Environmental impact assessment of producing frozen spinach in central Italy

Abstract

Europe has increased its production, processing, and export of vegetables in recent decades due to changing dietary patterns supporting a greater consumption of vegetables high in nutrition. The growing interest in environmental issues has led to advocacy for sustainable vegetable production and consumption. Thus, this study assessed the ecological impacts of producing 1 kg of frozen spinach (functional unit) by a food processor in central Italy (cradle-to-factory gate approach). We evaluated the global warming potential (GWP) for distributing the final to different destinations. We also compare the potential environmental credits for different spinach residue management strategies, residue reduction through improved process efficiency, and as a feedstock for biogas production (avoided maize silage) based on the total volatile solids content. The life cycle assessment was used following the CML_IA impact assessment method based mainly on primary data related to 2019/2020. The GWP was 1.55 kg CO2eq. with respect to the functional unit. Excluding the dominant cultivation phase, packaging, particularly corrugated board boxes, electricity, and wastewater treatment were significant contributors across the midpoint impact categories assessed. The GWP for distributing the packaged frozen to Australia was 24 times more impactful than regional inland distribution. When spinach residue is reduced to 20% and 10%, total impacts for all impact categories also decrease by 12% and 22%, respectively. The benefit of using the current amount of spinach residue to produce biomethane was less than 7% across all impact categories except terrestrial ecotoxicity (13%). Therefore, reducing spinach waste along the processing line and efficient end-of-packaging life management through recycling and reuse by the manufacturer can considerably reduce the environmental impacts of frozen spinach.