Fractionation of leaf proteins of lucerne (Medicago sativa) using organic solvents.

Proteins from lucerne juice were fractionated using iso-amyl alcohol, n-butanol, iso-butanol, ethyl acetate, diethyl ether, iso-propanol, ethanol and acetone, with % concn. ranging from 4 to 26 (v/v). Optimum pH for fractionation was 6.0-6.4. Yield of cytoplasmic leaf protein concentrate (LPC) decreased with increase in solvent level; with isoamyl alcohol, cytoplasmic LPC yield was max. (1.63 g/100 ml extract) at 10:0.40 (v/v) concn., whereas with ethyl acetate max. yield (1.51 g/100 ml extract) was at 10:0.75 (v/v) concn. Those solvents having limited water solubility brought more protein into the cytoplasmic fraction than water miscible solvents. Cytoplasmic protein concentrates did not have a green colour.