Characterisation of volatile compounds produced by bacteria isolated from the spoilage flora of cold-smoked salmon

This study investigated the volatile compounds produced by bacteria belongi ng to nine different bacterial groups: Lactobacillus sake, L. farciminis, L . alimentarius. Carnobacterium piscicola, Aeromonas sp., Shewanella putefac iens. Brochothrix thermosphacta, Photobacterium phosphoreum and Enterobacte riaceae isolated from cold-smoked salmon. Each bacterial group was represen ted by several strains. In addition, combinations of the groups were examin ed as well. Sterile blocks of cold-smoked salmon were inoculated, vacuum-pa cked and stored at 6 degreesC. After 40 days of storage at 6 degreesC, aero bic viable count and pH were recorded, the volatile fraction of the samples was analysed by gas chromatography-mass spectrometry (GC-MS). and spoilage was assessed by sensory evaluation. Among the 81 volatile compounds identi fied by GC-MS, 30 appeared to be released as a result of bacterial metaboli sm Some of the effects of inoculated bacterial strains on the composition o f the volatile fraction seemed to be characteristic of certain bacterial sp ecies. Sensory analysis showed relationships between bacteria, the composit ion of the volatile fraction and the organoleptic quality of smoked salmon. (C) 2001 Elsevier Science B.V. All rights reserved.