ADSORPTION OF BETA-LACTOGLOBULIN ONTO THE SURFACE OF STAINLESS-STEEL PARTICLES

The adsorption of beta-lactoglobulin (beta-Lg), one of the main consti tuents of fouling deposits in milk processing, onto the surface of sta inless steel particles was studied under various conditions, The adsor ption isotherm of beta-Lg at 25 degrees C was of the Langmuir type, an d the plateau suggested that the surface was covered by a monolayer of beta-Lg, The amount of beta-Lg adsorbed steeply increased above 65 de grees C, At 75 degrees C, it increased almost linearly with the protei n concentration in the bulk solution. Heating and chemical modificatio n of the SH-group caused a much smaller amount of beta-Lg to be adsorb ed at 75 degrees C, These findings indicate that the thermal aggregati on of denatured beta-Lg at the surface is important in the adsorption, More beta-Lg was adsorbed at pH 4 than at pH 6.85, This suggests that the electrostatic interaction between beta-Lg and the surface contrib utes to the adsorption behavior.