Assessment of the antimicrobial activity of potentially active substances (nanoparticled and non‐nanoparticled) against cheese‐derived micro‐organisms

Abstract

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.

Evaluation of the potential synergistic antimicrobial effects observed using combinations of nanoparticled and non‐nanoparticled agents on cheese‐derived micro‐organisms

“…They had MICs of 0.060, 0.076, 0.120, 0.207 and 0.238, respectively. This correlates with previous work reported by O' Callaghan and Kerry (), which showed that LMWC, MMWC and nanoparticled rosemary extract all showed the greatest antimicrobial activities of the agents assessed. Chitosan is evidently the most effective broad‐spectrum antimicrobial in this study due to its low MIC levels and, as evidenced by its presence in all of the five most effective active treatments, used either on its own or in combination.…”

“…The antimicrobial agents investigated in this study were selected based on results determined from previous work reported by O' Callaghan and Kerry (). The criteria for this selection comprised a balance of promising antimicrobial activity and/or enhanced solubility.…”

“…() demonstrated the considerable antimicrobial activity of nanoparticled sorbic and benzoic acid solubilisates relative to their non‐nano‐equivalents. Nanoparticled rosemary extract solubilisate showed a notable balance of enhanced solubility and an antimicrobial affinity towards cheese‐derived cultures and Gram‐positive bacteria (O' Callaghan and Kerry, ). To our knowledge, no other studies have explored the antimicrobial effect of nanoparticled rosemary or rosemary extract.…”

Antimicrobials Used in Active Packaging Films

“…Essential oils extracted from plants have become popular due to their natural sources such as rosemary, lemongrass, ginger and curcumin extracts and their non-toxicity, inherent antimicrobial and antioxidant activities (Klangmuang & Sothornvit, 2016;O' Callaghan & Kerry, 2014;Takala, Vu, Salmieri, Khan, & Lacroix, 2013;Wang et al, 2017). Herbal oils generally are considered to be replacement of organic acids due to their antibacterial, antifungal and antioxidant properties (Klangmuang & Sothornvit, 2016).…”

“…The molecular weight of chitosan is another important factor in terms of antimicrobial effects. The chitosan derivative having low molecular weight is more effective because that chitosan can enter the microbial cell more easily than its high molecule weight derivate (CruzRomero et al, 2013;O' Callaghan & Kerry, 2014). Soysal et al (2015) had stored chicken drumstick wrapped with multilayer LDPE active films containing chitosan at 5°C during 6 days and they reported that efficiency in inhibiting total aerobic mesophilic bacteria (APC), total coliforms and total molds and yeasts had been evaluated by comparison with control bag (LDPE-polyamide-LDPE).…”