HEAT-PUMP UTILIZATION IN MILK PASTEURIZATION

A heat pump system based on the liquid-to-liquid principle was designe d in order both to heat to the pasteurization temperature (at 69-degre es-C) and cool to the inoculation temperature (at 32-degrees-C). The q uantities of energy needed for the pasteurization and inoculation cycl es for both the present system and the classical system were experimen tally obtained and compared with the quantities of energy used. Some e xperiments were carried out to define how microbiological and chemical properties of milk changed during the pasteurization and inoculation cycle. The present results were compared with the properties of milk p asteurized in the classical system.