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Determination of the Total Soluble Nitrogen Content of Malt and Beer by the Dumas Combustion Method: Collaborative Trial
Author(s) -
Johnson B. A.,
Johansson C.G.
Publication year - 1999
Publication title -
journal of the institute of brewing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.523
H-Index - 51
eISSN - 2050-0416
pISSN - 0046-9750
DOI - 10.1002/j.2050-0416.1999.tb00026.x
Subject(s) - brewing , chemistry , nitrogen , content (measure theory) , food science , mathematics , mathematical analysis , organic chemistry , fermentation
The determination of the total soluble nitrogen content of malt and beer, by the Dumas procedure, has jointly been collaboratively tested by the Analysis Committee of the Institute of Brewing (IOB) and the European Brewery Convention (EBC). Five samples of beer (range 362 to 1159 mg/l) and five samples of malt (range EBC 0.598 to 0.798 %m/m (dry basis) and IOB 0.534 to 0.706 %m/m (dry basis)) were distributed to eighteen participating laboratories for analysis. Precision values were judged to be independent of the mean soluble nitrogen content for malt by both IOB and EBC methodologies. Values for r 95 and R 95 were 0.047 and 0.136%m/m for EBC laboratory wort and 0.039 and 0.144 %m/m for IOB laboratory wort respectively. Precision values for beer were judged to be dependent upon the mean nitrogen content (m) in the case of r 95 and independent of the mean nitrogen content in the case of R 95 . Values for r 95 and R 95 were 0.074m and 120 mg/l respectively.