Designing sustainable circular bioeconomy solutions for the pulse industry: The case of crude pea starch as a substrate for single cell protein production.

Valorization of crude pea starch has become a key focus in the pea industry's sustainability pursuit. This study aimed to explore the circularity potential of crude pea starch as a nutrient-dense substrate for the solid-state cultivation of yeast (Saccharomyces cerevisiae) Single Cell Protein (SCP). Following the ISO 2006:14040/44 standard, a life cycle assessment (LCA) was performed to ascertain the environmental performance and operational dynamics of baseline and scenario pea starch-based yeast SCP process designs and identify optimal design considerations. Results demonstrated a higher relative contribution to the toxicity categories, with a relatively less contribution to global warming and land use. The distribution and media enrichment processes were identified as the hotspots, contributing about 32-55 % and 40-56 % to global warming and land use, respectively. Generally, train and air freight were more sustainable than lorry freight, respective of mileage and mass. Regarding system alteration, eliminating the media enrichment process could offset about 26 % of land footprint, with a similar trend for most impact categories. Process benchmarking showed up to a 3-fold reduction in global warming impacts relative to soybean meal, and about 71 % offset relative to fishmeal. Consequential LCA showed a general sustainability preference for substituting the aquacultural feeds with pea starch-based SCP, with a stronger emphasis on fishmeal substitution. Overall, these findings highlight the potential of the proposed SCP design as a sustainable upcycling solution with substitutionary potentials for conventional food and feeds, recommending further exploration in value and wealth creation.