Oxidative stability of encapsulated seal blubber oil

Oils containing a large proportion of polyunsaturated fatty acids, especially the omega-3 type, are highly prone to oxidative deterioration and off-flavor development. Therefore, inhibition of oxidation is a major criterion when such oils are incorporated into food product. Encapsulation of omega-3 rich marine oils would confer better stability to products by preventing contact with air and light. It also provides a free-flowing powder which can be easily incorporated into foods. The present study was undertaken to stabilize seal blubber oil (SBO) by microencapsulation. SBO contains 21-26% long chain omega-3 fatty acids consisting of 6.5-8.5% eicosapentaenoic, 4-6% docosapentaenoic and 8-10% docosahexaenoic acids. Encapsulating materials examined were beta-cyclodextrin, corn-syrup solids and maltodextrin. Aqueous solutions containing the encapsulating material, Tween 80 as an emulsifier, and SBO were then spray-dried. The storage stability of these powdered products was determined by monitoring their peroxide and 2-thiobarbituric acid reactive substances values as well as changes of their fatty acid composition. Among the encapsulating materials tested, beta-cyclodextrin and corn-syrup solids were found to be good encapsulating agents for SBO.