Food Processing Using Supercritical Fluids

Abstract

A “green” revolution as a part of necessary sustainable development, use also high pressure as a tool. The main impetus for this conversion is on one way driven by a concern to the environment to reduce the usage of solvents and energy. On the other hand increasing consumer demand on new and natural products use high pressure as a tool to design and produce the natural products with completely new characteristics. Research in supercritical extraction technology started about two decades ago. Meanwhile several hundred supercritical extraction plants are in operation worldwide, with a strong increase in the past decade. Extraction of plant materials, like hop constituents, decaffeination of tea and coffee, separation of lecithin from oil are high pressure processes, which are performed on large industrial scale. Several smaller industrial units are in operation also for extraction of spices for food industry and natural substances for use in cosmetics (Proceedings of the fifth international symposium on high pressure process technology and chemical engineering, 24–27 June 2007, Segovia). The unique thermodynamic and fluid dynamic properties of different gases used as dense fluids, e.g., sub- or supercritical fluids can be used also for integrated extraction and in situ formulation like impregnation of solid particles, for formation of solid powderous emulsions, particle coating, etc. will be presented. We could summarize that extraction of substances from solids or liquids and their integrated formulation in products with specific properties is one of the very promising applications of supercritical fluids and several laboratory scale as well industrial scale applications, including fundamental data for design of high pressure processes, will be presented in details.