College of Light Industry and Food Sciences, South China University of Technology, 381# Wushan Road, Tianhe District, Guangzhou 510640, China; School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, China.
Food Chem Toxicol. 2013 Oct;60:536-41. doi: 10.1016/j.fct.2013.07.081. Epub 2013 Aug 16.
N(ε)-carboxymethyllysine (CML) is commonly found in food, and is considered as a potential hazard to human health. However, the effect of lipids on CML formation in Maillard reaction is still not clarified. In this study, the content of diet-derived CML and its key intermediates, epsilon-fructoselysine (FL) and glyoxal (GO), is determined with high performance liquid chromatography mass spectrum (HPLC-MS) in model system containing lipid compounds. According to the results, hydroxyl radical (OH) induced by Fenton reagent can promote the three pathways of CML formation. Moreover, in the Maillard reaction system, linoleic acid (Lin), oleic acid (Ole) and glycerol trioleate (Tri) can induce more OH·, which promotes CML formation. Their level of promoting CML formation is in the order of Ole>Lin>Tri. On the contrary, glycerol (Gly) can scavenge OH·, which inhibit the CML formation. Finally, it is proved that FL content and GO content decreases with heating time in model system, while CML content increases with heating time. Thus, it is concluded that in the Maillard reaction system lipids can induce more OH·, which promotes the conversion from FL and GO to CML. Our research may contribute to the development of inhibitory methods for diet-derived CML by scavenging OH·.
N(ε)-羧甲基赖氨酸（CML）普遍存在于食物中，被认为是对人类健康的潜在危害。然而，脂质对美拉德反应中 CML 形成的影响仍不清楚。在这项研究中，采用高效液相色谱质谱（HPLC-MS）法测定了模型体系中含有脂质化合物时饮食来源的 CML 及其关键中间产物ε-果糖赖氨酸（FL）和乙二醛（GO）的含量。结果表明，芬顿试剂诱导的羟基自由基（OH）可以促进 CML 形成的三条途径。此外，在美拉德反应体系中，亚油酸（Lin）、油酸（Ole）和三油酸甘油酯（Tri）可以诱导更多的 OH·，从而促进 CML 的形成。它们促进 CML 形成的程度顺序为 Ole>Lin>Tri。相反，甘油（Gly）可以清除 OH·，从而抑制 CML 的形成。最后，证明模型体系中 FL 含量和 GO 含量随加热时间的延长而减少，而 CML 含量随加热时间的延长而增加。因此，可以得出结论，在美拉德反应体系中，脂质可以诱导更多的 OH·，从而促进从 FL 和 GO 向 CML 的转化。我们的研究可能有助于通过清除 OH·来开发抑制饮食来源 CML 的方法。
