Determination of diacetyl in beer using differential-pulse polarography

• Type: Article in International Scientific Journal
• Date: 1997

Authors

Rodrigues, JA (Author) FCUP; Barros, AA (Author) FCUP; Cruz, JMM (Author) Other; Ferreira, AA (Author) Other

Journal

Title: Journal of the Institute of Brewing

Vol. 103

Pages: 311-314

ISSN: 0046-9750

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 15 Citations

Scopus - 13 Citations

Scientific classification

FOS: Agrarian Sciences > Other Agrarian Sciences

Other information

Authenticus ID: P-001-ATF

Abstract (EN): A polarographic method is proposed for the determination of diacetyl and other vicinal diketones in beer. Similar to the EBC official spectrophotometric method. diacetyl is derivatised with o-phenylenediamine, producing 2,3-dimethylquinoxaline, a polarographically active compound. The polarographic method allows discrimination between diacetyl and methylglyoxal and a detection limit ten times lower than the EBC method is obtained. In addition, problems of erratic results for diacetyl may be avoided and data are in good agreement with those obtained by gas chromatography with electron capture detection and headspace sampling. It is suggested that high results obtained with the spectrophotometric method may be attributed to an erroneous procedure used in the spectrophotometric calculations. An alternative procedure is proposed. with which lower values for diacetyl in beer are obtained, similar to those found with other methods. These low diacetyl values are near the detection limit of the spectrophotometric method.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 4