Volatile organic compound production of spoilage associated microorganisms of brown shrimp (Crangon crangon) and ray (Raya sp.).

Both brown shrimp (Crangon crangon) without preservatives and ray, an elasmobranch fish species, are prone to rapid spoilage. Brown shrimp and ray contain a high content of low molecular weight compounds, which are easily metabolised by microorganisms. Elasmobranch fish such as ray contain about twice as high concentrations of urea and trimethylamine oxide (TMAO) as does other seafood ?1?. Bacterial degradation of these low molecular weight components results in the formation of volatile organic metabolites (VOCs) ?2?. Some of these metabolites, such as trimethylamine (TMA) are responsible for the unpleasant and offensive off-odours and off-flavours that lead to sensory rejection and shorten the shelf life of the seafood ?3, 4?.

The aim of this study was to investigate the spoilage potential of several isolates by studying the sensory profile of an inoculated pure culture on a sterile seafood matrix as detected by gas chromatography coupled to mass spectrometry (GC-MS). The real-time quantification throughout the spoilage process of these chemical compounds was measured by selected ion flow tube mass spectrometry (SIFT-MS) analysis.