Tomato with Chitosan Coating and Bacteriophage Protection

Tomato Safety: How Edible Coatings & Bacteriophages Fight E. Coli

Rhea Morgan in Science & Nature September 2025 • 4 min read.

"A natural approach to reducing foodborne illness using chitosan coatings and targeted bacteriophages on tomatoes"

Foodborne illnesses are a significant public health concern globally, leading to high rates of morbidity and mortality, as well as substantial economic losses. Fruits and vegetables can become contaminated at any point during the food chain, from harvesting to post-harvest processing, storage, and distribution. This contamination can result in outbreaks of diseases like E. coli.

Escherichia coli (E. coli) is one of the most common culprits behind food poisoning incidents worldwide. These highly pathogenic bacteria can cause serious illness, making it crucial to find effective ways to combat them. The rise of antibiotic-resistant bacteria strains further complicates the issue, underscoring the urgent need for innovative solutions to ensure food safety.

Researchers have explored various strategies to mitigate the risk of food contamination. Among these strategies, edible coatings have emerged as an innovative technology to inactivate and reduce populations of microorganisms. These coatings offer benefits such as versatility, biodegradability, and low cost.

How Chitosan-Based Coatings Enhance Food Safety

Tomato with Chitosan Coating and Bacteriophage Protection

Edible coatings can act as carriers for antimicrobial additives, enhancing their functional properties and extending the shelf life of food products. While various antimicrobial agents like organic acids and plant essential oils have been studied, integrating bacteriophages with edible packaging materials is a promising area.

Bacteriophages, also known as phages, are viruses that infect and kill bacteria. They have gained attention as a promising alternative for decontaminating and eliminating pathogens from food sources. They can be used as biocontrol agents and food biopreservatives. Incorporation of antimicrobial agents directly into biopolymer-based coatings significantly contributes to food safety preservation.

Chitosan: A natural polymer with immense potential in the food industry due to its biocompatibility, non-antigenicity, non-toxicity, and biodegradability.
US FDA Approval: Chitosan has been approved by the United States Food and Drug Administration (USFDA) as Generally Recognized as Safe (GRAS) for food use purposes.
Antimicrobial Agents: Addition of natural antimicrobial agents incorporated into chitosan-based edible films improves packing functionality, leading to increased focus on its use for extending food shelf life.

Researchers Luis Amarillas, Luis Lightbourn-Rojas, Ana K. Angulo-Gaxiola, J. Basilio Heredia, Arturo González-Robles, and Josefina León-Félix conducted a study on developing chitosan-based edible coatings incorporated with bacteriophages to control E. coli on tomato surfaces. The study also isolated and characterized bacteriophages with lytic activity against E. coli strains.

Future Implications for Food Safety

The study successfully isolated and characterized three phages suitable for E. coli control, with vB_EcoMH2W showing great lytic activity. Antibacterial tests reveal a high potential for using the phage in chitosan coatings as active packaging materials. Future studies will focus on testing the effectiveness and safety of this new method for biological control of pathogenic bacteria.

About this Article -

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This article is based on research published under:

DOI-LINK: 10.1111/jfs.12571, Alternate LINK

Title: The Antibacterial Effect Of Chitosan‐Based Edible Coating Incorporated With A Lytic Bacteriophage Against Escherichia Coli O157:H7 On The Surface Of Tomatoes

Subject: Microbiology

Journal: Journal of Food Safety

Publisher: Wiley

Authors: Luis Amarillas, Luis Lightbourn‐Rojas, Ana K. Angulo‐Gaxiola, J. Basilio Heredia, Arturo González‐Robles, Josefina León‐Félix

Published: 2018-10-23

Everything You Need To Know

What is the primary method discussed to combat E. coli contamination on tomatoes?

The primary method discussed involves the use of chitosan-based edible coatings infused with lytic bacteriophages. This approach aims to eliminate E. coli O157:H7 on tomatoes, thus enhancing food safety naturally. The use of these coatings represents a natural and innovative solution to mitigate foodborne illnesses.

What role do Bacteriophages play in ensuring tomato safety?

Bacteriophages, or phages, are viruses that specifically infect and kill bacteria, including E. coli. In the context of tomato safety, these phages are incorporated into chitosan coatings. When applied to tomatoes, the bacteriophages actively seek out and destroy E. coli cells, reducing the risk of contamination and foodborne illness.

How does Chitosan contribute to food safety and why is it suitable for use in food?

Chitosan is a natural polymer used in edible coatings due to its biocompatibility, non-antigenicity, non-toxicity, and biodegradability. It acts as a carrier for antimicrobial agents, like bacteriophages, enhancing the effectiveness of these agents. It has also been approved by the US FDA as Generally Recognized as Safe (GRAS) for food use, making it a suitable and safe choice for food applications.

What are the benefits of using edible coatings on tomatoes, and how do they extend shelf life?

Edible coatings, especially those based on chitosan, offer multiple benefits. They can act as barriers against microbial contamination, reduce moisture loss, and improve the overall quality of the tomatoes. By incorporating antimicrobial agents like bacteriophages, these coatings actively combat pathogens such as E. coli. The addition of antimicrobial agents improves packing functionality, leading to increased focus on its use for extending food shelf life.

What are the implications of using bacteriophages in chitosan coatings for food preservation, and what does the study suggest for future research?

The use of bacteriophages in chitosan coatings represents a significant advancement in food preservation. The study successfully isolated and characterized phages suitable for E. coli control, with vB_EcoMH2W showing great lytic activity. This approach provides a natural alternative to chemical preservatives, reducing the risk of antibiotic resistance. Future research will focus on testing the effectiveness and safety of this new method for biological control of pathogenic bacteria, paving the way for broader applications in food safety.