OMB Meeting Book - Jan. 11, 2018

104 H ALBMAYR -J ECH ET AL . : J OURNAL OF AOAC I NTERNATIONAL V OL . 98, N O . 1, 2015

7DEOH 6SLNH UHFRYHU\ GDWD IURP VLQJOH ODERUDWRU\ YDOLGDWLRQ GDWD VDPSOHV ZHUH WHVWHG ERWK LQ WKHLU RULJLQDO VWDWH DQG VSLNHG ZLWK PJ NJ RI 9LWDO ZKHDW JOXWHQ H[WUDFW 3HUFHQWDJH UHFRYHU\ ZDV FDOFXODWHG DJDLQVW D SRVLWLYH FRQWURO VSLNHG LQWR H[WUDFWLRQ EXIIHU 5HFRYHU\ RI PJ NJ VSLNH ZDV DFKLHYHG IURP D UDQJH RI SURFHVVHG IRRG VDPSOHV ZLWKLQ DQ DFFHSWDEOH UDQJH ± 7KH DGGLWLRQ RI JHODWLQ WR WKH H[WUDFWLRQ VROXWLRQ VLJQL¿FDQWO\ LQFUHDVHG WKH H[WUDFWLRQ HI¿FLHQF\ IURP FKRFRODWH Romer extraction solution

Spike (10 ppm gluten)

Spike CV, % Recovery, %

Sample

No spike

laboratories, and kit suppliers fromEurope, United States, Canada, Australia, and New Zealand participated in the collaborative study.All collaborators are listed in the Acknowledgments section. &DOLEUDWLRQ FXUYH RI PRQRFORQDO * (/,6$ 6L[ UHSOLFDWHV HDFK RI WKH 9LWDO ZKHDW JOXWHQ DQG 3:* JOLDGLQ VWDQGDUGV ZHUH UXQ RQ WKH $JUD4XDQW *OXWHQ * WHVW NLW (UURU EDUV LQGLFDWH î 6' RI VWDQGDUG The following 12 samples were prepared for the collaborative VWXG\ JOXWHQ IUHH ULFH ÀRXU ULFH ÀRXU FRQWDLQLQJ PJ JOXWHQ NJ ULFH ÀRXU FRQWDLQLQJ PJ JOXWHQ NJ ULFH ÀRXU containing 100 mg gluten/kg, gluten-free chocolate cake, chocolate cake containing 10 mg gluten/kg, chocolate cake containing 20 mg gluten/kg, chocolate cake containing 100 mg gluten/kg, crisp bread containing 4.5 mg gluten/kg, crisp bread containing 15 mg gluten/kg, crisp bread containing 24 mg gluten/kg, and crisp bread containing 102 mg gluten/kg. Initial target concentrations of the crisp bread samples had been 0, 10, 20, and 100 mg/kg, but a gluten contamination occurred during the preparation of these samples. The contamination was LQGHSHQGHQWO\ FRQ¿UPHG ZLWK DQRWKHU DQWLERG\ EDVHG (/,6$ giving further reason to allow a re-estimation of gluten content of respective samples. $OO LQJUHGLHQWV H[FHSW ZKHDW ÀRXU ZHUH FRQ¿UPHG WR EH IUHH RI gluten contamination before use by means of the G12 Sandwich ELISA, which was also used in this collaborative study. 7KH JOLDGLQ FRQWHQW RI ZKHDW ÀRXU RI WKH *HUPDQ FXOWLYDU ‘Genius’ was determined by an extraction/RP-HPLC method as described byWieser et al. (5). HPLC absorbance values measured at 210 nm were converted to protein concentration using a standard solution of reference gliadin from the ProlaminWorking *URXS 7KH JOLDGLQ FRQWHQW RI WKH ZKHDW ÀRXU VDPSOH ZDV 67.8±0.16 g/kg ( n = 3) on an “as is” basis. The gluten content of 7DEOH &DOFXODWLRQ RI /2' IURP VLQJOH ODERUDWRU\ YDOLGDWLRQ GDWD UHSOLFDWHV RI EXIIHU EODQNV ZHUH UXQ RYHU LQGLYLGXDO $JUD4XDQW *OXWHQ * DVVD\V 7KH /2' ZDV GHWHUPLQHG E\ FDOFXODWLQJ WKH PHDQ 2' RI WKH PJ NJ VWDQGDUG 6' DQG WKHQ UHDGLQJ WKLV YDOXH EDFN RII WKH VWDQGDUG FXUYH 7KH ORZHU /24 ZDV GHWHUPLQHG E\ WKH ORZHVW VWDQGDUG RI FRQFHQWUDWLRQ Standard, mg/kg Mean (OD) SD (OD) CV, % (OD) Mean + 3 SD (OD) LOD, mg/kg 0 0.14 0.03 21.15 0.23 2.00 )LJXUH Description and Preparation of Samples

Crisps

<4 <4

12.6

1.35 NA a 1.84 5.33 0.16 2.44 0.88 0.31 7.00 1.31

134.0

NA

Chocolate

<4

Chocolate + gelatin <4

10.3

109.6

Cheesy corn snack

<4 <4 <4 <4 <4 <4

8.5

90.4

Paprika Chicken

10.8

114.9 103.2 100.0 131.9 144.7 100.0

9.7 9.4

Yogurt

Curry sauce Margarine

12.4 13.6

Positive control

NA

9.4

a

NA = Not applicable.

WKH ZKHDW ÀRXU ZDV FDOFXODWHG DFFRUGLQJ WR &RGH[ JOXWHQ î prolamin) and was 135.6 g/kg. Samples were heat-treated to a different extent during SURFHVVLQJ DV IRXQG LQ FRQVXPHU SURGXFWV 5LFH ÀRXU ZDV XVHG “as is” (not heat-treated) and represented a base material for the production of gluten-free rice based products. Gluten-free ULFH ÀRXU ZDV SURYLGHG E\ *HQHUDO 0LOOV 0LQQHDSROLV 01 *OXWHQ FRQWDLQLQJ VWRFN ULFH ÀRXU ZLWK D JOXWHQ FRQFHQWUDWLRQ RI PJ NJ ZDV SUHSDUHG E\ PL[LQJ ZKHDW ÀRXU LQWR ULFH ÀRXU DQG VXEVHTXHQWO\ GLOXWLQJ WKH PL[WXUH ZLWK ULFH ÀRXU *OXWHQ FRQWDLQLQJ ULFH ÀRXU VDPSOHV ZHUH SUHSDUHG DV IROORZV PJ NJ J VWRFN ULFH ÀRXU ZDV PL[HG ZLWK J JOXWHQ IUHH ULFH ÀRXU PJ NJ J VWRFN ULFH ÀRXU ZDV PL[HG ZLWK J JOXWHQ IUHH ULFH ÀRXU DQG PJ NJ J VWRFN ULFH ÀRXU ZDV PL[HG ZLWK J JOXWHQ IUHH ULFH ÀRXU 0L[WXUHV ZHUH shaken in an overhead shaker for at least 1 h. Chocolate cake represented a product that had been moderately heat-treated, but with typical chocolate components that are known to be challenging for ELISA tests. Gluten-free chocolate 7DEOH 6LQJOH ODERUDWRU\ YDOLGDWLRQ GDWD RQ UHSHDWDELOLW\ XVLQJ D VLQJOH NLW UHSOLFDWHV RI WKH VWDQGDUG FXUYH ZHUH UXQ XVLQJ D VLQJOH $JUD4XDQW *OXWHQ * WHVW NLW 0HDQ 2' YDOXHV 6' DQG &9 DUH VKRZQ EHORZ $OO &9 YDOXHV IRU LQWUD DVVD\ DQDO\VLV ZHUH OHVV WKDQ PHHWLQJ WKH

PDQXIDFWXUHU¶V 4& FULWHULD Standard, mg/kg Mean (OD)

SD (OD)

CV, % (OD)

0 4

0.138 0.359 0.698 1.340 1.877

0.018 0.035 0.058 0.073 0.109

12.80

9.88 8.34 5.43 5.82

20 80

200