Institute of Quality Standards and Testing Technology for Agro-products, Key Laboratory of Agro-product Quality and Safety, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
School of Mechanical Engineering, Hebei University of Technology, Tianjin 300401, China.
Food Chem. 2021 May 15;344:128622. doi: 10.1016/j.foodchem.2020.128622. Epub 2020 Nov 12.
Mitochondrial genes were generally adopted for PCR-based meat adulteration authentication due to their excellent specificity to species and numerous copies in one cell. However, the number of mitochondrial gene copies varies according to cells and tissues, which leads to quantification errors for meat adulteration. To address this problem, single-copy nuclear genes were selected to develop a quantitative method for identifying mutton adulteration in this study. Both single-copy genes specific to sheep species and single-copy reference genes show good linearity between Ct values and series diluted DNA concentrations, with the correlation coefficients of 0.9999 and 0.9993, respectively. Meanwhile, a constant (correction factor) was introduced to transform DNA concentrations into mutton proportions in adulterated meat. With this method, simulated mutton-pork, mutton-chicken and mutton-duck adulteration samples could be accurately quantified with the recovery rates of 89.56%, 107.13% and 95.20%, respectively.
线粒体基因因其对物种的优异特异性和在一个细胞中存在大量拷贝而被广泛应用于基于 PCR 的肉类掺假鉴定。然而，线粒体基因拷贝数会根据细胞和组织而有所变化，这导致了肉类掺假的定量误差。为了解决这个问题，本研究选择了单拷贝核基因来开发一种定量方法，用于识别羊肉掺假。绵羊种特异性的单拷贝基因和单拷贝参考基因的 Ct 值与系列稀释 DNA 浓度之间均表现出良好的线性关系，相关系数分别为 0.9999 和 0.9993。同时，引入了一个常数（校正因子）将 DNA 浓度转换为掺假肉中的羊肉比例。使用该方法，可以准确地定量模拟的羊肉-猪肉、羊肉-鸡肉和羊肉-鸭肉掺假样品，回收率分别为 89.56%、107.13%和 95.20%。
