Cross-linking oppositely charged oil-in-water emulsions to enhance heteroaggregate stability

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Christiane Maier - , University of Hohenheim (Author)
  • Anja M. Oechsle - , University of Hohenheim (Author)
  • Jochen Weiss - , University of Hohenheim (Author)

Abstract

The formation and subsequent enzymatic and chemical cross-linking of heteroaggregates from oppositely charged oil-in-water (O/W) emulsions was investigated. For this purpose, 10% (w/w) oil-in-water emulsions (d43<. 1. μm) were prepared at pH 4 using a positively charged emulsifier (Nα-lauroyl-L-arginine ethyl ester (LAE), cold water fish gelatin, or whey protein isolate) or a negatively charged one (sugar beet pectin or Quillaja saponins). The oppositely charged emulsions were then combined at a volume ratio of 1:1 and treated with laccase or glutaraldehyde in order to further stabilize the electrostatically attached aggregates by covalently cross-linking the oppositely charged membranes. Emulsions and heteroaggregates were characterized by their rheological properties, their surface charge, particle size distribution, and microstructure using dynamic and static light scattering as well as confocal laser scanning microscopy. Prior to cross-linking, the emulsifiers' stabilization mechanism were found to greatly influence the formation of heteroaggregates. Laccase treatment (1.34. mU/mL) increased aggregate expansion by ca. 30% for the combined emulsions stabilized by Quillaja saponins/whey protein isolate, while combined Quillaja saponins/fish gelatin stabilized emulsions remained unaffected. When combined emulsions were treated with 50. mM glutaraldehyde, aggregate size significantly increased 2- and 3-fold, respectively. Thus, our study provides novel insights into the enzymatic and chemical cross-linking of heteroaggregates composed of oppositely charged O/W emulsions.

Details

Original languageEnglish
Pages (from-to)525-532
Number of pages8
JournalColloids and Surfaces B: Biointerfaces
Volume135
Publication statusPublished - 1 Nov 2015
Peer-reviewedYes
Externally publishedYes

External IDs

PubMed 26298085
ORCID /0000-0003-3146-2454/work/170587811

Keywords

Keywords

  • Aggregation, Emulsifier, Glutaraldehyde, Laccase, Oil-in-water emulsion, Stability