Xia Wei, Budge Suzanne M
Dept. of Process Engineering and Applied Science, Dalhousie Univ., Halifax, NS, B3H 4R2, Canada.
Compr Rev Food Sci Food Saf. 2017 Jul;16(4):735-758. doi: 10.1111/1541-4337.12276. Epub 2017 Jun 20.
Lipid oxidation can lead to flavor and safety issues in fat-containing foods. In order to measure the extent of lipid oxidation, hydroperoxides and their scission products are normally targeted for analytical purposes. In recent years, the formation of rarely monitored oxygenated products, including epoxides, alcohols, and ketones, has also raised concerns. These products are thought to form from alternative pathways that compete with chain scissions, and should not be neglected. In this review, a number of instrumental techniques and approaches to determine epoxides, alcohols, and ketones are discussed, with a focus on their selectivity and sensitivity in applications to food lipids and oils. Special attention is given to methods employing gas chromatography (GC), high-performance liquid chromatography (HPLC), and nuclear magnetic resonance (NMR). For characterization purposes, GC-mass spectrometry (GC-MS) provides valuable information regarding the structures of individual oxygenated fatty acids, typically as methyl esters, isolated from oxygenated triacylglycerols (TAGs), while the use of liquid chromatography-MS (LC-MS) techniques allows analysis of intact oxygenated TAGs and offers information about the position of the oxygenated acyl chain on the glycerol backbone. For quantitative purposes, traditional chromatography methods have exhibited excellent sensitivity, while spectroscopic methods, including NMR, are superior to chromatography for their rapid analytical cycles. Future studies should focus on the development of a routine quantitative method that is both selective and sensitive.
脂质氧化会导致含脂食品出现风味和安全问题。为了测定脂质氧化的程度，通常以氢过氧化物及其裂解产物作为分析目标。近年来，包括环氧化物、醇类和酮类在内的极少受到监测的氧化产物的形成也引发了关注。这些产物被认为是通过与链断裂相竞争的替代途径形成的，不应被忽视。在这篇综述中，讨论了多种用于测定环氧化物、醇类和酮类的仪器技术和方法，重点关注它们在应用于食用油脂时的选择性和灵敏度。特别关注了采用气相色谱（GC）、高效液相色谱（HPLC）和核磁共振（NMR）的方法。为了进行表征，气相色谱 - 质谱联用（GC-MS）可提供有关从氧化三酰甘油（TAG）中分离出的单个氧化脂肪酸（通常为甲酯）结构的有价值信息，而液相色谱 - 质谱联用（LC-MS）技术的使用则允许对完整的氧化TAG进行分析，并提供有关甘油主链上氧化酰基链位置的信息。为了进行定量分析，传统的色谱方法表现出了出色的灵敏度，而包括NMR在内的光谱方法因其快速的分析周期而优于色谱方法。未来的研究应专注于开发一种兼具选择性和灵敏度的常规定量方法。
