Chinese scientists have recently developed a low-field NMR analyzer that can quickly detect whether cow's milk is adulterated. The use of this method for detecting cow's milk is simple in operation and low in cost, and is expected to effectively solve the problem that the milk is adulterated and the doping is difficult to detect.
China's dairy industry has entered a golden period of rapid development. However, the emergence of the "melamine" incident has caused a fatal blow to the dairy industry, and the adulteration of raw milk and dairy products has also received attention from all sectors of society. Dairy safety has become a food safety issue of greatest concern to the public.
According to Professor Han Jianzhong, the inventor of this test method and the Zhejiang Gongshang University, the research of the research group is based on the working principle of low-field NMR, which uses the activity characteristics of hydrogen nuclei in the magnetic field to trace the relevant hydrogen atoms in the tested substances, especially It is water, including bound water in food, water that is not easy to flow, and free water, and observes changes in its state of existence over time.
Han Jianzhong said that this method can not only identify pure milk and adulterated milk, but also has a good distinguishing effect on different adulterated forms of common adulterated milk. Moreover, experiments have shown that different adulterated samples are distributed with a certain proportion of adulteration. Therefore, this technique can also be used to monitor changes in the quality of milk caused by adulterants and their concentrations.
At present, adulterations commonly used for milk are mixed with water, salt, urea, soybean milk, and reconstituted milk. Physical and chemical methods are usually used for their detection. However, physical and chemical testing is targeted. If it is not clear what the additive is, it is necessary to conduct inspection and inspection one by one, which is time-consuming and laborious. However, once the added components have no ready-made detection method, the detection is difficult to perform. Even more difficult is that these methods are not suitable for large-scale sampling inspection in actual production.
At present, the multi-index milk component rapid detector on the international market is not only expensive, but also limited to known additives, which are often unacceptable to most manufacturers. The team believes that, in contrast, low-field NMR combined with principal component analysis is simple, fast, and inexpensive, can be used for detection of unspecified adulterated substances, and can be applied to sampling of large quantities of samples.
The results have now been identified through the results of relevant experts. Experts believe that this new detection technology provides new research ideas and effective means for modern dairy companies and relevant regulatory authorities to monitor, evaluate and control the quality of dairy products.