Aflatoxin – the strongest known chemical carcinogen
Aflatoxin, how toxic is it? Like the title says, the strongest known chemical carcinogen at the moment! So what exactly is it? This article is written by our professional teachers and may be a bit boring, but it is still recommended that you check it out!
<h1>1. What is aflatoxin? </h1>
1. Aflatoxin: Abbreviated in English (AF), is a class of compounds of similar structure containing difuran coumarin.
2. Toxic substances: Aspergillus aflex and parasitic Aspergillus.
3. The toxicity is mainly due to the double bond at the end of the difuran ring and carcinogenicity.
4. Classification: aflatoxin B1, aflatoxin G1, aflatoxin M1. AFB1 is the most common in naturally contaminated foods, and its toxicity and carcinogenicity are also the strongest.
5. Aflatoxin characteristics:
(1) Heat-resistant, rarely destroyed at the general cooking and processing temperature, and toxicity can only be destroyed at 280 ° C.
(2) It is almost insoluble in water, but under alkaline conditions (plus NaOH), soluble in water is eluted.
(3) It is easily soluble in oil and some organic solvents, such as chloroform and methanol, but insoluble in ether, petroleum ether and n-hexane.
6. Toxic production conditions: humidity (80% to 90%), temperature (25 ~ 30 ° C), oxygen (more than 1%). Natural matrix media (rice, corn, peanut flour) yield more toxic than synthetic media.
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<h1>Second, the main food is easy to contaminate</h1>
1. Mainly polluted grains and oils and their products, the most serious of which: peanuts and corn; less polluted: wheat, rice and sorghum.
2. Areas with serious aflatoxin pollution in China: along the Yangtze River and south of the Yangtze River.
Ps: In general, there are more strains in warm and humid areas than in cold and arid areas.
3. Industrially produced fermented products are generally pollution-free, but home-made fermented products can be contaminated.
<h1>3. How toxic is aflatoxin? </h1>
There are three types of toxic effects of aflatoxin: acute toxicity, chronic toxicity and carcinogenicity.
1. Acute toxicity: Aflatoxin is a highly toxic substance with strong liver toxicity. The most sensitive animals are duck chicks, with an LD50 of AFB1 of 0.24 mg/kg.
2. Chronic toxicity: the main manifestations are animal growth disorders, subacute or chronic damage to the liver, decreased albumin, non-protein nitrogen, liver glycogen and vitamin A, and proliferation of liver fibroblasts, the formation of regenerative nodules. Other symptoms include decreased food utilization, weight loss, slow growth and development, infertility of the female animal or low littering.
3. Carcinogenicity: Aflatoxin is the strongest chemical carcinogen found so far, the most important is to induce liver cancer, other can also induce gastric adenocarcinoma, kidney cancer, rectal cancer and breast, ovarian, small intestine and other parts of the tumor.
<h1>4. Preventive measures</h1>
1. Food anti-mildew:
(1) Insect control, anti-lodging;
(2) When harvesting, the moldy corn cob should be eliminated in time, and the corn after threshing should be dried in time;
(3) The moisture content of controlled grain grains is below 13%, usually corn is below 12.5%, and peanut kernels are below 8%;
(4) Low temperature preservation, ventilation, inert gas instead of air or the use of nitrogen filling method to prevent mildew;
(5) Antifungal agent to preserve grain, pay attention to its residue in food and its own toxicity;
(6) The use of radiation can not only prevent mildew, but also improve freshness.
2. Remove toxins:
(1) Selection of mold particles;
(2) Milling processing method: mainly suitable for contaminated rice;
(3) Vegetable oil plus alkali detoxification method: after adding alkali and then washing with water can remove toxins;
(4) Physical removal method: vegetable oil can be added to white clay or activated carbon;
(5) Scrubbing with water;
(6) Ammonia treatment method: in the state of 18kg ammonia pressure and 72 ~ 82 ° C, 98% to 100% of the AF in grain and feed will be removed;
(7) Ultraviolet light irradiation: the effect on liquid food (such as vegetable oil) is better, and the effect on solid food is worse.
3. Formulate the highest allowable amount of AF in food.