The control of microorganisms is one of the most important issues in food preservation. Water activity, temperature, pH and preservatives are all critical factors that affect microbial growth. The application of acid stress (low pH and weak acid preservatives) is widely used to inhibit bacterial growth, as it decreases the internal pH below the normal physiological range. In addition to low pH effects, acid preservatives compromise the functional integrity of the cell membrane, cell wall, metabolic enzymes, protein synthesis system and/or genetic material. Certain bacteria, such as Escherichia coli and Salmonella spp., are equipped with elegant systems that enable survival in acidic environments.
