OMB First to Final Action Recommendation Checklist 11-12-18

ERP - GLUTEN ASSAYS: AOAC 2015.05 FAR

3.4. Proficiency testing round DLA 10/2016: Allergens X – Gluten in “gluten‐free” Beer  In 2016, the Dienstleistung Lebensmittel Analytik GbR launched a proficiency test scheme on three  beers with different gluten sources and concentrations. The full report of this PT round is given in  Annex 5. As can be seen from table 6, 16 participants analyzed these samples and returned data back  to the PT provider. For sample A (a wheat gluten containing beer mixture) 14 out of 16 results were  accepted. The robust mean is at 251 mg/kg gluten with a robust standard deviation of 54.4 mg/kg  (table 7). Sample C (a barley gluten containing beer mixture) showed a mean of 20.4 mg/kg with a  standard deviation of 7.95 mg/kg. Converting this deviation to a relative standard deviation (RSD R ) led  to a value of 39% which is quite comparable with the value for a spiked beer samples at 40 mg/kg  hordein analyzed during the collaborative test that led to AOAC OMA First Action 2015.05 (Lacorn and  Weiss, 2015). With exception of participants 14 and 15, all participants analyzed the gluten‐free beer  as negative. Participant 14 had a very high z‐score for sample C which indicates a higher value than  expected. This may be due to a gluten contamination in the lab of this participant. Participant 15  submitted a very high gluten value for sample A which was eliminated as an outlier (table 6).  

Table 6. PT round DLA 10/2016 with 16 participants from all over Europe; three different beer  samples were analyzed and z‐scores were calculated according to methods stated in Annex 5. 

Lab

sample A (wheat)

sample B (gluten-free)

sample C (barley)

Gluten mg/kg

z-score

Gluten mg/kg

Gluten mg/kg

z-score

1 2 3 4 5 6 7 8 9

330 258 202 198 194 250 224 280 243 218 295 269 283

1.3 0.1

neg (< 10)

17.0 19.0 10.1 17.3 14.5 19.0 34.0 13.3 25.5 18.3 16.0 23.0 26.3 32.2 30.0 13.0

-0.7 -0.3 -2.0 -0.6 -1.2 -0.3

< 10

-0.8

neg (< 10)

> 270

< 10 neg

-0.8 -0.9 0.0 -0.4 0.5 -0.1 -0.5 0.7 0.3 0.5

neg (< 10) neg (< 2.72)

2.7

neg < 10

-1.4

1.0

10 11 12 13 14 15 16

neg (< 10)

-0.4 -0.9

< 1.36

< 10

0.5 1.1 2.3 1.9

neg (< 3)

18.0 17.0

471* 188

-1.0 -1.5 * outlier: value deviates more than 3 times the robust standard deviation from the robust mean neg (< 10)

10 

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