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Mycotoxins and the food chain

Mycotoxins and the food chain. Kofi Aidoo Professor of Food safety, Glasgow Caledonian University. Causes of food poisoning. Bacteria or their toxins Viruses Chemicals Poisonous plants ( eg. deadly nightshade ) and fungi ( poisonous mushrooms )

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Mycotoxins and the food chain

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  1. Mycotoxins and the food chain Kofi Aidoo Professor of Food safety, Glasgow Caledonian University REHIS Trainers' Seminar, October 2009

  2. Causes of food poisoning • Bacteria or their toxins • Viruses • Chemicals • Poisonous plants (eg.deadly nightshade) and fungi (poisonous mushrooms) • Natural toxicants - plants, fish, mycotoxins • Allergy - not the result of food being                contaminated. REHIS Trainers' Seminar, October 2009

  3. Mycotoxins • Mycotoxins - toxins produced by micro-fungi eg Aspergillus spp. (Macro-fungi, eg. mushrooms) • Mycotoxins have 4 basic toxicity - acute, chronic, mutagenic, teratogenic. REHIS Trainers' Seminar, October 2009

  4. Mycotoxins • Toxigenic moulds - Aspergillus, Penicillium, Fusarium arefound on human food and animal feed - animal products, eg meat or milk may become contaminated. • Other toxigenic moulds may be present in the environment. REHIS Trainers' Seminar, October 2009

  5. Fungal toxins • Unlike bacterial toxins, fungal toxins (mycotoxins) are not proteins and therefore are not usually detectable by the immune systems of humans and animals REHIS Trainers' Seminar, October 2009

  6. Symptoms of mycotoxicosis • Symptoms are diverse • Some elicit few symptoms until death • Severe effects include (a) skin necrosis and b) immunosuppression REHIS Trainers' Seminar, October 2009

  7. Rhizopus spp. Byssochlamys spp. Claviceps spp. Eupenicillium spp. Eurotium spp. Neosartorya spp. Talaromyces spp. Alternaria spp. Aspergillus spp. Penicillium spp. Fusarium spp. Cladosporium spp. Geotrichum candidum Paecilomyces variotii Phomopsis spp. Stachybotrys spp. Trichoderma viride Wallemia sebi Mycotoxigenic filamentous fungi REHIS Trainers' Seminar, October 2009

  8. Types of mycotoxins • There are over 300 mycotoxins but the commonly occurring ones in food and feed. • About 20 mycotoxins occur in food at levels and frequency to be of food safety concern. REHIS Trainers' Seminar, October 2009

  9. Aflatoxins (B1, B2, G1, G2, M1) Ochratoxin A Zearalenone Fumonisins Trichothecenes Patulin Moniliform Sterigmatocystin Citrinin Cyclopiazonic acid Kojic acid Maltoryzine ß-nitropropionic acid Aspergillic acid Penicillic acid Roquefortine C Mycotoxins associated with food and feed REHIS Trainers' Seminar, October 2009

  10. Mycotoxins and world food supply • It is estimated that 25% of world’s food crops are affected annually by variable levels of mycotoxins. • >100 countries have regulations regarding levels of mycotoxins in food and feed. REHIS Trainers' Seminar, October 2009

  11. Principal toxigenic moulds and food crops • Aspergillus ochraceus - cereals, nuts, pulses, oilseeds, corn….. ochratoxins, penicillic acid • A. flavus or A. parasiticus - cereals, nuts, root crops, oilseeds, pulses….…aflatoxins • Penicillium spp. - cereals, root crops, nuts, beans…………..ochratoxin, patulin, citrinin • Fusarium spp. - cereals, root crops ….. T-2 toxins, zearalenone REHIS Trainers' Seminar, October 2009

  12. Toxicological effects of AFLATOXINS • the most toxic mycotoxin (in particular AFB1) • they are genotoxic carcinogens • they cause cancer and have been linked to liver cancer in a number of developing countries • not possible to determine threshold below which this toxin has no effect • therefore No Tolerable Daily Intake has been recommended. REHIS Trainers' Seminar, October 2009

  13. Aflatoxin M1 • Aflatoxin M1 is an oxidative metabolite of Aflatoxin B1.(ie produced from AFB1 in mammals) • Aflatoxin M1 may be present in milk and dairy products. • Aflatoxin M1 has been reported in human breast milk particularly in developing countries - Middle East, Africa, South Asia. REHIS Trainers' Seminar, October 2009

  14. Toxicological effects of OCHRATOXIN A • damages and causes cancer of the kidneys (shown in laboratory animals); • has been associated with development of Balkan Endemic Nephropathy - a specific type of kidney disease in certain human population; • EU have set a TDI of <5 ng/kg per kg body wt per day (kg/bw/d) REHIS Trainers' Seminar, October 2009

  15. Toxicological effects of PATULIN • exhibits strong antibiotic activity against bacteria; • causes haemorrhage, oedema and dilation of the intestinal tract of experimental animals • EU have endorsed a provisional maximum TDI of 0.4 µg/kg bw/d REHIS Trainers' Seminar, October 2009

  16. Toxicological effects of FUSARIAL TOXINS • Fumonisins cause kidney and liver damage; oesophageal cancer; TDI of 2µg/kg bw/d • Trichothecenes (DON, T-2, HT-2 toxins) causes growth retardation, reproductive and intestinal effects, also affects immune systems; a group TDI of 1 µg/kg. • Zearalenone has oestrogenic effects. A possible incidence of precocious puberty associated with zearalenone in Hungary; EU TDI of 0.2 µg/kg bw/d. REHIS Trainers' Seminar, October 2009

  17. Human mycotoxicosis In 1967, 26 Taiwanese in a farming community became ill after eating contaminated rice; 3 children died. Cause of death: Contaminated rice showed >200 µg aflatoxin B1/kg. REHIS Trainers' Seminar, October 2009

  18. Human mycotoxicosis In 1974, an outbreak of hepatitis in India affected 400 people resulting in 100 deaths; Cause of death: aflatoxins in corn ( >15 mg/kg) REHIS Trainers' Seminar, October 2009

  19. Human mycotoxicosis In 2004, one of the largest aflatoxicosis outbreak occurred in rural Kenya resulting in 317 cases and 125 deaths. Cause of death: corn contaminated with 4,400 µg/kg of aflatoxin B1, 220 times higher than Kenyan regulatory limit for food. REHIS Trainers' Seminar, October 2009

  20. Mycotoxins and EU Regulation 1881/2006 REHIS Trainers' Seminar, October 2009

  21. EC Legislative limits of mycotoxins in food and feedstuffs (EC 1881/2006) • Aflatoxins in oilseed 2 ppb AFB1 (µg/kg) & 4 ppb total aflatoxin; 8 & 15 ppb respectively for oilseeds for further processing. • For almonds, hazelnuts, pistachios for direct human consumption 5 ppb for AFB1 & 10 ppb for total. • Aflatoxins B1 & M1 in baby milk/food < 0.1 & 0.05 ppb respectively. • OTA - 10 ppb in dried vine fruits & soluble coffee;5 ppb for roasted coffee; 6-10 ppb for instant coffee; 2 ppb for wine and grape juice; 0.2 ppb for beer • OTA - 15-30 ppb in spices applicable from 1 July 2010 REHIS Trainers' Seminar, October 2009

  22. EC Legislative limits of Fusarium toxins in food • DON- 500µg/kg in cereal based products and 100µg/kg for cereal based products in baby food • T-2 and HT-2 toxins - 200µg/kg in cereal based products and 50µg/kg for cereal based products in baby food. • Zearalenone- 50µg/kg in cereal based products and 20µg/kg for cereal based products in baby food. • Fumonisins - 500µg/kg in corn based products; 200µg/kg in cornflakes and 100µg/kg in baby food REHIS Trainers' Seminar, October 2009

  23. FSA’s strategy on mycotoxins Divided into 3 major themes: • (i) maintain current awareness of levels of mycotoxin contamination of foods in general, • (ii) identify factors contributing to occurrence of mycotoxins and thereby provide information necessary to manage the risk of mycotoxin formation and • (iii) provide stakeholders with advice/tools on how best to manage the problem of mycotoxin contamination. REHIS Trainers' Seminar, October 2009

  24. Potential uses of mycotoxins • Medical application - Trichothecenes are known to possess antileukaemic activity; zearalenone derivatives have been considered as potential treatment for menopausal syndrome in women; • Agriculture application - derivatives of zearalenone as growth promoter in sheep and cattle; other mycotoxins have been considered for use as herbicides and insecticides. REHIS Trainers' Seminar, October 2009

  25. Websites • UK Food Standards Agency,2002. Survey of nuts, nut products and dried tree fruits for mycotoxins. Food Survey Information Sheet 21/02 • http://www.food.gov.uk/science/surveillance/fsis2002/21nuts • UK Food Standards Agency, 2004. Survey of baby foods for mycotoxins, • Food Survey Information Sheet 68/04. • http://www.food.gov.uk/science/surveillance/fsis2004branch/fsis6804 • UK Food Standards Agency, 2005. Survey of wheat for ochratoxin A, Food Survey Information Sheet 77/05. • http://www.food.gov.uk/science/surveillance/fsis2005/fsis7705 • UK Food Standards Agency, 2005. Survey of spices for aflatoxins and ochratoxin A, Food Survey Information Sheet 73/05. • http://www.food.gov.uk/science/surveillance/fsis2005/fsis7305 • UK Food Standards Agency, 2005. Survey of maize-based retail products for mycotoxins, Food Survey Information Sheet 72/05 • http://www.food.gov.uk/science/surveillance/fsis2005/fsis7204 • UK Food Standards Agency (FSA) 2009a. Review of Programmes C03 & C04   (Mycotoxins and Nitrate). Final Report. 48pp. • UK Food Standards Agency (FSA) 2009. Food Contaminants. Update Bulletin, March.  www.food.gov.uk REHIS Trainers' Seminar, October 2009

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