A team of scientists from Nanyang Technological University, Singapore (NTU Singapore) and Harvard T.H. Chan School of Public Health, U.S., has developed a “smart” food packaging material that is biodegradable, sustainable and antimicrobial. It could also extend the shelf life of fresh fruit by two to three days.

In lab experiments, when exposed to an increase in humidity or enzymes from harmful bacteria, the fibers in the packaging have been shown to release the natural antimicrobial compounds, killing common dangerous bacteria that contaminate food, such as E. Coli and Listeria, as well as fungi.

The invention is the result of the collaboration by scientists from the NTU-Harvard T. H. Chan School of Public Health Initiative for Sustainable Nanotechnology (NTU-Harvard SusNano), which brings together NTU and Harvard Chan School researchers to work on innovative applications in agriculture and food, with an emphasis on developing non-toxic and environmentally safe nanomaterials.

“This invention would serve as a better option for packaging in the food industry, as it has demonstrated superior antimicrobial qualities in combatting a myriad of food-related bacteria and fungi that could be harmful to humans,” says Professor Mary Chan, director of NTU’s Centre of Antimicrobial Bioengineering, who co-led the project. We asked Professor Chan to detail this packaging further.

FE: How long has this material been in development?

Chan: It has been in development for several years. We researchers hope to scale up the technology with an industrial partner, and commercialize their food packaging within two years. They are currently working to fine-tune and optimize the material’s manufacturing process and its functionality. They are also looking into other types of biopolymers beyond corn protein to create different forms of sustainable packaging.

FE: Other similar methods have been considered, but they seem to be made with non-biodegradable materials, correct?

Chan: Yes, that’s correct. Our natural food packaging is made from a type of corn protein called zein, starch and other naturally derived biopolymers, infused with a cocktail of natural antimicrobial compounds. These include oil from thyme, a common herb used in cooking, and citric acid, which is commonly found in citrus fruits.

FE: Is this material only a film?

Chan: No, it is not only a film. As it is produced by electrospinning the zein, the antimicrobial compounds with cellulose, it can easily be shaped into other shapes and forms to best serve other purposes.

FE: How does the material keep food safe, and what makes it “smart”?

Chan: In lab experiments, when exposed to an increase in humidity or enzymes from harmful bacteria, the fibers in the packaging have been shown to release the natural antimicrobial compounds, killing common dangerous bacteria that contaminate food, such as E. Coli and Listeria, as well as fungi. It is “smart” as the packaging is designed to release the necessary miniscule amounts of antimicrobial compounds only in response to the presence of additional humidity or bacteria. This ensures that the packaging can endure several exposures, and last for months.

FE: What foods can be protected by the material?

Chan: As the compounds combat any bacteria that grow on the surface of the packaging as well as on the food product itself, it has the potential to be used for a large variety of products, including ready-to-eat foods, raw meat, fruits and vegetables.

FE: How long does it take the material to decompose in the soil?

Chan: Depending on humidity and soil conditions, it could take a few months, to over a year, which is a fraction of what conventional plastics take to degrade if you think about it.

FE: Are any food companies experimenting with the product?

Chan: Yes, we are in talks with an urban farming company in Singapore, who hopes to use our packaging for their vegetables.

FE: What other potential food applications may be practical?

Chan: Depending on geographical location and applicable rules, it can be the one and only packaging that farmers need to bring their products to the supermarket shelves, heavily cutting down on the need for additional wrappings or plastics.

FE: When will this material be commercially available?

Chan: The team of NTU and Harvard Chan School researchers hope to scale up their technology with an industrial partner, with the aim of commercialization within the next few years. They are also currently working on developing other technologies to develop biopolymer-based smart food package materials to enhance food safety and quality.