Department of Food Safety, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Strasse 8-10, Berlin, 10589, Germany.
Institute for Agro-food Standards and Testing Technology, Shanghai Academy of Agricultural Sciences, Shanghai, 201403, P. R. China.
Mol Nutr Food Res. 2021 Feb;65(4):e2000736. doi: 10.1002/mnfr.202000736. Epub 2021 Jan 4.
Fatty acid esters of 2-monochloropropane-1,3-diol (2-MCPD) and 3-monochloropropane-1,2-diol (3-MCPD) are formed during the deodorization of vegetable oils. After lipase-catalyzed hydrolysis in the intestine, 2- and 3-MCPD are absorbed, but their ensuing human metabolism is unknown.
The compounds 2-chlorohydracrylic acid (2-ClHA) and 3-chlorolactic acid (3-ClLA) resulting from oxidative metabolism of 2-MCPD and 3-MCPD, respectively, are identified and quantified in human urine samples. An exposure study with 12 adults is conducted to determine the urinary excretion of 2-ClHA and 3-ClLA. The participants eat 12 g of hazelnut oil containing 24.2 mg kg 2-MCPD and 54.5 mg kg 3-MCPD in the form of fatty acid esters. Average daily amounts of "background" excretion before the exposure are 69 nmol 2-ClHA and 3.0 nmol 3-ClLA. The additional mean excretion due to the uptake of the hazelnut oil amounts to 893 nmol 2-ClHA (34.0% of the 2-MCPD dose) and 16.4 nmol 3-ClLA (0.28% of the 3-MPCD dose).
The products of oxidative metabolism of 2- and 3-MCPD, 2-ClHA, and 3-ClLA, are described for the first time in humans. Due to the lack of specificity, the metabolites may not be used as exposure biomarkers to low doses of bound 2- and 3-MCPD, respectively.
2-氯-1,3-丙二醇（2-MCPD）和 3-氯-1,2-丙二醇（3-MCPD）脂肪酸酯在植物油脱臭过程中形成。在肠道中经脂肪酶催化水解后，2-MCPD 和 3-MCPD 被吸收，但随后的人体代谢途径尚不清楚。
分别来源于 2-MCPD 和 3-MCPD 氧化代谢的 2-氯羟丙酸（2-ClHA）和 3-氯乳酸（3-ClLA）两种化合物在人体尿液样本中被鉴定和定量。通过对 12 名成年人进行暴露研究，以确定 2-ClHA 和 3-ClLA 的尿排泄情况。研究参与者食用了 12 克含有 24.2mgkg 2-MCPD 和 54.5mgkg 3-MCPD 的脂肪酸酯形式的榛子油。暴露前“背景”排泄的平均日量为 69nmol 2-ClHA 和 3.0nmol 3-ClLA。由于摄入榛子油，平均额外排泄量为 893nmol 2-ClHA（2-MCPD 剂量的 34.0%）和 16.4nmol 3-ClLA（3-MPCD 剂量的 0.28%）。
首次在人体内描述了 2-MCPD 和 3-MCPD 的氧化代谢产物 2-ClHA 和 3-ClLA。由于缺乏特异性，这些代谢物可能不能用作分别检测低剂量结合 2-MCPD 和 3-MCPD 的暴露生物标志物。
