An improved method for isolation of β-lactoglobulin

A simple and useful method for β-lactoglobulin isolation from bovine whey is presented in this work. Differential precipitation with ammonium sulfate was used to isolate β-lactoglobulin from other whey proteins using 50% ammonium sulfate. The precipitate was dissolved and separated again using 70% ammonium sulfate, leaving a supernatant liquid enriched in β-lactoglobulin. After dialysis and lyophilization, isolation of the protein was performed by ion-exchange chromatography. This is a rapid, efficient and inexpensive two-step method that allows high homogeneous protein yield and has advantages over other methods since it preserves the native structure of β-lactoglobulin. The isolated product was compared with a commercial β-lactoglobulin standard that was also employed to induce mice polyclonal antibodies. Such antibodies were the tools for identifying the natural isolated β-lactoglobulin from bovine whey. Physicochemical and structural characterization of purified β-lactoglobulin is presented in this work.