AOAC ERP Gluten Assays - Dec 2018

Annex B

4.1.7.5

Recovery using spiked oat containing samples

According to AOAC SMPR ® 2017.021, recovery for gluten in oat product should be determined using incurred samples only. This was presented in chapter 4.1.7.4 and will be presented later on in chapter 4.1.7.6. Nevertheless, oat flour, oat flakes, and oat cereals were spiked with gluten from wheat over the whole calibration range (7 mg/kg up to 77 mg/kg). Table 17. Results from spiking experiments of oat flour, oat flakes, and cereals at 4 different levels with two replicates per concentration and lot; gluten from wheat was used for this experiment; the spike concentration was corrected by the concentration of blank samples (column spike*); for recovery calculation the analyzed value was compared with the blank- corrected spike level.

Lot 1 Flour

Lot 2 Flour

Lot 3 Flour

spike

spike*

conc.

corr. rec.

spike* mg/kg

conc.

corr. rec.

spike* mg/kg

conc.

corr. rec.

mg/kg

mg/kg mg/kg

(%)

mg/kg

(%)

mg/kg

(%)

0

2.60 2.85 7.63 5.96

1.56 1.56 7.45 5.56

3.51 3.54 8.42 7.08

7

9.7 9.7

78 61 88 84 79 83 80 76 66 60 88 87 84 89 74 73 59 56 75 77 87 72 67 68

8.6 8.6

87 65 94 93 87 90 90 84 66 60 89 89 88 92 76 76 74 56 86 87 93 78 73 71

10.5 10.5 20.5 20.5 40.5 40.5 80.5 80.5 10.3 10.3 20.3 20.3 40.3 40.3 80.3 80.3 11.4 11.4 21.4 21.4 41.4 41.4 81.4 81.4

80 67 96 93 87 90 90 83 71 75 94 95 90 92 81 81 70 60 85 86 93 81 76 75

17

19.7 19.7 39.7 39.7 79.7 79.7

17.38 16.65 31.37 33.01 64.07 60.89

18.6 18.6 38.6 38.6 78.6 78.6

17.50 17.34 33.39 34.71 70.66 66.19

19.78 19.11 35.45 36.64 72.19 66.97

37

77

Flakes

Flakes

Flakes

0

2.77 3.35 6.68 6.05

2.01 1.85 5.92 5.38

3.08 3.45 7.24 7.70

7

10.1 10.1 20.1 20.1 40.1 40.1 80.1 80.1 11.4 11.4 21.4 21.4 41.4 41.4 81.4 81.4

8.9 8.9

17

17.59 17.54 33.83 35.79 59.03 58.32

18.9 18.9 38.9 38.9 78.9 78.9

16.86 16.89 34.42 35.72 60.20 60.14

19.11 19.27 36.11 36.93 65.34 65.34

37

77

Cereals

Cereals

Cereals

0

3.74 5.08 6.77 6.43

2.90 2.74 7.25 5.49

4.24 4.50 7.97 6.77

7

9.8 9.8

17

16.03 16.39 35.86 29.89 54.40 55.21

19.8 19.8 39.8 39.8 79.8 79.8

17.10 17.23 37.21 30.94 58.03 56.80

18.22 18.42 38.62 33.38 61.47 60.74

37

77

Page 29 of 33

RIDASCREEN ® Total Gluten In-house validation report 2018-10-21