Do you know that a little serious moldy corn can kill two ducklings? The culprit behind this phenomenon is the 40 micrograms of aflatoxin contained in corn . Recently, the rapid and easy on-site detection method for this toxin has successfully developed by experts from the School of Life Sciences of Shanghai University. The qualitative detection technology will greatly shorten the inspection time of aflatoxin and help to further improve the multi-level and multi-link food testing in China.
Aflatoxin is a toxin produced by aspergillus flavus that can damage the liver and may lead to liver cancer. Aflatoxin is a highly toxic substance and is listed as a Class I carcinogen by the International Agency for Research on Cancer. If it is taken for a long time, it will induce liver cancer and tumors. However, aflatoxin is widely contaminated and exists in the production, transportation, storage, processing and sales of food and feed. The main sources of aflatoxin include corn, peanuts, cottonseed, and tree nuts.
To protect the people health, China and the rest of the world have established limit standards of aflatoxin in food testing. But the related detection technologies always have problems such as complicated operation, long time-consuming, and low precision, which brings certain difficulties to the actual monitoring.
Internationally, the most advanced aflatoxin detection method is the fluorescence spectroscopy based on immunoaffinity column. Although the sensitivity of it is high, fast and simple, the cost is high. The unit price of disposable consumables is as high as 160 yuan, which makes the technology difficult to popularize and apply. At the same time, most of the testing methods in existence are carried out in the laboratory, and the process of food safety inspection is out of demand in the standard.
How to develop a rapid and effective aflatoxin detection technology in consideration of China's needs? Since 2002 Professor Chen Yuguang from the School of Life Sciences of Shanghai University has led research and achieved relevant results. In simple terms, Professor Chen’s entire testing process is composed of three injections.
The first needle is that the extract of the substance is injected into the immunoaffinity column and to make aflatoxin that may be contained in the sample adhere to the immunoaffinity column. The second needle is that injecting the pure water into the test and further rinse the other substances in the sample. The third needle is that injecting the eluent to remove aflatoxin on the immunoaffinity column. The aspergillus is stripped into the test tube and placed directly into the portable fluorescence detector to observe the yes or no results. The total time is no more than 30 minutes, and the cost is only tens of dollars. Inspectable items range from solids like pork and corn to liquids like milk.
According to experts, this new detection method is highly sensitive, easy to operate, and short in time. It can detect a variety of major aflatoxins with good repeatability,for example aflatoxin b1,aflatoxin m1, etc. China has a large number of individual producers, inbreeding, feed, and food production, often need to take samples on the spot to monitor food safety. Therefore, the emergence of this new detection technology is more in line with China's national conditions. This method enables food safety monitoring to be carried out in supermarkets and farmhouses, providing technical support for the entire process from the head to the table. Gu Ming, Director of the Microbiology Department of the Food Inspection Center of Shanghai Entry-Exit Inspection and Quarantine Bureau said, this technology is a technological innovation with independent intellectual property rights in China. In the detection process, it is fast, sensitive, easy to operate, suitable for on-site inspection and use. At the same time, compared with similar foreign technology products, the cost is greatly reduced under the premise of ensuring the quality of testing.