College of Food Science and Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China.
Molecules. 2022 May 7;27(9):3017. doi: 10.3390/molecules27093017.
Food ingredient adulteration, especially the adulteration of milk and dairy products, is one of the important issues of food safety. The large price difference between camel milk powder, ovine, and bovine milk powder may be an incentive for the incorporation of ovine and bovine derived foods in camel milk products. This study evaluated the use of ordinary PCR and real-time PCR for the detection of camel milk powder adulteration based on the presence of ovine and bovine milk components. DNA was extracted from camel, ovine, and bovine milk powder using a deep-processed product column DNA extraction kit. The quality of the extracted DNA was detected by amplifying the target sequence from the mitochondrial Cytb gene, and the extracted DNA was used for the identification of milk powder based on PCR analysis. In addition, PCR-based methods (both ordinary PCR and real-time PCR) were used to detect laboratory adulteration models of milk powder using primers targeting mitochondrial genes. The results show that the ordinary PCR method had better sensitivity and could qualitatively detect ovine and bovine milk components in the range of 1% to 100% in camel milk powder. The commercial camel milk powder was used to verify the practicability of this method. The real-time PCR normalization system has a good exponential correlation (R = 0.9822 and 0.9923) between ovine or bovine content and Ct ratio (specific/internal reference gene) and allows for the quantitative determination of ovine or bovine milk contents in adulterated camel milk powder samples. Accuracy was effectively validated using simulated adulterated samples, with recoveries ranging from 80% to 110% with a coefficient of variation of less than 7%, exhibiting sufficient parameters of trueness. The ordinary PCR qualitative detection and real-time PCR quantitative detection method established in this study proved to be a specific, sensitive, and effective technology, which is expected to be used for market detection.
食品成分掺假,尤其是牛奶和乳制品的掺假,是食品安全的重要问题之一。骆驼奶粉、绵羊奶和牛奶粉之间的巨大价格差异可能是将绵羊和牛源食品掺入骆驼奶产品中的诱因。本研究评估了普通 PCR 和实时 PCR 基于存在绵羊和牛乳成分用于检测骆驼奶粉掺假的用途。使用深度处理产品柱 DNA 提取试剂盒从骆驼、绵羊和牛奶粉中提取 DNA。通过扩增线粒体 Cytb 基因的靶序列来检测提取 DNA 的质量,并基于 PCR 分析使用针对奶粉的鉴定提取 DNA。此外,还使用基于 PCR 的方法(普通 PCR 和实时 PCR)使用针对线粒体基因的引物检测奶粉的实验室掺假模型。结果表明,普通 PCR 方法具有更好的灵敏度,能够定性检测骆驼奶粉中 1%至 100%的绵羊和牛乳成分。使用商业骆驼奶粉验证了该方法的实用性。实时 PCR 归一化系统在绵羊或牛含量和 Ct 比值(特异性/内部参考基因)之间具有良好的指数相关性(R = 0.9822 和 0.9923),允许定量测定掺假骆驼奶粉样品中的绵羊或牛乳含量。使用模拟掺假样品有效地验证了准确性,回收率在 80%至 110%之间,变异系数小于 7%,表现出足够的真实性参数。本研究中建立的普通 PCR 定性检测和实时 PCR 定量检测方法被证明是一种特异性、灵敏和有效的技术,有望用于市场检测。