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Aflatoxins

 

Aflatoxines

CAS N° [7220-81-7]

- formula : C17H14O6

- molecular weight : 314.3 amu

- mp = 286-289 °C

[α] 546 = -37.4°

- UV absorption : 350 (ε = 22500 in acetonitrile) *

- The aflatoxins fluoresce strongly in ultraviolet light (ca. 365 nm); B1 and B2

produce a blue fluorescence where as G1 and G2 produce green fluorescence.

- LD50 (AFB1) = 5.5 mg/kg (po. male rats)

- NAOL (AFB1) = 0.75 µg/kg bw. day

- LD50 (AFB2) = 1.6 mg/kg (po. duckling)

 

*) Nesheim, M.W. Trucksess, S.W. Page, J. AOAC Int. 82, 251-258, (1999)

[Collaborative Study“]

Aflatoxines

Species

 

B1

B2

G1

G2

M1

M2

Formula

 

C17H12O6

C17H14O6

C17H12O7

C17H14O7

C17H12O7

C17H14

CAS N°

 

[1162-65-8]

[7220-81-7]

[1165-39-5]

[7241-98-7]

[6795-23-9]

[6885-57-0]

MW [amu]

 

312.3

314.3

328.3

330.3

328.3

330.3

IN A FEW LINES :

Turkeys - AflatoxinsAflatoxins were found to be responsible for the deaths of more than 100,000 turkey poults in the South of England in 1960. Peanut meal was given to the turkeys as a by-product of extraction of peanut oil. The by-product was heavily contaminated with Aspergillus flavus, which was found to produce the toxic aflatoxins. Not only poultry is affected by those mycotoxins, but also cattle, pigs and ducklings. Aflatoxins are polycyclic unsaturated and highly-substituted coumarin derivatives. They also are one of the most important mycotoxin groups. Aspergillus parasiticus is the other main producer of aflatoxins.

 

OCCURRENCE :

Both Aspergillus flavus and parasiticus are widely distributed, but A. parasiticus predominates in tropical and sub-tropical countries. They grow on a wide range of foodstuffs. Depending on climate conditions, they may infect foodstuffs before harvesting and contaminate them with aflatoxins. The foodstuffs might be maize, but also edible nuts (peanuts, Brazil-nuts, pistachios, dates, etc). Countries in temperate climate zones are affected by contamination either less or not at all. In those countries, aflatoxicosis can only occur via infected imported foods.

 

The highest prevalence of Aflatoxin B1 (AFB1) is found in maize and peanuts. Such ingestion contributes to the main risk of liver cancer in adults, rather than ingesting Aflatoxin M1 (AFM1) in milk or dairy products. AFM1 was the first aflatoxin metabolite identified found in cows' milk. AFM1 was also reported in other types of dairy products. AFM1 was also found in contaminated stored yellow maize.aflatoxins

 

TOXICITY :

AFB1 is, with effects that vary depending on the species, the strongest natural carcinogen and hepatocarcinogen in animals. The organ most severely affected by this mycotoxin is the liver (lesions, carcinoma, bile-duct proliferation). Kidneys and lungs are also affected. From experimental data, it was estimated that an intake of a food contaminated at 1700 µg/kg over a short period could be sufficient to cause severe liver damage. A single dose above 70,000 µg/kg bw could result in death. An AFB1 level of about 350 µg/kg bw doesn't produce acute aflatoxicosis.

In 1993, the International Agency for Research on Cancer (IARC) rated AFB1 as a class 1 human carcinogen. For this type of carcinogen, there is no threshold dose below which no tumour formation will occur. Only a zero level of concentration will produce a zero risk of liver cancer.

 

Aflatoxin B2 (AFB2) is found in smaller amounts in the same commodities, and has a markedly lower toxicity than AFB1.

 

Aflatoxin G1 (AFG1) has a similar structure and toxicity to that of AFB1. Compared with AFB1, AFG1 has an acute toxicity that is lower and slightly less liver-carcinogenic, but is a more potent kidney carcinogen. LD50 in rats was found to be twice that of AFB1.

 

AFM1 has an LD50 of 16.6 µg/kg bw / day-old duckling. The ability to induce hepatic carcinoma seems to be lower compared with AFB1. Infants may encounter some problems with AFM1 because of their low body weight, high milk consumption, high cell activity and immune system still in development.

 

STABILITY :

aflatoxinsThey are all heat-stable compounds in a dry environment. In general, they have very good heat stability during thermal processing of food and animal feeds. Only partial and variable concentration decreases were observed during autoclaving or roasting, boiling or cooking, extrusion or fermentation processes. For example, baking temperatures are usually not high enough to cause significant losses of AFB1 in bread.


NORMS AND LEGISLATION (maximal levels allowed in feed and food) :

Sampling

- http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:1998:201:0093:0101:EN:PDF
COMMISSION DIRECTIVE 98/53/EC of 16 July 1998 laying down the sampling methods and the methods of analysis for the official control of the levels for certain contaminants in foodstuffs. Official Journal of the European Union L201/93 (17/07/1998)

Max levels :

- http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2004:113:0014:0016:EN:PDF
COMMISSION DIRECTIVE 2004/43/EC of 13 April 2004 amending Directive 98/53/EC and Directive 2002/26/EC as regards sampling methods and methods of analysis for the official control of the levels of aflatoxin and ochratoxin A in food for infants and young children. Official Journal of the European Union L113/14 (20/4/2004)

- http://eur-lex.europa.eu/LexUriServ/site/en/oj/2006/l_364/l_36420061220en00050024.pdf
COMMISSION REGULATION (EC) No 1881/2006 of 19 December 2006 setting maximum levels for certain contaminants in foodstuffs, Official Journal of the European Union L364/5 (20/12/2006)

- http://eur-lex.europa.eu/LexUriServ/site/en/oj/2007/l_255/l_25520070929en00140017.pdf
COMMISSION REGULATION (EC) No 1126/2007 of 28 September 2007 amending Regulation (EC) No 1881/2006 setting maximum levels for certain contaminants in foodstuffs as regards Fusarium toxins in maize and maize products

- http://www.knowmycotoxins.com/regulations.htm#q1
Regulations in EU, non EU countries, Latin America, Asia Pacific, North America, Africa and Middle East

 

ROLE OF CODA-CERVA : aflatoxins

CODA-CERVA is dedicated primarily to scientific research and services in the field of food safety, public and animal health. It also provides analytical facilities to third parties by determining Fusarium toxins in cereals and cereal products. This work is accredited in accordance with European Quality norm ISO 17025.

 

Le CODA-CERVA is the Belgian national Reference Laboratory (NRL) for mycotoxins.
As NRL, CODA-CERVA's work is focused on scientific research to develop a cutting edge in order to help analytical laboratories in developing their own work and/or to use commercial analytical techniques properly. Our main work is:


- Control and comparison of quantitative or qualitative kits for deoxynivalenol (DON) or ochratoxin (OTA) determination sold on the market,


-Organising ring tests,


- Educating the staff of external laboratories, and co-ordination between the National reference laboratory (NRL), European reference laboratory (CEN) and analytical laboratories by organising scientific meetings on the work done by the NRL and emerging research,


- Assisting the authorities with regard to new legislation and regulation concerning emerging mycotoxins by developing new analytical methods.

 

SCIENTIFIC TEAM :

Alfons Callebaut

Philippe Debongnie

Emmanuel Tangni

Bart Huybrechts

Jorina Geys

 

LINKS TO OTHER WEBSITES :

- http://www.mycotox-society.org/
International Society for Mycotoxicology (ISM), Dr Angelo Visconti president), ISPRA, Bari, Italy.

- http://www.fapas.com/index.cfm?newlang=en
FAPAS®, The Food and Environment Research Agency, Sand Hutton, York, UK, YO41 1LZ

- https://www.inra.fr/
Institut National de Recherche Agronomique, 147 rue de l'Université 75338 Paris , France

- http://www.bipea.org
BIPEA, Organizing interlaboratory comparisons tests and assistance for laboratories to manage, maintain and improve their performances, F-92230 Gennevilliers, France.

- http://www.toulouse.inra.fr/layout/set/print/la_securite_mycotoxique