ORGANIC-ACIDS - CHEMISTRY, ANTIBACTERIAL ACTIVITY AND PRACTICAL APPLICATIONS

This chapter presents the chemistry and antimicrobial activity of the saturated straight-chain monocarboxylic acids, and reference is made, where appropriate, to derivatives of this group— for example, unsaturated (cinnamic, sorbic), hydroxylic (citric. lactic), phenolic (benzoic, cinnamic, salicylic) and multicarboxylic (azelaic, citric, succinic) acids. Organic acids are distinguished from other acids by the functional group COOH to which an organic group or a hydrogen atom may be attached. Common names used to describe this group of organic compounds include fatty, volatile fatty, lipophilic, weak, or carboxylic acids. There is no standard protocol for studying the antimicrobial activity of organic acids and many reports give only the pH value of the solution under test without indicating the concentration of the acid, thus making evaluation of the results difficult or impossible. In addition, it is difficult to compare the activity of different acids because it is influenced by the physical chemistry of the microbial species, the growth conditions, and the phase of growth. The chapter discusses two aspects of the use of organic acids: in animal husbandry as animal feed additives and in abattoirs and food-processing plants where they may be used in controlling microbial contamination of carcass meat. © 1991 Academic Press Inc.