Adsorption of b-Lactoglobulin onto Silica, Methylated Silica and Polysulphone

Research output: Contribution to journalArticle

Abstract

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.

Details

Authors
Organisations
External organisations
  • Lund University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Food Engineering

Keywords

Original languageEnglish
Pages (from-to)259-265
Number of pages7
JournalJournal of Colloid and Interface Science
Volume136
Issue number1
Publication statusPublished - 1990
Publication categoryResearch
Peer-reviewedYes