Novel LDPE Films with Prolonged Antimicrobial Activity

Novel LDPE films will demonstrate a solution for extending food shelf life by using plant-derived antimicrobials e.g., essential oils (EOs), 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. Herein, we employ halloysite nanotubes (HNTs) as efficient nano-carriers for carvacrol (a model EO). This pre-compounding encapsulation step imparts enhanced thermal stability to the carvacrol, allowing for its subsequent melt compounding with low-density polyethylene (LDPE). The resulting polymer films exhibit outstanding antimicrobial properties with a broad spectrum of inhibitory activity against Escherichia coli, Listeria innocua and Alternaria alternata. Their antimicrobial effectiveness is also successfully demonstrated in complex model food systems (fresh produce and bread). This superior activity, compared to other studied carvacrol containing films, is induced by the significantly higher carvacrol content in the film as well as its slower out-diffusion from the hybrid system. Thus, these new nanotechnology-based antimicrobial food packaging will enhance food safety, prevent foodborne illness outbreaks and reduce food waste caused by early spoilage.