Adsorption of Protein by Bentonite in a Model Wine Solution

The adsorption of bovine serum albumin by bentonite in model wine solutions was studied. The attainment of equilibrium was found to be rapid and complete within 30 seconds of the addition. The extent of adsorption was characterized using both the Langmuir and Freundlich equations. The constants and the goodness of fit were determined by linear regression of the transformed equations. The adsorption was independent of temperature but varied with protein content, pH, and ethanol content. A comparison of various types of bentonite showed that calcium bentonites had lower adsorptive capacities, even though their measured cation exchange capacities were similar.