Pasteurization of carabao's milk by microwave heating

Freshmilk is an excellent medium for microorganisms to thrive and multiply, hence,it is considered a highly perishable product. Today, a common expression used in reference to nutrition is that milk is the most nearly perfect food. It is the one foodstuff upon which all nutritionists agree concerning its value for the growth and development of children and young animals. The presence of large number of bacteria may be due to the age of milk, poor method of pasteurizing, unclean conditions, or the initial number of bacteria in the milk when it was drawn from the cow. Milk, to be high grade, must be clean and of good flavor. It may contain a minimun number of bacteria, none of which should be pathogenic. Microwave heating technology has proven its best application in cooking and heating of variety of foods. Several other applications have been explored using microwave heating, i.e., baking, roasting and even as heating medium for drying of grains. In the level of small scale milk producers, mostly the batch method of pasteurization is being employed. Milk is heated in bulk for a certain length of time until the temperature reaches 65 deg C. The temperature is then maintained for 15 minutes. The heating method, convection mode, besides requiring constant mixing, most often results in uneven heating and unpleasant burnt flavor. In microwave heating, energy absorption occurs within the bulk, or to be specific at each water molecule of the material as opposed to the other modes of heat transfer where the energy absorption originates on the surface. In other words, heating is simultaneous throughout the material, most especially when there is high moisture content, i.e. milk and juices. That phenomenon renders the high rate of heating, hence shorter time for the liquid foods to be pasteurized more efficiently. This study explored the utilization of quick heating property of microwave in pasteurization of fresh milk in the laboratory level.