This document discusses hurdle technology, which uses a combination of preservation methods to control microorganisms in foods. It describes several hurdles used in food preservation including high temperature processing like pasteurization, low temperature storage, increased acidity, and reduced water activity. Physical hurdles include heating, freezing, and packaging techniques. Physiochemical hurdles involve additives like salt, acids, and preservatives. Microbial hurdles utilize competitive microflora. The hurdles can be adjusted based on the pathogens present to ensure food safety while meeting consumer preferences and being economically viable. Intermediate moisture foods use adjusted water activity to preserve semi-moist foods without refrigeration.