The emergence of antibiotic resistance of pathogenic bacteria has led to renewed interest in exploring the potential of plant-derived antimicrobials e.g., essential oils (EOs), as an alternative strategy to reduce microbial contamination. However, the volatile nature of EOs presents a major challenge in their incorporation into polymers by conventional high-temperature processing techniques.
We employ nanomaterials such as, Halloysite nanotubes (HNTs), as efficient nano-carriers for essential oils. Using various pre-compounding processes, we encapsulate essential oils within HNTs. This step imparts enhanced thermal stability to the essential oil, allowing for its subsequent melt compounding with different polymers e.g., low-density polyethylene (LDPE).
The resulting polymer nanocomposites exhibit outstanding antimicrobial properties with a broad spectrum of inhibitory activity against Escherichia coli, Listeria innocua in biofilms, and Alternaria alternata. Their antimicrobial effectiveness is also successfully demonstrated in complex model food systems (such as soft cheese and bread). This superior activity, compared to other studied essential oil-containing films, is induced by the significantly higher oil content in the film as well as its slower out-diffusion from the hybrid system.
Thus, these new active polymer nanocomposites presents an immense potential in controlling microbial contamination and biofilm related adverse effects, rendering them as excellent candidate materials for a wide range of applications.
- Krepker M., Shemesh R., Danin-Poleg Y., Kashi Y., Vaxman A., Segal E., Active Food Packaging Films with Synergistic Antimicrobial Activity, Food Control, 76, 117–126 (2017).
- Shemesh R., Krepker M., Nitzan N., Vaxman A., Segal E., Active packaging containing encapsulated carvacrol for control of postharvest decay, Postharvest Biology and Technology, 118, 175-182
- Shemesh R., Krepker M., Nathan M., Banin E., Danin-Poleg Y., Kashi Y., Nitzan N., Vaxman A., Segal E., Novel LDPE/Halloysite Nanotubes Films with Sustained Carvacrol Release for Broad-Spectrum Antimicrobial Activity, RSC Advances, 5, 87108–87117 (2015).
- Shemesh R., Goldman D., Krepker M., Danin-Poleg Y., Kashi Y., Vaxman A., Segal E., LDPE/Clay/Carvacrol Nanocomposites with Prolonged Antimicrobial Activity, J. Appl. Polym. Sci., 132(2), 41261-41269 (2015).
- Shemesh R., Krepker M., Goldman D., Danin-Poleg Y., Kashi Y., Nitzan N., Vaxman A., Segal E., Antibacterial and Antifungal LDPE Films for Active Packaging, Polym. Adv. Tech., 26(1), 110-116 (2015).
Researchers: Dr. Naama Massad-Ivanir, Dr. Nadan Nitzan, and Maks Krepker.