What is the difference between whey protein isolate, concentrate and hydrolysate?

Man in blue vest doing shoulder press.
Whey proteins support muscle building and exercise regimes. Photo by patrisyu, courtesy of FreeDigitalPhotos.net
  • Whey protein supplements come in a few different forms.
  • Many supplement companies offer either one or a mix depending on the outcome you desire for your body building or strengthening development.

Introduction

Whey protein is now the most popular protein supplement for serious bodybuilders and sports enthusiasts. When ever you exercise, your muscle fibre suffer damage but the body is easily capable of rebuilding them if the nutrients which are the muscle’s building blocks are there. It is on the whole the cheapest protein source available given the great size of the dairy market. It is also easily incorporated into a wide range of products which also emphasis just how versatile it is. Clearly not one for the vegetarian however but it has accumulated a large body of clinical evidence to support its high level of use especially in meeting daily requirements for proteins.

It is available in a variety of forms depending on the type of nutrition and quality required as well as its cost. Whey protein is mostly albumen, lactoglobulin and lactoferrin with small amounts of immunoglobulins included.

The Main Benefits Of Whey Protein

  • a complete protein source
  • maintains lean muscle mass
  • easily and readily absorbed through the intestine into the body
  • improves immunity
  • increases your anabolic response
  • easy and convenient, versatile and soluble

The Source Of Whey Protein

The source of all whey proteins is of course milk but it is cheese whey that is the main commercial source. Remember,  milk is composed of two types of proteins, casein and whey. Whey is roughly 20 per cent of all the protein in milk whilst casein comprises 80 per cent. When milk curdles as in cheese making, it is the casein which precipitates out. The milky watery remnant contains the whey proteins which remain uncoagulated. Check out a yogurt pot when its been left in the fridge awhile, the top layer is your whey fraction!

Whey protein concentrate (WPC) is one of derivatives from the whey processing industry. It is used in cereal and nutrition bars, confectionary products, various processed cheeses, sports beverages, baked goods and muscle building (muscle gain) products. There are roughly two types: the 35 to 65% range and hen a second of even higher protein concentration from 70 to at least 90% w/w.    !

Whey Protein Concentrate And Whey Protein Isolate 

Generally, whey protein isolate (WPI) is the more pure version of whey protein concentrate (WPC). Why? Many of the non-protein components are removed from the isolates during processing.

A typical whey protein concentrate (WPC) will be 70% to 80% protein on a dry weight basis with the remainder being carbohydrates, milk sugar (lactose), fats, minerals and cholesterol. If you consume 100g of whey protein concentrate you are consuming on average 400 calories, 82g of protein, 9g of carbohydrate of which 4.5g is usually lactose, 6g of fat and 150mg of cholesterol.

The low protein WPCs (35-65%w/w) are produced by ultrafiltration (UF) so that most of the lactose, any minerals and non-protein nitrogen (NPN) are removed. Non-protein nitrogen includes amino acids and small peptides. The whey proteins are dried through spray drying. Any of the WPCs of a higher content (up to 90%) are also ultrafiltered but then cleaned up further by water diafiltration so that all the lactose and minerals are removed as well (Early, 2021).

*WPC is not recommended for the lactose intolerant.

Lipids in WPC

The remaining 10% in the purest whey protein concentrate is lipid. The composition of lipid in WPC is very similar to bulk milk. WPC is higher in phospholipids and milk fat globule membrane material. Lipids reduce the functional potential of WPCs as well as all other whey protein fractions.

Manufacturers have tried to remove as much as possible but to little success. The level of residual fat and lipid rises with increasing protein concentration which means that it is associated with the protein fraction. It is reasoned that a 35% protein WPC contains 2.1% fat, a 50% WPC contains 3.7% fat and an 80% WPC contains 7,2% fat. As the protein content rises the level of corresponding fat rises significantly. Given that WPC is added as a foaming agent increasingly higher levels of lipid reduces foaming capacity and alters the flavour and sensory feel of the WPC or any products containing it.  When lipids are removed, the overrun from whipping rises as does foaming stability. That former property based on lipid removal is important for ice-cream manufacturers. Lipids also inhibit heat gelation properties (Zadow, 2003).

From a process perspective, removing lipid improves flux-rates through ultrafiltration membranes. They foul membranes especially during ultrafiltration.

A whey protein isolate on the other hand is about 92% protein on a dry weight basis which means the protein content is richer per serving size. Nutritionally, 100g of WPI provides 370 calories which is less than a concentrate but contains more protein, usually 92g, and a lot less carbohydrate, fat and cholesterol and lactose (most of this sugar is removed).

Commercial whey protein isolates (WPIs) and for that matter whey protein concentrates are produced either by using ion-exchange chromatography (IEC) or microfiltration/ultrafiltration (MF/UF) processes (Huffman & Harper, 1999).

If you see whey protein hydrolysate (WPH) in your protein mix then you are ingesting a partially broken down form of the protein. Heat, acids and enzymes are used to generate what is termed an hydrolysate because the protein is broken down into smaller pieces. This makes digestion and absorption through the gut into the bloodstream much easier. Hydrolysis also induces a higher insulin spike than either the isolate or concentrate taste wise. Hydrolysates are more bitter tasting than the concentrates and isolates but at least they are absorbed more quickly.

Relative Costs

When it comes to deciding what’s best, then price might be the main feature given the amount being consumed. All whey protein offers excellent nutrients with an amino-acid profile suitable for the serious bodybuilder. Whey protein concentrates are generally cheaper than either the hydrolysate or isolate. The isolates and hydrolysates also lack some of the flavour and texture of the concentrate.

The choice is very much a trade-off between cost of ingredients versus availability of nutrients to the body. The concentrates still remain the best value for money but isolates are becoming extremely popular for their protein quality.

What To Look For On A Tub or Bucket Of Whey Protein

When checking out a supplier of whey protein of what ever form always consider the following:-

  • total calorie content
  • type and composition especially the mix of proteins
  • the total protein content
  • remaining fat and carbohydrate content
  • any added ingredients such as flavour, artificial sweeteners including sucralose, stevia and aspartame, amino acids for spiking, emulsifiers for ease of dissolving. Gums and thickeners are common and include xanthan, alginates, cellulose and starch.
  • added proteases. An interesting addition as they start hydrolysing the protein in the mix to make it more easily absorbed by the gut.

Protein powders differ in quality even when pure. The ratio of protein to carbohydrate and fat is one of your most important ratios to consider. When you are building muscle then a whey protein powder with a higher level of calories is desirable. Go for high carbohydrates and fat which are calories rich. When you are cutting down on the proteins then one with the highest available protein but low carbs and fat is preferred.

Whey protein isolates are available from many suppliers and we have selected a few brands that may be of interest (see article).

Use In Body Building

If you are looking for palatable ways to obtain your protein, consider adding whey to cakes and muffins and not just as a bland milkshake. To obtain the most from your whey protein supplement, calculate your caloric and macronutrient needs based on the level of training you have embarked upon.  Use whey to supplement your protein intake that  cannot be obtained from other foods.  Drink your shake whenever it’s convenient or when you need a quick meal on the go.  

Amino Acid Spiking Of Whey Proteins

Spiking of protein mixes with individual amino acids is seen by some as controversial although this may be ideal for your body building requirements. A number of amino acids are added to raise a particular content and also offer their own particular benefit. BCAAs – the branched chain amino acids are especially valuable as is glutamine. Creatine is a separate case and needs to be regarded separately because of its role in energy metabolism. In nutritional terms, the amino acids can artificially inflate the total nitrogen content which has been used by some unscrupulous suppliers to falsify their protein contents. Melamine which is not an amino acid is a classic adulterant and there have been a number of scandals associated with its inclusion in baby foods. Check the papers for adulteration!

References

Early, R. (2012) Chapt. 17 – Dairy products and milk-based food ingredients. In: Natural Food Additives, Ingredients and Flavourings. Wooidhead Publ. Series in Food Science, Technology and Nutrition. pp. 417-445 (Abstract)

Huffman, L. M., & Harper, W. J. (1999). Maximizing the value of milk through separation technologies. Journal of Dairy Science82(10), pp. 2238-2244.

Zadow, J.G. (2003) Whey and Whey Powders: Protein Concentrates and Fractions. In: Encyclopedia of Food Sciences and Nutrition (2nd edt.) .

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