Extraction and characterization of four proteins from wheat bran by Osborne

Wheat gluten is a kind of plant protein,studying the composition and properties of wheat gluten so as to be applied to the food industry.Four proteins including albumin,globulin,prolamin and glutenin were extracted from wheat bran by the Osborne method,with Coomassie brilliant blue measuring isoelectric points.Experimental results showed the relative contents of albumin,globulin,prolamin and glutenin were 48.06%,25.12%,18.70%,8.12%,and the isoelectric points were 4.0,5.0,5.8,5.2,respectively.The electron microscopy showed both albumin and globulin molecules were closely connected. Albumin surface meticulous and multilayer,with holes locally. Globulin surface loose and less holes. Prolamin and glutenin molecules were loosely connected. Prolamin appeared irregular globular,while glutenin surface smooth with many molecules. Functional properties showed globulin possessed both the highest waterbinding capacity( 5.00 g / g) and the best holding oil capacity( 2.40 g / g),while prolamin held the strongest foaming capacity( 376%) and stability( 71%),and the highest emulsibility( 75%). Therefore,globulin was suitable as additives in meat products,and Prolamin was suitable as additives in dairy and cake recipe.