Improving the fermentability of sorghum wort using sweetpotato as an adjunct during pito production

Abstract

Pito is a popular alcoholic beverage produced from malted sorghum grains. Sorghum, which is additionally used in brewing other beers, is flawed by the inadequacy of beta-amylases in its malts. Therefore, commercial beta-amylase enzymes are added to address this limitation, but they are expensive and difficult to handle during brewery and hence the need to explore alternative sources of amylases. The aim of this study was to improve the saccharification and fermentability of sorghum wort in pito production using sweetpotato as an additional source of amylase. Two sweetpotato varieties (Tuskegee and Apomuden) were obtained, processed by standard procedures and were used to prepare conventional and experimental pito beverages. The diastatic power, moisture content, extract yield, and attenuation limit, as well as sensory quality and consumer acceptability were assessed. The data gathered were analysed using STATA 14 (Strata Corp, College Station, TX, USA), ANOVA and Wilcoxon Sign Rank Test. Pito produced from the 10% Tuskegee sweetpotato variety had significantly higher diastatic power (mean difference = 4.120; p < 0.0001), lower moisture content (mean difference = -2.574; p < 0.0001), higher extract yield (mean difference = 9.006; p < 0.0001), and higher attenuation limit (mean difference = 1.584; p < 0.0001) than that of 10% Apomuden. Among the 50 pito consumers recruited, 78% (n = 39) could not tell the difference between the conventional pito and the 10% Tuskegee pito. Based on the findings of the study, it is concluded that 10% sweetpotato improved the fermentability of sorghum wort