Two hundred twenty-five million tons of plastic waste are produced globally in 2025, 33 percent of it from packaging. Most bioplastic alternatives claiming to solve this fail at one core problem: they protect food worse than conventional plastic and need industrial composting to break down. A University of Maryland team has developed a packaging film from natural materials that keeps cucumbers mold-free for 15 days and fully decomposes.
What's wrong with today's bioplastics
PLA, polylactic acid from corn starch, is one of the most widespread biopolymers. The material is biodegradable but only under industrial conditions: it needs temperatures of at least 60 degrees Celsius, available only at professional composting facilities. In home compost or landfills, PLA breaks down barely faster than conventional plastic. Ten U.S. states have no industrial composting facility at all. The material lands in waste despite green promises.
Plus: PLA underperforms polyethylene. As packaging film, it is less stable, less flexible, and lets more moisture and oxygen through. For fresh produce, it is barely suitable. The bioplastics industry faces a fundamental problem: whoever truly wants to replace conventional plastic must find material that is biodegradable and preserves better than plastic.
How chitosan and AI come together
Po-Yen Chen, assistant professor of chemical and biomolecular engineering at University of Maryland, has worked on this problem for more than three years. He chose chitosan, a natural polymer extracted from the shells of crabs and shrimp, typically waste from shellfish processing, and known for antibacterial and moisture-regulating properties. The problem: formulating a working packaging film from chitosan requires testing thousands of material combinations. Conventional methods would take 1.8 million years, Chen estimates.
Instead, his team built an AI-driven pipeline: machine learning predicted properties of different formulations, robots tested them physically, the system refined predictions based on results in a feedback loop. Within months, the team had a formula: chitosan combined with cellulose and other natural components from a library of 23 possible materials.
The result in comparison tests: cucumbers in the chitosan film stayed 15 days without mold or shrinkage. With conventional plastic film, the same cucumbers performed worse. Avocados also stayed fresher. The team now produces films one meter by one meter for commercial testing and has partnered with a chitosan producer using shellfish processing waste. First products are expected in specialized packaging channels by year-end 2026.
In comparison: Chitosan coatings and PLA's failure
Chitosan is not new to food preservation. A 2025 Scientific Reports study shows chitosan coatings—applied directly to food—extend avocado shelf life and leave no harmful residues. Coatings have a practical limit: they require application to each item individually and cannot function like rollable film on shelves. Chen's team makes a standalone film that handles like conventional plastic.
The direct comparison with PLA is clear. PLA thrives in niche markets like disposable cups and shipping cushions, but fails both core requirements for fresh produce: it preserves worse than polyethylene and decomposes only in industrial facilities, not home compost or landfills. The Maryland material aims to clear both hurdles.
What's needed until it reaches supermarket shelves
Before chitosan film appears widely, open questions remain. Raw material supply: Chitosan is shellfish processing waste, sustainably sourced. At global production scale, capacity could tighten if shellfish byproducts compete for new uses.
Cost: Polyethylene film costs pennies per square meter. Comparable cost estimates for chitosan film at industrial scale are missing. NSF and the University of Maryland funded the project with two million dollars to answer these economics questions.
Approval: A film in direct contact with food requires extensive safety testing in the EU and U.S. before commercial sale. Chen plans market entry by year-end 2026, initially in specialized distribution. Certification for broad retail is a further step.