Effect of extraction method on functional properties of flaxseed protein concentrates

Physicochemical (zeta potential (ζ), conductivity, surface hydrophobicity (H0), protein solubility (PS)) and emulsifying (emulsion capacity (EC), droplet size, polydispersity (PDI), emulsifying activity (EAI), and stability (ESI) indexes) properties of alkali-(A-FPC), enzymatic-(E-FPC), and enzymatic-solvent-(ES-FPC) extracted protein concentrates from flaxseed meal (FM) were investigated and compared to commercial pea protein concentrate (PPC). The yield, composition, and properties of the protein concentrates were significantly influenced by the methods of extraction. All emulsions were similar in polydispersity with mono-modal droplet distribution and size of ⩽0.43μm that carried a net negative charge at neutral conditions (pH 7.0). A-FPC showed significantly higher H0 (66.14) than that of ES-FPC (52.63), and E-FPC (43.27) and was comparable to PPC (68.47). The highest solubility was found for E-FPC followed by A-FPC at neutral pH. A-FPC displayed significantly (p<0.05) the highest EC (87.91%), EAI (87.18m(2)/g) and ESI (12.51min) compared to the other protein concentrates.