SOME PHYSICOCHEMICAL BASIS OF FOOD PRESERVATION BY COMBINED METHODS

Food preservation by combined methods consists of a combination of various parameters-also called hurdles-such as slight reduction in water activity (a(W)), lowered pH, addition of single/combined safe antimicrobial agents, moderate heat treatment (pasteurization), etc. The application of this combination of parameters may act synergistically to inhibit (or retard) microbial growth resulting in stable products at room temperature. The purpose of present work is to review some of the basic physico-chemical principles underlying each of the hurdles; this would allow a proper and intelligent combination of parameters for preservation of foods.