The process of pasteurization was named after Louis Pasteur who discovered that spoilage organisms could be inactivated in wine by applying heat at temperatures below its boiling point. The process was later applied to milk and remains the most important operation in the processing of milk. The heating of every particle of milk or milk product to a specific temperature for a specified period of time without allowing recontamination of that milk or milk product during the heat treatment process. Keeping Quality Aspect - to improve the keeping quality of milk and milk products.
Pasteurization can destroy some undesirable enzymes and many spoilage bacteria.
The extent of microorganism inactivation depends on the combination of temperature and holding time. Minimum temperature and time requirements for milk pasteurization are based on thermal death time studies for the most heat resistant pathogen found in milk, Coxelliae burnettii . Thermal lethality determinations require the applications of microbiology to appropriate processing determinations. An overview can be found here. Milk is deemed pasteurized if it tests negative for alkaline phosphatase.