Primary Studies On Application And Mechanism Of An Bioadditive In Malting Process

1 Primary Studies on Application and Mechanism of an Bioadditive in Malting Process Candidate: Cheng Zhongqin Supeivisor: Prof. Wang Thijtui Prof JiangYongming Abstract Malting is the first step of the brewing process. Because of the bad quality of Chinese malting barley, gibberellin (GA3) was usually used during malting as an additive to gain super malt. But gibberellin would result in darker wort color. We hope to find a new additive to substitute gibberellin, keep it抯 merits and overcome its shortcoming. Antibiotic P is a newly-found plant regulator. The effect of Antibiotic P on malt quality was at first examined. The results showed that the effect differed with different antibiotic P concentration. The special effect was that lighter wort color than the control could be found at lower concentration. In order to gain their both merits during malting, complex additives including antibiotic P and gibberellin were used. Afier many trial experiments, complex additives were found that they could increase malt quality and decrease wort color. Score a -AN and malt extract was 2.8 percent higher than control at least and was only 0.8 percent lower than GA3 at most. Depending on wort color and the cost a process was chosen.In this process 0.O5mglL gibberellin was added at beginning, then 50 mg/L Antibiotic P was added three hours later. Compared with the old one, wort color could decrease 18.6% while score on malt extract and a 桝N decreased 0.8% only in this new process. Our work included analyses about some enzymes.The key enzymes including a -amylase, proteinase and peroxidase in malt were examined. The results showed that this new process could increase a -amylase activity ,protease activity as much as gibberellin. Most of all, it could result in lower peroxidase activity than gibberellin. These results could explain the mechanism in the new process0...