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

Throughout food production chain toxin producing fungi can occur

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

•Cluster info

•Links

•Press Releasewww.mycotoxin-prevention.com

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 www.mycotoxin-prevention.com