Major breakthroughs in the application of prevention and control technology of mycotoxins in grain and oil in China

Comprehensively improve the quality and safety level of grain and oil

According to the United Nations Food and Agriculture Organization (FAO), about 25% of the world's grain and oil is contaminated by mycotoxins every year. In China, due to the influence of individual planting and storage methods of farmers and the weather of high temperature and humidity in the Yangtze River Basin and South China, grain and oil are more seriously polluted by mycotoxins, resulting in a grain loss of about 31 million tons every year. Mycotoxin pollution has become one of the important factors threatening China's food security, food safety and international trade of grain and oil.

A serious threat to food and food safety

Behind the delicious nutrition, how to ensure the food safety of grain and oil raw materials such as peanuts and corn from the planting of peanuts, corn and other edible agricultural products to the whole industry chain of harvesting, storage and processing products? It is an urgent problem to speed up the research on the control technology of mycotoxin in grain and oil. In August this year, at the on-site demonstration of grain and oil mycotoxin control technology held in Zhangshu City, Jiangxi Province, the organizers demonstrated the mycotoxin control and abatement technology of the whole industry chain of grain and oil planting, harvest, storage and processing, which truly demonstrated the latest achievements in grain and oil mycotoxin control technology in China.

According to experts, mycotoxins are secondary metabolites produced by fungi, including aflatoxin, zearalenone, vomiting toxin and so on. Mycotoxins are highly toxic and carcinogenic, which can pollute all kinds of food and feed agricultural products and seriously harm human and animal health. The pollution of mycotoxins in agricultural products has become a hot issue of food safety all over the world.

According to the United Nations Food and Agriculture Organization (FAO), an average of 25% of the world's grain and oil crops are contaminated with mycotoxins. Affected by climate, storage and other factors, China is one of the countries most seriously polluted by mycotoxins in the world. According to the incomplete statistics of the State Grain Administration, the total grain and oil losses caused by mycotoxin pollution are about 31 million tons each year, exceeding the total grain output of the five western provinces and regions of Shaanxi, Gansu, Qinghai, Ningxia and Xizang.

Mycotoxins are highly toxic and carcinogenic. In 1993, aflatoxin and Fusarium toxin were listed as one of the most dangerous food contaminants by FAO and World Health Organization (WHO). Aflatoxin was listed as grade I carcinogen, which is one of the main factors leading to malignant primary hepatocellular carcinoma, which can lead to liver necrosis and canceration within 24 weeks. In addition, the toxin can also cause acute pathological changes of the kidney and adrenal gland, and can also induce the outbreak of a variety of viral diseases. Among aflatoxins, B1 (AFB1) is the most toxic, which is 10 times as toxic as potassium cyanide and 68 times as toxic as arsenic.

Investigation in China found that excessive AFB1 in major grain and oil products in Jiangsu, Shanghai, Guangdong, Guangxi, Fujian, Sichuan and other areas with high incidence of liver cancer is more common. Among the Fusarium toxins, Tmur2 toxin was the most toxic, and its toxicity was similar to that of AFB1. Fusarium toxin inhibits immunity mainly by inhibiting the synthesis of DNA, RNA and protein, as well as mitochondrial function, cell division and membrane function, causing acute and chronic poisoning in humans and animals, such as vomiting, diarrhea, skin inflammation, antifeedant, nervous system disorder, abortion, malformation and so on. In 1991, 130000 people in Anhui were acutely poisoned by eating wheat flour contaminated with Fusarium toxin.

China's grain and oil is seriously polluted by mycotoxins, which is a serious threat to people's health. In 2006, according to the survey conducted by the Institute of Nutrition and Food Safety of the Chinese Center for Disease Control and Prevention, the detection rate of AFB1 in corn sold in Jiangsu, Shanghai and other nine provinces was 70.27%, and the average and maximum levels of AFB1 were 36.51 μ g / kg and 1098.36 μ g / kg, respectively, which were 1.8times and 54.9times of the national limit standard (national limit standard AFB1 ≤ 20 μ g / kg). According to the investigation by the key Laboratory of Animal Disease Resistance and Nutrition of the Ministry of Education, the detection rate of DON toxin (Deoxynivalenol) in 1081 feed samples from 11 provinces in 2008 was 95.8%, and the rate of exceeding the standard was 17.7% (national limited standard ≤ 1mg/kg). At the end of 2011, aflatoxin M1 in Mengniu milk exceeded the standard, which was also due to the contamination of AFB1 during feed storage. After eating contaminated feed, AFB1 was hydroxylated into aflatoxin M1 in milk, which existed in milk. It can be seen that the mycotoxin contamination of grain and oil products has become an important hidden danger of food safety in our country.

Grain and oil mycotoxin pollution caused huge economic losses, seriously affecting economic, trade and social development. The direct economic loss of grain and oil caused by mycotoxin pollution in China amounts to 68 billion-85 billion yuan every year, while the indirect losses caused by mycotoxin pollution of grain and oil products, such as emergency rescue, medical expenses, aftercare pension, death of livestock and poultry, destruction and treatment of diseased animals, are even more huge.

Dealing with mycotoxin pollution

Countries formulate limited standards and regulations

Because of the serious harmfulness of mycotoxin, countries all over the world have not only formulated the corresponding limit standards and regulations, but also the limit standard value continues to decrease and become more and more strict. The European Commission adopted Directive 1525 ≤ 98 more than 10 years ago, which promulgated the maximum limit of aflatoxins in food in EU countries: the total amount of aflatoxins (B1+B2+G1+G2) in peanuts and their products for human direct consumption was reduced from 20 μ g / kg to 4 μ g / kg, including B1 ≤ 2 μ g / kg. The standard limit of aflatoxin B1 is 10 times of the standard limit in China.

If the EU standard limit is implemented, the annual loss of grain, feed and its products due to postpartum mildew in China will be higher, and the loss of goods value will be more astonishing. Affected by mycotoxin pollution, during the 10 years from 2005 to 2014, there were 3039 violations of food exported to the European Union, of which mycotoxin exceeded the standard accounted for 24.9%, which was the highest proportion in a single event. Excessive mycotoxin has become the biggest obstacle to the export of Chinese agricultural products to the European Union, which has caused huge economic losses to China's grain and oil processing and export enterprises. Therefore, the pollution of grain and oil mycotoxins has become an important bottleneck restricting China's agricultural production, economic development and international trade.

Prevention and control technology of mycotoxin in grain and oil

Make significant progress

China's grain and oil products are seriously contaminated by mycotoxins, resulting in a grain loss of about 31 million tons every year. Strengthening the research on the prevention and control technology of grain and oil mycotoxins has become an urgent need to ensure China's food security, food safety and safeguard national economic interests.

Centering on the urgent need of the country for "prevention and control of grain and oil mycotoxins", the government organized agricultural experts to launch the public welfare industry (agriculture) scientific research project "grain and oil mycotoxin control technology research". Liu Yang, chief scientist of the 973 project and researcher of the Institute of Agricultural products processing of the Chinese Academy of Agricultural Sciences, is the chief expert. Since the launch of the project, the participating units have systematically carried out research on the whole industry chain control technology of grain and oil mycotoxins around the links of field, harvest, storage and processing, and achieved a series of breakthrough research results.

It will be learned from the integrated demonstration site of grain and oil mycotoxin prevention and control technology that in the field biological control, the project uses non-toxin-producing aflatoxin as a biocontrol agent to inhibit the production of aflatoxin in peanuts. After the application of three kinds of biocontrol agents, no aflatoxins were detected in harvested peanuts, and the aflatoxin pollution of peanuts decreased by more than 95% after storage. In the aspect of rapid drying in the post-harvest area, the high-efficiency peanut / corn and rice / wheat box reversing ventilation dryers were displayed on the spot, which realized the rapid drying of grain and oil products, and in the selection of grain and oil mycotoxin pollution, the gravity separation equipment of moldy grain was shown. after the wheat with DON toxin exceeded twice the standard, the content of DON toxin was lower than the national limit standard. In the aspect of grain and oil storage, the aflatoxin prevention and control storage facilities (small storage bag, ton bag storage equipment, medium mobile storage, anti-mildew agent atomization equipment) and supporting application technology were displayed on the spot. In the aspect of mycotoxin detoxification, the field showed that the safe and non-toxic mycotoxin detoxification enzyme preparation was used to remove mycotoxin in grain and oil. after adding detoxification enzyme for 1 hour, the toxin content was reduced below the national limit standard, and the degradation product was non-toxic; the aflatoxin in peanut oil was removed by adsorbent to reduce the aflatoxin in peanut oil to below the national limit standard. In the aspect of mycotoxin detection, the rapid toxin detection kit, gold label test strip and immunochromatography rapid detector were demonstrated on the spot.

Application of biocontrol agents in demonstration base

Reduce damage and increase production of grain and oil

With the strong support of relevant government departments, the scientific research team with Liu Yang as the chief expert is supported by the Agricultural products processing Institute of the Chinese Academy of Agricultural Sciences. Integrated Jiangnan University, Shandong Agricultural University, Nanjing Agricultural Mechanization Research Institute of the Ministry of Agriculture of the Chinese Academy of Agricultural Sciences, Jiangxi Academy of Agricultural Sciences, Oil crop Research Institute of the Chinese Academy of Agricultural Sciences, etc., six domestic grain and oil mycotoxin prevention and control and detection technology research and promotion of advantage units, the use of modern biology and agricultural products processing technology To carry out research on the technology, equipment and products of mycotoxin prevention and control, detoxification and detection of mycotoxins in the planting, harvesting, storage and processing of grain and oil crops such as wheat, corn, rice and peanuts. Through the implementation of this project, China's grain and oil mycotoxin pollution will be effectively reduced, the quality of grain and oil products will be improved, the economic benefits of farmers and grain and oil processing enterprises will be improved, and the export trade of grain and oil products and the healthy development of grain and oil processing industry will be promoted. At the same time, it will achieve the goal of reducing grain and oil damage and increasing production, and protecting the health of consumers.

The reporter learned that the project mainly focuses on grain and oil crops that are easily contaminated by mycotoxins, such as wheat, corn, rice, peanuts, and so on. to carry out research and demonstration of aflatoxin and Fusarium toxin control technology in the process of planting, harvesting, storage, and processing of grain and oil crops. The main research contents include: research and application of mycotoxin (aflatoxin, Fusarium toxin) control technology during the cultivation of grain and oil crops (wheat, corn, rice, peanut); research and development of rapid drying technology and equipment for low-cost post-harvest areas of grain and oil crops (wheat, corn, rice, peanut); research and application of modern processing and removal technology of grain and oil mycotoxins (aflatoxin, Fusarium toxin) Research and application of biodegradation and removal technology of grain and oil mycotoxins; research and development of detection technology and equipment of grain and oil mycotoxins; establishment of standardized system for prevention and control of grain and oil mycotoxins and establishment of HACCP system for safety control of grain and oil processing mycotoxins.

In Jiangxi camphor tree "grain and oil mycotoxin control technology" demonstration peanut base, the reporter saw that large tracts of peanuts have entered the harvest period. Chief expert Liu Yang and team members introduced a simple and easy-to-use biocontrol agent for aflatoxin and toxin-producing bacteria in the field. It is reported that the biocontrol agent can effectively prevent and control the production of aflatoxin in the field. The biocontrol agent was prepared by using wheat as substrate and cultured for 5 days to produce a large amount of spore production under the condition of 30 ℃. In the late flowering stage of peanut (50 to 65 days of sowing), the biocontrol agent was sown in the peanut field with a certain dose and slightly irrigated once after the strain was applied to facilitate the colonization of the biocontrol strain in the soil.

In addition, in the demonstration base, experts also introduced the application effect of aflatoxin biocontrol agent in peanut field. After the application of biocontrol agent, the proportion of aflatoxin-producing aflatoxin in soil was reduced by more than 90%. After one month of storage of peanuts after harvest, no aflatoxin was detected, while the content of aflatoxin B1 in the control group was close to the national limit (20 μ g / kg). Liu Yang told reporters that the biocontrol agent has the advantages of low production cost, simple application, effective application for many years, and can continue to play a role in inhibiting aflatoxin during storage; the biocontrol agent can also be used for the field control of aflatoxin in corn.

Experts and enterprise representatives at the meeting affirmed the effectiveness of the above-mentioned technologies, products, and equipment in controlling grain and oil mycotoxins, and representatives of grain and oil enterprises also expressed their desire for technical cooperation to reduce grain and oil mycotoxin pollution and improve the quality and safety level of grain and oil. Experts attending the meeting unanimously suggested that we should speed up the popularization, application and popularization of these efficient technologies, ensure China's food security and food safety, and safeguard the healthy development of international trade in grain and oil.