Corn fiber gum and milk protein conjugates with improved emulsion stability

Corn fiber gum (CFG), an alkaline hydrogen peroxide extract of the corn kernel milling by-product “corn fiber” was covalently conjugated with β-lactoglobulin (β-LG) and whey protein isolate (WPI). Covalent coupling of CFG to protein was achieved by dry heating reaction (Maillard-type) of CFG and protein mixtures (3:1) for up to 7 days at 75 °C and 79% relative humidity. The formation of the CFG and protein conjugate was confirmed by SDS–polyacrylamide gel electrophoresis. The conjugates as well as pure proteins and pure CFG were compared for their ability to stabilize oil-in-water (O/W) emulsions with 5% and 10% orange oil by turbidimetric and Dynamic Light Scattering (DLS) methods respectively. Measurements of turbidities, particles size distribution and average particle size in emulsions have shown that CFG–protein conjugates prepared by dry heating at 75 °C and 79% relative humidity for up to 2 days were more effective at stabilizing emulsions at room temperature than was CFG or protein alone.