VIEW ARTICLE    DOI: 10.1094/ASBCJ-43-0035

Characterization of Enzyme Inhibitors in Barley and Their Tentative Role in Malting and Brewing. L. Munck, J. Mundy, and P. Vaag, Carlsberg Research Laboratory, Department of Biotechnology, Gamle Carlsberg Vej 10, DK-2500 Valby, Copenhagen, Denmark. J. Am. Soc. Brew. Chem. 43:0035, 1985.

Enzyme inhibitors hereto studied in barley have been almost exclusively found to inhibit nonbarley proteolytic enzymes such as trypsin and chymotrypsin from mammals and subtilisin from bacteria. Such a protein is exemplified by the barley chymotrypsin inhibitor BCI-2, which inhibits subtilisin but not trypsin. We have recently found a new type of inhibitor in barley, barley amylase/subtilisin inhibitor (BASI), which is double-headed and which inhibits both α-amylase from barley and subtilisin. An extremely sensitive (1 ng/ml) and specific immunological analysis for detecting BASI was developed using enzyme-linked immunosorbent assay. The level of BASI was studied during ripening, preharvest sprouting, storing, malting, and mashing. BASI's inhibitory activity against α-amylase and its immunological activity are lost between 50 and 70° C. The role of enzyme inhibitors in seed physiology and in malting and mashing is discussed.

Keywords: α-Amylase inhibition, Barley, Enzyme inhibitors, Subtilisin inhibition