Life cycle energy and carbon emissions of ergosterol from mushroom residues

Abstract

Food waste is a significant problem requiring appropriate disposal measures. Waste valorization via high-value component extraction is one of the most interesting solutions, as natural food additives are expected to be healthier and more sustainable than synthetic ones. Yet, the selection of the most adequate disposal option should take into account both the economic and environmental aspects. Thus, in this work the life cycle energy consumption and carbon emissions of the extraction of ergosterol from mushroom residues is assessed. To support the development of a natural ergosterol extraction process, a cradle-to-gate study was done, for a functional unit of 1 g of extract. Data was obtained from a lab-scale experimental unit, complemented with literature data and life cycle environmental data from EcoInvent V3.3. Both CED and IPCC 2013 methods were used. Results show that lyophilization, evaporation and ultrasound assisted extraction are the processes with the highest carbon emissions and primary energy. Moreover, electricity, which supports most processes, was shown to be a key hotspot for improvement. Thus, two alternative scenarios with electricity mix and source (local photovoltaic production) were considered. Results showed that local photovoltaic production can potentially reduce non-renewable primary energy by 77% and carbon emissions by 83%.