Technical Session 05: Malts and Grain Session
Wataru Saito, SAPPORO BREWERIES LTD., JAPAN
Co-author(s): Takehiro Hoki, Tetsuya Saito, Tomokazu Takaoka, Shinichiro Yoshida, Masayuki Shimase, Kiyoshi Takoi, Naohiko Hirota, and Makoto Kihara, Sapporo Breweries Ltd., Japan; Brian Rossnagel, Crop Development Centre, Department of Plant Sciences, University of Saskatchewan, Canada; Jason Eglinton School of Agriculture, Food and Wine, Waite Campus, University of Adelaide, Australia; Shinji Yamada, Sapporo Breweries Ltd., Japan
ABSTRACT: Lipoxygenase (LOX) in malt is involved in the formation of trans-2-nonenal (T2N) which causes cardboard off-flavor in beer. There are two LOX isozymes (LOX-1 and LOX-2), with the formation of 9-hydroperoxide, a precursor to T2N, primarily catalyzed by LOX-1. The formation of trihydroxyoctadecenoic acid (THOD), which has negative effect on beer foam retention, is also catalyzed by LOX-1. Therefore LOX-1 is an enzyme affecting beer quality. Sapporo has been developing high quality malting barley varieties in Japan and with its partners in other countries. The LOX-1-less malting barley variety CDC PolarStar was developed by molecular marker assisted backcross breeding using a landrace from India with no seed LOX-1 activity as the donor parent and high malting quality Canadian malting barley variety CDC Kendall developed by the University of Saskatchewan as the recurrent parent. Applying a similar breeding strategy in Australia, a LOX-1-less variety has been developed from the joint breeding program with the University of Adelaide using the high quality Australian malting barley variety Flagship. Sapporo has conducted brewing trials comparing LOX-1-less varieties with the parents and a commercial variety to investigate the effect of the LOX-1 trait on beer quality. The results demonstrate expected positive effects on beer quality.
Wataru Saito received a master’s of agriculture degree in plant breeding from Okayama University in Japan. He began working for Sapporo Breweries Ltd. in April 1985 as a barley breeder in the laboratory on the raw material. Since April 1987, he has functioned as a malting barley breeder in the Hongri Seeds Co., Ltd., Hongxinglong, Heilongjiang, China. He joined the joint breeding project on malting barley with teh University of Saskatchewan in Canada from 1997 to 2007 and since has shifted to the breeding program with the University of Adelaide in Australia.