Gas Chromatography Principal component similarity system for detection of E-coli and S-aureus contaminating salmon and hamburger

Coho, Atlantic, Spring, and Sockeye salmon and five commercial samples of h amburger patties were analyzed by processing gas chromatography (GC) data o f volatile compounds using the principal component similarity (PCS) techniq ue. PCS scattergrams of the samples inoculated with Escherichia coli and St aphylococcus aureus followed by incubation showed the pattern-shift lines m oving away from the data point for uninoculated, unincubated reference samp les in different directions with increasing incubation time. When the PCS s cattergrams were drawn for samples incubated overnight, the samples inocula ted with the two bacterial species and the uninoculated samples appeared as three separated groups. This GC/PCS approach has the potential to ensure q uality of samples by discriminating good samples from potentially spoiled s amples. The latter may require further microbial assays to identify the bac teria species potentially contaminating foods.