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Free fatty acids in commercial krill oils: concentrations, compositions, and implications for oxidative stability

journal contribution
posted on 2020-08-01, 00:00 authored by I D Fuller, A H Cumming, A Card, E J Burgess, Colin BarrowColin Barrow, N B Perry, D P Killeen
The concentrations and pro-oxidative effects of free fatty acids in commercial krill oil are not well defined. We now report that krill oil free fatty acids account for 2–13% of total lipids in commercial krill oil (n = 8) that these compounds are enriched in eicosapentaenoic acid (+7.1%) and docosahexaenoic acid (+6.3%) relative to whole oils; and that this composition make them highly pro-oxidizing in marine triacylglycerol oils, but not in krill oil, which derives oxidative stability from both its phospholipids, and neutral lipids (the latter because of astaxanthin). Specific fatty acid esterification patterns showed that krill oil free fatty acids predominantly (88–93%) originated from phospholipids, mainly from the sn-2 position, which was eight-fold more hydrolyzed than the sn-1 position. Lipolysis was not ongoing in stored oils. Adding small amounts of krill oil (1–5%) to marine triacylglycerol oils significantly increased their oxidative stability and also their resistance to free fatty acid-mediated pro-oxidative effects.

History

Journal

JAOCS, Journal of the American Oil Chemists' Society

Volume

97

Issue

8

Pagination

889 - 900

Publisher

Wiley

Location

Chichester, Eng.

ISSN

0003-021X

Language

eng

Publication classification

C Journal article; C1 Refereed article in a scholarly journal