Antimicrobial and biodegradable flexible food packaging developed | 06-02-2022 |

A team of scientists from Nanyang Technological University, Singapore (NTU Singapore) and Harvard T.H. Chan School of Public Health, USA, has developed a ‘smart’ food packaging material that is biodegradable, sustainable and kills microbes that are harmful to humans, they claim. It could also extend the shelf-life of fresh fruit by two to three days.

The water-proof 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.

In lab experiments, when exposed to an increase in humidity or enzymes from harmful bacteria, the fibres 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 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.

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.

In an experiment, strawberries that were wrapped in the packaging stayed fresh for seven days before developing mould, compared to counterparts that were kept in mainstream fruit plastic boxes, which only stayed fresh for four days.

The development of this advanced food packaging material is part of the University’s efforts to promote sustainable food tech solutions, that is aligned with the NTU 2025 strategic plan, which aims to develop sustainable solutions to address some of humanity’s pressing grand challenges.

“This invention would serve as a better option for packaging in the food industry, as it has demonstrated superior antimicrobial qualities in combating a myriad of food-related bacteria and fungi that could be harmful to humans,” explained Mary Chan, director of NTU’s Centre of Antimicrobial Bioengineering. “It could serve as an environmentally-friendly alternative to petroleum-based polymers,” she added.

“Food safety and waste have become a major societal challenge of our times with immense public health and economic impact, which compromises food security,” said Philip Demokritou, adjunct professor of environmental health at Harvard TH Chan School. “We used nature-derived compounds to synthesise smart antimicrobial materials, which can be used not only to enhance food safety and quality, but also to eliminate the harm to the environment and health, reduce the use of non-biodegradable plastics at a global level, and promote sustainable agri-food systems.”