A contribution to the standardization of methods for the preparation of seed proteins ofAllium cepa L.

The study of certain conditions for the extraction of seed proteins of Allium cepa revealed that the best extractibility of proteins is obtained by the use of a buffered physiological solution at 20 °C in comparison with TRIS-glycine buffer at 5 °C. Using potassium phosphate buffer with 0.01 M mercaptoethanol and 0.4 M NaCl, an amount of proteins by up to 25 per cent higher passes into solution as compared with the physiological solution, but these extracts are unsuitable for the electrophoretic separation in polyacrylamide gels. The defatting of the seed meal under low temperature did not affect the qualitative composition of the protein complex studied, the addition of a 1 per cent soluble starch to the polyacrylamide gel. improved its resolution.