Abstract
Increasing consumer demand for minimally processed, additive-free, shelfstable products prompted food scientists to explore other physical preservation methods as alternative to traditional treatments such as freezing, canning, or drying that rely on heating or cooling operations. Although these technologies help ensure a high level of food safety, the heating and cooling of foods may contribute to the degradation of various food quality attributes. The color, flavor, and texture of foods processed solely by heating (thermal pasteurization up to 80°C and sterilization up to 120°C) may be irreversibly altered. To ameliorate the undesirable thermal effects on foods, considerable efforts have been made in commercial and academic circles to develop nonthermal technologies other than heating or cooling operations. Some of the investigated technologies are ionization radiation, high hydrostatic pressure (HHP), pulsed electrical fields, high-pressure homogenization, UV decontamination, pulsed high-intensity light, high-intensity laser, pulsed white light, manothermosonication (combined ultrasonic, heat, and pressure), oscillating magnetic fields, high voltage arc discharge, and streamer plasma. Among these emerging technologies, the most promising ones for food application are high-pressure processing, namely HHP and dense-phase carbon dioxide (DPCD). This chapter will describe and discuss the current knowledge in the pasteurization and sterilization of foodstuff by means of HHP and DPCD technologies. The most significant achievements will be summarized, including fundamental concepts, different hypotheses of bacteria inactivation mechanisms, and the main applications in the food industry focusing on the effects exerted on the microbial and quality aspects. Further, commercial applications of the technologies will be described and some conclusions about the two high-pressure processing will be drawn.