Department of Food Science and Technology, College of Agriculture and Environmental Sciences, University of California, Davis, California 95616, United States.
J Agric Food Chem. 2020 Sep 2;68(35):9329-9344. doi: 10.1021/acs.jafc.0c02461. Epub 2020 Aug 18.
Fish and algae oil supplements are enriched with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are precursors to oxidized fatty acids, known as oxylipins. Here, we optimized a base hydrolysis method for measuring oxylipins in oil with ultrahigh-performance liquid chromatography coupled to tandem mass-spectrometry (UPLC-MS/MS) and quantified them in fish and algae oil supplements. Hydrolysis of 2 μL of oil with sodium carbonate resulted in greater oxylipin concentrations and minimal matrix effects, compared to higher oil volumes (10, 20, and 30 μL). Oxylipin yield was higher when oil was hydrolyzed in methanol containing 0.1% acetic acid and 0.1% butylated hydroxytoluene, compared to no methanol, and using sodium hydroxide versus sodium carbonate. Oxylipins extracted from 2 μL of oil using sodium hydroxide in solvent showed that EPA-derived oxylipins were most abundant in fish oil (84-87%), whereas DHA-oxylipins were abundant in algae oil (83%). This study shows that fish and algae oils are direct sources of EPA- and DHA-derived oxylipins.
鱼类和藻类油补充剂富含二十碳五烯酸（EPA）和二十二碳六烯酸（DHA），它们是氧化脂肪酸的前体，称为氧化脂类。在这里，我们优化了一种使用超高效液相色谱-串联质谱（UPLC-MS/MS）测量油中氧化脂类的基础水解方法，并对鱼类和藻类油补充剂中的氧化脂类进行了定量分析。与使用更高体积的油（10、20 和 30 μL）相比，用碳酸钠水解 2 μL 的油会产生更高的氧化脂类浓度和最小的基质效应。与不使用甲醇相比，在含有 0.1%乙酸和 0.1%叔丁基对羟基甲苯的甲醇中水解油时，氧化脂类的产量更高，与使用氢氧化钠相比，使用碳酸钠时的产量更高。使用氢氧化钠在溶剂中从 2 μL 油中提取的氧化脂类表明，源自 EPA 的氧化脂类在鱼油中最为丰富（84-87%），而 DHA 氧化脂类在藻类油中丰富（83%）。本研究表明，鱼类和藻类油是 EPA 和 DHA 衍生氧化脂类的直接来源。
