Abstract
The composition of quinoa proteins has hardly been studied. We here applied an Osborne type extraction procedure. High protein yield and little protein denaturation was obtained with extraction (2x) with water followed by extraction (2x) with 0.4 mol/l sodium chloride. Albumins, globulins, prolamins and glutelins accounted for 41–50, 7–11, 4–6 and 14–16% of the total protein of four quinoa cultivars, respectively. Protein extracts were separated by size exclusion high performance liquid chromatography (SE-HPLC) with a sodium dodecyl sulfate containing elution medium. Electrophoretic separation followed by mass spectrometry allowed identifying the proteins in the Osborne type extracts. Aqueous extracts contained different chloroplastic and cytoplasmic enzymes as well as legumin-like and vicilin-like proteins. Dilute salt extracts mainly contained legumin-like proteins. Aqueous alcohol extracts contained small proteins while dilute base extracts proteins were similar to those present in the aqueous and dilute salt extracts. In one cultivar, only the monomer of the 11S globulin seed storage protein 2-like was observed while the other cultivars studied also contained its acidic and basic subunits separately. This SE-HPLC method allows analyzing food processing induced changes in quinoa protein extractability and size distribution.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have