|Bacterial composition and succession during storage of North-Atlantic cod (Gadus morhua) at superchilled temperatures|Reynisson, E.; Lauzon, H.L.; Magnusson, M.; Jónsdóttir, R.; Ólafsdóttir, G.; Marteinsson, V.; Hreggvidsson, G.O. (2009). Bacterial composition and succession during storage of North-Atlantic cod (Gadus morhua) at superchilled temperatures. BMC Microbiol. 9(250): 250 [1-12]. dx.doi.org/10.1186/1471-2180-9-250
In: BMC Microbiology. BioMed Central: London. ISSN 1471-2180; e-ISSN 1471-2180
|Auteurs|| || Top |
- Reynisson, E.
- Lauzon, H.L.
- Magnusson, M.
- Jónsdóttir, R.
- Ólafsdóttir, G.
- Marteinsson, V.
- Hreggvidsson, G.O.
Background: The bacteriology during storage of the North-Atlantic cod has been investigated for the past decades using conventional cultivation strategies which have generated large amount of information. This paper presents a study where both conventional cultivation and cultivation independent approaches were used to investigate the bacterial succession during storage of cod loins at chilled and superchilled temperatures.Results: Unbrined (0.4% NaCl) and brined (2.5% NaCl) cod loins were stored at chilled (0°C) and superchilled (-2 and -3.6°C) temperatures in air or modified atmosphere (MA, % CO2/O2/N2: 49.0 ± 0.6/7.4 ± 0.2/43.7 ± 0.4). Discrepancy was observed between cultivation enumeration and culture independent methods where the former showed a general dominance of Pseudomonas spp. (up to 59%) while the latter showed a dominance of Photobacterium phosphoreum (up to 100%).
Gas chromatography-mass spectrophotometry (GC-MC) showed that trimethylamine was the most abundant volatile in mid- and late storage periods. Terminal restriction polymorphism (t-RFLP) analysis showed that the relative abundance of P. phosphoreum increased with storage time.Conclusion: The present study shows the bacteriological developments on lightly salted or non-salted cod loins during storage at superchilled temperatures. It furthermore confirms the importance of P. phosphoreum as a spoilage organism during storage of cod loins at low temperatures using molecular techniques. The methods used compensate each other, giving more detailed data on bacterial population developments during spoilage.