Scientists in China have developed an edible, transparent, and biodegradable material that has high potential for use in food packaging.
Plastic food packaging accounts for a significant portion of plastic waste in landfills worldwide. With growing environmental concerns among consumers, researchers and producers around the world are increasingly looking for planet-friendly alternatives.
Now, scientists at the Chinese University of Hong Kong (CUHK) have developed an edible, transparent, and biodegradable material that they say offers significant potential for use in food packaging.
Bacterial cellulose
A team at CUHK has been working on bacterial cellulose (BC) – an organic compound derived from certain species of bacteria that has attracted attention as a sustainable, readily available, and non-toxic solution to the ubiquitous use of plastics. Professor To Ngai from CUHK’s Department of Chemistry and corresponding author of the underlying study explained that BC’s impressive tensile strength and high versatility are key to its potential.
To Ngai commented, “Extensive research has been conducted on BC, including its use in smart packaging, smart films and functionalized materials made by blending, coating and other techniques. These studies show the potential of BC as a replacement for single-use plastic packaging materials, making it a logical starting point for our research.”
Unlike cellulose, which is found in the cell walls of plants, BC can be produced by microbial fermentation, so there is no need to use trees or plants, making BC a more sustainable and environmentally friendly material alternative to plant cellulose. To date, the widespread use of BC has been limited by its unfavorable sensitivity to atmospheric moisture (hygroscopicity), which adversely affects its physical properties.
Innovative use of soy proteins
In the paper recently published in the SCI Journal of the Science of Food and Agriculture, CUHK researchers present a novel approach to overcome the limitations of BC-based materials. By incorporating certain soy proteins into the structure and coating it with an oil-resistant composite, the scientists were able to create an edible, transparent and robust BC-based composite packaging. Unlike other biologically produced plastics such as polylactic acid, the BC-based composite does not require special industrial composting conditions to degrade.
Other companies working in the area of sustainable alternatives to plastic packaging include Notpla in the UK and Sway in the US, both of which utilize seaweed / algae ingredients to offer solutions to the vast planetary disaster that is plastic pollution.
The researchers at CUHK are now looking into which direction to take the research. They hope to improve the versatility of modified BC films to make them suitable for a wider range of applications. In particular, they are focusing on developing a thermosetting adhesive that can create strong bonds between the bacterial cellulose so that it can be easily formed into different shapes when heated.
“One of the biggest challenges with films made from bacterial cellulose is that they are not thermoplastic, which limits their use in certain applications. By addressing this problem, we hope to make bacterial cellulose films more competitive with conventional plastics while maintaining their environmental friendliness,” Ngai explained.
Read more at www.cuhk.edu.hk/english.
