Experimental Study On The High Pressure Treatment Of Food

High pressure sterilization technology of food is a new technology developed in recent years, which is also called cold sterilization technology. The technology has attracted great attentions in many fields such as materials, chemicals, biology, medicine, and promoted the study and manufacture of the high pressure equipment. It also shows a wide prospect for the new food production.Because of relative short time for the development of the high pressure treatment technology of food, the research work on the technology at early stage. Some domestic scientists have studied the technology, but their work are mainly focused on the high pressure sterilization of the bacteria. There exist some problems as follows: Firstly, the experimental equipment is not designed for scientific experiments and quite expensive. Secondly, the experimental data of high pressure food are seldom, and the foods and bacterias involved in the study are limited.A high pressure equipment is designed and setted up in this paper. The concept of the design is concentrated on manufacturing easily, running safely and operating conveniencely. Some improvements on the traditional high pressure equipment are made in order to reduce the cost. The improved equipment is proved to be of good condition and performance. It can meet the needs of experimental study.Four kinds of bacterias (E-coil, Cl.perfringens, Bacillus subtilis and C.glutamicum) and three kinds of foods (egg, pork, fish) are experimentally studied in this paper. The relationship of the bacteria mortality with the operation pressure, operation time, pH of the bacteria and the pressure rising rate are studied through bacteria experiments. The trend of bacteria mortility is examined under different operating conditions. The efficets of bacteria characteristics and the high pressure processing on the shelf time of the food is studed through food experiments.The results of above study show that two most effective factors on the sterilization are pressure and operation time. G+ bacteria is more stable than the G- bacteria under high pressure condition. The bacterias are less active and harder to breed after the treatment under high pressure. The bacterias in the food are more stable than in the solution when they are subjected with high pressure. The mortility of the bacteras is more than 99.9% at the pressure of 300MPa with the operation time of 20min, and this has reached the national health standard. The eggs treated in the high pressure are able to keep fresh for a longer time.