Novel strategies for thawing of pre-rigor frozen Atlantic cod (Gadus morhua) in water with air circulation, applying different and controlled temperatures are presented. After thawing (day 0) and ...after six days of storage at 2.9 ± 0.6 °C (day 6), quality parameters (thawing- and drip loss, cooking yield, sensory evaluation, and textural properties), chemical (pH, water content, total volatile basic nitrogen (TVB-N)) and microbiological analyses (total viable counts (TVC-IA), H2S-producing bacteria (H2S-IA), coliforms, thermo-tolerant coliforms and presumptive E. coli, and Listeria monocytogenes) were performed. The results obtained were compared statistically. Both thawing strategies, thawing at 10 °C and −0.5 °C or at constant 10 °C, preserved good quality fish. The hygienic conditions during the thawing processes were satisfactory and there were no indications of impaired food safety during any of the thawing strategies. No pathogens were detected in any of the cod samples, nor in the thawing media. The results showed that water thawing at −0.5 to 10 °C is suitable for frozen cod, without compromising quality and safety, and that no significant difference were seen between the selected thawing temperature regimes.
•Water thawing with air circulation at controlled temperatures gave good quality cod.•Comparable results when thawing at 10 °C and −0.5 °C or at constant 10 °C.•Thawing water loss was less for the constant 10 °C approach.•Neither Listeria monocytogenes nor any coliforms was detected.•Water thawing suitable for frozen cod without compromising quality and safety.
: Freezing of herring (Clupea harengus) for human consumption is increasing in the Nordic herring industry, either onboard the fishing vessels or right after landing. The quality of frozen herring ...as a raw material does not only depend on the frozen storage conditions applied, but also on compositional features, something which in turn can vary with season and catching ground. To unravel the link between biological variations, basic muscle composition, and sensory properties of frozen herring, a unique herring raw material was caught by commercial fishing vessels at three locations: around Iceland, outside the Norwegian coast, and in Kattegat/Skagerrak. The samplings were done according to a specific scheme and conducted over several seasons and 2 years. The herring was converted into butterfly fillets, packed in cardboard boxes, frozen, and then stored at –20 °C or –80 °C for up to 18 mo. The sensory quality was characterized by objective sensory profiling. It was shown that two generalized sensory variables could be defined from a principal component analysis of the sensory data. Except for the expected pronounced effect from storage time, the most distinct variation followed the lipid content, which in turn varied with season. An unexpected conclusion was that catching location only had a minor affect on the changes in sensory quality of herring during frozen storage. Knowledge about how season and catching location affect herring during frozen storage will be useful for optimizing the utilization of herring for frozen storage for human consumption.
Practical Application: The results of this study constitute important information for the herring processing industry when handling raw materials with different geographical and seasonal history. The reported information on a highly equal sensory quality of geographically diverse raw materials will give consumers and retailers valuable knowledge on the changes in eating quality to expect after long‐term frozen storage under conditions similar to household freezers or refrigerated counters in supermarkets.
The effect of different pre-salting methods (brine injection with salt with/without polyphosphates, brining and pickling) on the water and salt distribution in dry salted Atlantic cod (Gadus morhua) ...fillets was studied with proton and sodium NMR and MRI methods, supported by physicochemical analysis of salt and water content as well as water holding capacity. The study indicated that double head brine injection with salt and phosphates lead to the least heterogeneous water distribution, while pickle salting had the least heterogeneous salt distribution. Fillets from all treatments contained spots with unsaturated brine, increasing the risk of microbial denaturation of the fillets during storage. Since a homogeneous water and salt distribution was not achieved with the studied pre-salting methods, further optimizations of the salting process, including the pre-salting and dry salting steps, must be made in the future.
Smoldering multiple myeloma (SMM) is an asymptomatic precursor to multiple myeloma. Here we define the epidemiological characteristics of SMM in the general population in Iceland. The iStopMM study ...(ClinicalTrials.gov ID: NCT03327597 ) is a nationwide screening study for multiple myeloma precursors where all residents in Iceland 40 years or older were invited to participate. SMM was defined as 10-60% bone marrow plasma cells and/or monoclonal (M) protein concentration ≥3 g dl
, in the absence of myeloma-defining events. Of the 80,759 who gave informed consent to participate, 75,422 (93%) were screened. The prevalence of SMM in the total population was 0.53% (95% confidence interval (CI) = 0.49-0.57%) in individuals 40 years or older. In men and women, the prevalence of SMM was 0.67% (95% CI = 0.62-0.73%) and 0.39% (95% CI = 0.35-0.43%), respectively; it increased with age in both sexes. For the 193 individuals with SMM, median age was 70 years (range 44-92 years) and 60% were males. The mean M protein concentration of individuals with SMM was 0.62 g dl
(range 0.01-3.5 g dl
) and 73% had 11-20% bone marrow plasma cell infiltration. The high prevalence of SMM has implications for future treatment policies in multiple myeloma as the evidence supporting treatment initiation at the SMM stage is emerging.
Monoclonal gammopathy of undetermined significance (MGUS) precedes multiple myeloma (MM). Population-based screening for MGUS could identify candidates for early treatment in MM. Here we describe the ...Iceland Screens, Treats, or Prevents Multiple Myeloma study (iStopMM), the first population-based screening study for MGUS including a randomized trial of follow-up strategies. Icelandic residents born before 1976 were offered participation. Blood samples are collected alongside blood sampling in the Icelandic healthcare system. Participants with MGUS are randomized to three study arms. Arm 1 is not contacted, arm 2 follows current guidelines, and arm 3 follows a more intensive strategy. Participants who progress are offered early treatment. Samples are collected longitudinally from arms 2 and 3 for the study biobank. All participants repeatedly answer questionnaires on various exposures and outcomes including quality of life and psychiatric health. National registries on health are cross-linked to all participants. Of the 148,704 individuals in the target population, 80 759 (54.3%) provided informed consent for participation. With a very high participation rate, the data from the iStopMM study will answer important questions on MGUS, including potentials harms and benefits of screening. The study can lead to a paradigm shift in MM therapy towards screening and early therapy.
Atlantic Mackerel (Scombrus scombrus) is a novel species in Iceland, caught during the heavy feeding period. The feeding has an impact on quality and stability of the products, which requires ...optimization of storage and processing conditions. Physicochemical changes of brined and un-brined mackerel were analysed during frozen storage (6, 9, 12 months) at −18 °C vs. −25 °C with the aim of investigating the suitability of using well-fed frozen mackerel as raw material for canned and hot-smoked products. Heat treatments to a core temperature of 90 °C (representing canning) and 75 °C (representing hot-smoking) were applied. Prolonged frozen storage showed negative effects on the raw material prior to heat processing due to an increased level of lipid oxidation, where fish stored at −18 °C was of significantly poorer quality than fish stored at −25 °C. Moreover, the results indicated that heat treatment resulting in a core temperature of 75 °C showed higher water content, liquid holding capacity, heating yield as well as lower maximum shear force of texture compared to mackerel heated to a core temperature of 90 °C. Overall, analyses indicated that the fatty summer mackerel was well suitable for production of canned and hot-smoked products.
•Atlantic mackerel caught during heavy feeding suitable for canning and smoking.•Effect of brining and freezing of mackerel on raw material before heat treatments.•Physicochemical changes of mackerel affected by canning and hot-smoking.•Lipid deterioration of mackerel during frozen storage at different temperature.•Frozen storage conditions before heat treatment affected final product stability.
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