PRODUCTION AND DEBITTERING OF EDIBLE OIL AND A PROTEIN-CONCENTRATE FROM SEEDS OF LUPINUS-MUTABILIS

Abstract

Lupine oil was produced from seeds of L. mutabilis using an extraction and refining process of soya oil. The refining included a step of debittering by washing with diluted acids. This decreased the alkaloid content from 0.14 % in the raw oil to 5 ppm in the endproduct, a content of rest alkaloids, which can be considered as unobjectionable. The oil alkaloids are not identical with those of the seeds. While in seeds Lupanin is the main alkaloid fraction, in the oil 13-Hydroxylupanin and N-Methyl angustofolin are dominant. The raw oil contained 800 ppm γ-Tocopherol 39 ppm α-Tocopherol. During the refining process the Tocopherol content decreased from about 840 ppm to 530 ppm total Tocopherol in the endproduct. The oil-cake contained about 4 % alkaloids. With aqueous alcohol (70 %−90 % ethanol) was debittered to a protein concentrate, which contained 73% protein and 0.06% rest alkaloids. By changing the pH value of the debittering medium both in the acid (pH 5) and alkaline (pH 9) range the alkaloid extraction could be improved and the loses of protein could be diminished. Qualitatively the alkaloid pattern of the protein concentrate was similar to that of seeds, although the hydroxylupanin fraction increased from 32.7% of total alkaloids before the debittering to 42.3% in the debittered concentrate. This is advantageous because the toxicity of hydroxylupanin is only about 1/10 of that of Lupanin.