MYCOTOXIN PREVENTION CLUSTER

Transcription

1 MYCOTOXIN PREVENTION CLUSTER Co-ordinator Prof. Naresh Magan Applied Mycology Group, Biotechnology Centre, Cranfield University, Silsoe, Bedford, UK MK45 4DT

2 BACKGROUND 1 Evidence suggest that a significant amount of food world-wide is contaminated with mycotoxins (25-30%) In Europe concern about contamination and presence of ochratoxins and Fusarium toxins in food raw materials and levels of human exposure Historically, mycotoxin contamination has been associated with Alimentary Toxic Aleukia (trichothecenes in over-wintered grain in Russia); and Balkan Endemic Nephropathy (ochratoxina) Turkey X disease in UK in 1960s from feed infected with aflatoxins

3 What are the main drivers for research on mycotoxins in the food chain? Legislation - limits - although not unified Risks to human and animal health Socio-economic aspects - Trade Consumer perceptions Surveillance impacts on cost to producers and ultimately consumers

4 Process flow diagram Sustainable/organic supply chain complex specific Land Preparation Crop Development Harvest pre-harvest farmers merchants transporters processors Drying Storage Transport Processing postharvest Food products

5 Throughout food production chain toxin producing fungi can occur

6 02 Stored grain ecosystem Energy Grain Microflora - mycotoxins Insects Mites Nutrients C02 Pest Emigration Immigration Moisture Temperature TYPE OF BULK GRAIN

7 LIST OF MOST IMPORTANT MYCOTOXINS, FUNGAL SPECIES AND TOXIC EFFECTS Mycotoxin Species Effect Aflatoxins Asp.flavus Liver Asp.parasiticus Ochratoxin A Pen.verrucosum Kidney Asp.ochraceus Asp.niger group Trichothecenes Fusarium spp. Alimentary/circulatory (T-2, DON, NIV) Zearelenone Fusarium spp. Alimentary, circulatory Fumonisins Fusarium spp. Cytoxic, affects animals Patulin Pen.expansum Cytoxic Citrinin Pen.verrucosum Kidney

8 A.flavus-aflatoxins: groundnuts/maize P.verrucosum/Asp/ochraceus - Ochratoxin Fusarium spp. - DON/NIV Aspergillus niger group- Ochratoxin

9 Range of potency of carconigens in test animals Compound Dose Relative potency Trichloroethylene 3 1 Carbon tetrachloride Nitrosamines Aflatoxin B ,000 Sterigmatocystin ,000,000

10 Original three project cluster (2000) DETOX-FUNGI Dr. Antonio Logrieco Molecular tools for mycotoxigenic fungi OTA PREV Dr. Monica Olsen HACCP, mapping of species, ecology, diagnostic systems, prevention strategies CONTROL MYCOTOX FOOD Prof. Naresh Magan Hazard analysis, pre-/post harvest control and decontamination strategies

11 The whole cluster with all components: Original 3 projects (2000) OCHRATOXINa-RISK ASSESSMENT (2001) Mechanisms of OTA induced carcinogenicity as a basis for improved Risk assessment EMAN (2001) Thematic network to promote awareness of mycotoxins in food: European Mycotoxins Awareness Network Safe organic vegetables (2000) Alternaria model WINE-OCHRA RISK (2001) Risk assessment and integrated OTA management in grape and wine MYCOSENS (CRAFT) (2001) Development of a novel test kit for rapid onsite determination of mycotoxins in food RAFBCA (2001) Risk assess-ment of biocontrol agents

12 What information did we need? Where does contamination occur field, harvesting, post-harvest? Which species are involved in different climatic regions Ecology and biology of mycotoxin-producing fungi and toxin contamination Growth and mycotoxin production are governed by grain type and physiological state; water availability & temperature Use of existing good manufacturing procedures A detailed flow chart of raw materials through the supply chain

13 Overall key objectives of this EU Cluster: Framework of HACCP system and Risk Analysis Mycotoxigenic moulds and their toxins ochratoxins, trichothecenes, zearelenone, fumonisins Identification of Critical Control points where entry can be prevented into human and animal food chain Early detection and diagnostics ELISA, Biosensors, Molecular tools Fate of toxins in animals Where necessary control and decontamination systems Sources of toxins in grapes and wine Mycotoxin network for dissemination of information

14 Agrofood product from farm to processor Monitoring system at different stages Rapid detection systems Critical control points Verification systems Steps Risk Factors Control Measures QA/QC aspects Crop Climate Adopt reliable fungicide Best practice develop. Chemical treat. Regime to climate evidence to history- which do satisfy crop ass. not stimulate toxins schemes

15 Rapid diagnostics for detection of toxins in the food chain Relevant/reliable detection systems with real time/online applications for a range of mycotoxins in the food/feed chain required Appropriate technology for stake-holders in food chain; farmers to central surveillance labs to meet legislative requirements and monitoring of CCPs infra red spectroscopy, antibodies, lateral flow devices, molecular imprint polymer development- all at economic price +ve -ve

16 Pre- and post-harvest decision support systems HACCP approaches to the whole food chain Conditions which lead to pre-harvest and post-harvest risk Biocontrol of mycotoxigenic moulds has been quite successful Ecological information now becoming available which will be useful for defining more accurately risk/no risk from toxins - in relation to the legislative limits Novel antimould compounds for treating moist grain postharvest

17 Comparison of profiles/limits for germination (*), growth (mm day -1 ) and DON (ug g -1 ) production: (a) F.culmorum (b)f.graminearum on wheat grain. Water activity/moisture content > 30% M.C % % % 0.91 (a) (a) Growth rate (mm day -1 ) (b) (a) Growth rate (mm day -1 ) % 0.85 Applied Mycology Group (b) Deoxynivalenol (ppm) Temperature ( o C) (b) Deoxynivalenol (ppm)

18 Isopleth lines showing the limit combinations a w /T for FB 1 production (1 ppm), growth (0.1 mm d -1 ), and germination (10% spores) of Fusarium isolates WATER ACTIVITY Fusarium verticilloides FB 1 production Growth Germination Fusarium proliferatum FB 1 production Growth Germination TEMPERATURE ( C)

19 Post-harvest control of mycotoxins?? Moist cereals have been treated with preservatives Predominantly fungistats and not fungicides We have examined in some detail the potential of using antioxidants and essential oils for treating grain: resvaretol, propyl paraben, hydroxybutyl anisole, essential oils

20 Processing and managing mycotoxins Where prevention is not possible-traceability and fate during processing and food production needs to be effectively managed and understood Studies have now successfully enabled quantifiable information on percentage of ochratoxin entering various milling fractions More information still needed about fate of others during processing Detoxification Fate in animals being examined

21 CLUSTER ACTIVITIES 1. Web page for the Cluster of projects links to other projects ( 2. Four W.G.s have been set up across the Cluster: (a) HACCP/Risk Analysis (A. Alldrick/D.Aldred) (b) Pre-harvest (Jurgen Kohl) (c) Post-harvest (Nils Jonsson) (d) Dissemination (Naresh Magan, Monica Olsen, Giusy Mule). In (a), (b) and (c) cross project collaboration is being carried out. Dissemination meetings which have been organised annually

22 Cluster info Links Press Release

23 Series of position papers are available on the Cluster activities Preharvest biocontrol Analysis of trichothecenes PCR methods Molecular markers and DNA arrays for detection Mycotoxins and malting Detection of mycotoxigenic fungi Decontamination strategies Post-harvest control Processing effects on OTS production Selective medium for P.verrucosum Contact me for a CD: n.magan@cranfield.ac.uk