Food safety

In the ongoing battle against antibiotic-resistant bacteria, a groundbreaking study published in the journal Carbohydrate Polymers paves the way for a novel antibacterial approach. Researchers from the Middle East Technical University in Ankara, Turkey, have developed an innovative thin film containing bacteriophages – the natural predators of bacteria – to be used as an antibacterial coating for food packaging applications. This development holds the potential to revolutionize food safety and offer a sustainable solution to the growing issue of antibiotic resistance.

The article, “Layer-by-layer assembly of chitosan/alginate thin films containing Salmonella enterica bacteriophages for antibacterial applications,” sheds light on a cutting-edge technology in the realm of food biotechnology. The research team, led by Dr. Irem Erel-Goktepe, has successfully harnessed the power of bacteriophages in creating an antibacterial film by deploying layer-by-layer (LbL) self-assembly of chitosan and alginate polymers. This study has been endowed with the DOI: 10.1016/j.carbpol.2023.121710 and can be found online for further inquiry.

The Emergence of a New Antibacterial Strategy

The international community has long been voicing concerns over the inadequate effectiveness of traditional biocides against multi-drug-resistant bacteria. This issue poses a significant threat to global health, food safety, and the environment. As the frequency of antibiotic resistance rises, there is an unprecedented need for alternative antibacterial agents.

Enter bacteriophages, viruses that specifically infect and kill bacteria. Unlike broad-spectrum antibiotics, bacteriophages have a high specificity towards their bacterial hosts, which means they can target harmful bacteria without disturbing the beneficial microbiota. In the study conducted at the Middle East Technical University, a particular bacteriophage, identified as belonging to the Siphoviridae morphotype (MET P1-001_43), was chosen for its ability to infect Salmonella enterica subsp. enterica serovar Enteritidis, commonly known as Salmonella Enteritidis.

Harnessing Chitosan and Alginate

Chitosan and alginate, both derived from natural sources, are well-documented for their biocompatibility, biodegradability, and non-toxicity – characteristics integral for applications in food packaging. The research team has meticulously created a chitosan/alginate film that serves as the scaffold to incorporate the bacteriophages. By employing the LbL self-assembly technique, they managed to arrange these polymers into ultra-thin, stable films loaded with bacteriophages.

The methodology involved alternate deposition of positively charged chitosan and negatively charged alginate layers to build the film, with bacteriophages embedded within. The team utilized advanced analytical techniques, including ellipsometry, Quartz Crystal Microbalance with Dissipation monitoring (QCM-D), and Atomic Force Microscopy (AFM), to characterize the LbL growth, stability, and surface morphology of the films.

Antibacterial Activity and Food Packaging Applications

The study revealed that the bacteriophage-loaded chitosan/alginate films displayed significant antibacterial activity at a neutral pH of 7.0. However, this activity was not observed under acidic conditions, highlighting the importance of pH in the effectiveness of the coating. Demonstrating the practicality of their research, the team wrapped a piece of chicken meat contaminated with Salmonella Enteritidis using aluminum foil coated with the phage-laden film. Results were promising; the number of bacterial colonies on the meat significantly decreased, showcasing effectiveness comparable to treating the meat directly with bacteriophage solution.

This innovative approach suggests a potential paradigm shift in food packaging, promoting the usage of such bacteriophage-containing films to prevent foodborne illnesses caused by pathogenic bacteria like Salmonella Enteritidis.

Keywords

1. Antibacterial Coating
2. Bacteriophage Food Safety
3. Chitosan Alginate Film
4. Antibiotic Resistance Solutions
5. Food Packaging Technology

Conclusion

The integration of bacteriophages in a film capable of being used in food packaging heralds a novel, efficient tool in the realm of antibacterial treatments. Such technology not only aligns with the exigencies to outmaneuver antibiotic resistance but also embodies an eco-friendly framework, given the natural origin of the materials used.

References:
Gökçe, T., et al. (2024). Layer-by-layer assembly of chitosan/alginate thin films containing Salmonella enterica bacteriophages for antibacterial applications. Carbohydrate Polymers, 328, 121710. https://doi.org/10.1016/j.carbpol.2023.121710

Declaration of Competing Interest
The authors have declared no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.