​​Do Starch-Degrading Enzymes in Hop Samples Originate in Microorganisms?

​MBAA TQ https://doi.org/10.1094/TQ-58-3​-0705-01​  | VIEW ARTICLE

Ryohei Teraoka (1), Makoto Kanauchi (1), and Charles W. Bamforth (2). 1. Department of Food Management, Miyagi University, Hatatate Taihaku-ku Sendai Miyagi, 982-0215, Japan. 2. Sierra Nevada Brewing Company, Chico, CA 95928, U.S.A.
 
Abstract
 
Starch-degrading enzymes, notably α- and β-amylase, are present in fresh hops, dried hops, and pellets. The levels of α-amylase were found to decay on storage. Hop samples were immersed in various solutions containing sugar or starches and monitored for enzyme levels over a period of 28 days. Proportionately more α-amylase was synthesized by ground samples of hops in response to starch as the sole source of carbon in aqueous solution. When either starch or glucose was provided there was a removal of carbohydrate over time, something not observed when azide was added, suggesting that there was microbial growth in these samples. It is hypothesized that the starch-degrading enzymes reported in hop materials are primarily furnished by microorganisms.

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