of it’s horrible taste due to the hydrolysis process making the whey taste bitter, as well as an increased production cost. The greater the degree of hydrolysis, the worse the taste and the more expensive the product.
When we start talking about whey protein, a number of terms are used that may be a bit confusing. So let’s start by explaining these terms before moving on. Whey protein is not simply one big blob of protein, but it is made up of many types of protein that loosely or tightly clump together to form whey protein. Each of these protein types is known as a protein fraction, and given the right processing conditions, can be separated from the other types of protein fractions in whey. These proteins can be classified based on how big they are, and the functions they play in the body.
The key protein fractions in whey are:-
•Beta-lactoglobulin – the major protein in whey. There is no suggested major function for this protein so it’s presence is considered mainly as a food source for growth and development.
•Immunoglobulins – antibodies for immune boosting.
•Lactoferrin – anti-viral and anti-microbial properties, anti-cancer and immune enhancing effects.
•Alpha lactalbumin – contains large amounts of essential amino acids.
Because of their structure, some whey protein fractions survive the harsh digestive environment of the stomach and enter into the small intestine where they become active. Some proteins act as natural antibiotics in so far as they kill off bad bacteria in the intestines and help to maintain a healthy gut. Other peptides are actually absorbed through the intestinal wall and into the blood where they can provide a host of beneficial effects, including cholesterol reduction and immune system enhancement. It is from this perspective that some nutritionists consider that undenatured whey is better than denatured whey i.e. keeping some of the bioactive peptides complete rather than broken down may aid their function in the body.
However, if an athlete merely requires protein for muscle recovery and protein synthesis, then having whey with or without bioactive components is not really necessary.
Nutrition X and Whey Protein
Nutrition X products that contain protein employ a variety of types of whey. Table 2 illustrates the type of protein contained. Invariably the products include a mixture of concentrate and isolate to provide a ‘healthy’ mix of sufficient actual protein content and a good spectrum of essential amino acids (in addition to some added leucine and glutamine in selected products). In the case of whey isolate, the technique of cross-filtration has been employed.
|Big Whey||Pro X||Slender Pro||Mass X||Ultimate||Amino Shots||MRM|
Nutrition X are a leading supplier of performance nutrition products. They provide high quality, scientifically supported products to professionals and amateurs alike. Nutrition X pride themselves on great customer service and great value. For more information, visit www.nutritionx.co.uk