Pasteurization (or pasteurisation) is a process invented by French scientist Louis Pasteur during the nineteenth century. Unlike sterilization, pasteurization is not intended to kill all micro-organisms in the food. Instead, it aims to reduce the number of viable pathogens so they are unlikely to cause disease. Commercial-scale sterilization of food is not common because it adversely affects the taste a-nd quality of the product. For the dairy industry, the terms "pasteurization," "pasteurized" a-nd similar terms mean the process of heating every particle of milk or milk product, in properly designed a-nd operated equipment, to one of the temperatures given in the following c-hart a-nd held continuously at or above that temperature for at least the corresponding specified time:

1. Vat Pasteurization. Temperature: 63ºC (145ºF) , Time: 30 minutes

2. High temperature short time Pasteurization (HTST). Temperature: 72ºC (161ºF) , Time: 15 seconds

3. Higher-Heat Shorter Time (HHST). Temperature: 89ºC (191ºF) , Time: 1.0 second

4. Higher-Heat Shorter Time (HHST). Temperature: 90ºC (194ºF) , Time: 0.5 seconds

5. Higher-Heat Shorter Time (HHST). Temperature: 94ºC (201ºF) , Time: 0.1 seconds

6. Higher-Heat Shorter Time (HHST). Temperature: 96ºC (204ºF) , Time: 0.05seconds

7. Higher-Heat Shorter Time (HHST). Temperature: 100ºC (212ºF) , Time: 0.01seconds

8. Ultra Pasteurization (UP). Temperature: 138ºC (280ºF) , Time: 2.0 seconds