Β-d-Glucosidase as "key enzyme" for sorghum cyanogenic glucoside (dhurrin) removal and beer bioflavouring. (November 2016)

• Record Type: Journal Article
• Authors: Tokpohozin, Sedjro Emile; Fischer, Susann; Sacher, Bertram; Becker, Thomas
• Is Part Of: Food and chemical toxicology. Volume 97(2016)
• Page Start: 217
• Page End: 223
• Publication Date: 2016-11
• Subjects: Sorghum-beer -- Dhurrin residue -- Ethyl carbamate -- β-d-Glucosidase -- Beer bio-flavoring; Toxicology -- Periodicals; Food poisoning -- Periodicals; Food Poisoning -- Periodicals; Toxicology -- Periodicals; Toxicologie -- Périodiques; Intoxications alimentaires -- Périodiques; Food poisoning; Toxicology; Periodicals; Electronic journals; 615.9
• DOI: 10.1016/j.fct.2016.09.015
• Languages: English
• ISSNs: 0278-6915

Abstract

Abstract: 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. Highlights: Sorghum germination induces a tremendous increase of dhurrin. Several toxico-nutritional diseases are associated with consuming cyanide containing foods. Dhurrin residue is an ultimate precursor of toxicogenic ethyl carbamate. Optimizing dhurrinase as well as deculming significantly reduces dhurrin. Lactic acid bacteria expressing a β-d -glucosidase improves dhurrin removal. β-d -glucosidase with transglycosylation property is a key enzyme for beer bioflavouring.