When is a Bug a Feature? : Enzymatic Activity in the Beer Brewing Process

Abstract

The beer brewing industry has grown rapidly over the past several years. Because of this, the number of hop varieties has greatly expanded, making them a very valuable resource. To alleviate the financial strain, a beta-glucosidase enzyme product (X-zyme) has been created with the intention to reduce the amount of hops used in the brewing process while maintaining the levels of aroma and flavor. However, in previous studies, Xzyme has displayed potential esterase activity, producing undesirable phenolic off-flavors (POFs). To study this esterase activity of X-zyme, a spectrophotometric assay was designed using para-nitrophenyl ferulate. Detected esterase activity could indicate that X-zyme has potential off-target effects that could lead to the dumping of an entire load of beer, a significant financial loss. The assay showed significant feruloyl esterase activity that may have an impact on the conditions X-zyme should and should not be used.