Investigation of the malting behavior of oats for brewing purposes

Response surface methodology was used to investigate the impact of germination time and temperature during malting on the quality of oat malt. Significant effects (P < 0.05) of germination time on the activities of α- and β-amylase and proteases were found, whereas β-glucanase activity was not significantly influenced. Fermentability of Congress mash worts increased with prolonged germination times to maximum values and afterward declined. Although total nitrogen content was not significantly influenced, soluble nitrogen (SN) increased with prolonged germination time. Free amino nitrogen (FAN) was the only analyzed parameter affected by both varied germination conditions. High viscosities and low extract contents remained unaffected by the varied germination parameters. Optimal germination conditions were observed for germination times between 88 and 124 hr at temperatures between 19 and 20°C or at 10°C. These conditions yielded malts with fermentability and SN in the range expected for barley malt and slightly less FAN.