EXTRACTION AND ISOLATION OF PROTEIN FROM LUPINE (Lupinus termis L.) SEEDS

Abstract

Extraction and isolation of protein from lupine seeds by using distilled water, salt solution, and alkaline solution and precipitation with 0.1 N hydrochloric acid at pH 4.00, followed by centrifugation and freeze drying was studied. Extraction with water yielded 28.5%, with 5% sodium chloride solution 43.5% and with 0.1 N sodium hydroxide solution 79.7% protein. Alkaline solution was found most satisfactory for maximal extraction of protein from lupine seeds. The effect of various factors on the protein extraction, concentration of extractant, time of extraction and relative amount of solvent to dry seeds were also investigated. The digestibility of isolated protein - measured with in vitro enzymatic method - was high (90%).