Transforming oilseed blends: the impact of low-moisture extrusion on antinutritional factors, protein structure, and nutritional value

Oilseed cakes from hemp, rapeseed, and flaxseed are protein-rich, sustainable sources but are limited in food applications by antinutritional factors. This study blended meals from these oilseeds with pea or hemp protein ingredients (50:50 w/w) and applied low moisture extrusion (10 % and 20 %) at 122 °C to investigate their impact on physicochemical characteristics of oilseeds blends. Extrusion preserved protein content, reduced protein solubility by up to 44.5 %, and improved in vitro digestibility by up to 13.5 %. Antinutritional factors, including polyphenols (-10.18 % to -52.80 %), saponins (-4.48 % to -21.31 %), condensed tannins (-20.37 % to -41.05 %), and trypsin inhibitors (-2.26 TIU/mg to -13.31 TIU/mg), were significantly reduced, though phytic acid content was less affected. Extrusion decreased surface hydrophobicity, disrupted protein-protein interactions, altered secondary structures, and retained protein profiles under reducing conditions. These findings provided valuable scientific insights into the application of extrusion in enhancing nutritional value and modifying structure of plant-based meat alternatives.