1. Bacterial composition and succession during storage of North-Atlantic cod (Gadus morhua) at superchilled temperatures.
- Author
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Reynisson E, Lauzon HL, Magnússon H, Jónsdóttir R, Olafsdóttir G, Marteinsson V, and Hreggvidsson GO
- Subjects
- Animals, Colony Count, Microbial, DNA, Bacterial genetics, Food Preservation methods, Gas Chromatography-Mass Spectrometry, Photobacterium genetics, Photobacterium isolation & purification, Polymorphism, Restriction Fragment Length, Pseudomonas genetics, Pseudomonas isolation & purification, RNA, Ribosomal, 16S genetics, Cold Temperature, Food Microbiology, Gadus morhua microbiology, Seafood microbiology
- Abstract
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 degrees C) and superchilled (-2 and -3.6 degrees 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.
- Published
- 2009
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