Freezing point of heat-treated drinking milk in the Czech Republic

In the Czech Republic, the freezing point of milk is presently used as a quality indicator of cows' raw milk as well as of heat-treated drinking milk, and its limit value is ≤ -0.520°C. Of the total of 295 drinking milk samples examined over a period of one year, 145 were samples of pasteurised milk and 150 were samples of UHT milk. In compliance with the Czech State Standard 57 05 38, the freezing point was determined by a thermistor cryoscope. The measured mean value of the freezing point of the heat-treated drinking milk was -0.515°C ± 0.0078. A total of 207 (70.2%) samples of the heat-treated drinking milk, i.e. 93 (64.1%) samples of pasteurised and 114 (76%) samples of UHT milk, were found above the maximum limit value. The unsatisfactory results of the monitoring of the freezing point of drinking milk emphasise the need for a reassessment of the current system of the milk quality evaluation with respect to this quality index.