Effect of Amyloglucosidase on Properties of Lager Beers Produced from Sorghum Malt and Waxy Grits

Abstract

A trifactorial experiment with a level of confidence of P < 0.05 was performed to study worts and lagers produced with barley or sorghum malts, refined maize (MZ), or waxy sorghum (WXSOR) grits treated during mashing with or without amyloglucosidase (AMG). Worts were produced from the different malts, type of adjunct, and enzyme treatment combinations following a double-mashing procedure. The diastatic activity levels of the barley and sorghum malts were 119 and 20°Lintner, respectively. The barley malt produced 35% more 12°Plato (°P) wort with higher amounts of free amino nitrogen and total fermentable carbohydrates compared with counterparts produced from sorghum malt. The barley malt wort contained higher amounts of maltose but lower amounts of glucose compared with the sorghum malt wort. The WXSOR grits produced worts with similar yield and properties as did the worts produced from MZ grits. AMG addition led to a 3% increment on wort yield and increased glucose from 9.3 to 21.5 g/L of wort and total fermentable sugar equivalents from 59.2 to 72.6 g/L of wort. After 144 hr of fermentation, lagers from barley malt and treated with AMG contained 1.0 and 0.25% units higher ethanol than did the counterparts produced from sorghum malt and without AMG. For AMG treated beers, nonsignificant differences in ethanol content were observed between samples mashed with barley malt and beers produced from sorghum malt and MZ grits. Results demonstrated that AMG could be used to increase the initial amount of fermentable sugars especially in sorghum mashes.