Research led by Youhong Tang at Flinders University is contributing to a growing body of work aimed at reducing reliance on conventional plastics by developing biodegradable alternatives made from widely available natural materials. The study explores how milk-derived proteins, combined with starch and nanoclay, can be engineered into plastic-like films that degrade in soil within a relatively short time frame.
Gomez Mesa, N. E., Pataquiva-Mateus, A. Y., & Tang, Y. (2025). Exploring Biodegradable Polymeric Nanocomposite Films for Sustainable Food Packaging Application. Polymers, 17(16), 2207. https://doi.org/10.3390/polym17162207
The work focuses on calcium caseinate, a compound derived from casein, the primary protein found in milk. Casein has long been studied for its film-forming properties, but on its own it lacks the mechanical strength and stability required for most packaging applications. To address this, the research team blended calcium caseinate with modified starch and bentonite nanoclay, while adding glycerol and polyvinyl alcohol to improve flexibility and durability.
Youhong Tang at Flinders University stated,
“Most of our single-use plastic comes from food packaging, so these sorts of options should be explored further and join the circular economy revolution to conserve resources.”
The resulting material forms a thin film with properties comparable to certain single-use packaging plastics. Laboratory tests showed that the film maintained sufficient strength and handling performance while remaining fully biodegradable. When placed in natural soil conditions, the material steadily broke down, with complete degradation expected in roughly three months.
The research was carried out at Flinders University in collaboration with chemical engineering researchers from Universidad de Bogotá Jorge Tadeo Lozano in Colombia. The international team brought together expertise in nanomaterials, polymer engineering, and biodegradable composites to refine the formulation and evaluate its environmental behavior.
A key aspect of the study was understanding how different components contribute to performance. Starch improved biodegradability and reduced material cost, while bentonite nanoclay enhanced mechanical strength and barrier properties. Nanoclays are often used in polymer composites to improve resistance to moisture and gas transfer, both important factors in food packaging. By carefully dispersing the nanoclay within the protein-starch matrix, the team was able to improve performance without compromising biodegradation.
Microbial testing was also conducted to assess whether the material introduced harmful biological effects. The researchers found that bacterial growth levels remained within acceptable ranges for biodegradable packaging materials that are not designed to inhibit microbes. This suggests the films do not introduce additional toxicity risks during decomposition, an important consideration for materials intended to break down in soil.
From an engineering perspective, the work highlights how combining biopolymers with naturally occurring fillers can address some of the longstanding limitations of biodegradable plastics. Many bioplastics degrade too slowly, lack strength, or require industrial composting conditions. The milk-based composite developed in this study shows that it is possible to balance mechanical performance with rapid breakdown under typical environmental conditions.
The motivation for this research is tied to broader concerns about plastic pollution and chemical exposure. Conventional plastics can contain a wide range of additives, including dyes, plasticizers, and flame retardants, some of which are associated with health and environmental risks. At the same time, global plastic production continues to rise, driven largely by single-use packaging.
While the new material is still at an early stage, the researchers see potential for further development, particularly for short-life packaging applications such as food wrapping or disposable liners. Additional testing will be needed to assess long-term stability during storage, resistance to moisture and temperature changes, and compatibility with existing manufacturing processes.
The study adds to ongoing efforts to rethink plastic design from a materials engineering standpoint. Rather than relying on petroleum-based polymers optimized for permanence, this work demonstrates how biodegradable materials can be engineered for functionality first, then designed to safely return to the environment at the end of their use.
Adrian graduated with a Masters Degree (1st Class Honours) in Chemical Engineering from Chester University along with Harris. His master’s research aimed to develop a standardadised clean water oxygenation transfer procedure to test bubble diffusers that are currently used in the wastewater industry commercial market. He has also undergone placments in both US and China primarely focused within the R&D department and is an associate member of the Institute of Chemical Engineers (IChemE).
