Raw Milk & Pasteurized Milk: Debunking Milk Myths

While pasteurization has helped provide safe, nutrient-rich milk and cheese for over 120 years, some people continue to believe that pasteurization harms milk and that raw milk is a safe healthier alternative.
Here are some common myths and proven facts about milk and pasteurization:

• Pasteurizing milk DOES NOT cause lactose intolerance and allergic reactions. Both raw milk and pasteurized milk can cause allergic reactions in people sensitive to milk proteins.
• Raw milk DOES NOT kill dangerous pathogens by itself.
• Pasteurization DOES NOT reduce milk's nutritional value.
• Pasteurization DOES NOT mean that it is safe to leave milk out of the refrigerator for extended time, particularly after it has been opened.
• Pasteurization DOES kill harmful bacteria.
• Pasteurization DOES save lives.

Raw Milk
It is cow's milk taken straight from animals fed only fresh, organic, green grass, rapidly cooled to somewhere around 36-38 degrees F., and bottled. Commercial distribution of packaged raw milk is prohibited in most countries. However, 28 US states allow sales of raw milk, and in other parts of the world, raw milk can often be bought direct from the farmer. In England, about 200 producers sell raw, or "green top" milk direct to consumers, either at the farm or through a delivery service. Raw milk is sometimes distributed through a share program, wherein the consumer owns a share in the dairy animal or the herd, and can be considered to be consuming milk from their own animal. In the United States, Arizona, California, and Washington allow raw milk sales in retail stores with appropriate warning labeling.

What pathogens can raw milk contain?
Milk can contain dangerous disease-causing bacteria or germs, also known as pathogens. Pathogens that may be found in milk include:

• E. coli O157: H7 - This is a very dangerous bug that has emerged in recent years. It can lead to kidney failure or even death. Even tiny numbers of E. coli can cause serious trouble.
• Listeria monocytogenes - This can also cause a serious illness in humans known as Listeriosis. Infection in pregnant women can lead to stillbirths or to infant death soon after birth. Listeria is widespread in the farm environment, especially in the soil. This can lead to the contamination of milk at milking time.
• Brucellosis - This can cause abortions and "Undulating Fever" in humans.
  Other diseases that can be contracted from the consumption of raw milk include:

Tuberculosis, Salmonellosis and Campylobacteriosis.

How does milk become contaminated?

With healthy cows, the milk inside the cows udder has very few germs. However, if animals have diseases such as mastitis or TB then pathogens can be present in the milk even inside the udder. During milking there is the possibility of contamination of the milk from the cow (surfaces of teats, cow hairs etc) and from unclean milking equipment or the milking environment.

Pasteurized Milk

Pasteurization is a process that kills harmful bacteria by heating milk to a specific temperature for a set period of time. First developed by Louis Pasteur in 1864, pasteurization kills harmful organisms responsible for such diseases as listeriosis, typhoid fever, tuberculosis, diphtheria, and brucellosis.
Researches show no meaningful difference in the nutritional values of pasteurized and unpasteurized milk. Pasteurized milk contains low levels of the type of nonpathogenic bacteria that can cause food spoilage, so storing your pasteurized milk in the refrigeratorstill important.

Figure 1. Pasteurisation process

What does Pasteurisation do?

Pasteurisation kills or inactivates all pathogens including E. coli O157, Listeria etc. It involves heating the milk to a high temperature for a short time (72°C for 15 seconds). Rapid cooling after pasteurisation is important. Pasteurisation has little effect on the flavour or nutritional value of the milk.

References
http://www.cfsan.fda.gov/~dms/rawmilk.html
http://www.safefood.qld.gov.au/docs/fs%20-%20raw%20milk%20pathogens%20141003.pdf
http://www.raw-milk-facts.com/About_Raw_Milk.html
Figure 1. http://food.ege.edu.tr/resimler/sut_pilot_tes.JPG

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