What Is Ochratoxin A and Its Basic Features

• Posted by Samantha James January 31, 2021 Filed in Arts & Culture #dhsfgj  205 views
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  Ochratoxin A (OTA) is a secondary metabolite produced by a variety of Aspergillus and Penicillium fungi. It mainly contaminates grain crops. It is detected in a variety of grains and products.

  After humans and animals eat food contaminated by OTA, it will cause the accumulation of OTA in the body and slow metabolism. OTA mainly endangers human and animal kidneys. It is highly carcinogenic, teratogenic and mutagenic. It is believed to be related to human Balkan nephropathy and urinary system tumors. The International Agency for Research on Cancer has positioned it as a 2B carcinogen. The Food and Agriculture Organization of the United Nations and the World Health Organization recommend that the weekly intake of OTA should not exceed 100 ng/kg of body weight. There is currently no evaluation study on the dietary intake of OTA in the population, but the national food safety standards stipulate that the limit OTA standard in grains and other food products is 5ug/kg.

  1. The basic characteristics of OTA

  OTA (molecular formula: C20H18Cl NO6; molecular mass: 403.8 Da), that is, 7-carboxy-5-chloro-8-hydroxy-3,4-dihydro-3-R-methylisocoumarin-7-L-β- Phenylalanine is a white, odorless, heat-stable solid crystal, which is made up of chlorinated isocoumarin analogues and phenylalanine connected by an amide bond. Its melting point is about 168-173°C. Ochratoxin A is poorly water-soluble, soluble in sodium bicarbonate solution, and easily soluble in organic solvents such as alcohol, ketone and chloroform. OTA was first discovered in the Balkans. Balkan epidemic nephropathy and its related urinary tract tumors are closely related to the pollution of OTA. Balkan epidemic nephropathy is a chronic and progressive disease, and long-term (6--10 years) patients may cause irreversibility. Kidney failure. In addition, OTA is also considered to be the main cause of kidney disease in Tunisia. The toxic mechanism of OTA may be: 1) inhibit the activity of phenylalanine-tRNA synthetase, thereby inhibiting protein synthesis; 2) cause abnormal mitochondrial function, thereby inhibiting cell energy metabolism; 3) oxidative stress caused by OTA makes it carcinogenic.

  2. The harm of OTA to the health of pigs

  OTA is a kind of mycotoxin produced by Aspergillus ochracea and Penicillium pure green. It is widely present in feed. Pigs are more sensitive to it and have a synergistic effect with aflatoxin. OTA has a strong diuretic effect and mainly damages the kidneys of pigs. Clinical manifestations include increased drinking water, frequent urination, growth retardation, reduced feed utilization, and body stiffness. A large amount of toxins can also cause liver damage in pigs, leading to inflammation or necrosis of the intestinal mucosa, neurotoxicity and other symptoms. In addition, it can also inhibit the activity of cellular immunity, leading to immunosuppression in pigs. Other clinical hazards are also manifested as diarrhea, anorexia, dehydration and so on.

  3. Preventive measures for farmers

  Under the pig-raising philosophy that prevention is more important than cure, the prevention of pigs starts with the most basic and important "eating". Anti-mold and detoxification of feed and raw materials are currently the two most critical steps to prevent molds and mycotoxins from harming pigs. Among them, anti-mold work of feed and raw materials is the most important.

  1). Control the source. As far as possible, choose the raw materials with normal color, low moisture content, low impurity content and short storage time. The storage warehouse should be kept dry, ventilated, clean, and the temperature and humidity should be controlled within an appropriate range. At the same time, mycotoxin inhibitors should be added to the stored raw materials to inhibit the mold from occurring in the raw materials stored in the warehouse. Real-time monitoring and detection of mycotoxins in the feed should be carried out, and appropriate amount of mold release agents and adsorbents should be added to promptly pick or destroy raw materials with excessive toxins.

  2). Strengthen feeding management. Do a good job in the vaccine immunization of pigs to improve the resistance of pigs; do a good job in raising environmental hygiene, keep the environment ventilated, dry, and clean, and do frequent cleaning and frequent disinfection. Feeding pigs should strictly control their food intake, try to avoid mold problems caused by excess feed in the trough, and clean up in time if the excess feed is over. During the feeding process, some nutritional antioxidants should be supplemented timely and appropriately to reduce or prevent the harm of mycotoxins to pigs.