title: Tuning of shell thickness of solid lipid particles impacts the chemical stability of encapsulated ω-3 fish oil.
abstract: OBJECTIVE
  This study demonstrates that tuning the shell thickness of lipid particles can modulate their oxidative stability. We hypothesized that a thick crystallized shell around the incorporated fish oil would improve the oxidative stability due to the reduced diffusion of prooxidants and oxygen.
  
  
  METHODS
  We prepared solid lipid nanoparticles (5%w/w lipid phase, 1.5%w/w surfactant, pH 7) by using different ratios of tristearin as carrier lipid and ω-3 fish oil as incorporated liquid lipid stabilized by high- or low-melting lecithin. The physical, polymorphic and oxidative stability of the lipid particles was assessed.
  
  
  RESULTS
  The high-melting lecithin was the key in inducing the formation of a solidified tristearin shell around the lipid particles by interfacial heterogeneous nucleation. Lipid particles containing a higher ratio of tristearin showed a better oxidative stability. The results revealed that a crystallized tristearin layer above 10nm was required to inhibit oxidation of the incorporated fish oil. This cut-off was shown for lipid particles containing 50-60% fish oil. This research gives important insights into understanding the relation between the thickness of the crystallized shell around the lipid particles and their chemical stability.
authors.affiliation: Department of Food Physics and Meat Science, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstrasse 21/25, 70599 Stuttgart, Germany. Electronic address: hanna.salminen@uni-hohenheim.de.
authors.forename: Hanna
authors.initials: H
authors.lastname: Salminen
authors.affiliation: Department of Food Physics and Meat Science, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstrasse 21/25, 70599 Stuttgart, Germany. Electronic address: helgason01@gmail.com.
authors.forename: Thrandur
authors.initials: T
authors.lastname: Helgason
authors.affiliation: Faculty of Food Science and Nutrition, University of Iceland, Eiriksgötu 2, 101 Reykjavik, Iceland. Electronic address: bhk1@hi.is.
authors.forename: Bjarki
authors.initials: B
authors.lastname: Kristinsson
authors.affiliation: Faculty of Food Science and Nutrition, University of Iceland, Eiriksgötu 2, 101 Reykjavik, Iceland. Electronic address: kk@hi.is.
authors.forename: Kristberg
authors.initials: K
authors.lastname: Kristbergsson
authors.affiliation: Department of Food Physics and Meat Science, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstrasse 21/25, 70599 Stuttgart, Germany. Electronic address: j.weiss@uni-hohenheim.de.
authors.forename: Jochen
authors.initials: J
authors.lastname: Weiss
mesh_terms: D003460:Crystallization; D004655:Emulsions / Q000737:chemistry*; D005079:Excipients / Q000737:chemistry*; D015525:Fatty Acids, Omega-3 / Q000737:chemistry*; D005395:Fish Oils / Q000737:chemistry*; D054709:Lecithins / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry; D010084:Oxidation-Reduction; D044367:Phase Transition; D013501:Surface-Active Agents / Q000737:chemistry; D014280:Triglycerides / Q000737:chemistry*
chemical_list: D004655:Emulsions; D005079:Excipients; D015525:Fatty Acids, Omega-3; D005395:Fish Oils; D054709:Lecithins; D013501:Surface-Active Agents; D014280:Triglycerides; C022618:tristearin
keywords: Crystallization; Fish oil; Lecithin; Lipid oxidation; Nanoemulsions; Polymorphic transition; Shell thickness; Solid lipid nanoparticles; Tristearin; ω-3 fatty acids