Current Developments in Malting and Brewing Trials with Sorghum in Nigeria: A Review

摘要

Initially, large-scale lager beer brewing with sorghum malts proved highly intractable due to a number of biochemical problems including: high malting losses estimated at 10-30% as against 8-10% for barley; high gelatinisation temperatures which limited starch solubilisation/ hydrolysis by the amylolytic enzymes during mashing; low extract yield/low diastatic power (DP) due to inadequate hydrolytic enzyme activities especially P-amylase; low free cx-amino nitrogen (FAN) due to inadequate proteolysis limiting yeast growth during fermentation; high wort viscosities/beer filtration problems due to low endo-P-1,3; 1-4-glucanase activities on the endosperm cell walls causing the release of some |3-glucans. Strident research efforts using improved Nigerian sorghum malt varieties (SK5912, KSV8 and ICSV400) have reported some encouraging results. The knowledge of the biochemical integrity of the endo-P-glucanases of the sorghum malt is helping to elucidate their mode of activity in the depolymerisation of the p-glucans. This is bound to ensure process efficiency in sorghum beer brewing, reduce beer production costs and ultimately, produce a Pilsner-type of lager beer with 100% sorghum malt.