Abstract
The need for a food preservation method that is safe and inexpensive and that preserves heat-sensitive compounds resulted in the use of pressurized carbon dioxide (CO) as a food preservation method. Dense-phase carbon dioxide (DPCD) treatment has attracted great interest in the nonthermal treatment of liquid foods or liquid model solutions. DPCD has been shown to inactivate microorganisms as well as conventional heat pasteurization without the loss of nutrients or quality changes that may occur due to thermal effects. Pressure and temperature are the main control parameters for DPCD. They significantly affect microbial inactivation, and they influence the CO physical state (i.e., liquid, gas, or supercritical) and its properties such as viscosity and diffusivity. Most of the DPCD inactivation studies currently available in the scientific literature have been performed in inoculated or spoiled foods or in inoculated simple model systems and liquid substrates, such as physiological saline solution or culture media. In recent years, the number of published studies in which natural microorganisms in real foods are targeted and inactivated by DPCD has increased. DPCD has progressed, both in terms of theoretical and predictive capabilities and in the accumulation of experience in its applications to many juices and beverages. However, the lack of the first commercially successful DPCD operation is making new entries into the field difficult. Another issue is the use of CO, which is a greenhouse gas. Therefore, this technology can only be used in some niche areas, which calls for further research and investigation studies.