Rapid Protein Extraction from Canola Meal Pre-Treated with Enzymatic Reactive Extrusion

Abstract

Conventional alkaline extraction of plant proteins typically requires highly alkaline conditions (pH ≥ 11) and extended extraction times (~1 h). Although protease addition can lower extraction pH and improve functionality, it often requires prolonged hydrolysis. In this study, enzymatic reactive extrusion (eREX) using Alcalase, followed by a short duration alkaline extraction (5 min, pH 9), was evaluated as an alternative approach for producing protein-rich extracts from canola meal. The eREX process increased protein recovery by 48% and 42% compared with alkaline extraction conducted without and with Alcalase, respectively. The resulting powdered extracts reached a protein content of up to 49% and consisted primarily of partially hydrolyzed proteins (10–23 kDa) with increased surface hydrophobicity. Amino acid analysis showed substantial enrichment of essential amino acids, particularly histidine and sulfur-containing amino acids. Functional properties were improved, including enhanced solubility across pH 2–10, high foaming stability (88%), and increased oil-binding capacity (~5.5 g g−1), while in vitro digestibility remained comparable (~85%). Techno-economic analysis indicated reductions in water use (~11%), energy consumption (~48%), and production cost (16–25%). Overall, eREX provides a rapid, higher-throughput, and cost-effective strategy for producing premium canola protein ingredients.