Authors: K.A.M. O’ Callaghan, J.P. Kerry
Affilation: University College Cork, Ireland
Pages: 196 - 199
Keywords: antimicrobial, nanoparticles, cheese, rosemary, chitosan, active
The aim of the this study was to examine the antimicrobial effectiveness of a number of agents (nanoparticled and non-nanoparticled) applied individually and in combination to cheese derived cultures to determine their suitably as active agents to be incorporated into the packaging of cheese products. Combinations of these agents were used to evaluate if a synergistic effect could be achieved, by either targeting a greater spectrum of microorganisms, or by reducing the amount of antimicrobial required to cause inhibition. Five agents (nanoparticled solubilisates - sorbic acid, benzoic acid and rosemary, and non-nanoparticled chitosans, of two molecular weights – low and medium) were selected based on promising antimicrobial activity and/or enhanced solubility demonstrated from previous work. The microorganisms used for testing included Gram-negative and Gram-positive species derived from cheese samples and general mixed cheese cultures derived from Emmental and cottage cheese. The solutions were evaluated for their antimicrobial activity via minimum inhibition concentration (MIC) testing, through the micro-dilution method. The study found the top performing antimicrobials contained chitosan and/or nanoparticled rosemary, individually or in combination, although synergism was not exhibited. These findings encourage their use as active agents in cheese packaging.