High Pressure Pasteurisation and Sterilisation of Tomato Puree

Abstract

The effects of high-pressure (HP) pasteurisation and sterilisation on the microbial safety and quality of tomato puree were compared to conventional heat treatments. HP pasteurisation was achieved by a HP treatment at ambient temperature and 700 MPa. This treatment also reduced the naturally present spores to a level below the detection limit. HP sterilisation was reached by a two pulse treatment at 700 MPa and a starting temperature of 90¡ãC. HP pasteurisation and conventional pasteurisation resulted in an activation of pectin methylesterase and a reduction of the polygalacturonase activity. Both enzymes were inactivated after conventional and HP sterilisation. HP treatments resulted in an equal or improved retention of the red colour compared to the heat treatments. Heat with or without pressure induced a reduction in the viscosity, while HP pasteurisation at ambient temperature increased the viscosity.