Free Fatty Acids in Commercial Krill Oils: Concentrations, Compositions, and Implications for Oxidative Stability

• Main Authors: ID Fuller, AH Cumming, A Card, EJ Burgess, Colin Barrow, NB Perry, DP Killeen
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2020
• Subjects: Chemical engineering not elsewhere classified; Science & Technology; Physical Sciences; Life Sciences & Biomedicine; Chemistry; Applied; Food Science & Technology; Krill oil; Oxidation; Free fatty acids; Phospholipids; Omega-3; Docosahexaenoic acid; Eicosapentaenoic acid; Phytanic acid; NONENZYMATIC BROWNING REACTIONS; ANTARCTIC KRILL; LIPID OXIDATION; EXTRACTION; MECHANISMS; P-31; School of Life and Environmental Sciences; Centre for Chemistry and Biotechnology; 4004 Chemical engineering; Antarctic; Browning; Antarc*; Antarctic Krill
• Online Access: http://hdl.handle.net/10536/DRO/DU:30139024; https://figshare.com/articles/journal_contribution/Free_fatty_acids_in_commercial_krill_oils_concentrations_compositions_and_implications_for_oxidative_stability/20702866

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.