Composition Changes of Strawberry Puree during High Pressure Pasteurisation

摘要

The ultra high pressure pasteurisation in combination with aseptic filling systems seems to be one of the most promising applications of high pressure technology in fruit food processing [1,2]. The high pressure treatment for 5 - 10 min under 300 - 600 MPa at 20 - 50 deg C allows the reduction of vegetative microbial cells by 4 - 5 log cycles, however some enzymes especially polyphenolowidase in fruit juices are more pressure resistant and their inactivation needs additional approaches [1-3]. The main advantage of high pressure pasteurisation is that products retain the flavour, colour and nutrition level of fresh fruits [1,4]. However, high pressure processing affects chemical reactions in food material in both, positive and negative ways. Nonenzymatic browning (Maillard reaction ) as well as hydrolysis of sucrose is inhibited by pressure. Degradation of colour and slight changes of flavour due to the higher content of dissolved oxygen in products are mentioned as an example of negative pressure effects [1,4].