Packaging materials designed for cured meat products: a comparison between conventional and more sustainable solutions

Introduction and motivation Common packaging types for cured meat products rely on plastic multi-material trays and lids, which possess poor sustainability because they are generally made from non-renewable sources and are difficult to recycle. In this context, using a thinner plastic multilayer, a mono-material, paper or biobased packaging solution has recently emerged as a valid strategy for increasing sustainability. Therefore, this work aimed to compare the functional properties (optical, mechanical, and barrier) of different packaging materials for cured meat products. Methodologies Conventional tray solution consisted of a standard multi-layer structure that is composed of APETPE/EVOH/PE, with 4 different alternative solutions: a thinner multi-layer film (APET-PE/EVOH/PE), a mono-PET (PET/r-PET/PET), a paper-PE/EVOH/PE, and a compostable biopolymer obtained by the polycondensations of diacids and diol. In a similar way, standard PET-PE-EVOH and PET-PE-AlOx lids were compared with those based on SiOx-coated PET, and a biopolymer film. Results Regardless of the tested material, a good UV-light (l = 200 - 390 nm) screening ability was displayed, whereas all the lid films showed high transmittance values (87 – 89 %) and, hence, remarkable transparency. As far as the tensile properties are concerned, tray films had good elastic modulus (E) ranging between 1600 and 2300 MPa. Interestingly, the compostable tray was characterized by the highest E value (4544 MPa), as well as by the lowest elongation at break value (eB = 2.5%), due to the high rigidity and reduced degree of plasticity typical of biobased polyesters. At last, no appreciable differences in terms of oxygen (OTR = 0.11 - 3.18 cm3 m-2 day-1) and water vapor (WVTR = 0.86 - 4.97 g m-2 day-1) barrier properties of lids were detected although, in the case of CO2, a greater variability was obtained (CO2TR = 3.20 – 19.74 cm3 m-2 day-1). Regarding tray materials, water vapor barrier properties showed the highest variability (WVTR = 3.96 – 25.80 g m-2 day-1). Significance of the work The results obtained in this study showed the potential of different alternative systems to replace current packaging configurations intended for perishable foods like cured meat products, so as to offer alternative and greener solutions for the industrial sector.