Measuring Hordein (Gluten) in Beer - A Comparison of ELISA and Mass Spectrometry
News Mar 27, 2013
Subjects suffering from coeliac disease, gluten allergy/intolerance must adopt a lifelong avoidance of gluten. Beer contains trace levels of hordeins (gluten) which are too high to be safely consumed by most coeliacs. Accurate measurement of trace hordeins by ELISA is problematic.
We have compared hordein levels in sixty beers, by sandwich ELISA, with the level determined using multiple reaction monitoring mass spectrometry (MRM-MS).
Hordein levels measured by ELISA varied by four orders of magnitude, from zero (for known gluten-free beers) to 47,000 µg/mL (ppm; for a wheat-based beer). Half the commercial gluten-free beers were free of hordein by MS and ELISA. Two gluten-free and two low-gluten beers had zero ELISA readings, but contained significant hordein levels (p<0.05), or near average (60-140%) hordein levels, by MS, respectively. Six beers gave false negatives, with zero ELISA readings but near average hordein content by MS. Approximately 20% of commercial beers had ELISA readings less than 1 ppm, but a near average hordein content by MS. Several barley beers also contained undeclared wheat proteins.
ELISA results did not correlate with the relative content of hordein peptides determined by MS, with all barley based beers containing hordein. We suggest that mass spectrometry is more reliable than ELISA, as ELISA enumerates only the concentration of particular amino-acid epitopes; this may vary between different hordeins and may not be related to the absolute hordein concentration. MS quantification is undertaken using peptides that are specific and unique, enabling the quantification of individual hordein isoforms. This outlines the problem of relying solely on ELISA determination of gluten in beverages such as beer and highlights the need for the development of new sensitive and selective quantitative assay such as MS.
The article is published online in the journal PLoS ONE and is free to access.
Steaming Fish Eliminates More Cyanotoxins Than BoilingNews
Utilizing UHPLC researchers have shown that steaming freshwater fish for more than two minutes reduces the presence of the cyanotoxin, cylindrospermopsin, by up to 26% compared to 18% for boiling.READ MORE
Tiny “Tornado” Boosts Performance of Electrospray Ionization Mass SpectrometryNews
Known as Dry Ion Localization and Locomotion (DRILL), the new device creates a swirling flow that can separate electrospray droplets depending on their size.READ MORE
Agilent Technologies Presents Thought Leader Award to Dr. Ram SasisekharanNews
Agilent Technologies awards Dr. Ram Sasisekharan with the Agilent Thought Leader Award in recognition of his contributions in the field of biologics characterization.READ MORE
Comments | 0 ADD COMMENT
18th International Conference and Exhibition on Analytical & Bioanalytical Chromatographic Techniques
Nov 02 - Nov 03, 2017
8th Edition of International Conference on Mass Spectromerty
Mar 12 - Mar 13, 2018