Question

Bacteria in milk may also be detected directly, that is, by examining a small quantity of milk under the microscope and counting the number of cells present. Despite the fact that this is a very accurate method of counting cells, the FDA requires a viable cell count be performed. Why is a viable cell count a better indicator of the safety of milk (especially pasteurized milk)?

Answer 1

• viable cell count help to identify the growing bacteria in the sample.
• FDA of US allows 750 million pus cells in every one liter of milk.
• pasteurization uses heat to destroy harmful bacteria in milk without changing the nutritional value.
• milk can be contaminated with bacteria in the farms.
• pasteurized milk from cows, goat, horse and sheep are coming under FDA grade A milk.
• The total viable count represent the number of colony forming units per ml of milk.
• i.e. viable count indicate the concentration of micro organisms . which in turn indicate poor quality of milk.
• the methods used for the identification of pathogens in pasteurized milk include methylene blue reduction and phosphatase test.