Why Does Not Pasteurization Make Our Milk Completely Safe
Why does not pasteurization make our milk completely safe? What is the journey of milk from the cow to our table? How to ensure milk safety?
The Cow: Before the cow is even milked, pathogens in the surrounding environment can get into the cows feed or water. During milking, bacteria on the inside or outside of the cows udder can get into the milk. If the milking device (human or mechanical) has not been properly sanitized it may contaminate the raw milk. So we must ensure the safety of the cows feed an-d water, an-d the milking device.
Storage an-d Transfer of Raw Milk: Any time the milk is transferred or stored, all equipment an-d containers must be sterile to prevent contamination. The storage temperature must be low enough (usually 4 ºC, about 39.2 ºF) to keep any bacteria remaining in the milk from growing.
Pasteurization: We know that pasteurization does not kill all the bacteria in milk, but it will not even kill the ones it is supposed to if the guidelines for time an-d temperature are not met. One way the dairy industry checks milk to make sure it has been properly pasteurized is by testing for alkaline phosphatase. This enzyme has the same D-value as the tuberculosis bacterium, so if it is found in pasteurized milk, that means that time an-d temperature requirements were not met.
Equipment: Post pasteurization contamination (PPC) because of flaws in equipment or poor sanitation practices is the most common reason for pasteurization failures. Equipment has to be properly maintained an-d tested, an-d cleaned an-d sterilized between uses.
The plate heat exchanger is one potential source of PPC, since cold raw milk an-d hot pasteurized milk pass each other on opposite sides of the heat exchange plates. If the plates have leaks or cracks, the raw milk can contaminate the pasteurized milk. We must use high quality plate heat exchangers, an-d maintained properly.
Storage an-d Transfer After Pasteurization: Milk is vulnerable to what the industry calls time-temperature abuse whenever the milk is transferred or stored. This includes all points at or between the processing plant, the warehouse, the store an-d your home. The weak link in the overall cold chain is usually that indeterminate period after (the milk) leaves the retail outlet an-d reaches the consumers refrigerator.
Now that has been brought to your attention, the pressure is on to get the milk home an-d into the fridge as quickly as possible. Check the temperature of your refrigerator regularly, too. It should always be less than 5 ºC ( 41 ºF ).
The Cow: Before the cow is even milked, pathogens in the surrounding environment can get into the cows feed or water. During milking, bacteria on the inside or outside of the cows udder can get into the milk. If the milking device (human or mechanical) has not been properly sanitized it may contaminate the raw milk. So we must ensure the safety of the cows feed an-d water, an-d the milking device.
Storage an-d Transfer of Raw Milk: Any time the milk is transferred or stored, all equipment an-d containers must be sterile to prevent contamination. The storage temperature must be low enough (usually 4 ºC, about 39.2 ºF) to keep any bacteria remaining in the milk from growing.
Pasteurization: We know that pasteurization does not kill all the bacteria in milk, but it will not even kill the ones it is supposed to if the guidelines for time an-d temperature are not met. One way the dairy industry checks milk to make sure it has been properly pasteurized is by testing for alkaline phosphatase. This enzyme has the same D-value as the tuberculosis bacterium, so if it is found in pasteurized milk, that means that time an-d temperature requirements were not met.
Equipment: Post pasteurization contamination (PPC) because of flaws in equipment or poor sanitation practices is the most common reason for pasteurization failures. Equipment has to be properly maintained an-d tested, an-d cleaned an-d sterilized between uses.
The plate heat exchanger is one potential source of PPC, since cold raw milk an-d hot pasteurized milk pass each other on opposite sides of the heat exchange plates. If the plates have leaks or cracks, the raw milk can contaminate the pasteurized milk. We must use high quality plate heat exchangers, an-d maintained properly.
Storage an-d Transfer After Pasteurization: Milk is vulnerable to what the industry calls time-temperature abuse whenever the milk is transferred or stored. This includes all points at or between the processing plant, the warehouse, the store an-d your home. The weak link in the overall cold chain is usually that indeterminate period after (the milk) leaves the retail outlet an-d reaches the consumers refrigerator.
Now that has been brought to your attention, the pressure is on to get the milk home an-d into the fridge as quickly as possible. Check the temperature of your refrigerator regularly, too. It should always be less than 5 ºC ( 41 ºF ).
