Adsorption of b-Lactoglobulin onto Silica, Methylated Silica and Polysulphone
Research output: Contribution to journal › Article
Milk and whey are widely processed by membrane filtration, often using polysulphone membranes. Adsorption of β-lactoglobulin onto polysulphone was studied at protein concn. of 0.1 and 1.0%, as well as 12% to represent concn. encountered during ultrafiltration. Adsorption onto silica and methylated silica surfaces (representing strongly hydrophilic and strongly hydrophobic surfaces resp.) was also studied. Protein was dissolved in 0.01 smallcap˜M phosphate buffer pH 7.0 containing 0.15 smallcap˜M NaC1 and adsorption/desorption was monitored in situ using a Rudolph Thin Film ellipsometer. Polysulphone surfaces adsorbed the greatest amount of β-lactoglobulin and silica the least; methylated silica was intermediate. Differences between methylated silica and polysulphone may reflect differences in surface roughness. Adsorption to polysulphone and methylated silica was not reversed on dilution, whereas adsorption to silica was partially reversible. Pretreatment of polysulphone and methylated silica surfaces with 0.1% β-lactoglobulin markedly reduced subsequent adsorption from 12% β-lactoglobulin (equivalent to adsorption from 0.1% solution alone); preadsorption to silica surfaces had much less effect on subsequent adsorption. Methylated silica was concluded to be a representative model for a polysulphone surface.
|Research areas and keywords||
Subject classification (UKÄ) – MANDATORY
|Number of pages||7|
|Journal||Journal of Colloid and Interface Science|
|Publication status||Published - 1990|