Lipid oxidation reactions in foods rich in healthy unsaturated fatty acids result in the formation of a wide range of oxidation products that can have adverse effects on food quality and safety. To improve the understanding of oxidation reactions and methods for their inhibition, detailed information on the type and levels of the oxidation products formed is required. Accurate measurement of lipid oxidation products, especially of the non-volatile aldehyde products, has so far been a challenge due to the low sensitivity and limited specificity of most analytical methods. Here, a novel normal-phase LC method that uses selective labeling of aldehydes and epoxides with 7-(diethylamino)coumarin-3-carbohydrazide (CHH) is described. Labeling of alkanals is quantitative within 10 h. For alkenals, conversion is only around 50% at 24 h reaction time. Detailed MS identification of all aldehydes and epoxides is possible by using high-resolution MS and data-dependent MS² acquisition. Fluorescence detection was successfully used to quantify groups of oxidation products. Sensitivity was high enough to allow accurate quantification even in fresh mayonnaises, where levels of around only 0.3 g total aldehydes/kg oil were found. Individual species can be quantified by MS if suitable reference standards are available. If no standards can be used, semi-quantification using an average response factor is an option. Clearly, the novel derivatization method is suitable for monitoring secondary lipid oxidation products in the early stages of shelf life. This makes it an important tool for developing improved food products.

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富含健康不饱和脂肪酸的食品中的脂质氧化反应导致形成多种氧化产物，这些氧化产物可能对食品质量和安全性产生不利影响。为了增进对氧化反应及其抑制方法的理解，需要有关形成的氧化产物的类型和水平的详细信息。迄今为止，由于大多数分析方法的灵敏度低且特异性有限，因此准确测量脂质氧化产物（尤其是非挥发性醛产物）一直是一项挑战。在这里，描述了一种新颖的正相液相色谱方法，该方法使用7-（二乙氨基）香豆素-3-碳酰肼（CHH）选择性标记醛和环氧化物。链烷烃的标记在10小时内是定量的。对于烯烃，在24小时的反应时间转化率仅为50％左右。²采集。荧光检测已成功用于定量氧化产物的组。灵敏度很高，甚至在新鲜蛋黄酱中也能进行准确定量，在蛋黄酱中，总醛含量仅为0.3 g / kg油。如果可以使用合适的参考标准，则可以通过MS对单个物种进行定量。如果无法使用任何标准，则可以选择使用平均响应因子进行半定量。显然，这种新的衍生化方法适用于在保质期的早期监测次级脂质氧化产物。这使其成为开发改良食品的重要工具。

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