Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/31/2000
Publication Date: N/A
Technical Abstract: A partial solubilization of the barley storage proteins must occur during the malting and mashing processes to ensure that the worts formed are acceptable for brewing. This solubilization is apparently controlled by endoproteinases that form in the grain during malting, and the activities of some of these proteinases are regulated by the presence of endogenous barley and malt protease inhibitors. We are studying these endoproteinases and their inhibitors to define how the protein hydrolysis system operates so that it can be more precisely regulated to produce improved worts. In this study, malt enzymes (E) and inhibitors (I) were extracted and treated in various ways. The treated samples were then passed through a P-30 size exclusion column to determine whether the inhibitors were complexed with the proteinases (large, voided column) or were free (small, retarded on column). As soon as the malts dissolved, enzyme-inhibitor complexes (EI) formed. It was not possible to determine whether these complexes already existed within the malt kernels. The EI complexes dissociated when heated to boiling, but not when subjected to several other rigorous treatments, indicating that the inhibitors were bound tightly to the proteinases. The I prepared from heat-degraded EI complex readily recomplexed with added E. By collecting the EI, dissociating it, and separating the resultant I compounds, an 'affinity' method was devised for purifying the bound inhibitors.