2017 Master Brewers Conference
 
37. Influence of high-molecular-weight polypeptides on the smoothness and mouthfeel of beer and applications for commercial beer products

Masaru Kato, Research Laboratories for Alcoholic Beverage Technologies, Kirin Co., Ltd., Yokohama, Japan

Coauthor(s): Takumi Sugiyama, Research Laboratories for Alcoholic Beverage Technologies, Kirin Co., Ltd., Yokohama, Japan; Aiko Hiromasa, Research Laboratories for Alcoholic Beverage Technologies, Kirin Co., Ltd., Yokohama, Japan; Mayura Mochizuki, Research Laboratories for Alcoholic Beverage Technologies, Kirin Co., Ltd., Yokohama, Japan; Toshihiro Kamada, Research Laboratories for Alcoholic Beverage Technologies, Kirin Co., Ltd., Yokohama, Japan; Takeo Imai, Research Laboratories for Alcoholic Beverage Technologies, Kirin Co., Ltd., Yokohama, Japan

Malt and Grains II
Friday, October 13
10:00–11:45 a.m.
Imperial Salon B

Smoothness and mouthfeel are important parameters in designing the taste of beer. Low malt beers have large sales volumes in Japan, but improving the taste, including the smoothness and mouthfeel, of these beers is challenging because the compounds responsible for controlling these important taste parameters remain unknown. It has been reported that low- and high-molecular-weight (HMW) maltodextrins contribute to the fullness and mouthfeel of beer. In 2012, we reported at the World Brewing Congress that fractions purified from beer using size-exclusion chromatography and solid-phase extraction and containing 10~20 kDa or 40 kDa HMW polypeptides improved the smoothness and mouthfeel of low malt beer. However, these fractions contained impurities, and thus the effects of these 10~20 kDa and 40 kDa HMW polypeptides were unclear. In addition, the technology required to enrich these compounds in commercial low malt beer had not been developed, and the effect of these compounds on the taste of low malt beer had not been evaluated. In this study, we purified these HMW polypeptides using multiple techniques, including preparative size-exclusion chromatography, solid-phase extraction, and ammonium sulfate precipitation steps. These purified fractions were added to low malt beer, which consisted of 49% malt and 51% barley, to increase the corresponding polypeptide content by 25% compared to the original beer. The results of subsequent sensory evaluations indicated that the addition of highly purified 10~20 kDa HMW polypeptide from which low molecular weight compounds had been removed improved both the smoothness and mouthfeel of beer. Furthermore, the addition of the 40 kDa HMW polypeptide fraction to low malt beer had a less pronounced effect on smoothness and mouthfeel than the addition of the 10~20 kDa HMW polypeptide. We therefore developed a new method for preparing the mash, degrading barley and malt in separate mashing tanks. Low malt beer commercially produced in a brewery using this modified process contained considerably higher levels of 10~20 kDa HMW protein. Sensory evaluation of this new low malt beer product showed overall improved smoothness and mouthfeel.

Masaru Kato received an M.A. in agricultural chemistry from Tokyo University of Agriculture and Technology in Fuchu, Tokyo. He began employment with Kirin Brewery Company, Limited, in March 1990 as a researcher for enzymology in the Applied Bioresearch Center. He also received a Ph.D. degree from Tokyo University of Agriculture and Technology in 2002. Since March 2005, he has been the manager of the Microbial Enzyme Group in the Central Laboratories for Key Technology, Kirin Brewery Company, Limited. He has been working at the Research Laboratories for Alcoholic Beverage Technologies, Kirin Company, Limited, since 2010.