Exogenous enzyme performance during fermentation of red sorghum malt wort

The use of red sorghum in brewing is limited by its low endogenous enzyme activity, mainly due to its high polyphenol and tannin content, which are known to inhibit the enzymes involved in starch hydrolysis. This study evaluated the performance of exogenous plant-derived amylases during the fermentation of red sorghum malt wort. Enzyme extracts were obtained from corn malt, sweet potato, and munkoyo roots using an acetate buffer solution at pH 5.5. Amylases from corn resulted in the highest alcohol content (4.3% v/v), followed by those from munkoyo (4.1% v/v) and sweet potato (2.6% v/v). Among the enzyme combinations tested, only the corn-sweet potato combination improved alcohol production (4.5% v/v), while the corn-munkoyo and munkoyo-sweet potato combinations resulted in lower alcohol contents (2.0% v/v). The simultaneous application of the three enzyme extracts resulted in a further decrease in alcohol production (2.1% v/v). These results suggest the existence of inhibitory interactions between the different enzyme sources, possibly related to the presence of polyphenolic compounds in the sorghum mash.