Journal article
Interfacial structure of 70% fish oil-in-water emulsions stabilized with combinations of sodium caseinate and phosphatidylcholine
National Food Institute, Technical University of Denmark1
Research Group for Bioactives – Analysis and Application, National Food Institute, Technical University of Denmark2
Department of Physics, Technical University of Denmark3
Hungarian Academy of Sciences4
Rutherford Appleton Laboratory5
Neutrons and X-rays for Materials Physics, Department of Physics, Technical University of Denmark6
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.
Language: | English |
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Year: | 2019 |
Pages: | 183-190 |
ISSN: | 10957103 and 00219797 |
Types: | Journal article |
DOI: | 10.1016/j.jcis.2019.06.103 |
ORCIDs: | Yesiltas, Betül , Torkkeli, Mika , García-Moreno, Pedro Jesús , Moltke Sørensen, Ann Dorit , Jacobsen, Charlotte , Knaapila, Matti and 0000-0001-5750-5788 |
Caseins Emulsifying Agents Emulsions Fish Oils Phosphatidylcholines Water