BACKGROUND To clarify the formation mechanism of trans linoleic acid isomers in edible oils during the heating process, trilinolein and trilinoelaidin, as representative oils, were placed in glass ampoules and sealed before heating at 180, 240 and 320 °C. The glass ampoules were removed at regular time intervals, and the contents were analyzed by infrared spectroscopy. The samples were then subjected to derivatization into their methyl esters for gas chromatographic analysis. RESULTS Analysis results show that 9c,12c and 9t,12t fatty acids from trilinolein and trilinoelaidin molecules undergo chemical bond rotation, migration and degradation, leading to the formation of non-conjugated linoleic acids (NLAs), conjugated linoleic acids (CLAs) and aldehydes. The formation rate of isomers from the 9c,12c fatty acid is higher than that of the 9t,12t fatty acid. The production of aldehydes increases with heating temperature and time. The isomerization pathways involved in the formation of NLAs and CLAs during heating are clearly presented. CONCLUSION These findings suggest possible pathways of NFA and CFA formation from heated trilinolein and trilinoelaidin, complement the mechanistic studies previously published in the literature, and provide a theoretical basis for future control of the quality and safety of fats and oils. © 2016 Society of Chemical Industry.

中文翻译：

---

9,12-亚油酸三酰甘油热致异构化反应途径机制

背景技术为阐明食用油中反式亚油酸异构体在加热过程中的形成机理，将三亚油酸和三亚油酸作为代表性油类，分别置于玻璃安瓿瓶中密封，然后分别加热至180、240和320℃。定期取出玻璃安瓿，并通过红外光谱分析其内容物。然后将样品衍生成它们的甲酯用于气相色谱分析。结果 分析结果表明，三亚油酸和三亚油酸甘油酯分子中的 9c,12c 和 9t,12t 脂肪酸发生化学键旋转、迁移和降解，导致形成非共轭亚油酸 (NLA)、共轭亚油酸 (CLA) 和醛类. 9c、12c脂肪酸的异构体形成率高于9t，12t脂肪酸。醛的产生随着加热温度和时间的增加而增加。清晰地呈现了加热过程中 NLA 和 CLA 形成所涉及的异构化途径。结论 这些发现表明加热的三亚油酸和三亚油酸甘油酯形成 NFA 和 CFA 的可能途径，补充了先前发表在文献中的机理研究，并为未来控制油脂的质量和安全性提供了理论基础。© 2016 化学工业协会。补充了之前发表在文献中的机理研究，为未来控制油脂的质量和安全提供了理论依据。© 2016 化学工业协会。补充了之前发表在文献中的机理研究，为未来控制油脂的质量和安全提供了理论依据。© 2016 化学工业协会。