Protein Fractionation of Green Leaves as an Underutilized Food Source—Protein Yield and the Effect of Process Parameters
Nynäs, Anna-Lovisa; Newson, William; Johansson, EvaAbstract
Green biomass has potential as a sustainable protein source for human consumption, due to its abundance and favorable properties of its main protein, RuBisCO. Here, protein fractionation outcomes of green leafy biomass from nine crops were evaluated using a standard protocol with three major steps: juicing, thermal precipitation, and acid precipitation. Successful protein fractionation, with a freeze-dried, resolubilized white protein isolate containing RuBisCO as the final fraction, was achieved for seven of the crops, although the amount and quality of the resulting fractions differed considerably between crops. Biomass structure was negatively correlated with successful fractionation of proteins from biomass to green juice. The proteins in carrot and cabbage leaves were strongly associated with particles in the green juice, resulting in unsuccessful fractionation. Differences in thermal stability were correlated with relatedness of the biomass types, e.g., Beta vulgaris varieties showed similar performance in thermal precipitation. The optimal pH values identified for acid precipitation of soluble leaf proteins were lower than the theoretical value for RuBisCO for all biomass types, but with clear differences between biomass types. These findings reveal the challenges in using one standard fractionation protocol for production of food proteins from all types of green biomass and indicate that a general fractionation procedure where parameters are easily adjusted based on biomass type should instead be developed.
Keywords
leaf protein extraction; RuBisCO; green biorefinery; leaf protein concentrate; white protein precipitation; thermal protein precipitationPublished in
Foods2021, volume: 10, number: 11, article number: 2533
Authors' information
Sustainable Development Goals
SDG2 Zero hunger
UKÄ Subject classification
Agricultural Science
Publication Identifiers
DOI: https://doi.org/10.3390/foods10112533
URI (permanent link to this page)
https://res.slu.se/id/publ/114313