Abstract

Utilization of 40% sweet potato in brewing increased mashing time and decreased the wort quality. The use of microbial enzymes for acceleration of mashing process and improvement in wort quality was therefore essential. Commercial Neutrase 0.5L with endoprotease activity (from Novo Nordisk Fermented Ltd.) was added to the 60% malt 40% sweet potato mash. The higher the enzyme content and the longer the catalytic time, the higher the extraction yield and the higher the amino nitrogen content in the obtained wort. However, the concentrations of sugar and amino nitrogen in the malt-sweet potato wort were lower than those in the 100% malt wort. The use of enzyme complex: Termamyl 120L with alpha-amylase activity (from Novo Nordisk Fermented Ltd.) and Neutrase 0.5L gave a better effect. The extraction yield of the 60% malt-40% sweet potato mash with Termamyl 120L and Neutrase 0.5L was higher than that of 100% malt mash. The physio-chemical characteristics of the two obtained worts were similar.