The development of high hydrostatic pressure processes as an alternative to other pathogen reduction methods.

In biology, scientist's interest for high hydrostatic pressure (HHP) has increased over the last 20 years, for both research and industrial developments, mainly because of the low energy associated with its application in liquid phase and its capacity to inactivate pathogens. It is now considered as an interesting alternative to heat treatments for the inactivation of contaminants in many products, from foods to pharmaceutical preparations. This last statement implies different objectives according to the type of product. The therapeutic properties of pharmaceutical preparations or other biological media of physiological importance are in general associated with specific and well-defined molecules such as proteins. Their activity mainly depends on their spatial conformation, maintained by weak chemical bonds that are often pressure sensitive. In this case, the optimization of a HHP process can be more complex than for foods, for which the organoleptic molecules are less pressure sensitive, and the evaluation of their preservation is more subjective and highly dependent on the consumers acceptance. The objective of this review is therefore to underline how, even if the basic concept for the optimization of a pathogen reduction process using HHP is the same whatever the product, major differences arise from the product itself and its final use.