Effect of different solvents on protein recovery and neurotoxin and trypsin inhibitor contents of grass pea (Lathyrus sativus)

Abstract

AbstractThe efficiencies of several solvent systems for the solubilization of grass pea (Lathyrus sativus) proteins and for the removal of the neurotoxin, β‐N‐oxalylamino‐L‐alanine (BOAA) and trypsin inhibitor were investigated. On a seed protein basis, over 700 g kg−1 protein was recovered under alkaline conditions, 610 g kg−1 using isoelectric protein precipitation and about 500 g kg−1 in sulphate salts of sodium and potassium. Grass pea proteins were least soluble in the sodium acetate system. In contrast to the trypsin inhibitor that was concentrated in the protein isolates, BOAA levels decreased by about 50–85% depending on the extractant used. A characteristic SDS–PAGE profile of sodium‐acetate‐extracted proteins demonstrated their being soluble to a greater degree at pH 4–6, while the others showed a minimal protein solubility around pH 5.0.