Gluten reduction in beer by hydrodynamic cavitation assisted brewing of barley malts

- Beer brewing assisted by hydrodynamic cavitation is shown capable to reduce gluten.
- Process parameters for gluten-free and very low gluten content beers are identified.
- Hypotheses on underlying mechanisms based upon proline degradation are advanced.
- No drawbacks from gluten-specific hydrodynamic cavitation processes are identified.
- Hydrodynamic cavitation processes can replace more complex and costly technologies.

While gluten content in beers can be quite toxic to coeliac patients as well as to the broader group of gluten-intolerant people, using gluten-free raw ingredients leads to severe deprivation of flavor and taste, as well as other existing methods to lower the gluten concentration are still generally not firmly established as well as quite costly. During the development and test of a novel brewing technology based on controlled hydrodynamic cavitation, early evidence arose of gluten reduction in wort and finished beer from 100% barley malt, in correspondence with suitable cavitation regimes during both mashing and fermentation. Experimental tests are reviewed and discussed, while few hypotheses are advanced, pointing to the degradation of proline residues, the most recalcitrant among gluten constituents, leading to gluten concentration reduction in the unfermented wort and/or during fermentation and maturation, the latter due to the enhanced proline assimilation by yeasts. Direction for further research includes at least repetition of experiments and design of new ones, extension of the range of cavitation regimes, and identification of strict operational parameters as functions of brewing recipes.

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