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.
UK Not Ready for Brexit’s Impact on Food, Report WarnsNews
Severe problems with the UK food system are likely unless issues are addressed, according to latest expert reportREAD MORE
Cranberries May Help to Nourish Our Beneficial Gut BacteriaNews
Findings could add value to future food products or lead to a new supplement based on the cranberry.READ MORE
Are People ‘Rolling the Dice’ When it Comes to Food Safety?News
A new study has revealed the levels of bad behaviours in UK kitchens which increase the public’s risk of getting food poisoning.
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