Jia Liu (1), Yang He (1); (1) Tsingtao Brewery Co. Ltd., Qingdao, China

Malt and Grains

Sensitive protein has an important effect on the colloidal stability of beer. It is mainly from malt, and there are no specific indicators in connection with malt. In order to predict wort sensitive protein from malt, an extraction method of barley malt’s sensitive protein was established, and the relationship between malt’s sensitive protein and wort’s was studied. Twenty batches of malts were experimented with, and a significant positive correlation (r = 0.869; P < 0.01) was found. Then, the differences of two sensitive proteins were analyzed. The molecular weight distributions of two were similar, one part was 7-17 kDa and the other part was 46 kDa. In order to analyze different compositions of two proteins, mass spectrometry identification was carried out. The two kinds of sensitive protein both contained protein z-type serpin–alpha-amylase inhibitor–trypsin inhibitor Cme and so forth. These results showed that a method that can predict wort sensitive protein from malt was established.

Yang He is a scientist at State Key Laboratory of Biological Fermentation Engineering of Beer, Tsingtao Brewing Ltd. Most of her research is related to beer flavor production during fermentation by monitoring yeast gene expression. She received her Ph.D. degree in marine science from the Ocean University of China in 2011.