A new study from researchers at the University of Seville’s Department of Microbiology and Parasitology in Spain brings much-needed clarity to a question that has concerned many in the celiac disease community: Can biodegradable or compostable plates made from plant-based materials contaminate gluten-free foods?
As eco-friendly tableware becomes more widely used in restaurants, schools, catered events, hospitals, and take-out settings, understanding whether these products are safe for people with celiac disease is increasingly important. This new research, published in the Journal of Agricultural and Food Chemistry, is the first to thoroughly evaluate gluten transfer from biodegradable tableware under real-world conditions.
The researchers examined eight types of biodegradable plates, cups, and straws made from materials such as wheat straw, wheat pulp, palm leaf, and sugarcane. They analyzed both the gluten content of the tableware itself and whether gluten could migrate into gluten-free foods such as milk, vegetable cream, omelet, and rice. While several items were made from wheat or wheat by-products, only one product identified as “dish 5” contained significant gluten, and it was the only item marketed as an “eatable.” This product contained an extremely high gluten concentration of about 48,000 mg/kg, making it a genuine hazard for anyone with celiac disease if eaten.
When gluten-free foods were placed on this eatable wheat-based plate, gluten transferred into the food at levels far above the gluten-free standard of 20mg/kg. The study also showed that gluten migration depended heavily on the food matrix, contact time, and temperature. Liquid and emulsified foods like milk and vegetable cream were far more susceptible to gluten transfer than solid foods, especially because they spread across the plate’s surface and interacted more readily with its material. Hot foods or foods briefly heated on the plate absorbed significantly more gluten than foods kept at room temperature. And in many cases, gluten transfer increased with longer contact times, meaning even short exposure could cause contamination, while prolonged contact made the problem worse. These findings underscore that the risk is not only the presence of gluten in the plate but also how the food behaves on it.
Importantly, all of the other biodegradable items (even those made from wheat straw or wheat pulp but not designed to be eaten) tested below detectable gluten levels and did not transfer gluten into food. This means the primary danger identified by the study is specifically tied to biodegradable tableware intended to be “eatable.” However, the authors note that “it cannot be ruled out that other non-eatable tableware made from wheat or by-products might also transfer gluten to foods.”
The research also highlights a major regulatory gap: Food products must clearly label allergens, but food-contact materials like biodegradable plates are not required to disclose whether they contain wheat, gluten, or other allergens. The study documented that the eatable wheat-based dish softened and partially disintegrated when in contact with hot or liquid foods, making contamination even more likely.
For now, the guidance is simple and essential: If a biodegradable product is made from wheat and labeled as “eatable,” people with celiac disease should not use it to serve gluten-free food and should not eat it if it is marketed as “eatable.”
Until allergen labeling is required for biodegradable and compostable tableware, it is safest to choose alternatives such as palm leaf or other verified gluten-free materials. This study provides strong evidence that sustainability efforts must be paired with clear safety standards to protect medically vulnerable communities.