China Achieves Major Breakthrough in the Application of Mycotoxin Prevention and Control Technology for Grain and Oil Crops
Comprehensively Elevating the Quality and Safety Level of Grain and Oil Products
According to statistics from the Food and Agriculture Organization of the United Nations (FAO), approximately 25% of the world's grain and oil crops are contaminated by mycotoxins each year. In China, due to individual farmer planting and storage practices as well as the high-temperature and high-humidity weather in the Yangtze River Basin and South China region, grain and oil crops are more severely contaminated by mycotoxins, resulting in annual grain losses of approximately 31 million tons. Mycotoxin contamination has become one of the important factors threatening China's food security, food safety and international trade in grain and oil products.
A Serious Threat to Food and Feed Safety
Behind the deliciousness and nutrition, how can food safety of peanut, corn and other grain and oil raw materials be guaranteed across the entire industry chain, from the cultivation of edible agricultural products such as peanuts and corn at the source, all the way through harvesting, storage and processing? Accelerating research on mycotoxin control technology for grain and oil crops has become an urgent major issue. In August of this year, at the on-site demonstration meeting on integrated mycotoxin control technology for grain and oil crops held in Zhangshu City, Jiangxi Province, the organizers conducted an integrated demonstration of mycotoxin control and reduction technologies across the entire industry chain of grain and oil crop cultivation, harvesting, storage and processing, truly showcasing China's latest achievements in mycotoxin control technology for grain and oil crops.
Experts explained that mycotoxins are secondary metabolites produced by fungi, mainly including aflatoxins, zearalenone, deoxynivalenol and others. Mycotoxins are highly toxic and carcinogenic, capable of contaminating all types of edible and feed agricultural products, seriously endangering human and animal health. The issue of mycotoxin contamination in agricultural products has become a food safety hot topic of great concern to countries around the world.
According to statistics from the Food and Agriculture Organization of the United Nations (FAO), an average of 25% of the world's grain and oil crops are contaminated by mycotoxins. Affected by climate and storage factors, China is one of the countries most severely affected by mycotoxin contamination in the world. According to incomplete statistics from the State Administration of Grain, annual grain and oil losses caused by mycotoxin contamination total approximately 31 million tons, exceeding the combined annual grain output of five western provinces and regions: Shaanxi, Gansu, Qinghai, Ningxia and Tibet.
Mycotoxins are highly toxic and carcinogenic. In 1993, aflatoxins and Fusarium toxins were listed by the FAO and the World Health Organization (WHO) as among the most dangerous naturally occurring food contaminants. Aflatoxins were further classified as a Class I carcinogen and are one of the main factors inducing malignant primary hepatocellular carcinoma, capable of causing liver necrosis and cancerous changes within 24 weeks. In addition, these toxins can cause acute lesions of the kidneys and adrenal glands, and can also trigger outbreaks and epidemics of various viral diseases. Among aflatoxins, B1 (AFB1) is the most toxic, with toxicity 10 times that of potassium cyanide and 68 times that of arsenic, making it one of the strongest known chemical carcinogens.
Surveys in China have found that AFB1 levels exceeding standards are relatively common in major grain and oil products in areas with high liver cancer incidence such as Jiangsu, Shanghai, Guangdong, Guangxi, Fujian and Sichuan. Among Fusarium toxins, T-2 toxin is the most toxic, with toxicity similar to that of AFB1. Fusarium toxins mainly suppress immunity by inhibiting the synthesis of DNA, RNA and proteins as well as inhibiting mitochondrial function, cell division and membrane function, causing acute and chronic poisoning in humans and animals, such as vomiting, diarrhea, skin inflammation, refusal to eat, nervous system disorders, miscarriage and deformities. In 1991, 130,000 people in Anhui suffered acute poisoning after consuming wheat flour contaminated with Fusarium toxins.
China's grain and oil crops are severely contaminated by mycotoxins, seriously threatening public health. In 2006, a survey by the Institute of Nutrition and Food Safety of the Chinese Center for Disease Control and Prevention found that the detection rate of AFB1 in market-sold corn in nine provinces and municipalities including Jiangsu and Shanghai was 70.27%, with average and maximum levels of 36.51 μg/kg and 1098.36 μg/kg respectively, which were 1.8 times and 54.9 times the national limit standard (national limit standard AFB1 ≤ 20 μg/kg). A survey by the Key Laboratory of Animal Disease-Resistant Nutrition of the Ministry of Education found that in the 2008-2009 period, the detection rate of DON toxin (Deoxynivalenol) in 1081 feed samples from 11 provinces nationwide was 95.8%, with a rate of exceeding standards of 17.7% (national limit standard ≤ 1 mg/kg). At the end of 2011, Mengniu milk was found to have aflatoxin M1 levels exceeding standards; the cause was also AFB1 contamination during the storage of dairy cattle feed. After cows consumed contaminated feed, AFB1 was converted into aflatoxin M1 through hydroxylation in the body and was present in the milk. It can be seen that the issue of mycotoxin contamination in grain and oil products has become an important hidden danger to China's food safety.
Mycotoxin contamination of grain and oil crops causes enormous economic losses, seriously affecting the economy, trade and social development. China's annual direct economic losses from mycotoxin contamination of grain and oil crops amount to 68 billion to 85 billion yuan, while indirect losses caused by mycotoxin contamination of grain and oil products, including emergency rescue, medical expenses, follow-up compensation, livestock and poultry deaths from disease and destruction and disposal of diseased animals, are even more enormous.
Responding to Mycotoxin Contamination
Countries Establish Limit Standards and Regulations
Due to the serious hazards of mycotoxins, countries around the world have not only established corresponding limit standards and regulations, but their limit values have been continuously lowered and made increasingly strict. The European Commission adopted Directive 1525/98 more than 10 years ago, publishing the maximum limit standards for aflatoxins in food in EU countries: the total aflatoxin content (B1+B2+G1+G2) in peanuts and their products for direct human consumption was reduced from 20 μg/kg to 4 μg/kg, with B1 ≤ 2 μg/kg. This aflatoxin B1 standard limit is 1/10 of China's standard limit.
If the EU standard limits were implemented, the quantity of grain, feed and their products lost to post-harvest mold in China each year would be even higher, and the loss in goods value would be even more staggering. Affected by mycotoxin contamination, during the 10 years from 2005 to 2014, there were 3039 cases of Chinese food exports to the EU being found in violation, of which mycotoxin exceeding standards accounted for 24.9%, the highest proportion among single events. Mycotoxin exceeding standards has become the greatest obstacle to China's agricultural product exports to the EU, causing enormous economic losses to China's grain and oil processing and export enterprises. Therefore, the issue of mycotoxin contamination in grain and oil crops has become an important bottleneck restricting China's agricultural production, economic development and international trade.
Mycotoxin Prevention and Control Technology for Grain and Oil Crops
Achieves Major Progress
China's grain and oil products are severely contaminated by mycotoxins, causing annual grain losses of approximately 31 million tons. Strengthening research on mycotoxin prevention and control technology for grain and oil crops has become an urgent need for safeguarding China's food security, food safety and national economic interests.
Focusing on the urgent national need of "mycotoxin prevention and control for grain and oil crops," the government organized agricultural experts to launch a special public welfare industry (agriculture) scientific research project titled "Research on Mycotoxin Control Technology for Grain and Oil Crops," with Liu Yang, chief scientist of the 973 Project and researcher at the Institute of Food Science and Technology of the Chinese Academy of Agricultural Sciences, as chief expert. Since the project was launched, all participating institutions have systematically carried out research on full-industry-chain mycotoxin control technology for grain and oil crops covering field, harvest, storage and processing stages, achieving a series of breakthrough research results.
According to information from the on-site demonstration meeting on integrated mycotoxin prevention and control technology for grain and oil crops, in the area of field biological control, the project used non-toxigenic Aspergillus flavus as a biocontrol agent to suppress aflatoxin production in peanuts. After applying 3 types of biocontrol agents, no aflatoxins were detected in harvested peanuts, and after storage, aflatoxin contamination in peanuts was reduced by more than 95%. In the area of rapid post-harvest drying at the production site, a high-efficiency box-type reversing ventilation dryer for peanuts/corn and rice/wheat was demonstrated on-site, achieving rapid drying of grain and oil products. In the area of sorting contaminated grain and oil crops, moldy grain gravity separation equipment was demonstrated on-site; after sorting wheat with DON toxin levels 1 time above the standard, the DON toxin content fell below the national limit standard. In the area of grain and oil storage, aflatoxin prevention and control storage facilities (small storage bags, ton-bag storage equipment, medium-sized mobile storage, anti-mold agent atomization equipment) and supporting application technologies were demonstrated on-site. In the area of mycotoxin detoxification, on-site demonstrations showed the use of safe, non-toxic mycotoxin-detoxifying enzyme preparations to remove mycotoxins from grain and oil products; after adding detoxifying enzymes to products exceeding standards by 5 times and treating for 1 hour, toxin levels dropped below national limit standards, with non-toxic degradation products. Adsorbents were used to remove aflatoxins from peanut oil, reducing aflatoxin in peanut oil exceeding standards by 1 time to below national limit standards. In the area of mycotoxin detection, rapid toxin detection kits with 5-10 times improved sensitivity, gold-labeled test strips and immunochromatographic rapid detectors were demonstrated on-site.
Demonstration Base Applies Biocontrol Agents
Helping Grain and Oil Crops Reduce Losses and Increase Output
With strong support from relevant government departments, the research team led by chief expert Liu Yang, relying on the Institute of Food Science and Technology of the Chinese Academy of Agricultural Sciences, integrated 6 leading domestic institutions in mycotoxin prevention and control and detection technology research and extension for grain and oil crops, including Jiangnan University, Shandong Agricultural University, the Nanjing Institute of Agricultural Mechanization of the Ministry of Agriculture of the Chinese Academy of Agricultural Sciences, Jiangxi Academy of Agricultural Sciences and the Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences. Using modern biological and agricultural product processing technologies, they carried out research on mycotoxin prevention and control, detoxification and detection technologies, equipment and products during the cultivation, harvesting, storage and processing of grain and oil crops such as wheat, corn, rice and peanuts. Through the implementation of this project, mycotoxin contamination of grain and oil crops in China 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 enhanced, export trade of grain and oil products and the healthy development of the grain and oil processing industry will be promoted, while also achieving the goals of reducing losses and increasing output of grain and oil crops and protecting consumer health.
The reporter learned that the project research mainly targets grain and oil crops susceptible to mycotoxin contamination, such as wheat, corn, rice and peanuts, conducting research and demonstration on aflatoxin and Fusarium toxin control technologies during cultivation, harvesting, storage and processing of grain and oil crops. The main research contents include: research and application of mycotoxin (aflatoxin, Fusarium toxin) control technologies during the cultivation of grain and oil crops (wheat, corn, rice, peanuts); research and equipment development of low-cost rapid drying technology at the production site after harvesting of grain and oil crops (wheat, corn, rice, peanuts); research and application of modern processing removal technology for mycotoxins (aflatoxin, Fusarium toxin) in grain and oil crops; research and application of biodegradation and removal technology for mycotoxins in grain and oil crops; research and equipment development of mycotoxin detection technology for grain and oil crops; establishment of a standardization system for mycotoxin prevention and control in grain and oil crops and a HACCP system for mycotoxin safety control in grain and oil processing.
At the demonstration peanut base of the "Research on Mycotoxin Control Technology for Grain and Oil Crops" in Zhangshu, Jiangxi, the reporter saw that large fields of peanuts had entered the harvest period. Chief expert Liu Yang and team members introduced in the fields a simple and easy-to-use biocontrol agent that suppresses aflatoxins and toxigenic fungi. According to the introduction, this biocontrol agent can efficiently prevent and control aflatoxin production when applied in the field. The biocontrol agent uses wheat as a substrate; under conditions of 30°C, it is cultured for 5 days until massive sporulation occurs to produce the biocontrol preparation. During the late flowering stage of peanuts (50 to 65 days after sowing), it is spread in peanut fields at a certain dosage, and after applying the strain, light irrigation is applied once to facilitate colonization of the biocontrol strain in the soil.
In addition, at the demonstration base, experts also introduced the field application effects of the aflatoxin biocontrol agent in peanut fields. After applying the biocontrol agent, the proportion of toxigenic Aspergillus flavus in the soil decreased by more than 90%. After 1 month of storage following harvest, no aflatoxins were detected in the peanuts, while in the control group, the aflatoxin B1 content was close to the national limit standard (20 μg/kg). Liu Yang told the reporter that the biocontrol agent has low production cost, is simple to apply, remains effective for multiple years after a single application, and can continue to exert its aflatoxin-suppressing effect during storage. This biocontrol agent can similarly be used for field control of aflatoxins in corn.
Experts and enterprise representatives at the meeting affirmed the effectiveness of the above technologies, products and equipment in controlling mycotoxins in grain and oil crops. Grain and oil enterprise representatives also expressed their desire for technical cooperation to reduce mycotoxin contamination in grain and oil crops and improve the quality and safety level of grain and oil products. Experts at the meeting unanimously recommended accelerating the promotion and popularization of these high-efficiency technologies to ensure China's food security and food safety and maintain the healthy development of international trade in grain and oil products.