Functional properties of protein fractions from gentle membrane separation of green biomass (legume grass) compared to traditional animal- and plant-based proteins

Legume grasses are rich in the functional protein ribulose-1,5-bisphosphate carboxylase/oxygenase, making legume grass concentrates (LGC) a promising ingredient for plant-based foods. To facilitate their industrial adoption, it is essential to understand their performance against established ingredients. In this study, LGCs were produced using multi-stage filtration without heat or acid, followed by freeze (LGC-F) or spray-drying (LGC-S). The two LGCs were compared to common protein ingredients (whey, egg white, soy, and pea). LGCs contained ∼60% protein (w/w), with LGC-F proteins remaining native, while LGC-S were denatured. LGCs exhibited high solubility (>90%) at pH > 6, comparable to whey and egg white. Moreover, LGCs formed gels at just 1.5% protein (w/w), while egg white required 5%. The foaming capacity of LGCs was similar to that of whey and egg white-based foams, although slightly less stable. LGC emulsions displayed small oil droplets; however, stability was compromised due to droplet growth within 14 days, similar to soy and pea emulsions. Importantly, the drying method did not impair the functionality of the LGC; hence, from an industrial perspective, spray drying could be an efficient method for large-scale production. Overall, the functionality of LGC aligns more closely with egg white and whey than with plant ingredients.