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.

中文翻译：

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商业磷虾油中的游离脂肪酸：浓度，组成和对氧化稳定性的影响

商业磷虾油中游离脂肪酸的浓度和促氧化作用尚不明确。我们现在报告说，磷虾油中游离脂肪酸占商业磷虾油中总脂质的2–13％（n= 8）相对于全油，这些化合物富含二十碳五烯酸（+ 7.1％）和二十二碳六烯酸（+ 6.3％）；而且这种成分使它们在船用三酰基甘油油中具有很高的预氧化作用，而在磷虾油中则没有，后者从其磷脂和中性脂质（由于虾青素的存在）中获得了氧化稳定性。特定的脂肪酸酯化模式显示，磷虾无油脂肪酸主要（88–93％）源自磷脂，主要源自sn-2位置，水解程度比sn-1位置高8倍。储存的油中没有进行脂解。在船用三酰基甘油油中添加少量的磷虾油（1-5％）可显着提高其氧化稳定性，并增强其对游离脂肪酸介导的促氧化作用的抵抗力。