Whey protein is an increasingly popular product, especially among body builders who consume large quantities of whey regularly. The demand for cheap whey has resulted in corners being cut in the processing methods and reducing the quality of whey. This article will cover how whey is made from milk, and look at what makes a good quality whey.
On the farm
Whey is made from milk, and the processing of whey starts on the farm, in the body of the cows which make the milk. There are a number of studies which show that cows with a natural grass based diet produce a higher quality milk than cows which are fed on a conventional diet (which usually consists of soy and corn). The quality of the milk is measured on the quantity of nutrients such as proteins, fats (such as conjugated linoleic acid (CLA) and omega-3 fatty acids) and probiotics. High quality milk is high in CLA, has a much better protein profile (more essential amino acids and branched chain amino acids) and is higher in healthy fatty acids.
Quality is also measured by the amount of heavy metals (such as cadmium) and artificial chemicals (such as pesticides and fertilizers) which are found in the milk. Cows can be exposed to these chemicals from their food, and they are often are found in the milk they produce, and ultimately the whey powder. In 2010 an independent third party testing of a number of whey protein powders found high levels of arsenic, lead, cadmium and mercury, which have detrimental effects on our healthy. This highlights the importance of getting whey from a reputable source, and shows you often do get what you pay for with cheap value whey.
The quality of the milk and whey is also affected by the antibiotics and hormones which some cattle are fed. The are used to avoid infection and illness among the cattle, and also help speed up their development. This reduces expense to the farmer and gives a higher yield of produce, which allows the farmer to sell the milk cheaper. However, these antibiotics and hormones have also been found to be present in the milk of these cows, which kills any probiotics and can have an adverse effect on our own health, especially if consumed in high quantities.
In the dairy
Whey is a co-product in cheese production, or caesin production. Whey which is produced from cheese production is known as ‘sweet’ whey, and whey from caesin production is known as ‘acid’ whey. Technically speaking, acid whey has a better amino acid profile than sweet whey, but due to taste, sweet whey is more common in whey protein supplements. At this stage, the whey has not undergone and major processing, and contains a number of vitamins, minerals, carbohydrates, fats and protein.
In the factory
The protein is extracted from liquid whey to make a concentrated protein powder, this can be done in two ways – micro-filtration or ion exchange.
Ion exchange is about 1/5 as expensive as micro-filtration, and the majority of protein powders are made made using this method. This process uses a number of chemical reagents to isolate the protein from the liquid whey, and can also denature the proteins and damage other nutrients. This is often done at high temperatures which can cause further damage to the nutrients. This damage makes the proteins harder to absorb and any additional nutrients biologically useless. There is also speculation that this is another source of heavy metals which have been found in many whey protein supplements, but this has not been confirmed.
Micro-filtration filters molecules out based on their size. This doesn’t damage the proteins and other nutrients in the whey, resulting in a higher quality protein, but the end result has a slightly lower concentration of protein compared to ion exchange. Micro-filtration can also be carried out at low temperatures, which prevents heat damaging any other nutrients in the whey. The main advantage of this method is the quality of the proteins, and proteins such as immunoglobins and lactoferin are intact, which help support the immune system. Whey protein products made from micro-filtration are sometimes thought of as a very high protein food instead of a supplement because they do contain other nutrients and are more ‘complete’.
There are a number of factors which affect the quality and price of whey. Cheap whey, from poor quality milk and extracted with ion filtration has a low bioavailability, contains low quality proteins, and could have negative health implications. Highest quality whey protein is made from organic grass fed cows and concentrated using cold processing micro-filtration. This provides you with a number of other health benefits and provides better quality protein.