Material Properties of Paperboard With Biodegradable and Nonbiodegradable Coatings Affected by Storage Conditions and Contact With Selected Food Products

Sammendrag

This study aimed to evaluate the suitability of paperboard with biodegradable and nonbiodegradable coatings as alternatives to conventional plastics under realistic storage conditions and in contact with moist and fatty foods. Paperboard with biodegradable (PLA/PBAT) and nonbiodegradable (PET and PE) coatings in contact with mayonnaise, cream cheese and butter were stored under refrigerated conditions (4°C/85%RH) for 1, 3, 6 and 9 weeks. To evaluate the impact on functional properties, tensile strength, puncture resistance, water vapour transmission rate (WVTR) and thickness were measured before and after storage. The mechanical properties of coated paperboards were significantly affected by storage conditions and food contact. Moisture from humid air led to swelling of the cellulose fibres that caused structural changes and weakening. Paperboard with the biodegradable coating was more prone to weakening by food contact than by refrigerated storage alone, with mayonnaise having the greatest effect. For paperboard with the nonbiodegradable coatings, the impact of different foods was less pronounced. These materials generally experienced similar or less weakening from food contact than refrigerated storage alone, highlighting the effectiveness of the coating layers as barrier between moist and fatty foods and the cellulose fibres. These findings emphasise the need to test functional properties after storage under realistic conditions in contact with relevant food products for extended periods, when considering the feasibility of replacing plastic packaging with fibre-based alternatives.