Theoretical And Experimental Study On Hypobaric And Refrigerated Preservation Of Foods

Hypobaric and refrigerated preservation integrates vacuum cooling, low temperature preservation and gas storage. It has the feature of low temperature and low oxygen, which restrains the growth and breeding of microbe and abates the harm of oxygen and carbon dioxide to food. Therefore, it not only has the virtues of fast cooling, long storage time and good quality, but also prolongs shelf life of foods.1. The historical development of foods storage and its current study domestic and abroad were reviewed. Hypobaric and refrigerated preservation was put forward from the combination of refrigerated storage and lower pressure technology at the first time. The foods were preserved at the temperature above its freezing point or the critical temperature below which the cold harm occurred.2. The change of water and temperature at the food surface and inside food had been analyzed in the hypobaric environment as well as their relationship. A physical model and a mathematics model were set up on the change of water and temperature.3. A proper numerical method was chosen to calculate the change of water and temperature inside food during the cooling procedure in the hypobaric environment by computer. The theoretical simulation was used to analyze the influence of pressure, different operation, wet surface and three kinds of shape to the cooling of food.4. An existing experimental apparatus in the institute was rebuilt for experiment, and detailed experimental research had been carried out5. The effect of the preservation was fine with the guidance of theoretical simulation. The experimental results verified that the theoretical model was fit. The quality of preservation was good, as long as the pressure, temperature and moisture in the air were appropriate.