UHT processing of milk combined with aseptic packaging was introduced to produce a shelf-stable product with minimal chemical damage compared with in-container sterilised milk.

 

Processing condition: Continous flow; 135-150°C for 1-4 seconds

 

Effects on enzymes: Does not inactivate some of the enzymes produced by psychrotrophic bacteria, such as Pseudomonas species, which are common in raw milk.

 

Effects on bacteria: Destroys all vegetative bacteria and most sporeformers.

 

Advantages: 

 

• Minimises heat denaturation

 

• Has long shelf-life (up to 12 months)

 

Disadvantages:

 

• Presence of 'cooked' flavour due to high heat processing.