Epoxy fatty acids in triacylglycerols: Elucidating the influences of oxidation conditions and lipid structures on formation and accumulation during lipid oxidation to enable their precise analysis in food

三酰甘油中的环氧脂肪酸：阐明氧化条件和脂质结构对脂质氧化过程中形成和积累的影响，以便能够在食品中对其进行精确分析

• 批准号: 520944998
• 负责人: Professor Dr. Simon Hammann
• 金额: --
• 依托单位: Fachgruppe Lebensmittelchemie und Analytische Chemie (170a)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/520944998?language=en
• 关键词: Epoxy; fatty; acids; triacylglycerols; Elucidating

Lipid oxidation in food frequently comes with quality loss, as nutritionally valuable lipids such as polyunsaturated fatty acids can be lost in the process. In addition, there are implications for food safety since some lipid oxidation products have unfavorable bioactivities and are undesired in food. Amongst these, epoxy fatty acids are one of the most important secondary lipid oxidation products, also from a quantitative point of view. In food, they are usually occurring esterified to triacylglycerol as an epoxy-modified fatty acid chain. Due to the high structural complexity of the oxidized lipid fraction in food and largely absent experimental reference data the analysis of epoxy modified triacylglycerol still comes with significant challenges. Therefore, the (quantitative) analysis of epoxy fatty acids is by and large achieved on the fatty acid level after liberation of the epoxy fatty acid chains from the glycerol backbones instead. However, in this process important structural information (for example about the position of the epoxy fatty acid on the glycerol backbone), with importance to understand bioactivities, formation and hence mitigation strategies, are lost. The goal of this project is to elucidate the impact of oxidation conditions and lipid structures on the formation and accumulation of triacylglycerol-bound epoxy fatty acids and, together with newly acquired experimental reference data, achieve a structurally refined analysis of these compounds in food. For this purpose, >40 epoxy-modified triacylglycerols will by synthesized and characterized thoroughly by chromatography, mass spectrometry and NMR spectroscopy (Aim 1). In extensive incubation experiments with oxidation-susceptible reference triacylglycerols, under conditions favouring autoxidation or photooxygenation, the impact of different oxidation conditions on the formation and accumulation of epoxy modifications will be investigated. Furthermore, by employing structurally different triacylglycerols in these experiments, e.g., with the labile fatty acid chain esterified to the outer sn-1/3 or the inner sn-2 position of the triacylglycerol, the impact of lipid structures will be assessed as well and the principal formation mechanism of the epoxy modification in different conditions elucidated (Aim 2). Finally, using the data from reference compound synthesis and incubation experiments we will analyse epoxy-modified triacylglycerols and evaluate the patterns in a set of lipid rich food items (Aim 3). This project will provide the research community with the required reference data for analysis of epoxy-modified triacylglycerols and will significantly improve our understanding about these compounds and their analysis in food.

食物中的脂肪氧化经常伴随着质量的损失，因为在这个过程中，有营养价值的脂肪，如多不饱和脂肪酸，可能会丢失。此外，由于一些脂质氧化产物具有不利的生物活性，在食品中不受欢迎，因此对食品安全也有影响。其中，从定量的角度来看，环氧脂肪酸也是最重要的二次脂质氧化产物之一。在食品中，它们通常以环氧改性脂肪酸链的形式酯化为三酰甘油。由于食品中氧化脂肪组分的高度结构复杂性和缺乏实验参考数据，环氧改性三酰甘油的分析仍然面临着巨大的挑战。因此，环氧脂肪酸的定量分析大体上是在脂肪酸水平上实现的，而不是从甘油主链上解放出环氧脂肪酸链。然而，在这个过程中，重要的结构信息(例如，关于环氧脂肪酸在甘油主链上的位置)丢失了，这些信息对于了解生物活性、形成和缓解策略具有重要意义。该项目的目标是阐明氧化条件和脂类结构对三酰甘油结合的环氧脂肪酸的形成和积累的影响，并与新获得的实验参考数据一起，实现对食品中这些化合物的结构精细化分析。为此，将合成&gt；40环氧改性三酰甘油，并用色层、质谱学和核磁共振谱对其进行了详细的表征(目标1)。在广泛的与氧化敏感的参考三酰甘油的孵化实验中，在有利于自氧化或光氧化的条件下，将研究不同的氧化条件对环氧改性形成和积累的影响。此外，通过在这些实验中使用结构不同的三酰甘油，例如，将不稳定的脂肪链酯化到三酰甘油的外部sn-1/3或内部sn-2位置，也将评估脂结构的影响，并阐明不同条件下环氧改性的主要形成机理(目标2)。最后，使用参考化合物合成和孵化实验的数据，我们将分析环氧改性三酰甘油，并评估一组富含脂肪的食品中的模式(目标3)。该项目将为研究界提供环氧改性三酰甘油分析所需的参考数据，并将显著提高我们对这些化合物及其在食品中的分析的了解。