Stored Cod Research Articles

The globalization of naval provisioning: ancient DNA and stable isotope analyses of stored cod from the wreck of the Mary Rose, AD 1545.

A comparison of ancient DNA (single-nucleotide polymorphisms) and carbon and nitrogen stable isotope evidence suggests that stored cod provisions recovered from the wreck of the Tudor warship Mary Rose, which sank in the Solent, southern England, in 1545, had been caught in northern and transatlantic waters such as the northern North Sea and the fishing grounds of Iceland and Newfoundland. This discovery, underpinned by control data from archaeological samples of cod bones from potential source regions, illuminates the role of naval provisioning in the early development of extensive sea fisheries, with their long-term economic and ecological impacts.

Photobacterium piscicola sp. nov., isolated from marine fish and spoiled packed cod

Five isolates from marine fish (W3T, WM, W1S, S2 and S3) and three isolates misclassified as Photobacterium phosphoreum, originating from spoiled modified atmosphere packed stored cod (NCIMB 13482 and NCIMB 13483) and the intestine of skate (NCIMB 192), were subjected to a polyphasic taxonomic study. Phylogenetic analysis of 16S rRNA gene sequences showed that the isolates were members of the genus Photobacterium. Sequence analysis using the gapA, gyrB, pyrH, recA and rpoA loci showed that these isolates formed a distinct branch in the genus Photobacterium, and were most closely related to Photobacterium aquimaris, Photobacterium kishitanii, Photobacterium phosphoreum and Photobacterium iliopiscarium. The luxA gene was present in isolates W3T, WM, W1S, S2 and S3 but not in NCIMB 13482, NCIMB 13483 and NCIMB 192. AFLP and (GTG)5-PCR fingerprinting indicated that the eight isolates represented at least five distinct genotypes. DNA–DNA hybridizations revealed 89% relatedness between isolate W3T and NCIMB 192, and values below 70% with the type strains of the phylogenetically closest species, P. iliopiscarium LMG 19543T, P. kishitanii LMG 23890T, P. aquimaris LMG 26951T and P. phosphoreum LMG4233T. The strains of this new taxon could also be distinguished from the latter species by phenotypic characteristics. Therefore, we propose to classify this new taxon as Photobacterium piscicola sp. nov., with W3T (=NCCB 100098T=LMG 27681T) as the type strain.

Recognition of fish storage time by a metalloporphyrins-coated QMB sensor array

`Electronic nose' applications have been increasing in number in recent years. The reliability of these applications is mainly based on the selectivity properties of the sensors composing the array and on the stability of their characteristics. In this paper an electronic nose based on metalloporphyrins-coated quartz microbalance sensors is described. Due to the nature of the chosen metals, the sensors are particularly suitable to classify environments in which compounds containing donor atoms, such as amines, alcohols and sulphides, play a key role. The aroma of fish during storage is one of these environments. The array has been applied both for classification and for identification of the degree of freshness of stored cod fish. Data on the recognition of storage days and continuous short time monitoring are reported and discussed. Results of the electronic nose response are displayed by a method that is based on the parametrization of the input temporal evolution and allows an adequate representation of the evolving chemical environment.

Low-Field Nuclear Magnetic Resonance Relaxation Study of Stored or Processed Cod

Proton transverse relaxation has been measured in heated, pressure-treated, and frozen stored cod by pulse low-resolution NMR spectroscopy. These treatments resulted in the appearance of an additional component in the proton transverse relaxation which can be explained in terms of water exudation. The transverse relaxation time associated with this supplemental component increased with the temperature of the thermal treatment or with the temperature and duration of the frozen storage. For cod, these variations in NMR relaxation parameters can be used to detect nonreversible deterioration due to frozen storage or high hydrostatic pressure treatment.

Separation of Cod (Gadus morhua) Fillet Proteins by Electrophoresis and HPLC after Various Frozen Storage Treatments

ABSTRACTMyofibrillar, sarcoplasmic (SAR) and total extractable proteins (TEP) were isolated from the same lot of frozen cod (Gadus morhua) fillets stored at ‐30°C, ‐22°C, ‐15°C, and ‐12°C and a simulated industrial fluctuating temperature (SIFT) program. HPLC and SDS‐PAGE showed that myofibrillar and SAR of the fillets stored at ‐12°C and ‐15°C exhibited low and high molecular weight changes similar to the SIFT. A new indicator of myofibrillar frozen storage quality was developed using SDS‐PAGE. TEP profiles by HPLC were time and temperature dependent. These observations by SDS‐PAGE and HPLC were further evidence that changes in frozen stored cod muscle were partially due to covalent S‐S crosslinking.

Identification of Volatile Aroma Compounds from Oxidized Frozen Whitefish (Coregonus clupeaformis)

Volatile compounds collected on Tenax GC® at 21 °C from oxidized whitefish (Coregonus clupeaformis) were separated by fused silica capillary gas chromatography and identified by mass spectrometry and retention indices (IE). The major volatile compounds found in oxidized whitefish that were absent in freshly caught whitefish included (E,Z)- and (E,E)-2,4-heptadienal, (E,Z)- and (E,E)-2,4-decadienal, pentanal, (Z,E)- and (E,E)-3,5-octadien-2one, (Z,E)- and (E,E)-3,5-nonadien-2-one, 3-octen-2-one, l-penten-3-one, 2,3-pentaneione, and 1-pentadecene. Hexanal (approximately 40% total peak area) was the most abundant volatile compound in oxidized whitefish, and much smaller amounts were found in fresh whitefish. (Z)-4-heptenal,compound reported to be responsible for the off-flavor that develops in frozen stored cod (Gadus morhua), was not found in oxidized whitefish.

Further analysis of the volatile components of frozen cold stored cod and the influence of these on flavour

AbstractIn previous reports it was shown that hept‐cis‐4‐enal is the major component responsible for the off‐flavour that develops in cod (Gadus morhua) during frozen storage. Many other volatile components are present and a number are identified in this paper. Two of these, hept‐trans‐2‐enal and hepta‐trans‐2, cis‐4‐dienal have been shown to possess flavour notes or tones similar in character to the cold storage flavour. Recognition thresholds of these compounds have been determined in aqueous solution and from this, and the nature of their flavour it has been concluded that they are not as important in the cold storage flavour as hept‐cis‐4‐enal. Production of these three compounds has been monitored and found to increase with time and temperature of frozen storage. Taste panel assessments of the fish show a good correlation (0.84) with the hept‐cis‐4‐enal content. Evidence is presented which is strongly indicative that these compounds are produced by liquid oxidation.

EFFECT OF SODIUM PYRUVATE ON THE TEXTURE OF FROZEN STORED COD FILLETS

Journal of Food ScienceVolume 40, Issue 4 p. 888-889 EFFECT OF SODIUM PYRUVATE ON THE TEXTURE OF FROZEN STORED COD FILLETS V. D. TRAN, V. D. TRAN Technological Service, Marine Fisheries Branch Dept. of Industry and Commerce Quebec, 2700 rue Einstein, Quebec, Canada G1P 3W8Search for more papers by this author V. D. TRAN, V. D. TRAN Technological Service, Marine Fisheries Branch Dept. of Industry and Commerce Quebec, 2700 rue Einstein, Quebec, Canada G1P 3W8Search for more papers by this author First published: July‐August 1975 https://doi.org/10.1111/j.1365-2621.1975.tb00583.xCitations: 5 Acknowledgment is made to Mr. H.-P. Dussault, Chief Technological Service, Québec, for constant interest and support during this study. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume40, Issue4July‐August 1975Pages 888-889 RelatedInformation

The effect of low temperature freezing on quality changes in cold stored cod

Summary. God fillets, frozen at temperatures between — 7°C and —195°C have been stored at —7°C to establish whether ‘deep’frozen fillets deteriorate faster than ‘shallow’frozen fillets when both are stored at the same temperature. Neither objective nor organoleptic assessment of quality gave any evidence for such an effect and it was found that quality changes occurred at a rate which was independent of freezing temperature.

Sensory and objective measurements of the quality of frozen stored cod of different initial freshnesses

AbstractThe eating quality of cod kept for different periods in melting ice before being frozen and stored at three different temperatures has been evaluated by a taste panel using a new score sheet. Objective measurements of both initial freshness before freezing and deterioration during frozen storage were carried out on the same samples. Correlations were obtained between the objective measurements and various aspects of eating quality. The relative contributions of the various aspects of eating quality to the final overall acceptability were obtained, and the value of the objective measurements in predicting overall acceptability assessed.

Further Studies on the Bacteriological Reduction of Nitrite in Fish During Spoilage

The reduction of added nitrite in stored cod fillets is due to bacterial agencies. There are two mechanisms of nitrite reduction, the first inhibiting bacterial growth in acid media, and the second inhibiting trimethylamine oxide reduction in neutral solution. The effect of several levels of nitrite concentration on spoilage in fillets stored at 3 °C. as measured organoleptically and by spoilage tests was determined.

Bacterial Reduction of Sodium Nitrite and Formation of Trimethylamine in Fish

Bacteria reduce sodium nitrite in stored cod fillets. Rapid reduction of trimethylamine oxide is inhibited by the nitrite in the concentrations used, up to 700 p.p.m., trimethylamine formation occurring only after the nitrite is reduced to about 50 p.p.m. This results in an increased keeping time in fillets treated with nitrite. The surface pH remains acid until the rapid trimethylamine formation takes place.Nitrate alone, more slowly in the presence of nitrite, is rapidly reduced to nitrite and beyond. The trimethylamine oxide reduction is not affected by the nitrate reduction, the former being usually reduced before the nitrate.