This study evaluated the antimicrobial potential of various naturally occurring substances, for use as active agents in cheese packaging. Sorbic acid and benzoic acid were examined as standard‐sized and nanoparticled solutions. Rosemary, curcumin and ascorbic acid were employed as nanoparticled solutions only, while non‐nanoparticled chitosan, of two molecular weights, were also selected for evaluation. All agents were assessed against micro‐organisms derived from cheese. Chitosan proved to be the most effective, with low molecular weight chitosan performing best. The most antimicrobial nanoparticle was found to be rosemary. Comparison of normal‐ and nanoparticle‐sized organic acid solutions showed little difference in terms of antimicrobial properties.

The objective of this study was to determine whether a combination of agents could produce a synergistic antimicrobial effect, by either targeting a greater spectrum of micro-organisms or reducing the concentration of antimicrobial required to cause inhibition. Five agents (nanoparticled solubilisatessorbic acid, benzoic acid and rosemary extract, and non-nanoparticled chitosansof two different molecular weights) were selected based on promising antimicrobial activity and/or enhanced solubility. Combinations of these agents were examined against cultures derived from cheese. The study found the top-performing antimicrobials contained chitosan and/or rosemary, individually or in combination. These findings encourage their use as active agents in cheese packaging.