Electrophoretic Properties, Functionality of Barley Protein Isolates

Three different protein fractions were isolated from barley bran and flour. Electrophoretic properties, including molecular weight and fraction patterns of barley protein isolates (BPIs), were characterized and examined by Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The functional properties of BPIs also were investigated, and then compared with soy, and zein protein. SDS-PAGE indicated that BPI-1 was albumin and globulin fractions together; BPI-2 was mainly composed by glutelin and a little hordein; BPI-3 was totally hordein fraction. Foaming capacity of BPI-3 was 18.5% higher than soy protein, about 7 times than zein protein. Foaming stability of BPI-3 was highest among these proteins. All BPIs had the equal emulsion capacity and stability as soy, which higher than zein protein. The water holding capacity (WHC) of BPI-2 was much higher than BPI-1, zein and soy, followed by BPI-3. BPI-2 and zein had the greatest oil holding capacity among these proteins.