Life cycle assessment of protein extraction from microalgae biomass using ohmic heating

Abstract

Life Cycle Assessment (LCA) is an effective tool for assessing the environmental impacts associated with the implementation of innovative processing technologies in biotechnology. This study focuses on the life cycle environmental impacts of thermal protein extraction from microalgae biomass using ohmic heating. Coelastrella was selected as the model organism due to its double cell wall, which presents the worst-case extraction scenario. The environmental impact assessment was conducted using the ReCiPe 2016 method from an equalitarian perspective, encompassing eighteen environmental impact categories. The results demonstrate that applying an electric field of 217 V/cm during protein extraction significantly enhances extraction efficiency while simultaneously promoting a more environmentally sustainable performance. This is achieved through a rapid heating pulse that reaches a maximum temperature of around 100 °C, with a holding time of <1 s. In addition, an alternative energy scenario utilizing entirely renewable energy was evaluated for both the worst and best treatments identified in the LCA study, compared to the reference treatment. The results indicate improvements in at least fifteen of the eighteen indicators assessed under this renewable energy scenario.