​Microbial Gluten Reduction in Beer Using Lactic Acid Bacteria and Standard Process Methods

MBAA TQ https://doi.org/10.1094/TQ-55-1-0305-01 | VIEW ARTICLE
 
Brett F. Taubman (1), Stephan Sommer (2), Jacob Edwards (1), Travis Laws (3), Logan Hamm (1), and Brenton A. Frank (2). 1. Appalachian State University, Department of Chemistry, Boone, NC 28608, U.S.A. 2. Appalachian State University, Fermentation Sciences, Boone, NC 28608, U.S.A. 3. University of Tennessee, Department of Chemical and Biomolecular Engineering, Knoxville, TN 37996, U.S.A.
 
Abstract
Because brewing with gluten-free raw material does not always meet stylistic goals, the objective of this study was to investigate the effect of different treatments and technological parameters on gluten concentration. The attributes investigated were mash temperature, mash pH, liquor-to-grist ratios, boiling times, kettle fining additions, and microbial gluten reduction by different lactic acid bacteria. Gluten concentrations were analyzed using a competitive ELISA assay. A trained sensory panel evaluated samples that were produced with a combination of yeast and bacteria using difference testing and descriptive analysis. The results indicate that some lactic acid bacteria can reduce gluten below the detection limit of the ELISA assay. Other treatments such as boiling time, mash pH, or the liquor-to-grist ratio can reduce gluten significantly but do not come close to that reduction level. On the other hand, sensory testing revealed that beers produced with lactic acid bacteria might not meet consumer expectations owing to unusual descriptors such as sweaty, earthy, and fishy. However, if used under controlled conditions, lactic acid bacteria are a promising treatment option to degrade gluten protein in beer.

Keywords: Gluten, Bacteria, Sour beer