In Simple Terms
Researchers mixed an extract from a coastal Australian plant into a thin material made from seaweed. Some mixtures became stronger and stretchier, and let less water vapor through, but they still dissolved when submerged. The work points to possible future uses, not to a ready-made, proven-safe replacement for plastic packaging.
Researchers tested an extract from pigface, a coastal Australian plant, in thin films made from a substance derived from seaweed. Some recipes made the films stronger and more flexible, while reducing how much water vapor passed through them. But the films still dissolved when submerged in water. The findings suggest possible future uses; they do not mean that ready-to-use, safe packaging is now available.
Finding alternatives to plastic pollution takes more than choosing a material from a renewable source or one that can break down. A replacement also has to hold up in use and retain its useful properties under everyday conditions. That challenge led a team at the University of New South Wales in Australia to test an extract from a native plant in a gel-like material made from seaweed. The initial results were striking: among nine different formulations, one was about 38% stronger than a film made from the seaweed material alone. It also stretched nearly twice as far before breaking.
From Seaweed to a More Durable Film
The researchers used agar as the base for their experiments. Agar is a gel-like substance extracted from seaweed that can be formed into thin, transparent, biodegradable films. But those qualities do not automatically make it practical. A film made from agar alone can be brittle, break or crumble easily, and be affected by moisture. Those weaknesses make it harder to develop a material that can be carried, folded, or used to wrap a product.
Plasticizers—additives used to make some materials more flexible—are a common way to improve a material’s ability to bend. With that in mind, a team led by Dr. Rishi Ravindra Naik of the University of New South Wales School of Chemical Engineering investigated whether natural compounds in an Australian native plant could improve the films. The question was not simply whether the plant contained interesting substances, but whether adding its extract to agar would produce measurable changes in the resulting film.
The team chose pigface, whose scientific name is Carpobrotus glaucescens. This drought-tolerant succulent grows along Australia’s east coast. Its fleshy leaves contain natural compounds, including sugars, organic acids, and polyphenols. The researchers extracted material from the leaves and mixed it with agar to make nine film formulations. They then tested the films’ strength, flexibility, resistance to moisture passing through, and antioxidant activity.
The Middle-Strength Mix Came Out on Top
The results did not show that adding more extract consistently made the films better. In fact, a formulation with a moderate amount of pigface extract performed best overall. Increasing the amount did not bring further improvements; instead, it was associated with lower strength and flexibility. The experiment highlights an important detail in developing composite materials: a natural ingredient does not necessarily work better in larger amounts. Its effect may depend on the balance among the ingredients in a formulation.
In the best-performing formulation, the film was about 38% stronger than agar alone and stretched nearly twice as far before breaking. Its water-vapor permeability was also about 57% lower than that of an agar-only film, meaning that less water vapor passed through it in the test. The figures matter because they point to improvements in more than one property, rather than merely a change in the film’s appearance or feel.
But allowing less water vapor through does not mean the material became fully waterproof. Measuring vapor passing through a film is different from putting it in direct contact with liquid water. In the tests, the films still dissolved substantially when submerged. So the 57% improvement should not be taken as proof that the material is suitable for every type of packaging or will remain intact in damp conditions.
The team also found that the films retained some of the antioxidant activity associated with the plant extract. This suggests the extract affected more than just the films’ mechanical properties. However, that observation does not mean the material is a food product or that it has a proven health effect when used in packaging. It is an additional property observed by the researchers, and one that could merit further study.
Possible Uses—and Clear Limits
The films’ ability to dissolve in water limits their use in many conventional packaging applications, especially those where a wrapper must remain intact during prolonged exposure to moisture. At the same time, that quality could be useful for applications where a wrapper is meant to dissolve at the point of use. One possibility raised by the researchers is a dissolvable wrapper for products such as laundry detergent capsules, designed to dissolve during use rather than remain as a separate piece of packaging.
That possibility is still a concept for a material that might be developed, not an announcement of a finished product. The idea that it might leave no microplastic residue was presented as an expected advantage of a material that can dissolve and biodegrade, but that expectation does not replace testing how an actual product behaves under different conditions of use. Packaging for dry goods could be another avenue to explore, but the researchers say the material would need improvement and safety testing before it could be considered for contact with food.
Water remains one of the main questions future research will need to answer. Comparing vapor permeability with water solubility helps show that packaging materials have multiple properties: improving one does not eliminate challenges in another. The research, as reported, does not show that the films are ready to replace common plastic packaging directly. Instead, it demonstrates that plant compounds may improve some properties of agar while identifying a practical weakness that still needs to be addressed.
For that reason, Naik described the work as an early step. Turning a laboratory result into a material that can be used in practice will require a better understanding of how the extract’s components interact with agar, followed by tests of performance and safety for the intended applications. It is also important not to assume that a material is suitable for every use simply because it is plant-based or biodegradable. The right choice depends on the material’s properties, the product it will wrap, and the conditions it will encounter.
A Research Idea That Began with a Local Dish
The idea to study pigface began with an unexpected encounter at a food conference in Coffs Harbour in 2025. Naik attended a dinner featuring native Australian ingredients, prepared by Mindy Woods, a Bundjalung woman and former contestant on MasterChef Australia. Pigface was an ingredient in a salad served that evening. The plant caught the researcher’s attention; he knew little about it and became curious about its properties.
That curiosity led to a collaboration with IndigiGrow, an Indigenous-led nursery specializing in native Australian plants. The partnership contributed to a broader project examining pigface’s chemical composition and potential. Analysis found bioactive substances, including antioxidants, polyphenols, and other natural compounds. But the researchers did not treat the plant as risk-free simply because it is native or has a history of traditional use.
The analysis also detected arsenic in the plant material and highlighted pigface’s ability to absorb contaminants from its growing environment, including heavy metals. The researchers found higher levels of heavy metals in plants collected from more polluted sites. That makes knowing where the plant comes from an essential part of any future work, particularly if the goal is to develop a material that could touch food or be used in a consumer product.
This finding places a practical condition on expanding the plant’s use: knowing the species’ general composition is not enough. Researchers also need to consider where a sample grew and what contaminants it may have absorbed. Plant properties can vary with the environment, so the team emphasized the importance of verifying the source and conducting appropriate safety assessments before pursuing food-related applications. Useful compounds in the leaves do not rule out the possibility that unwanted substances have accumulated from the environment.
Indigenous Knowledge and a Voice in Decisions
Pigface has a long history in the lives of Indigenous communities in Australia, which have used it for food and medicine for generations. Researching a native plant, then, is about more than finding a new raw material. It also involves knowledge passed down long before modern research began, and communities that should have a say in how the plant is used and what opportunities emerge from that work.
The project was carried out with the consent of the Indigenous community. The research team said it wanted to share its findings so communities could make their own decisions about how the knowledge might be used and developed. IndigiGrow, led by Peter Cooley, a Bidjigal man, was part of that effort. Cooley said Indigenous communities have known pigface’s food and medicinal benefits for thousands of years, and that their interest in the project came from a desire to explore other ways the plant might be used in contemporary life.
At the same time, Cooley stressed that opportunities involving native plants should not become a way to exploit knowledge or resources while excluding the people who hold them from the benefits and decisions. This issue is not separate from the project’s science. Responsible collaboration means community involvement goes beyond providing samples or information; it includes a meaningful role in deciding what might be developed and how it can be used. The researchers also hope that exploring other native plants could create opportunities for small businesses led by Indigenous communities.
This approach connects two distinct but intertwined questions: Can the plant extract improve a biodegradable material? And who gets to decide how the knowledge and resources behind that development are used? The scientific answer is still incomplete. The team measured improvements in strength and stretch, as well as reduced water-vapor passage, but the films still dissolve in water and safety questions remain. The second question calls for continued partnership and for Indigenous communities to remain central to decisions and opportunities arising from any development.
The Bottom Line
A University of New South Wales experiment suggests that pigface leaf extract can improve some properties of agar films. In a formulation containing a moderate amount of extract, the film was about 38% stronger, stretched nearly twice as far as the baseline film, and had about 57% lower water-vapor permeability. Those results do not mean a commercial packaging material is ready: the films still dissolve when submerged, and the detection of arsenic and the possibility of heavy-metal accumulation make source verification and safety testing essential. The project points to a possible future for dissolvable packaging while underscoring the importance of respecting inherited knowledge—not a quick promise to replace plastic.