Effect of evacuation rate on the vacuum cooling process of a cooked beef product Original Research Article

The influence of evacuation rate during vacuum cooling on the mass loss, temperature reduction per percent mass loss, speed of cooling, temperature distribution and final product yield, in a cooked beef product was studied. Samples were cooled from a core temperature of 72°C to 4°C in a laboratory scale vacuum cooler. Six different evacuation rates were used in the study. Mean results indicated that vacuum cooling was very rapid (<150 min) in cooling the beef product. However, the chill loss was higher and total product yield lower than conventional cooling methods commonly available in the food industry. Final evacuation rate had a significant effect on chilling loss and total product yield with slower evacuation rate increasing total product yield and decreasing chilling loss. However, cooling time was increased as evacuation rate decreased.