Pasteurization Of Milk Flashcards
(20 cards)
What is pasteurization?
Pasteurization is the heating of milk to temperatures and for periods of time required to destroy pathogens while causing minimal changes in composition, flavour, and nutritive value.
What are the three widely used methods of pasteurization?
The three widely used methods of pasteurization are: 1) Holder (Vat) method, 2) HTST method, 3) UH method.
Describe the Holder (Vat) method.
In the Holder method, milk is kept at 63-66 deg C for at least 30 minutes and then quickly cooled to 5 deg C. It is recommended for small and rural communities.
What is the HTST method?
The HTST method, or High Temperature and Short Time Method, heats milk to nearly 72 deg C for not less than 15 seconds and then rapidly cools it to 4 deg C. It is the most widely used method.
What is the UH method?
The UH method, or ultra-high temperature method, rapidly heats milk to 125 deg C for a few seconds and then quickly cools it and bottles it.
What is the public health importance of pasteurization?
Pasteurization is a preventive measure of public health importance that kills nearly 90% of bacteria in milk, including heat-resistant tubercle bacillus and Q fever organisms.
What bacteria are not killed by pasteurization?
Pasteurization does not kill thermoduric bacteria or bacterial spores.
How should pasteurized milk be stored?
Pasteurized milk should be rapidly cooled to 4 deg C and kept cold until it reaches the consumer, with a keeping quality of not more than 8 to 12 hours at 18 deg C.
What is the phosphatase test?
The phosphatase test checks the efficiency of pasteurization by detecting the presence of the enzyme phosphatase, which is destroyed at temperatures corresponding to standard pasteurization.
What does the standard plate count measure?
The standard plate count determines the bacteriological quality of pasteurized milk, with a limit of 30,000 bacterial count per ml enforced in most Western countries.
What does the presence of coliforms in pasteurized milk indicate?
The presence of coliforms in pasteurized milk indicates improper pasteurization or post-pasteurization contamination, with the standard being that coliforms must be absent in 1 ml of milk.
Describe the Holder (Vat) method.
In the Holder method, milk is kept at 63-66 deg C for at least 30 minutes and then quickly cooled to 5 deg C. It is recommended for small and rural communities.
What is the HTST method?
The HTST method, or High Temperature and Short Time Method, heats milk to nearly 72 deg C for not less than 15 seconds and then rapidly cools it to 4 deg C. It is the most widely used method.
What is the UH method?
The UH method, or ultra-high temperature method, rapidly heats milk to 125 deg C for a few seconds and then quickly cools it and bottles it.
What is the public health importance of pasteurization?
Pasteurization is a preventive measure of public health importance that kills nearly 90% of bacteria in milk, including heat-resistant tubercle bacillus and Q fever organisms.
What bacteria are not killed by pasteurization?
Pasteurization does not kill thermoduric bacteria or bacterial spores.
How should pasteurized milk be stored?
Pasteurized milk should be rapidly cooled to 4 deg C and kept cold until it reaches the consumer, with a keeping quality of not more than 8 to 12 hours at 18 deg C.
What is the phosphatase test?
The phosphatase test checks the efficiency of pasteurization by detecting the presence of the enzyme phosphatase, which is destroyed at temperatures corresponding to standard pasteurization.
What does the standard plate count measure?
The standard plate count determines the bacteriological quality of pasteurized milk, with a limit of 30,000 bacterial count per ml enforced in most Western countries.
What does the presence of coliforms in pasteurized milk indicate?
The presence of coliforms in pasteurized milk indicates improper pasteurization or post-pasteurization contamination, with the standard being that coliforms must be absent in 1 ml of milk.
