Unaided efficient transglutaminase cross-linking of whey proteins strongly impacts the formation and structure of protein alginate particles

Research output: Contribution to journalJournal articleResearchpeer-review


  • Fulltext

    Final published version, 5.02 MB, PDF document

  • Mikkel Madsen
  • Sanaullah Khan
  • Sonja Kunstmann
  • Finn L. Aachmann
  • Ipsen, Richard
  • Peter Westh
  • Cecilia Emanuelsson
  • Birte Svensson

There is a dogma within whey protein modification, which dictates the necessity of pretreatment to enzymatic cross-linking of β-lactoglobulin (β-Lg). Here microbial transglutaminase (MTG) cross-linked whey proteins and β-Lg effectively in 50 mM NaHCO3, pH 8.5, without pretreatment. Cross-linked β-Lg spanned 18 to >240 kDa, where 6 of 9 glutamines reacted with 8 of 15 lysines. The initial isopeptide bond formation caused loss of β-Lg native structure with t1/2 = 3 h, while the polymerization occurred with t1/2 = 10 h. Further, cross-linking effects on protein carbohydrate interaction have been overlooked, leaving a gap in understanding of these complex food matrices. Complexation with alginate showed that β-Lg cross-linking decreased onset of particle formation, hydrodynamic diameter, stoichiometry (β-Lg/alginate) and dissociation constant. The complexation was favored at higher temperatures (40 °C), suggesting that hydrophobic interactions were important. Thus, β-Lg was cross-linked without pretreatment and the resulting polymers gave rise to altered complexation with alginate.

Original languageEnglish
Article number100137
JournalFood Chemistry: Molecular Sciences
Number of pages11
Publication statusPublished - 2022

Bibliographical note

Publisher Copyright:
© 2022 The Authors

    Research areas

  • Dynamic light scattering, Far- and near-UV CD, Intrinsic and ANS fluorescence spectra, LC-MS/MS cross-link identification, Molecular dynamics inter-residue distance analysis, Size exclusion chromatography

ID: 321847705