Interfacial structure of 70% fish oil-in-water emulsions stabilized with combinations of sodium caseinate and phosphatidylcholine

Betül Yesiltas, Mika Torkkeli, László Almásy, Zoltán Dudás, András Ferenc Wacha, Robert Dalgliesh, Pedro J. García-Moreno, Ann Dorit M. Sørensen, Charlotte Jacobsen, Matti Knaapila

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

We report on the structural evaluation of high fat fish oil-in-water emulsions emulsified with sodium caseinate (CAS) and phosphatidylcholine (PC). The microemulsions contained 70% (w/w) fish oil with 1.05–1.4% (w/w) CAS and 0.4–1.75% (w/w) PC and were studied by the combination of light scattering together with small-angle X-ray and neutron scattering (SAXS/SANS). Aqueous CAS forms aggregates having a denser core of about 100 kDa and less dense shell about 400 kDa with the hard sphere diameter of 20.4 nm. PC appears as multilayers whose coherence length spans from 40 to 100 nm. PC monolayer separates oil and water phases. Moreover, 80% CAS particles are loosely bound to the interface but are not forming continuous coverage. The distance between aggregated CAS particles in microemulsion is increased compared to CAS aggregates in pure CAS-in-water system. PC multilayers become larger in the presence of oil-water interface compared to the pure PC mixtures. Bilayers become larger with increasing PC concentration. This study forms a structural base for the combination of CAS and PC emulsifiers forming a well-defined thin and dense PC layer together with thick but less dense CAS layer, which is assumed to explain its better oxidative stability compared to single emulsifiers.

Original languageEnglish
Pages (from-to)183-190
Number of pages8
JournalJournal of colloid and interface science
Volume554
DOIs
Publication statusPublished - Oct 15 2019

Keywords

  • Emulsifier adsorption
  • High fat omega-3 delivery emulsions
  • Interfacial structure
  • SANS
  • SAXS

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Surfaces, Coatings and Films
  • Colloid and Surface Chemistry

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  • Cite this

    Yesiltas, B., Torkkeli, M., Almásy, L., Dudás, Z., Wacha, A. F., Dalgliesh, R., García-Moreno, P. J., Sørensen, A. D. M., Jacobsen, C., & Knaapila, M. (2019). Interfacial structure of 70% fish oil-in-water emulsions stabilized with combinations of sodium caseinate and phosphatidylcholine. Journal of colloid and interface science, 554, 183-190. https://doi.org/10.1016/j.jcis.2019.06.103