Comparison of hordein detection by MS vs ELISA.

The relative MS response for beer from cv Sloop, Risø 56, Risø 1508, ULG 2.0 or 60 international beers was determined by Colgrave et al[36], ranked by ELISA score, and reproduced here with permission.
1 & 2: The peak area of the most intense MRM transition for each peptide was integrated and expressed here either as 1: % of cv Sloop, or 2: the average over all beers (excluding cv Sloop, Risø 56, Risø 1508, ULG 2.0, low-hordein and gluten-free lines).
3: All ELISA readings were calibrated against a standard curve made from total hordeins purified from cv Sloop, except for beers made from hordein deletion lines Risø 56, Risø 1508, and ULG 2.0 which were calibrated against standard curves made from hordeins purified from the respective grains. ELISA readings less than 0.10 ppm were not significantly different to zero.
4: MS analysis of beers after tryptic digestion revealed the presence (✓) or absence (✗) of wheat proteins: α-gliadin, γ-gliadin and low- and high- molecular weight glutenins indicative of the beer containing wheat (see Fig. 3).
*Gluten-free. The small peak area by MS seen for the gluten-free beers was due to integration of baseline noise. Values <5% were not significantly different to blank samples.
#Low gluten claim <20 ppm for this beer.