Use of digital aroma technology and SPME GC-MS to compare volatile compounds produced by bacteria isolated from processed poultry

Digital aroma technology, solid-phase micro-extraction (SPME) and gas chromatographic mass spectral (GC-MS) analysis of the headspace volatile organic compounds were used to compare bacterial species important for food safety and common to biofilms in the poultry processing environment. The instrument for digital aroma technology, called the electronic nose, measured changes in resistance of polymer sensors caused by volatile gases from the headspace of samples. Graphical output by the Sammon mapping technique produced patterns of differences or similarities among the samples. Artificial neural network software was used to model groups of samples and classify subsequent unknowns. Compounds isolated from the headspace of sealed cultures using polydimethylsiloxane SPME fibres and identified by GC-MS analyses were predominantly alcohols and indole. These qualitative profiles were repetitive for specific organisms in relation to purity and repeatability of the cultures, differed by species and were used as objective standards to compare the graphical outputs of the electronic nose.