Title : Use of compostable or recyclable material as a sustainable alternative packaging of sheeps cheese
Abstract:
Food industry is currently engaged in the search for new packaging alternatives that offer adequate food preservation, taking into account environmental aspects and consumer preferences. The work stems from the need to improve the sustainability of packaging in the local cheese industry in the Basque Country (northern Spain). Currently, cheese sector companies use nonrecyclable multilayer plastic (mixture of polyethylene and polyamide) to package cheese. The aim is to investigate the performance of two biodegradable compostable and two recyclable materials for packaging sheep´s cheese wedges as an alternative to conventional unsustainable plastics. In each case, two different packaging conditions were studied (vacuum and modified atmosphere (MA) with a 50/50% (v/v) mixture of CO2/N2 gas). Changes in the gas composition (O2/CO2) of theheadspace of the packaging, overall composition(percentages of protein, fat and dry matter), weight loss, pH, aw, colour (L*, a*, b*, yellow index (Yi) and yellowness index (Zi) parameters) , microbiology (count of total microorganisms, lactic acid bacteria, enterobacteria and Listeria) and sensory properties (texture, flavour, appearance of rind and paste, and holes) of the cheeses were investigated over 8 months of storage at 5±1ºC. Preliminary results showed that the changes in the headspace atmosphere observed were consistent with those described in our previous works in cheeses stored in different types of plastic materials (conventional and sustainable), although some differences in their behaviour were observed. Three materials showed a very similar evolution of CO2 over the storage period, maintaining a concentration of around 35%. On the other hand, in the case of the fourth material, a sharp decrease in CO2 concentration was observed from the first month of packaging, reaching concentrations of around 20%. In general, four materials showed similar behaviour for all physicochemical and colour parameters, as well as in sensory analysis of the cheeses. A downward trend was observed in b* and Yi color parameters in the modified atmosphere packaging condition compared to vacuum packaging, although the differences were not statistically significant. The evolution of lactic acid bacteria and the total microorganism count was similar in all types of materials and conditions, and with regard to Listeria and Enterobacteriaceae counts all samples analysed were found to be below the detection levels for the medium used. The results seem to show the possibility of using high-barrier biodegradable compostable or recyclable plastic materials with specific technical requirements,under the conditionsdescribed, for cheese packaging guaranteeing its safety and quality, while also taking into account environmental aspects and consumer preferences. Other aspects, such as commercial availability to ensure supply in the necessary quantities and formats, cost or consumer acceptance could also be decisive in selecting materials for commercial use in the sector.
