No existent analytical method allowed the determination of the vicinal diketones (VDK), 2,3-butanedione (diacetyl) and 2,3-pentanedione, by liquid chromatography/mass spectrometry (LC/MS). An LC/MS method was developed for the simultaneous determination of diacetyl and 2,3-pentanedione in beer. A method allowing the determination of the amino acids (AA) related to the formation of VDK during fermentation was also developed. VDK were derivatized with o-phenylenediamine (OPDA) to form quinoxaline compounds. The reaction of VDK with OPDA was studied to optimize reaction time. Conversion of the diacetyl precursor, alpha-acetolactate, was tested using multiple oxidative decarboxylation techniques. Attempts were also made to determine simultaneously the AA, leucine, isoleucine and valine with the VDK. Simultaneous determination was unsuitable for the AA levels found in beer fermentation and separate methods for the determination of AA were developed. Total VDK were measured over a concentration range of 10 mug/L to 10 mg/L with less than 10% variation. These analytical methods were tested using a laboratory scale experiment to assess the impact of fermentation temperature on total VDK production and AA absorption. Samples collected in a local brewery were analyzed for total VDK using the developed method.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.100772 |
| Date | January 2006 |
| Creators | Blanchette, Maxime. |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Bioresource Engineering.) |
| Rights | © Maxime Blanchette, 2006 |
| Relation | alephsysno: 002592783, proquestno: AAIMR32668, Theses scanned by UMI/ProQuest. |
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