AUSTRALIA – Researchers at Australia’s Deakin University have developed a sustainable antimicrobial food packaging prototype that can increase product shelf life to minimize food wastage and illness.
The research was led by the university’s Consumer, Analytical, Safety and Sensory Food Research Centre’s Ph.D. researcher Agnes Mukurumbira.
Mukurumbira aimed to understand how to utilize plant-based antimicrobials for killing fungi and bacteria that grow on food and result in 1.3 billion tonnes of food wastage and 600 million cases of foodborne illnesses, annually.
To develop this antimicrobial food packaging, Mukurumbira said the first ingredient required was a suitable antimicrobial.
She said: “In my study, we are using native Australian essential oils Tasmanian mountain pepper and lemon myrtle for sustainability reasons and due to growing demand for natural products.
“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.
“It turns out their 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.”
After confirming the antimicrobial effectiveness of the oils, Mukurumbira, in collaboration with her team, worked to address the chemical and physical instability and the strong odour issues of these oils by utilizing the ‘encapsulation’ technique.
Mukurumbira added: “Encapsulation is essentially trapping the oil in some sort of wall material. We successfully encapsulated oils giving them stability and allowing for controlled release.”
The team found that the process of encapsulation helped in enhancing the oils’ antimicrobial activity.
In the final steps of the process, the team integrated these encapsulated essential oils into biodegradable plastic formulations, which helped in producing a new form of packaging that releases essential oils, inhibits/kills bacteria and fungi growing on food, as well as extends the shelf life of products.
‘Self-healing’ mineral plastic
In another development, Scientists at the University of Konstanz have developed a ‘self-healing’ mineral plastic that can be formed and reformed in water, enhanced with bio-based building blocks for degradability in the natural environment.
According to its developers, the plastic is energy-efficient, as it can be developed at room temperature in water without the need for toxic solvents. It is also said to be non-flammable and firmer than commonly utilized alternatives.
Before it is hardened, the plastic can be shaped to fit the needs of individual products, with its texture compared to that of chewing gum.
It can be restored to this state and reshaped at any time by adding water, which is thought to make it a circular material.
Although a research team led by Konstanz chemist Helmut Cölfen originally developed a similar plastic back in 2016, this initial material was difficult to biodegrade.
Therefore, Cölfen and postdoctoral fellow Ilesha Avasthi have headed further research for an alternative basic building block to maintain the mechanical and sustainability-minded features of the previous design while achieving microbiological degradability.
“Previously, we used polyacrylic acid to produce our mineral plastic,” Cölfen explains. “Chemically, this acid has the same backbone as polyethylene, which is known to cause major problems in the environment because it is hardly biodegradable.”
The team also worked with Dr. David Schleheck and postdoctoral fellow Harry Lerner from the Department of Biology to test the biodegradability of the whole plastic rather than its components.
Degradation experiments reportedly proved that microorganisms found in forest soils completely degraded the plastic after 32 days.
For all the latest packaging and printing industry news from Africa and the World, subscribe to our NEWSLETTER, follow us on Twitter and LinkedIn, like us on Facebook, and subscribe to our YouTube channel.
