Agnes Mukurumbira from the Deakin CASS Food Research Center makes the food packaging prototype using native Australian essential oils. She is investigating using plant-based antimicrobials to help kill the bacteria and fungi that grow on foods. 

Food microbes are responsible for over 1.3 billion metric tons of food waste and 600 million cases of foodborne illnesses annually.

“It turns out [the essential oils] activity is better than tea tree oil, which has historically been used extensively as an antimicrobial. We also stumbled upon the fact that not only are these oils antimicrobial in the liquid phase, but their volatiles, or gases they release, are equally as effective,” she explains.

Oiling up
The research into antimicrobial activity to create more durable food packaging expands on Mukurumbira’s previous research. She explored using starch nanocrystals to improve the physicochemical properties of biodegradable food packaging, such as strength and durability and water and oxygen permeability.

“From the findings of my first study, we now know that these essential oils are potent antimicrobials against common food spoilage and pathogenic bacteria and fungi,” says Mukurumbira.

Three Minute Thesis winner develops food waste prevention packaging.“In my study, we’re using the native Australian essential oils Tasmanian mountain pepper and lemon myrtle for sustainability reasons and due to the growing demand for natural products.”

The Australian essential oils’ antimicrobial activity was confirmed through research, leading to addressing the problems of the oils’ chemical and physical instability and strong odor using a technique called encapsulation.

“Think of a chocolate truffle with a gooey center, but in nanometre size. We successfully encapsulated the oils giving them stability and allowing for controlled release,” explains Mukurumbira. 

Mukurumbira describes encapsulation as trapping the oil in “some sort of wall material.” The encapsulation enhanced the oils’ antimicrobial activity as an unexpected result.

Looking forward
Next, the encapsulated essential oils will be integrated into biodegradable plastic formulations to produce packaging that will release the essential oils, killing or inhibiting the bacteria and fungi growing on food and extending product shelf life.

“I took part in the competition because I realized that public perception and ultimate acceptance of science depends on our ability to articulate or interpret our heavily scientific work. So this was an opportunity to use my science communication skills and translate my work into a language everyone can understand,” concludes Mukurumbira.

The essential oils have the potential to be implemented on food packaging worldwide to reduce the rates of food waste while shiting the packaging industry away from other more environmentally damaging solutions that are typically used to preserve food, such as plastic.