Researchers at Penn State have developed a process for creating milk protein and cellulose derived from plants that could potentially be used in the making of biodegradable and edible food packaging.

According to its developers, the process involves electrospinning, which uses a voltage to force a liquid solution into a cone shape that stretches and transforms into tiny fibers. Once the solution streams from an ejector, the researchers mixed the milk protein casein with hydroxypropyl methylcellulose, which is a plant-derived compound also known as hypromellose, to create nanofibers 1,000 times thinner than a human hair. Those fibers were then arranged into mats that could potentially be used in the making of products like biodegradable and edible food packaging.

Source: Journal of Colloid and Interface Science. DOI: 10.1016/j.jcis.2025.137601

"In a proof-of-concept study, we demonstrated the successful fabrication of stand-alone casein-rich electrospun mats. Protein-based electrospun nanofibers are highly sought after for their potential use in tissue engineering, biomedical applications such as wound dressings, and emerging roles in edible packaging, offering sustainable food preservation and safety solutions," the researchers explained.

The researchers determined that casein enriched with hypromellose could be successfully electrospun at cellulose-to-casein ratios as high as 1 to 4. Yet, fibers featuring the fewest beads, which are thickened, irregular sections and possess the greatest surface area, making them appropriate for inclusion in the mats, were spun from a solution featuring a cellulose-to-casein ratio of 1 to 12.

The team also discovered that at 100% relative humidity, the fiber mats chemically reacted to moisture and transformed into clear films that could potentially be used as food wrap.

Beyond food packaging, this material can also reportedly enhance food textures and nutritional values, and be incorporated into the making of glues, paints, paper coatings, cosmetics and pharmaceuticals.