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Thesis (Master's)

University of Iceland > Heilbrigðisvísindasvið > Meistaraprófsritgerðir - Heilbrigðisvísindasvið >

Please use this identifier to cite or link to this item: https://hdl.handle.net/1946/16159

Title: 
  • Nano-laminated Fish Oil Droplets: Influence of Chitosan Charge Density on Emulsion Stability
Degree: 
  • Master's
Abstract: 
  • The benefits of wholesome consumption, are for example decreased risk of type 2 diabetes, hypertension, and certain cancer, decreased risk of overweigh and obesity and decreased risk of micronutrient deficiencies. Omega-3 fatty acids provide essential fatty acids that our body needs. Fish oil is probably the most beneficial source of omega-3 fatty acids, and there for there could be a substantial marked for ω-3 fatty acid incorporated food, function foods. However, there are some obstacles that need to be overcome before this will be commercially
    viable.
    Fish oil oxidation is very rapid so that could be a problem when it’s incorporated in food. Another problem is that fish oil has a rather strong odor as well as taste. With a technique that encapsulates the oil by creating layer or layer´s around the lipid droplets it’s possible control the absorption in the body and also to conceal the odor and the taste.
    A series of emulsions containing the same oil [1% (w/w) fish oil] and protein [0.1% (w/w) sodium caseinate] contents but different deacetylated chitosan/chitin (50 DDA, 70 DDA and 92% DDA) were prepared by mixing different ratios of stock emulsion [10% (w/w)
    fish oil, 1% wt% sodium caseinate], chitosan solution [0.04% (w/w) chitosan] and buffer solution. The 1°emulsion contained sodium caseinate layer around the fish oil droplets, the 2°emulsion contained chitosan layer around the sodium caseinate layer and the 3°emulsion contained a pectin layer around the chitosan layer. We compared the influence of repeated freeze-thaw cycles and different pH on the mean particle diameter, microstructure, zetapotential
    and creaming stability of primary, secondary and tertiary emulsions. We also compared the influence of oxidation rate on different layered emulsions.
    This study has shown that the freeze-thaw stability of oil-in-water emulsions can be improved by engineering the characteristics of the interfacial layers surrounding the lipid droplets using layer-by-layer electrostatic deposition technique. The study also showed that we were able to improve oxidative stability of the emulsion droplets, stabilized by either caseinate or caseinate-chitosan layers versus emulsion droplets stabilized by tween20.

Accepted: 
  • Aug 16, 2013
URI: 
  • http://hdl.handle.net/1946/16159


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