Study On The Influence Of Additive Enzymes On The No-Biological Stability Of Beer

To deeply research for the production process of wort by enzymatic method with domestic malt and the influence of enzymes on the no-biological stability of wort and beer, the optimal pH value and temperature of enzymes were identified. The research showed that:1 The single factor experiment identified that the optimal pH value and temperature of B-glucanase, xylanase and neutral protease this three enzymes respectively focused on 6.5,50℃, and it was 5.5,60℃for B-amylase, glucoamylase. In order to fully utilize catalysis of these enzymes, we put forward two-step saccharification. According to the determined process conditions, the enzymes were added in different paragraphs, tracked the changes of protein and reducing sugar, then identified the time of saccharification, it was 1.5h and 1h respectively.2 Saccharification tests showed that the affect of B-amylase and glucoamylase on the no-biological stability was minimum, only improved the no-biological stability of wort by reducing the turbidity. B-glucanase and xylanase could significantly reduce the viscosity and turbidity of wort. Their coalescent saccharification could drop the turbidity from 27.52 EBC to 11.23 EBC, with a lower rate above 50 percent,which had a good effect on improving the no-biological stability of wot. Protease especially neutral protease saccharified either individually or together with acid protease and papain, showed great superiority on lowering the protein-turbidity and improving the no-biological stability of wort. When the adding amount of neutral protease was 100u/g, the contents of alpha amino nitrogen and soluble nitrogen (12°P) could respectively achieve 223.3mg/L and 1035.6mg/L, the soluble nitrogen distinguish were A area 12.56%, B area 24.04%, C area 63.40%, which according with that of ordinary wort and improving the no-biological stability of wort. Through the experiment, we chosedβ-amylase, glucoamylase,β-glucanase, xylanase and neutral protease for orthogonal test.3 Through orthogonal test L16 (45), we obtained that the most suitable amount ofβ-amylase, glucoamylase, neutral protease,β-glucanase, xylanase was 150u/g, 7u/g, 100u/g,3.0 u/g and 3.0 u/g.4 Preliminary beer fementation test showed that adding enzyme preparation could sharply reduce the content of sensitive protein, the turbidity of beer, and be helpful for improving the no-biological stability of beer; there was no obvious influence on the number and vigor of yeast, beer maturity and other flavor substances; the sensual evaluation of finished product liquor reached the national standard.