Supercritical Fluid Pasteurization and Food Safety

Abstract

Processes based on supercritical fluids, especially carbon dioxide, have been extensively investigated for their utility in pasteurizing milk, fruit and vegetable juices, raw vegetables, meat, and fish. This chapter initially reviews current issues in food pasteurization, then presents the thermodynamic fundamentals of supercritical fluid behavior and how SCFs can be utilized for pasteurization. The chapter includes possible mechanisms and models for the inactivation of a variety of hazardous microorganisms. This is followed by a comprehensive overview of specific studies of applications to a wide range of foodstuffs. Finally, the commercial viability of SCF pasteurization and the recent patent literature is discussed. The goal of this chapter is to enable both researchers and process developers to understand the scientific fundamentals behind the use of supercritical fluids for food pasteurization and assess the breadth of applications that have been considered.

Potentialities and Limits of Some Non-thermal Technologies to Improve Sustainability of Food Processing

“…Carbon dioxide is a cheap, non-toxic and non-flammable compound which has been intensively studied in food processing for the purpose of pasteurization and sterilization, product texturing and functionalization, as well as for fractionation and extraction of compounds (23–26). These processes generally consist in mixing carbon dioxide under gas, liquid or supercritical state into a liquid or solid matter and maintaining a pressure/temperature condition during a sufficient period to allow for matter transfer between both (Figure 3).…”

“…Hence, four domains are often distinguished according to the targeted effect of the treatment (Figure 4): destabilization of the native structure of pH-sensitive proteins, inactivation of vegetative microorganisms, solubilisation of non-polar (or low polar) compounds in SC-CO 2 , and inactivation of endospores. As only few data can be found on the cost of these treatments (26), as a first approximation it can be assumed that the energetic cost increases when temperature and pressure increase. Nonetheless, for the range of applications considered (stabilization of a product, extraction, etc.…”

“…Nonetheless, for the range of applications considered (stabilization of a product, extraction, etc. ), processes using CO 2 are considered green processes, as they represent an alternative to thermal treatment, high pressure (above 200 MPa) treatment, and solvent extraction (25, 26). These processes do not generate CO 2 but use existing resources, which is an important point for sustainability requirements (26).…”

“…CO 2 processes have been investigated for their ability to stabilize products according to several criteria: bacterial content (26), undesired enzymatic activity (39), texture (31), or nutritional quality (27, 35, 39). To our knowledge, no experimental data have been published on the cost of processes using CO 2 for these purposes (26). Nonetheless, the treatment intensity in terms of pressure/temperature can be discussed and compared with currently used technologies.…”

Long-term maintenance of dried acellular matrices

“…SC-CO2 has a low critical temperature that doesn't degrade thermo sensitive components. SC-CO2 has also bactericidal properties and it has been deeply investigated as alternative pasteurization and sterilization methods [12,13].…”