Current usage of paperboard packaging: a case study of the European landscape on tomato packaging

Current pressures to decrease plastic packaging for food have resulted in increased demand for paperboard packaging of fruits and vegetables. Additionally, the new European Regulation on packaging waste calls for recyclable and for incorporation of recycled fibre in packages which challenges safety. Resistance in humid conditions is critical for paper-based packaging for fresh fruits and vegetables and cellulosic materials are typically chemically treated for improving these parameters. The content in recycled fibre also affects the resistance to moisture and as consequence the composition in additives required for sizing. It is recognised that several factors contribute to the behaviour of the paperboard, including the fibre origin, physic-mechanical treatments, bulk composition and material surface treatments. This work aimed at addressing the relationship between these factors, by conducting a deep physic-chemical characterisation of packages of cherry tomato collected in 4 European countries, in both high and low-cost supermarkets. Samples varied in terms of fibre origin, treatments (bleaching, printing), functional additives (surface or bulk agents). Statistical analysis demonstrated that it is possible to group samples according to different properties that are inter-related, such as the type of fibre and typical formulations (i.e. plasticizers and functional additives used). Materials varied significantly in their performance regarding the hydrophobicity character. Repulpability was also tested as step needed for recyclability. A number of chemicals of concern with Cramer class III toxicity such as mineral oil hydrocarbon, biocide, DiPN isomers and BPA replacers were observed across the samples. This work represents a concept study for larger inter-European studies and clearly points to the need for harmonization of practices and regulations for the utilization of paperboard as food contact material.