Legumin, or vegetable casein, is a protein substance analogous to the casein of milk, obtained from beans, peas, lentils, vetches and other leguminous seeds. It is a globulin and structurally similar to the 11S globulin family.
Properties
Karl Heinrich Ritthausen found legumin from peas, vetches, lentils, and field beans to contain the elements in the following proportions: carbon, 51.48%; hydrogen, 7.02%; nitrogen, 16.77%; and oxygen, 24.32%. Legumin is soluble in water,and is soluble in very weak acids and alkalies; and it is not coagulated by heat.
It resembles the casein of mammalian milk, with which it was considered identical by Liebig and others, and was therefore called “vegetable casein.” It contains less carbon and more nitrogen, however, than true casein. Upon treatment with sulphuric acid, legumin gives leucin, tyrosin, and glutamic and aspartic acids.