Please use this identifier to cite or link to this item: https://knowledgecommons.lakeheadu.ca/handle/2453/594
Title: Using SIFT-MS for detection of beer spoilage bacteria and compounds causing off-flavour in beer
Authors: Georgieva, Dimka
Keywords: Beer production;Role of hops in beer;Hop plant;Beer spoilage bacteria;Hop resistance of lactic acid bacteria;Bacterial contamination of beer;Selected ion flow mass spectrometry (SIFT-MS)
Issue Date: 18-Dec-2014
Abstract: Selected ion flow tube mass spectrometry (SIFT-MS) was used for detection of spoilage bacteria in wort and beer. Samples were analysed in triplicate using SIFT-MS Full Scan mode to identify volatile compounds in the headspace of the samples. Volatile compounds in wort headspace included acetaldehyde, propanol, 2-methylpropanal, hexanal, methanethiol, 2-methylbutanal. Volatile compounds in the headspace of the wort inoculated with Lactobacillus brevis included ethanol, acetic acid and propanol. The following compounds were identified in the headspace of the sample of degassed beer: ethanol, propanol, 2-methyl-1-propanol, acetaldehydes, and ethyl formate. The detected volatile compounds coming from the headspace of wort inoculated with Lactobacillus brevis revealed changes in the compounds due to unwanted bacterial fermentation. In addition, an unidentified product ion having m/z 39 was detected. Calculations of relative abundance for this product ion and further investigations demonstrated that it can be considered as a result of compounds formed due to contamination with L. brevis. These data suggest that SIFT-MS has great potential for detection of volatile compounds coming from beer spoilage bacteria.
URI: http://knowledgecommons.lakeheadu.ca/handle/2453/594
metadata.etd.degree.discipline: Biology
metadata.etd.degree.name: M.Sc.
metadata.etd.degree.level: Master
metadata.dc.contributor.advisor: Malek, Ladislav
Ross, Brian
metadata.dc.contributor.committeemember: Leung, Kam
Appears in Collections:Electronic Theses and Dissertations from 2009

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