ABSTRACT
Since prehistoric times, chemicals have been added to preserve freshly harvested foods for later use. Drying, cooling, fermenting, and heating have always been the primary methods used to prolong the shelf life of food products. Whereas some chemical food preservatives, such as salt, nitrites, and sulfites, have been in use for many years, most others have seen extensive use only recently. One of the reasons for increased use of chemical preservatives has been the change in the ways foods are produced and marketed. Today, consumers expect foods to be readily available yearround, to be “free” of foodborne pathogens, and to have a reasonably long shelf life. Although some improvements have been made using packaging and processing systems to preserve foods without chemicals, antimicrobial preservatives play a significant role in protecting the food supply (Davidson et al., 2002). In addition, because of changes in the marketing for foods to a more global system, products seldom are grown and sold locally as in the past. Today, foods produced in one area are often shipped to another area for processing and to several other areas for distribution. Several months or years may elapse from the time food is produced until it is consumed. To accomplish the long-term shelf life necessary for such a marketing system, multiple effective means of preservation are often required. It is important to note that, with rare exceptions, food antimicrobials are not able to conceal spoilage of a food product (i.e., the food remains wholesome during its extended shelf life). In addition, because food antimicrobials are generally bacteriostatic or fungistatic, they will not preserve a food indefinitely.
