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The selection of Saccharomyces yeast which is able to produce high amounts of relevant aroma components from sorghum wort has been scarcely explored. Furthermore, generating sorghum beer with low levels of vicinal diketones (VDKs) is a permanent concern of brewers because of the wort's low amino acid content. To address these challenges, a performant Saccharomyces cerevisiae yeast was selected based on the higher alcohols and esters it synthesizes, and conditions influencing the young beer's VDK content were studied. Our results confirm that the low amino acid content limits aromagenesis by industrial ale yeast. By contrast, the selected yeast is able to efficiently produce higher alcohols and esters and is well adapted to tropical temperatures (27 °C). The young beer obtained from 13 °P sorghum wort using the isolated strain is characterized by a higher amount of aroma-active components such as isoamyl alcohol (116.25 ± 0.38 mg/L), isoamyl acetate (1.81 ± 0.02 mg/L) and ethyl acetate (22.07 ± 0.74 mg/L). The VDK content, however, is not only yeast strain dependent; it is strongly reduced by high fermentation temperature (27 °C) and increased wort gravity., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Sorghum malt used during African beer processing contains a high level of cyanogenic glucoside (dhurrin), up to 1375 ppm. In traditional sorghum malting and mashing, dhurrin is not sufficiently hydrolyzed due to uncontrolled germination and a high gelatinization temperature. The cyanide content of traditional African beers (11 ppm) is higher than the minimum dose (1 ppm) required to form carcinogenic ethyl carbamate during alcoholic fermentation. In the detoxification process, aryl-β-d-glucosidase (dhurrinase) is the "key component". For significant dhurrin hydrolysis during mashing, optimizing dhurrinase synthesis during malting is a good solution to reduce dhurrin completely to below the harmful dose in the sorghum wort. Lactic acid bacteria which exhibit aryl-β-d-glucosidase prior to alcoholic fermentation may help to reduce ethyl carbamate content in alcoholic beverages. Moreover, some specific β-d-glucosidases have a dual property, being able to cleave and synthesize glucosides bonds and thereby generating good precursors for beer bioflavouring., (Copyright © 2016 Elsevier Ltd. All rights reserved.)