Food Process Sustainability: a Life Cycle Assessment of a supercritical CO2 packaging technology for the preservation of squash

Food waste reduction is an essential priority in driving global environmental sustainability since nearly one-third of food grown for human consumption, representing an estimated 1.3 billion tonnes annually, is lost or wasted during the supply chain (FAO, 2011). These inefficiencies contribute to around 8–10% of world greenhouse gas emissions, freshwater abstraction, soil loss, and loss of biodiversity, all worse with population growth, increase in world temperature, and diminishing reserves of arable lands. Reduction of food loss and waste reduces environmental impacts, enhances resource efficiency, and accelerate the transition to sustainable food systems. Some of the most promising options are the innovative preservation and packaging technologies that enhance shelf life, ensure food quality, and minimize loss due to spoilage. This thesis evaluates the environmental performance of one such emerging preservation technology, Supercritical Carbon Dioxide (ScCO₂) Packaging. The technique employs the supercritical state of CO₂, with gas-like diffusibility and liquid-like solvation, to preserve the sensory and nutritional qualities of fresh-cut produce and is not based on heat or chemical preservatives. The system boundary followed was cradle-to-gate, and the functional unit was defined as 1 kg of packaged fresh-cut squash (Cucurbita moschata). Primary data were obtained from a pilot CO₂ packaging facility, complemented by peer-reviewed literature and further sources to represent the whole system in the LCA. The LCA encompasses phases like cultivation and harvesting of squash, transportation, scCO₂-based preservation and packaging, production of packaging material, and end-of-life treatment of packaging and food waste. The sensitivity analysis was used to compare the use of fossil-based with biogenic sources of CO₂. Furthermore, shelf-life differences within the packaging technologies were also assessed to estimate their impacts on food spoilage and subsequent environmental impacts. For comparison, data for Modified Atmosphere Packaging (MAP), utilising unaltered ambient air, were acquired from the same source as the ScCO₂ Packaging data. Conversely, figures for Vacuum Packaging (VP), involving removal of air to suppress aerobic microbes, came from another source. Baseline analysis indicates that ScCO₂ Packaging holds moderate environmental burden with hotspots being CO₂ release and pressurization energy. However, if functional value in the form of shelf-life extension and reduction in spoilage is considered, ScCO₂ Packaging surpasses both, due to lower value-chain losses and less utilisation of resources. Plus, using biogenic CO₂ increases its sustainability further by minimizing its carbon footprint. For its full potential, future studies should investigate its scalability in foods of different matrix structures, its industrial applicability in terms of cost-effectiveness, as well as integration of renewable resources to further improve its environmental sustainability.