Performance Assessment and Lab‐Scale Economic Evaluation of Alkaline Extraction and Comparative Precipitation of Cyanobacterial Proteins

Algal proteins from cyanobacteria serve as a natural source of biopolymers. The principal challenge manifests as nonoptimization of unit operations in downstream process accounting for higher costs. This study focuses on process assessment of unit‐operations for selecting suitable recovery strategies not only based on yield, but also considers economic feasibility, process sustainability (evaluated by Analytical GREEnness calculator) and potential industrial applicability. The extracted proteins from Spirulina platensis are termed as “cyanobacterial proteins.” S. platensis is renowned for high protein content of ~70% (w/w). Total yield from alkaline extraction was 319.17 mg/g dry weight at 40°C for 90 min treatment. The observed yield at different processing parameters was observed as 187.43–319.17 mg/g dry weight representing process‐performance variability. Extracted protein at optimal parameters was precipitated using different precipitating agents. The highest recovery was obtained by acid‐based (~89.46%) followed by solvent‐based (85.95%) and salt‐based (83.54%) precipitation. Further, functional group analysis by Fourier‐transform infrared spectroscopy showed similarity with commercial whey protein. Additionally, process performance of process was evaluated by comparing yield, recovery, and associated cost contributions of extraction and precipitation stages. Protein precipitation by acids was comparatively cost‐effective compared to precipitation by salts and solvent. Additionally, Analytical GREEnness demonstrated a moderate level of green performance.