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Barley malt is the natural raw material for beer production. During malt and beer processing the storage proteins (prolamins) of barley are hydrolysed by the natural proteolytic enzymes of grains. Normal beer contains variable amounts of prolamins (gluten) and the hydrolysed peptides. The prolamin content and the susceptibility to coeliac disease is depending on the beer type, raw materials and processing methods used.
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Materials and Methods |
Samples were commercial beers from different locations in Europe and Finland. Samples from process trials were also analysed.
Prolamins from the beers were extracted with ethanol or cocktail solution (1) and analysed by sandwich (2) and competitive R5-ELISA (3) as previously described. Western Blot was carried out as previously described (2). |
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Results |
The total of 93 beers all over Europe were tested. Western Blot analysis proved that most
of the prolamins in beer have been hydrolysed to shorter peptides during beer processing. (Figure 1.)
The sandwich R5-ELISA method for gluten analysis detected gluten in only 11 beers. Beers were also tested
with more sensitive competitive R5-ELISA method, that is developed especially for hydrolysed prolamins.
The competitive method detected gluten in total of 62 beers. (Figure 2.)
The test results showed that many Finnish barley malt beers had a very low content of gluten compared to
many European and especially to Belgian and German beers.
The observation led to an idea of an improved process to reduce the amount of gluten in barley malt beers.
Further process trials proved that it is possible to control the brewing process in a way that beers made from
malted barley repeatedly show prolamin and gluten levels well below the 20 ppm level, the level for natural gluten
free products. Even below detection limit (5 ppm). (Figure 3.)
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Conclusions |
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The natural barley malt can be used as a raw material for high quality gluten free beer. |
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The sandwich R5-ELISA method is not suitable for detecting hydrolyzed prolamins in beers,
instead a competitive R5-ELISA method should be applied. |
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Due to these trials The Finnish Coeliac Society has granted Sinebrychoff/Carlsberg breweries
a permission to use gluten free logo and claims in two commercial beers in Finland. |
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Clinical trials are in progress. |
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Literature references |
| 1 |
Garcia, E., Llorente, M., Hernando, A.,
Kieffer, R., Wieser, H. & Mendez, E. Development of a general procedure for complete extraction of gliadins for heat processed and unheated foods. Eur J Gastroenterol Hepatol 17, 529-39 (2005). |
| 2 |
Valdes, I., Garcia, E., Llorente, M. & Mendez, E. Innovative approach to low-level gluten
determination in foods using a novel sandwich enzyme-linked immunosorbent assay protocol. Eur J Gastroenterol Hepatol 15, 465-74 (2003). |
| 3 |
Ferre, S., Garcia, E., & Mendez, E. Measurement of hydrolysed gliadins by a competitiva ELISA based on monoclonal antibody R5: Analysis of syrups and beers. Proceedings of the 18th meeting of the Working Group on Prolamin Analysis and Toxicity, 2-5 October 2003. Martin Stern, Verlag Wissenschafliche Scripten, Zwickau, Germany (2004).
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Credits |
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Mäki M1, Hernando A2, Mena MC2, Lombardia M2, Lehtonen P3, Pöyri S4, Soininen-Tengvall P4, Pajunen E4, Mendez E2 |
| 1 |
University of Tampere, Tampere |
| 2 |
Universidad Autónoma, Madrid, Spain |
| 3 |
Alko Inc., ACL, Vantaa |
| 4 |
Sinebrychoff Oy/Carlsberg Breweries, Kerava, Finland |
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This infomation was published at:
XII International Celiac Disease Symposium 2006, New York 9.-11.11.2006.
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Figure 1.
The Western
Blot analysis of
European and
Finnish beers |
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Figure 2.
The amount
of gluten in
beers using two different methods |
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Figure 3. Reduction
of beer gluten with different process methods |
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