R. KANATANI (1), W. Saito (1), T. Hoki (1), T. Iimure (1), N. Hirota (1), M. Kihara (1), K. Takoi (2), T. Shinkai (2), A. Tanigawa (2), T. Watanabe (2), K. Takazumi (2), J. Eglinton (3), B. G. Rossnagel (4), K. Ogushi (1); (1) Sapporo Breweries Ltd., Ota, Japan; (2) Sapporo Breweries Ltd., Yaizu, Japan; (3) University of Adelaide, Adelaide, Australia; (4) University of Saskatchewan, Saskatoon, SK, Canada
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, which has a negative effect on beer foam retention, is also catalyzed by LOX-1. Therefore, LOX-1 is an enzyme that has negative effects on beer quality. Sapporo has been developing high-quality malting barley varieties in Japan and other countries with its partners. In these barley breeding programs, we have developed LOX-1–less varieties by backcrossing using high-quality malting barley varieties as recurrent parents and released ‘CDC PolarStar’ in Canada, ‘SouthernStar’ in Australia, and ‘Satsuiku 2’ in Japan. In the process of breeding, we have confirmed the performance of the LOX-1–less traits compared with their recurrent parents in a series of brewing trials. The results demonstrate that the LOX-1–less varieties clearly show the expected positive effects on beer quality.
Ryoichi Kanatani has worked for Sapporo Breweries since 1987. Ryoichi is a barley breeder of Japanese varieties. This is Ryoichi’s first time presenting at an MBAA Annual Conference.