Researchers in Singapore and the US claim to have developed a ‘smart’ food packaging material that could extend the shelf life of fresh fruit.
The team, from Nanyang Technological University (NTU Singapore) and Harvard TH Chan School of Public Health, said the packaging material is biodegradable, sustainable and kills microbes that are harmful to humans.
According to researchers, the material could extend the shelf life by two to three days. The natural packaging is made from a type of corn protein called zein, starch and other naturally derived biopolymers infused with natural microbial compounds. These include oil from the common herb thyme and citric acid commonly found in citrus fruits.
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Described in the news ACS Applied Materials & Interfaces, the material was produced by electrospinning the zein and antimicrobial compounds with cellulose, a natural polymer starch that forms the cell walls of plants, and acetic acid commonly found in vinegar.
Laboratory experiments showed that when exposed to increased humidity or enzymes from harmful bacteria, the fibers in the packaging release the natural antimicrobial compounds. This killed common dangerous bacteria that contaminate food, such as E. Coli and Listeria, as well as mold.
The nature-inspired packaging is designed to release the necessary miniscule amounts of antimicrobials only in response to the presence of additional moisture or bacteria, the team said. This ensures that the packaging can withstand multiple exposures and last for months.
Strawberries wrapped in packaging during an experiment stayed fresh for seven days before developing mold, compared to counterparts in regular plastic boxes that only stayed fresh for four days.
Co-leader of the project, Professor Mary Chan, director of NTU’s Center of Antimicrobial Bioengineering, said the invention is a better option for packaging in the food industry because of its “excellent” antimicrobial properties.
“The packaging can be applied to various products such as fish, meat, vegetables and fruits,” Chan says. “The smart delivery of antimicrobials only when bacteria or high humidity are present provides protection only when needed, minimizing the use of chemicals and preserving the natural makeup of packaged foods.”
Professor Philip Demokritou, adjunct professor of Environmental Health at Harvard Chan School, director of the Nanotechnology and Nanotoxicology Center, and co-director of the NTU-Harvard Initiative on Sustainable Nanotechnology led the research.
“Food safety and waste have become a major societal challenge of our time with a huge impact on public health and the economy, endangering food security,” noted Demokritou, adding that the team’s scalable material cannot be used alone. to improve food safety and quality, but also to improve food safety and quality. reduce the use of non-biodegradable plastics at a global level and promote sustainable agri-food systems.