Researchers in Australia have developed a method to convert food waste into bioplastic films using avocado peels, stale bread, and sago palm starch. According to the researchers, the approach is designed to be scalable and cost-effective, while addressing food waste and plastic disposal at the same time. The findings were published in the journal Matter.
The work was carried out by researchers at Deakin University, who note that the materials could be used not only for food packaging but also in biomedical, environmental, and pharmaceutical applications. "This method leverages underutilized waste materials, offering a cost-effective and environment-friendly alternative to conventional bioplastics," the researchers write. "The inherent biodegradability of the starch-based matrix further supports eco-friendly disposal and aligns with circular economy principles."
Globally, about one-third of all food produced is discarded each year, estimated at around 1.3 billion tonnes. Bread is one of the most commonly wasted foods in Australia, largely due to its short shelf life. Its high starch content has previously enabled the Deakin team to develop biodegradable plastic films from bread waste.
In the latest study, the researchers combined bread waste with avocado peels, another widely available by-product. Global avocado consumption generates large volumes of peel and pit waste. Avocado residues contain compounds such as antioxidants, carbohydrates, oils, and dietary fiber, which are being explored for use in food, cosmetic, pharmaceutical, and energy applications. Similar work has been carried out in Mexico, where avocado pits have been processed into biodegradable plastic products.
The Australian team applied a hydrothermal process to avocado peels to produce microscopic spherical carbon particles known as carbon dots. These were incorporated into a starch blend made from stale bread and sago palm starch. The resulting films showed improved mechanical strength compared to films made without carbon dots and reduced air permeability, a relevant property for food packaging. The films also demonstrated antioxidant and antibacterial activity.
According to the researchers, further work will focus on scaling up carbon dot extraction and film production, adjusting gas and moisture transfer through design changes, and testing the materials with real food products. As stated in the study, "Future work should focus on scaling up the [carbon dot] extraction and film fabrication process, optimizing gas and moisture transfer through multilayer or micro-perforated designs, and validating real-food applications, including fresh produce, meats, bakery items, and UV-sensitive snacks."
Source: Shima Jafarzadeh et al. Bioactive Bioplastic Films Incorporating Waste-Derived Carbon Dots and Starch for Sustainable Packaging. Adv. Mater. 2026. / Anthropocene Magazine
