Packaging made of board can replace plastic but demands smarter coatings
Recent studies show that cellulose-based food packaging may replace plastic, but it is not suitable for all types of food. The coatings applied to packaging trays must fulfill high requirements if they are to resist moisture and provide effective gas barriers.
Barrier properties refer to how well a material prevents gases, moisture, light, odours and fats from passing through the packaging.
Global plastic consumption must be reduced. In food packaging, this can be achieved either by replacing plastics with alternatives such as cellulose-based materials or by using recycled plastics.
Nofima scientist Agnete Jordhøy Lindstad has investigated in her doctoral work, how cellulose-based packaging—such as paper and board—can act as a substitute for plastics in food applications. The main challenges are that paper and board do not withstand moisture and generally possess poor barrier properties. She explored whether a barrier coating between the cellulose and food could endow the packaging with the same performance as plastic. She tested several coatings based on various materials.
Not all barrier coatings are suitable for food contact
“It is not sufficient to develop a material that looks promising in laboratory conditions. We need to understand how the packaging handles contact with relevant foodstuffs and, in particular, how it responds to fat and moisture—such as drip loss from meat,” explains Agnete.
Much of the research in this field has focused on new coatings derived from plant starches, alginate from seaweed, or chitosan from shellfish. Yet there are limited studies assessing how these coatings perform in practice, that is, as packaging in direct contact with different foods.
Agnete has conducted tests on actual food items. She has, for example, stored butter, cream cheese and mayonnaise in contact with cellulose-based materials with a range of coatings. These packaging materials were stored under refrigerated conditions for up to nine weeks. The packaging with biodegradable coating performed well with butter, but less so with cream cheese and especially mayonnaise. In the case of mayonnaise, the packaging actually disintegrated. In contrast, coatings made from non-biodegradable plastics performed adequately, with just small differences between the foods.
“It is crucial to consider environmental impact in a broader context. A more environmental-friendly material is not a more environmental-friendly solution if it leads to reduced food quality and a shorter shelf life—as this may increase food waste and burden shifting” highlights Agnete.
Three key challenges: gas, moisture and fat
The cellulose-based packaging and its coating must not only withstand moisture and fat but also act as a barrier to the gases used when packaging certain foods, such as meat and fish.
To extend the shelf life of foods, modified atmosphere packaging (MAP) is often used. In this technique, the packaging is filled with a gas mixture that slows bacterial growth and keeps the food fresh for longer. For MAP to be effective, the packaging must provide sufficient gas barrier to keep the gas inside and be securely sealed. This remains a challenge for cellulose-based materials. In addition, packaging for foods like meat and fish must tolerate both moisture and fat that could otherwise compromise the level of protection.
Agnete has tested cellulose-based trays with various plastic coatings for packaging chicken, beef and salmon using MAP. Salmon is particularly challenging because it is both fatty and moist, making it an interesting test case for this type of packaging.
“In one experiment, we used a recyclable plastic coating, which performed well in maintaining food quality overall, though especially with salmon the trays lost some of their shape and strength. In other trials, we tested biodegradable coatings. We succeeded in developing a cellulose-based tray with a biodegradable coating that worked for MAP and maintained the seal for the entire storage period—a result which has proven difficult to achieve to date,” Agnete notes.
A key finding from this doctoral work is that, despite providing a good oxygen barrier and strong sealing, high carbon dioxide (CO₂) permeability can limit the suitability of the packaging for MAP. Previously, it was believed that the balance between CO₂ and oxygen permeability was relatively stable across packaging materials.
She also emphasizes that the CO₂ barrier is not adequate, and this leads to shortened shelf life. This is an important consideration because meat and fish are typically packaged using CO₂ to extend their shelf life. Even though the packaging provided a solid oxygen barrier and seal, CO₂ transmission still occurred. While oxygen permeability is often measured, it is equally important to test how well the packaging retains CO₂.
The way forward towards more sustainable packaging
Agnete continues as a scientist at Nofima following her doctorate, with ongoing work to reduce the use of plastics without compromising food quality and shelf life. Her research will further examine how cellulose-based materials with bio-based and biodegradable coatings can be used to package moist and fatty foods such as meat, fish and cheese. An important objective is to identify coating materials that can prevent excessive CO₂ permeation, enabling optimal performance for foods requiring MAP.
“Our aim is to develop packaging that protects both the food and the environment. Collaboration with industry partners and continuous practical testing are essential to succeed with these solutions,” Agnete concludes.
Research facts
This work forms part of the doctoral thesis of Agnete Jordhøy Lindstad, entitled Cellulose-based materials coated with biodegradable and non-biodegradable barrier layers: Suitability for packaging food in challenging applications.
Agnete defended her thesis on Wednesday, 25 June 2025.
The principal supervisor was Senior Scientist/Associate Professor Marit Kvalvåg Pettersen (Nofima/NMBU); co-supervisors were Professor Elling-Olav Rukke (NMBU) and Senior Scientist Anlaug Ådland Hansen (Nofima).
The evaluation panel consisted of:
Professor Johan Tryding, Lund University, Sweden;
Professor Eva Falch, NTNU;
Professor Tove Guldbrandsen Devold, NMBU.
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