Effects of ultra-high hydrostatic pressure treatments on the quality of tomato juice

The effects of ultra-high hydrostatic pressure (UHP) treatments on some physicochemical, microbiological and sensory properties of single-strength natural tomato juice were evaluated using response surface methods. Application of graphical optimization techniques showed that UHP processing yields products which, beside being microbiologically stable, have improved viscosity and colour properties in comparison with their conventional heat-processed counterparts. Enzyme inactivation was found to be less than that caused by the conventional hot-break treatment. During UHP processing, very high n-hexanal and cis-3-hexenal concentrations were formed from free fatty acid oxidation.