Wang Wenjie, Zhang Zhiwen, Liu Xiaoying, Cao Xiaoji, Wang Lianzhu, Ding Yuting, Zhou Xuxia
College of Food Science and Technology, Zhejiang University of Technology, Hangzhou 310014, China.
Key Laboratory of Marine Fishery Resources Exploitment & Utilization of Zhejiang Province, Hangzhou 310014, China.
Foods. 2022 Apr 19;11(9):1176. doi: 10.3390/foods11091176.
Malondialdehyde (MDA) is one of the representative end products under lipid peroxidation, indicating the degree of lipid oxidation in foods. However, compounds in pickled products, especially the nitrite in salted lean pork can react with MDA under the acidic condition, leads to the loss of MDA and an underestimation on lipid oxidation through the conventional assay. In this study, the quantification for MDA in the sample containing sodium nitrite were found lacking accuracy by the thiobarbituric acid (TBA) assay and chromatography assay based on alkaline hydrolysis as the reaction between them were difficult to be completely inhibited. Among other trials, the improvement GC-MS analysis utilizing deuterium substituted MDA (MDA-d) as an internal standard and applying perfluorophenylhydrazine (PFPH) as a derivative reagent can reduce the deviations from the presence of nitrite in the salted lean pork meat and the recovery is between 93.9% and 98.4% and coefficient of variation for the intermediate precision is between 1.1 and 3.5% using the method. The advanced gas chromatograph mass spectrometer (GC-MS) assay also has a very low detection limit (0.25 ng/mL) with both hydrolysis types.
丙二醛（MDA）是脂质过氧化作用的代表性终产物之一，可指示食品中的脂质氧化程度。然而，腌制产品中的化合物，尤其是腌制瘦肉中的亚硝酸盐，在酸性条件下会与MDA发生反应，导致MDA损失，并通过传统检测方法低估脂质氧化程度。在本研究中，基于硫代巴比妥酸（TBA）法和碱性水解色谱法对含有亚硝酸钠样品中的MDA进行定量时，发现准确性不足，因为它们之间的反应难以完全抑制。在其他试验中，以氘代丙二醛（MDA-d）为内标，使用全氟苯肼（PFPH）作为衍生试剂的改进型气相色谱-质谱联用（GC-MS）分析方法，可以减少腌制瘦肉中亚硝酸盐存在所导致的偏差，该方法的回收率在93.9%至98.4%之间，中间精密度的变异系数在1.1%至3.5%之间。先进的气相色谱-质谱联用（GC-MS）分析法对两种水解类型的检测限都非常低（0.25 ng/mL）。
