Packaging materials designed for cured meat products: conventional and alternative solutions

Typical packaging types for cured meat products count on plastic multilayer, trays, and lids, which possess scarce sustainability due to their origin from non-renewable sources and recycling-related issues. In this context, the application of a thinner plastic multilayer, mono-material, paper, or bio-based packaging solution has recently emerged as an effective strategy to improve sustainability in the meat sector. In this context, this work aimed to study the optical, mechanical, and barrier properties of different packaging materials specifically used in cured meat products. Conventional tray solution is represented by a standard multilayer structure that consists of APET-PE/EVOH/PE, with four different alternative solutions: a thinner multilayer film (APET-PE/EVOH/PE), a mono-PET (PET/r-PET/PET), a paper-PE/EVOH/PE, and a compostable biopolymer derived from the polycondensations of diacids and diol. Similarly, standard PET-PE-EVOH and PET-PE-AlOx lids were compared with those based on SiOx-coated PET and a compostable biopolymer film. Regarding the optical properties of the tested material, a good UV-light (= 200 - 390 nm) screening ability was displayed. In particular, all the lid films showed high transmittance values (87 – 89 %) and, thus, notable transparency. As far as the tensile properties, tray films possessed good elastic modulus (E) ranging between 1900 and 2300 MPa. Remarkably, the compostable tray was characterized by the highest E value (4268 MPa), as well as by the lowest elongation at break value (B = 2.5%), caused by the high rigidity and the reduced degree of plasticity that distinguishes biobased polyesters. Lastly, no appreciable differences concerning oxygen (OTR = 0.05 - 3.18 cm3 m-2 day-1) and water vapor (WVTR = 0.86 - 4.97 g m-2 day-1) barrier properties of both lids and trays were noted although, in the case of CO2, a greater variability was detected (CO2TR = 4.32 - 18.19 cm3 m-2 day-1). The results achieved in this study demonstrated the potential of different alternative systems to replace current packaging configurations destined for perishable foods like cured meat products, moving forward in terms of sustainability for the industrial sector.