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Sampling and Analysis of Grain Cleaning Byproducts for Truly Rapid Screening of the Mycotoxin Deoxynivalenol in WheatSheryl A. Tittlemier,1 D Sobering2, K Bowler2, T Zirdum2, D Gaba1, JM Chan1, M Roscoe1, R Blagden1, L Campbell31Grain Research Laboratory, Canadian Grain Commission, Winnipeg, MB, Canada2Industry Services, Canadian Grain Commission, Winnipeg, MB, Canada3National Monitoring Unit, Canadian Grain Commission, Winnipeg, MB, Canada

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Canadian Grain Commission certifies the quality, safety

and weight of Canadian grain that is delivered to domestic and export markets quality and quantity

assurance programs scientific research to

understand all aspects of grain quality and safety

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Fusarium head blight

“scab”, “FHB” disease caused by infection

with Fusarium fungal species bleached heads and shriveled

chalky/pinkish kernels (FDK) decreased yield and quality a variety of mycotoxins can be

produced

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Deoxynivalenol (DON)

main mycotoxin produced by F. graminearum

“vomitoxin” maximum limits in wheat: 2 mg/kg Codex (raw grain, proposed) 1 -2 mg/kg Canada (under review) 1.25 – 1.75 mg/kg EU 1.1 mg/kg Japan (provisional standard) 1 mg/kg US (finished wheat products)

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Analysis – chemical testing

primary sampling

laboratorysample

test portion

officialsample

secondary sampling

chemical analysis

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Analysis – chemical testing

primary sampling

laboratorysample

test portion

secondary sampling

chemical analysis

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Piggyback on existing analyses dockage

dockage analyzed during grain inspection dockage = wheat with long rootlets, unthreshed wheat

heads or spikelets, chaff, dust, loose hulls, fragments of stem or rachis, soft earth pellets, broken kernels, bunt balls, stones, wild oats, etc.

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Piggyback on existing analyses dockage

dockage analyzed during grain inspection dockage must be removed from grain by use of

approved cleaning equipment so grain can be assigned a grade (Canada Grain Act)

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Mycotoxins are present in dockage

Cleaning byproduct N samples DON

(mg/kg)OTA

(mg/kg)ZEA

(mg/kg)

chaff and other light material 1 0.75 0.019 0.045

broken grain and weed seeds 3 1.42 – 1.86 0.004 – 0.007 <0.010 – 0.019

waste 9 0.21 – 2.94 <0.001 – 0.014 <0.010

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Piggyback on existing analyses dockage

dockage analyzed during grain inspection dockage must be removed from grain by use of

approved cleaning equipment so grain can be assigned a grade (Canada Grain Act)

dockage is a readily available sample matrix

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Dockage removal

Carter Day dockage tester

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Dockage removal

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Dockage fractions contain mycotoxins

small dockage

largedockage

light dockage

cleanedgrain

mg/kg

0.00

0.05

0.10

0.15

0.20

0.25

0.0

0.1

0.2

0.3

0.4

0

5

10

15

20

25

30

35

OTA

ZEA

DON

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Light dockage is a small proportion of wheat

average percentage of mass of un‐cleaned wheat

clean wheat

large dockage

light dockage

small dockage

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Pilot: DON in light dockage and wheat

single railcar composites collected by CGC inspectors using automatic

samplers at terminal elevator facilities samples with FDK and dockage selected because of

increased likelihood of detecting DON homogenized and divided into two portions using

Boerner divider one half (~ 1 kg) run through dockage tester to

collect light dockage other half was kept as whole, un-cleaned grain

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Sample analysis

grind 1 kg 50 g test portion

NeogenVeratox DON

ELISA

Whole un-cleaned grain:

all light dockage

NeogenVeratox DON

ELISA

Light dockage:

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Performance of ELISA: un-cleaned wheat

ELISA (mg/kg)

0 2 4 6 8 10 12

GC

-MS

(mg/

kg)

0

2

4

6

8

10

12

14

y = 0.907x + 0.0503R² = 0.881

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Performance of ELISA: light dockage

ELISA (mg/kg)0 5 10 15 20 25

GC

-MS

(mg/

kg)

0

5

10

15

20

25

y = 1.059x - 0.1557R² = 0.986

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DON in whole grain (mg/kg)0 1 2 3 4 5

DO

N in

ligh

t doc

kage

(mg/

kg)

0

10

20

30

40

y = 5.8688x + 0.4324R² = 0.6066

DON in whole grain is correlated to DON in light dockage

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Conclusions

use of light dockage for screening DON in wheat is promising benefits increased sensitivity save time by eliminating grinding and prep steps save resources by removing need for grinders uses available material does not require additional equipment

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