Pasteurization is processed with the purpose of destruction of heat sensitive microorganisms: the pathogens and also food spoilers. This leads to the increase of the shelf live of the food to 1-2 weeks, when kept at refrigerated temperatures.
In the case of milk it is the heat inactivation of the endogenous enzyme – alkaline phosphatase – which indicates the effectiveness of the pasteurization process (adequate time-vs-temperature application to the raw milk). The determination of alkaline phosphatase activity is chosen because:
- Alkaline phosphatase has a resistance to heat-treatment close but higher than that of the human pathogens in milk (alkaline phosphatase is one of the more heat-resistant native enzymes of milk); - Its detection is faster than the detection of eventual residual pathogens.