A process applied to a milk product with the object of minimising possible health hazards arising from pathogenic microorganisms associated with milk, by heat treatment which is consistent with minimal chemical, physical and organoleptic change to the product.

 

Processing condition: 

• Batch process: 63.5°C for 30 min (Upper limit: 65.6°C)

 

• HTST process: 71.7°C for 15 s before being rapidly cooled (Upper limit: 80°C)

 

Effects on ezymes: 

• Phosphatase negative since phosphatase is inactivated at 71.7°C/15 s

 

• Peroxidase positive since peroxidase is not inactivated until 80°C/15 s is exceeded

 

Effects on microorganisms: 

• Pasteurisation kills most of the spoilage microorganisms, except thermoduric bacteria

 

Advantages:

 

• Minimum damage to the chemical, physical and organoleptic properties of the milk

 

Disadvantages:

 

• Short shelf-life (6-8 days)