QUANTITATIVE-ANALYSIS OF BARLEY (1-]3), (1-]4)-BETA-GLUCANASE ISOENZYMES BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

The two isoenzymes of (1 → 3), (1 → 4)-β)-glucanase (EC 3.2.1.73) from malting barley were separated by high performance cation-exchange chromatography. Separation was achieved in less than 20 min with high recoveries of enzyme activity. Isoenzyme 1 was the major component (63–82 % of the total) after steeping and 48 h of germination suggesting that this isoenzyme may be the most important in determining the rate of modification. In a comparison of samples of four different varieties Grimmett, with the highest level of modification, also had the highest amount of isoenzyme 1. However, the variety Roland apparently achieved higher modification than Bandulla by having more of enzyme 2, indicating that total β-glucanase activity determined the rate of modification. The variety, Peyote, had the lowest level of enzyme 1 and total β-glucanase. Only isoenzyme 2 could be detected in kilned malt. © 1990, Academic Press Limited. All rights reserved.