食品加工与技术杂志

抽象的

Milk Flash Pasteurization by the Microwave and Study its Chemical, Microbiological and Thermo Physical Characteristics

Asaad R Saeed Al-Hilphy and Haider I Ali

The study included pasteurization of cow’s milk by the Flash Pasteurization method and using temperature of 100°C for a period of 0.01 seconds. The chemical tests were measured and included determination of moisture, fat, lactose, ash and protein. The microbiological tests included estimating of the total number of microbes, bacteria of the colon (E. coli) and surviving fraction. Thermo physical properties were calculated for milk and included specific heat, viscosity, thermal conductivity and density during the different temperatures. TBA and free fatty acids were measured. Productivity of the device reached to 80 liters/hour and heating rate is 22.22°C/min. The results showed that the microbiological characteristics were improved after the flash pasteurization process by reducing the total number of microbial, and absence of Coliform bacteria in pasteurized milk. The pasteurization value, specific heat and thermal conductivity of the milk were increased with increasing time of heating, while viscosity and density of the milk were decreased with increasing temperature. Moisture, acidity and pH were decreased after the flash pasteurization process. Ash and carbohydrates have been increased. Fat and protein were not affected with pasteurization process. Results also showed the absence of alkaline phosphatase in pasteurized milk. TBA and free fatty acids were significantly (p<0.05) reduced by using microwave flash pasteurization.