Robert C. BakerHead of Food Safety, Mars Incorporated

26 February 2009

“Managing Aflatoxin Risks From Farm To Fork”

4TH Dubai International Food Safety Conference

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Objectives

• Provide basic awareness of Aflatoxin and potential risks in the Food Chain

• Provide a framework for managing Aflatoxin risks

• Provide a means of monitoring and verifying the effectiveness of aflatoxin management processes

• In 30 minutes…..

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Agenda

• What are aflatoxins? • At risk materials• Factors influencing

aflatoxin production• Methods for managing

aflatoxin risks• Methods of aflatoxin

detection• Summary

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Mycotoxins

• Secondary fungal metabolites that exert toxic effects on animals and human beings.

• More than 300 secondary metabolites have been described but only thirty really exert toxic effects.

• The chemical structure of mycotoxin is very diverse

Polyacetates : aflatoxins, citrinine, ochratoxins patulin, zearalenone, fumonisins,Terpenes : trichothecenes (sesqui), tremorgenes,Peptides : ergotamin (alcaloïdes), tryptoquivaline,..Piperazines : sporidesmin, gliotoxin, roquefortine,..

O O

O

OMe

OO

Aflatoxin B1

Deoxynivalenol

CH3CH3

O

CH3OH

OH OH

NH2CH3O

O

OHOOC

HOOC

HOOC

HOOC

Fumonisin B1

O

O

OOH

OH

CH3H

Zearalenone

O

O

H

Cl

O

NH

COOH OH

Ochratoxin A

OH

O

OH CH3OH

O

O

CH3

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Aflatoxins

• Four aflatoxins (order of toxicity):

• B1 >G1 > B2 > G2

• Other aflatoxins occur as metabolic products (e.g., aflatoxin M1 in milk)

• Highly toxic• Aflatoxins are among the most toxic naturally

occurring substances known.

• Carcinogenic, hepatotoxic, mutagenic and teratogenic

• All animal species affected by aflatoxins.

• Can be passed through food chain (e.g., milk of animals which are fed contaminated feed).

• Heat Stable

• Withstand typical food processing temperatures

Aflatoxin B1

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Aflatoxin production

Aflatoxin is produced by species of the fungus Aspergillus:

• Aspergillus flavus

•aw range: 0.80-0.99

•Temperature range: 10-43oC

• Aspergillus parasiticus

•aw range: 0.83-0.99

•Temperature range: 10-43oC

Toxins can be produced over a wide temperature range: 15-37oC

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Aflatoxin associated alerts

• 2007 - Peanuts – Saudi Arabia

• 2006 - Dog food – US (23 dog deaths)

• 2004 - Maize – Kenya (125 deaths)

• 2004 - Paprika – Hungary

• 2001 – Rice – China

**THESE ARE TAKEN FROM ALERTS via PROMED ARCHIVE**

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RASFF Aflatoxin reports

• RASFF: Rapid Alert System for Food and Feed.

• Aflatoxin most significant mycotoxin.

(Rapid Alert System for Food and Feed (RASFF) Annual Report, 2005)

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Aflatoxin associated notifications (EU)

In 2005 : 947 aflatoxin notifications•498 pistachio nuts : (92% from Iran)

•219 peanuts and derived products : (36% from China, 15% Brazil)

•64 hazelnuts and derived products : (83% from Turkey)

•33 almonds and derived products : (85% from US)

•48 dried figs : (96% from Turkey)

•13 melon seeds : (77% from Nigeria)

•48 herbs and spices : (56% from India)

**RASFF alerts 2005 – border inspection etc – Europe**(Rapid Alert System for Food and Feed (RASFF) Annual Report, 2005)

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Legal limits – raw materials

Material Limit ReferenceHuman Raws

Nuts & dried fruits for direct consumption or ingredient use.

Total Aflatoxin: 4 ppbAflatoxin B1: 2 ppb

Commission Regulation (EC) 1881/2006

Nuts & dried fruits to be subjected physical treatment prior to consumption.

Total Aflatoxin : 10 ppbAflatoxin B1: 5 ppb

Commission Regulation (EC) 1881/2006

All Cereals and derived products.

Total Aflatoxin: 4 ppbAflatoxin B1: 2 ppb

Commission Regulation (EC) 1881/2006

Spices (inc. chilli powder, nutmeg, ginger etc).

Total Aflatoxin : 10 ppbAflatoxin B1: 5 ppb

Commission Regulation (EC) 1881/2006

Petfood Raws

Maize and co-products Total Aflatoxin : 20 ppbAflatoxin B1: 10 ppb

Commission Regulation (EC) 2002/32/EC

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Crops which are frequently affected include:

•Cereals (barley, wheat, oats, maize, rice, sorghum, dried grains).

•Nuts (peanuts, walnuts, almonds, hazelnuts, Brazil nuts, pistachio nuts, pecans, macadamia nuts, pine nuts).

•Spices (chilli peppers, black pepper, coriander, tumeric, ginger)

•Animal products from which contaminated feeds were consumed (i.e. milk & dairy products. protein meals)

Materials at risk of aflatoxin contamination

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Factors influencing aflatoxin production

In the field

• Agricultural Practices• Climate (humidity /

temperature / rainfall)

• Crop variety • Treatments (insects

and fungi)

At harvesting

• Maturity at harvesting• Moisture• Disease State During storage

• Temperature• Moisture • Insect treatment

During transformation &

process

• Cleaning• Temperature• Process

Need to understand risks at eachStep and evaluate every year!!!

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Aflatoxin management• Starts with a comprehensive “Material Quality Management Program”

• Needs to be risk based and cover the entire pipeline

• Risk assessments are not static and need to be performed for each material and harvested crop.

•In the Field (GAP, climate & crop monitoring)•During Harvest / Storage (moisture control, interim storage conditions)

•Inbound acceptance (specifications)•Storage (silo design / management, conditioning, cleaning, monitoring)

•Finished Product (specifications and distribution)

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Aflatoxin management: In the Field

• Farm geography and climate.

• Crop species and variety.

• Regional crop risk assessment via industry, government or academic sources, where available, on a seasonal basis.

• Good Agricultural Practices (GAP).

• Biocontrol systems

Drought during pollination

Monsoon after Drought

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Aflatoxin management: Harvest

• Harvest weather conditions.

• Harvesting at appropriate moisture content (max. moisture 13%).

• Harvest maturity.

• Interim storage of harvested materials.

• Disease state of crop & bushel weight.

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Aflatoxin management: Inbound

• Robust sampling of inbound raws:•Risk Based

•Take into account that mycotoxin contaminations are skewed and not evenly distributed

•Stationary bulk loads (flatbed trucks, rail cars, and barges), sampled using probes as approved by GIPSA (GIPSA, Grain Sampling Procedures, Jan 2001).

•At least 10 incremental samples taken and aggregated into one sample.

• Personnel must be trained on importance of sampling

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A A A A A

A A A A A

B B B B

B B B BBB

x x x

x x x

x x x

x x x

x x x

x x xTop of Truck

Sample Points

Manual SamplingInsert the probe to the bottom of the truck

Automatic Sampling (pneumatic)Insert the probe and take a sample at the top, middle and bottom of the truck at sample point

Two sets of samples, A and B.

Truck Sampling Plan

• Sampling 20 samples from truck• 10 first points combined as Group A• 10 latter points combined as Group B• Sample A&B are individually ground for testing

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Aflatoxin management: Storage

• Materials stored under conditions to minimise mould growth.

• Suitable material (stainless steel, plastic).

• Smooth/flat walled bins & silos.

• Vessels designed to prevent moisture and pest ingress.

• Vessels shall be designed such that they empty completely.

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Aflatoxin management: Finished Product

• Product designs and specifications must take into account legal and material risks

• Solid understanding of distribution pipeline and potential for temperature shock

• Finished product testing is a valid means of verifying “Front End” risk management processes.

• Mycotoxin binders ???

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Methods of aflatoxin detection: HPLC

• Gold-standard for mycotoxin detection.

• Reverse phase HPLC used most widely.

• Can be automated.

• Method must to be validated for specific material and toxin.

• Operator needs to be well trained.

• Participation in recognized proficiency testing program Highly Recommended.

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Methods of aflatoxin detection: ELISA

• Rapid and reliable ‘screen’ for aflatoxin.

• Does not require specialised equipment (like HPLC).

• Commercial ELISA kits available for detection of total aflatoxins.

• Easily trained to factory personnel

• Must be validated for specific material

• Comparable to HPLC in 4-40 ppb range (Zheng et al, Mycopathologia; 2005).

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Methods of aflatoxin detection: Black (UV) Light

• Not recommended

•Works through florescence of contaminated kernels

•Florescence based on detection of Kojic Acid not aflatoxin

•Kojic acid breaks down leading to false “negative” results

•Issue greater in tropical regions

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Summary

• Key Points in Aflatoxin Management

•A sound Material Quality Management program is critical.

•Aflatoxin risk can change with every new crop, growing location, supplier and / or change along the pipeline.

•Effective sampling, validated methods and trained personnel are required

•Be prepared for the unexpected….

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Thank You!!!