The Working Principle and Use of High Pressures in the Food Industry

High pressure in the food industry, as a new non-thermal method, is applied in many phases of food processing. This new non-thermal technology was developed in the 1990s. The main advantages of high-pressure processing are in the short time of processing which is between a few seconds and 30 minutes. Processing of solid or liquid food products with or without packaginghappens in the temperature interval 5 – 90 °C, and pressures 50 – 1000 MPa. The driving pressure is distributed uniformly through the whole product independently of its quantity and shape. These processing characteristics combined with improved food microbiological safety, less energy expenditure, low concentration of waste products and longer shelf life make high-pressure processing a very promising novel food technology. Combined with lower cost of treatment (but unfortunately higher initial cost of equipment) compared to traditional processing technologies, it is also economically profitable. The main purpose of such treated food products are in preservation of sensory, nutritive and textural properties. As the temperature increase is very low, there are no significant changes in sensory properties, in contrast to conventional thermal processing (sterilization, pasteurization). However, with the combination of heating or cooling and high pressure, modification of existing and creation of new food products is possible. Today, high pressure is used for the treatment of meat products (inactivation of microorganisms), freezing and defrosting of foodstuffs, production of fruit juices (pasteurization), processing of oysters, modificationof milk characteristics (foaming) etc. The main purpose of this work is to present the working principle and application of high pressure in the food industry.