MYCOTOXIN PREVENTION
CLUSTERCo-ordinator
Prof. Naresh MaganApplied Mycology Group, Biotechnology Centre,
Cranfield University, Silsoe, Bedford, UK MK45 4DT
www.mycotoxin-prevention.com
• 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
BACKGROUND 1
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
“Process” flow diagramSustainable/organic supply chain
Processing
Transport
Storage
Drying
Harvest
Crop Development
Land Preparationcomplex
specific
farmersmerchantstransportersprocessors
post-harvest
pre-harvest
Food products
Grain
Microflora -mycotoxins
Insects
Mites Nutrients
Energy
TYPE OF BULK GRAIN
Moisture
Temperature
02
C02
Pest Emigration Immigration
Stored grain
ecosystem
LIST OF MOST IMPORTANT MYCOTOXINS, FUNGAL SPECIES AND TOXIC EFFECTS
Mycotoxin Species EffectAflatoxins Asp.flavus Liver
Asp.parasiticusOchratoxin A Pen.verrucosum Kidney
Asp.ochraceusAsp.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
A.flavus-aflatoxins: groundnuts/maize
Fusarium spp. -DON/NIV
P.verrucosum/Asp/ochraceus- Ochratoxin
Aspergillus nigergroup- Ochratoxin
Range of potency of carconigens in test animals
Compound Dose Relative potency
Trichloroethylene 3 1
Carbon tetrachloride 0.02 150
Nitrosamines 0.005 6000
Aflatoxin B1 0.00003 100,000
Sterigmatocystin 0.000001 3,000,000
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
The whole cluster with all components:
OCHRATOXINa-RISK ASSESSMENT (2001)
Mechanisms of OTA induced carcinogenicity as a basis for improved Risk assessment
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 on-site determination of mycotoxins in food
EMAN (2001)
Thematic network to promote awareness of mycotoxins in food: European Mycotoxins Awareness Network
Original 3 projects
(2000)
Safe organic vegetables (2000)
Alternaria model
RAFBCA (2001)
Risk assess-mentof biocontrolagents
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
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
Agrofood product from farm to processor
Monitoring system – at different stagesRapid detection systemsCritical control pointsVerification systems
Steps Risk Factors Control Measures QA/QC aspectsCrop Climate Adopt reliable fungicide Best practicedevelop. Chemical treat. Regime to climate evidence to
history- which do satisfy crop ass.not stimulate toxins schemes
Rapid diagnostics for detection of toxins in the food chain•Relevant/reliable detection systems – with real time/on-line 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
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 post-harvest
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.
Wat
er a
ctiv
ity/M
oist
ure
cont
ent
0 10 20 30 40
Temperature (oC)
0.85
0.87
0.89
0.91
0.93
0.95
0.97
0.99
0.87
0.89
0.91
0.93
0.95
0.97
0.99
0.1
1.0
3.05.0
0.1
0.25
101.0
0.01
(a) Growth rate (mm day-1)
(b) Deoxynivalenol (ppm)
> 30%M.C.
18-19%
18-19%
21-22%
21-22%
0 10 20 30 40
0.01
0.11.0
5.0
0.1
1.02.0
4.0
(a) Growth rate (mm day-1)
(b) Deoxynivalenol (ppm)
(a) (b)
Applied Mycology Group
Isopleth lines showing the limit combinations aw/T for FB1 production (1 ppm), growth (0.1 mm d-1), and germination (10% spores) of Fusarium isolates
5 10 15 20 25 30 35 40
FB1 production
Growth
Germination
Fusarium proliferatum
WA
TE
R A
CT
IVIT
Y
0.900.890.88
0.990.980.970.960.950.940.930.920.91
0.87
FB1 production
Growth
Germination
Fusarium verticilloides
5 10 15 20 25 30 35 40TEMPERATURE (°C)
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
Processing and managing mycotoxinsWhere 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
CLUSTER ACTIVITIES1. Web page for the Cluster of projects – links to other
projects (www.mycotoxin-prevention.com)
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
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: [email protected] www.mycotoxin-prevention.com