The circumstances circling the simple act of storing your food plagues kitchens the world over. Diners and chefs are in a constant race against time, scouring their shelves and cabinets for the nearest film that they can then use to wrap around their fresh meat or produce, ready to be used again in the next meal.
Of course, given the plastic nature of the film, the continuous usage of it contributes to the build-up of plastic waste on our planet’s surface. Using the common biodegradable alternatives, however, also usually involve a trade-off, either on the quality of packaging or with some other metric.
Luckily for intrepid chefs or food connoisseurs, scientists from Harvard University and Nanyang Technological University are on the case. For them, the solution may lie not too far from your last dinner plate: it’s in corn, as it turns out. Their novel research was published in the journal ACS Applied Materials & Interfaces.
The base fibers of the novel polymer film were made from zein, a corn protein. Along with other naturally-derived polymers like starch and cellulose, the polymer itself was infused with naturally-occurring antibacterial compounds and was synthesized via electrospinning.
To test the biocompatibility and the functional properties of the resulting biodegradable film, the team placed the film around items like meat or fresh produce. Upon a rise in humidity, or when particularly harmful bacteria start to release enzymes near the film, it starts releasing its antibacterial compounds, which then immediately transfer to the food. This, according to the authors, keeps the food from spoiling.
The resulting film was also biodegradable, given the nature of its components; it also possessed eco-friendly production, as the zein used for the film was sourced from a material called corn gluten meal, which is a by-product of the ethanol production process.
“The sustainable and biodegradable active food packaging, which has inbuilt technology to keep bacteria and fungus at bay, is of great importance to the food industry,” said co-author Mary Chan-Park according to news source New Atlas. “It could serve as an environmentally friendly alternative to petroleum-based polymers used in commercial food packaging, such as plastic, which have a significant negative environmental impact.”
(To know more about plastics in packaging, check out our primer on plastic recycling numbers.)
References
- Aytac, Z., Xu, J., Raman Pillai, S. K., Eitzer, B. D., Xu, T., Vaze, N., Ng, K. W., White, J. C., Chan-Park, M. B., Luo, Y., & Demokritou, P. (2021). Enzyme- and relative humidity-responsive antimicrobial fibers for active food packaging. ACS Applied Materials & Interfaces, 13(42), 50298–50308. https://doi.org/10.1021/acsami.1c12319
- Coxworth, B. (2021, December 30). Corn-based biodegradable film shown to help fresh foods last longer. New Atlas. https://newatlas.com/materials/corn-biodegradable-film-food-spoilage/
- Keep food fresh with this bacteria-killing packaging. (2021, December 28). Nanyang Technological University. https://www.ntu.edu.sg/news/detail/bacteria-killing-food-packaging-that-keeps-food-fresh
