Bacterial composition and succession during storage of North-Atlantic cod <it>(Gadus morhua) </it>at superchilled temperatures

• Main Authors: Marteinsson Viggó, Ólafsdóttir Guðrún, Jónsdóttir Rósa, Magnússon Hannes, Lauzon Hélène L, Reynisson Eyjólfur, Hreggviðsson Guðmundur
• Format: Article
• Language: English
• Published: BMC 2009-12-01
• Series: BMC Microbiology
• Online Access: http://www.biomedcentral.com/1471-2180/9/250

<p>Abstract</p> <p>Background</p> <p>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.</p> <p>Results</p> <p>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 <it>Pseudomonas </it>spp. (up to 59%) while the latter showed a dominance of <it>Photobacterium phosphoreum </it>(up to 100%).</p> <p>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 <it>P. phosphoreum </it>increased with storage time.</p> <p>Conclusion</p> <p>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 <it>P. phosphoreum </it>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.</p>