Sampling and Analysis of Grain Cleaning Byproducts for Truly Rapid Screening of the Mycotoxin Deoxynivalenol in Wheat Sheryl A. Tittlemier, 1 D Sobering 2, K Bowler 2, T Zirdum 2, D Gaba 1, JM Chan 1, M Roscoe 1, R Blagden 1, L Campbell 3 1 Grain Research Laboratory, Canadian Grain Commission, Winnipeg, MB, Canada 2 Industry Services, Canadian Grain Commission, Winnipeg, MB, Canada 3 National Monitoring Unit, Canadian Grain Commission, Winnipeg, MB, Canada 1
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 2
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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 4
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) 5
Analysis chemical testing primary sampling official sample secondary sampling test portion laboratory sample chemical analysis 6
Analysis chemical testing primary sampling secondary sampling test portion laboratory sample chemical analysis 7
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. 8
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) 9
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 10
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 11
Dockage removal Carter Day dockage tester 12
Dockage removal 13
Dockage fractions contain mycotoxins 35 30 25 20 15 10 5 0 DON 0.4 mg/kg 0.3 0.2 ZEA 0.1 0.0 0.25 0.20 0.15 0.10 OTA 0.05 0.00 small dockage large dockage light dockage cleaned grain 14
Light dockage is a small proportion of wheat clean wheat large dockage light dockage small dockage average percentage of mass of un cleaned wheat 15
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 16
Sample analysis Whole un-cleaned grain: grind 1 kg 50 g test portion Neogen Veratox DON ELISA Light dockage: all light dockage Neogen Veratox DON ELISA 17
Performance of ELISA: un-cleaned wheat 14 12 GC-MS (mg/kg) 10 8 6 4 y = 0.907x + 0.0503 R² = 0.881 2 0 0 2 4 6 8 10 12 ELISA (mg/kg) 18
Performance of ELISA: light dockage 25 20 GC-MS (mg/kg) 15 10 y = 1.059x - 0.1557 R² = 0.986 5 0 0 5 10 15 20 25 ELISA (mg/kg) 19
DON in whole grain is correlated to DON in light dockage 40 DON in light dockage (mg/kg) 30 20 10 y = 5.8688x + 0.4324 R² = 0.6066 0 0 1 2 3 4 5 DON in whole grain (mg/kg) 20
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 21
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