Animal protein comes in different groups, these have been classified as Whey, Casein and Bovine Colostrum.
Whey is produced during the processing of cheese. It describes the translucent liquid part of milk that remains following coagulation and curd removal. Using various techniques, whey proteins are purified and separated which ten yields different concentrations of this protein. Two major proteins exist in milk and these are casein, which amounts to 80% and whey which accounts for 20%.
Whey Protein Powder
Whey protein powder is used as an additive in food products and has many applications throughout the food industry. This comes in many forms including sweet whey, acid whey, demineralised and reduced forms. The reduced and demineralised forms of whey are found in products other than sports supplements.
Whey Protein Concentrate
By further processing whey the water, lactose, ash and some minerals are removed. When compared to whey isolates they generally contain more proteins and biologically active components, thus making them particularly suitable as a sports supplement.
Whey Protein Isolate
When processing whey protein isolate (WPI) there is a substantial removal of lactose and fat. whey protein isolate (WPI)contains protein concentrations of 90% or higher and is the purest protein source available. The very nature of the processing tends to denature some proteins. This breaking down of structure and lost peptide bonds reduces the overall effectiveness of the protein. One advantage of this type of whey protein is that it can be used by individuals who are lactose intolerant.
Casein is a major protein component found in bovine milk. The uptake of nutrients and vitamins in the body rely on milk proteins for some of their functionality; they are also a source of biologically active peptides. A property of casein that is very useful is its ability to form a gel or clot in the stomach. This occurs because it exists in a large colloidal particle known as a micelle. This clotting actions provides an efficient nutrient supply. It provides a sustained slow release of amino acids into the blood stream for as long as several hours, This provides enhanced nitrogen utilisation and retention in the body.
In the first few days after birth, female mammals secrete colostrum. This provides immunities and assists in the growth of developing tissue due to its nutrient density. There is some evidence that bovine colostrum contains growth factors that stimulate DNA synthesis and cellular growth. This fact makes it attractive as a sport supplement. Oral supplementation has been shown to elevate insulin-like-growth-factor 1 (IGF-1) and enhance lean tissue accruement. However,less conclusive results have been found in athletic performance improvement, but further research is required.
Animal proteins are found in red meat, chicken, fish, dairy products and eggs are known as complete proteins and contain all nine essential amino acids in the right proportions. Although meats may be a complete protein, unfortunately many meat sources are also high in saturated fats.
Examples include, a lean beefsteak has approximately 22.4g of protein per 100g and 28.8g of fat. A pork chop has 28.5g of protein per 100g and 24.2g of fat. A pork sausage typically has 13.8g of protein per 100g, compared to 24.5g of fat. While a skinless turkey and chicken is the exception and the only unprocessed animal foods that provide a good proportion of protein without the large amounts of accompanying fat are egg whites, shellfish and fish.