Improvement of beer flavor stability through the LOX-less barley approach

Malt and Grains Session
Junhong YU, Tsingtao Brewery Co., Ltd, Qingdao, China
Co-author(s): Jianjun Dong, Shuxia Huang, Shuli Huang, Jia Liu, Zongming Chang, Yuhong Tian, and Junhuang Hao, Tsingtao Brewery Co., Ltd., Qingdao, China

ABSTRACT: A set of pilot scale (1,000 L) brewing trials was conducted in the R&D Center of Tsingtao Brewery Co., Ltd. to investigate the effect of a LOX-less barley malt on the flavor stability of beer. The results clearly indicated the LOX-less variety has less nonenal potential (T2NP) than the control, although their LOX activities in malt were both relatively low. It was found that the beer brewed from the LOX-less barley malt contained much lower concentrations of trans-2-nonenal (T2N) and gamma-nonalactone, especially after the (forced or natural) aging of the beer, than those brewed under the same conditions from the barley variety with normal LOX activity. While the sensory panel indicated similar results in the general flavor profile, the freshness score of beer brewed from the test malt was higher than those from the control, especially after forced aging. Another exciting finding was that the trial beer had much better foam stability based on NIBEM value, by almost 30 sec. These results indicate that the use of LOX-less barley malt may be beneficial to beer flavor and foam stability. The LOX-less barley variety used was PolarStar, a new malting barley variety developed by the joint breeding program of Sapporo, Prairie Malt Limited, and the University of Saskatchewan. Metcalfe barley malt was the control for normal LOX activity.

Junhong Yu is the deputy director of the R&D Center of Tsingtao Brewery Co., Ltd. Junhong is responsible for research and development in new applied brewing technology, as well as technical support for almost 60 breweries of the Tsingtao Brewery Co., Ltd. across China. She joined Tsingtao in 1997 after she received her master’s degree in biological engineering from Wuxi University of Light Industry (now known as Jiangnan University). She received her Ph.D. degree in microbiology from Ocean University of China in 2001. Her research interests focus on the biochemistry and chemistry of beer quality, especially foam stability, haze stability, malt LOX, and starch-degrading enzymes. In her position with the company, she was sent to Brewing Research International (BRi) for training for three months in 2007. She was an oral presenter at the 2007 ASBC Annual Meeting.