Flokkur: Greinar

Tengiliður

Guðjón Þorkelsson

Stefnumótandi sérfræðingur

gudjon.thorkelsson@matis.is

Native livestock breeds are part of the history of the Nordic people and comprise a resource for future foodproduction. In this study, net gain and carcass characteristics of two Danish, three Finnish, one Icelandic, six Norwegian andfive Swedish native cattle breeds were retrieved and compared to commercial breeds: two beef breeds and two dairy breeds.Breed data were collected from national databases and sorted into six animal categories: young bull, bull, steer, heifer, youngcow and cow, for which means and standard deviations were calculated within each country. The native breeds ranged fromsmall-sized milking type breeds with low net gain, carcass weights and EUROP classification to larger multipurpose breedswith high net gains, carcass weights and EUROP classification.

All Finnish and most of the Norwegian and Swedish native breeds had lower net gain and carcass weight than the dairy breedsin the same category and country, but with similar carcass conformation and fatness scores. The two Danish native breedshad higher net gain, carcass weight and conformation class than the reference dairy breed, but lower than the reference beefbreeds. The net gain and carcass traits of the Icelandic native breed were similar to the smallest-sized native breeds fromthe other countries. The carcass traits of the native breeds indicate that they have comparative advantages in an extensiveproduction system based on forage and marginal grasslands. They may also succeed better in the value-added markets thanin mainstream beef production.

Current patterns of meat consumption are considered unsustainable. Plant-based products are presented as a solution. However, while some plant-based products thrive, others do not make the cut due to the information “framing” effect issues related to the way information is presented to the consumers. Information on the nutrition and health properties of food products are usually made available at the point of purchase, but their effect on consumer product evaluation and subsequent purchase intent can also occur later, during or after consumption. This research demonstrates that the effect of nutrition information on product evaluation and purchase intention depends on when such information is made available–before first tasting or after first tasting–and that the information interacts with the taste experience in its effect on product evaluation and subsequent purchase intent. Using three plant-based products as an example, we conducted a cross-cultural experimental sensory evaluation with temporal order of information as the main between-subject experimental condition (informed before taste vs. informed after taste vs. control condition), and product experience phase (expectation vs. experience vs. post-experience phase) and information content as within-subject conditions. Information content had two levels: lower vs. higher share of oat protein in the product (i.e., source of protein vs. high in protein). The results indicate that information generally increases consumers’ purchase intentions with information before tasting having a higher weight when compared to the condition when information was presented after tasting. Presenting the information before tasting also mitigates a drop in the evaluation of taste after tasting, observed in the two other conditions. Further, taste acts as a healthiness cue, but the direction of the inference depends on the availability of health-related information: tasting in the informed condition increased the healthiness perception, whereas tasting in the uninformed condition had the opposite effect. Giving the information before the first tasting also increased the weight of healthiness as compared to taste in the formation of purchase intentions. These findings contribute to a better understanding of the effect of temporal order of information and product tasting have on the consumers’ product evaluations of plant-based products from theoretical and managerial perspectives.

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The study aimed to provide insight into the lipid quality of pelagic fishmeal and fish oil processing of mackerel and herring cut-offs, and the effect of temperature changes in the cooker (85-95 °C) during production. Samples were collected after each processing step at a traditional processing line where water and lipid content, free fatty acids (FFA), phospholipids (PL) and fatty acid composition (FAC) were measured. Results showed that the standard procedures at 90 °C included ineffective draining and concentration steps. Moreover, the solid streams entering the driers variated in chemical composition, suggesting that processing each stream separately could be beneficial for maintaining the lipid quality. The cooking temperature affected the lipid removal from the fishmeal processing, where lowering the temperature to 85 °C resulted in a lower lipid content of the final fishmeal, along with lower FFA and PL values. Hence, the fishmeal and fish oil factories could save energy by lowering the cooking temperature, as well as obtaining more stable and higher value products. Further recommendations include more focus on the initial steps for a better homogenization and breakdown of the raw material, as well as investigation of different drying techniques applied on each processing stream entering the drying steps.

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Little is known about the role of dietary amino acids on male reproductive performance and gamete quality in fishes. Thus, the objective of this study was to investigate how “enhanced” feeds (EH-4, EH-5, EH-6), with modified amino acid composition, and the standard on-growing diet (DAN-EX) impact body composition, milt biochemistry, and sperm performance in male European eel, Anguilla anguilla. The fatty acid composition of EH-4, EH-5, and EH-6 was similar but differed to that in DAN-EX, while amino acid composition varied between all four diets. Diet did not influence organ-somatic indices (e.g. HSI, GSI), while males fed EH-4 were heavier than other groups. Arginine, alanine, and lysine were the most abundant amino acids in milt (>11%), followed by glycine, aspartic acid, valine, glutamic acid, and leucine (>5.66%). Diet impacted milt arginine, serine, proline, methionine, and histidine levels. Specifically, males fed DAN-EX, EH-4, and EH-5 had the highest percentages of arginine, while males fed EH-4 to EH-6 had higher percentages of serine. Proline was most abundant in males fed DAN-EX, EH-5, and EH-6. Both methionine and histidine were detected at low percentages (<2%), and were impacted by diet, where males fed EH-4 and EH-5 had higher percentages of methionine, and males fed DAN-EX, EH-4, and EH-6 had the highest percentage of histidine. Milt production increased over time, where eels fed EH-4 and EH-6 showed the highest probability of producing suited milt volumes (>0.5 mL) for fertilization procedures. Spermatocrit (43.1 ± 1.80%) did not differ between the diets (ranged from 37.57 to 47.21%). Dietary regime had an impact on sperm motility, such that eels fed EH-5 and EH-6 had the greatest percentage of motile cells. In addition, fish fed EH-5 and EH-6 (or DAN-EX) had the fastest swimming sperm. Spermatogenic maturity index of hormonally treated eels varied within groups but did not differ between dietary treatment groups after 9 weeks of injections (ranged from 0.54 to 0.80). The most interesting amino acids to scrutinize from PCA plots were proline, histidine, and valine as well as lysine and arginine. Here, eels with highly motile sperm had milt with high relative proportions of proline, histidine, and valine, but were particularly low in lysine and arginine. Together, our findings add evidence that certain amino acids regulate milt biochemistry, and that male ejaculate traits may be promoted by amino acid intake. Further studies to evaluate effects of supplemented amino acid diets on fertilization ability and inter-linked early developmental stages are required.

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Most fish meal and fish oil production facilities run with outdated processes, producing low-value products, typically not intended for human consumption. The aim of the study was to perform a detailed analysis of the current fishmeal and oil production processes of capelin (Mallotus villosus), and compare the key locations of both fattier and leaner pelagic raw material to identify which steps need to be improved for the production of higher-value products. Results indicated inefficient draining and concentration during the production process and ineffective break-down of the raw material, as lipid separation was ineffective in all studied species. Although the raw material initially differed in lipid content (2%–20%, depending on the species), all fishmeal produced resulted in high-lipid fishmeal (9%–14%). Chemical composition variations in the solid steams entering the dryers suggested that drying these streams individually could lead to more process and product flexibility, which can result in higher-value products, such as fish meal and protein powders for human consumption. Practical applications: Traditional production lines of fishmeal and fish oil factories have remained the same for decades, resulting in low-quality products with a low market price. Therefore, optimization and redesign of the production processes are needed to increase the product quality. This study analyzed the lipid quality and water content in all processing steps. The current evaluations will help to shift the traditional fishmeal and fish oil production process from low-quality to high-quality products intended for human consumption by presenting a detailed analysis of the production process not available in the literature to date. Our results can act as reference values for other fishmeal and fish oil producers to assess their production quality. That includes identification of bottlenecks affecting the efficiency and effectiveness of their production processes.

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This study assessed the environmental impacts of a pelagic fishmeal and fish oil production plant in Iceland with the life cycle assessment methodology. The study focused on assessing the effects of different energy sources for utility production due to the high energy intensity of fishmeal and fish oil production, as quality improved with lower cooking temperature. The environmental hotspots of three different processing scenarios were assessed, where the factory was run on hydropower (Scenario 0), heavy fuel (Scenario 1) and a composition of both (Scenario 2), from cradle-to-factory gate. Midpoint results showed that the raw material acquisition contributed the most to the environmental impact when the fishmeal factory was operating on hydropower. However, drying had the highest impact when heavy fuel oil was used for utility production. This study also demonstrated that lowering the cooking temperature from 90 to 85 °C, led to improved quality and simultaneously reduced environmental impacts during processing. This indicated that a small energy adjustment in the production can have an environmental gain, demonstrating the necessity to optimize each processing step in the fishmeal and fish oil production process both for increased product quality and minimizing environmental impacts.

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Quality changes of protein and non-protein nitrogen compounds during industrial fishmeal processing of fatty pelagic species (mackerel/herring rest material blend, MHB) and lean fish (whole blue whiting, BW) were studied to identify processing steps that require optimization to allow production of products for human consumption. Samples from protein-rich processing streams throughout the fishmeal production were analyzed for proximate composition, salt soluble protein content (SSP), biogenic amines (BA), total volatile basic nitrogen (TVB-N), trimethylamine (TMA), and dimethylamine (DMA). Mass flows throughout processing were balanced based on the total mass and proximate composition data. The quality of the final fishmeal products was highly dependent on the fish species being processed, indicating that the processes require optimization towards each raw material. The chemical composition changed in each processing step, resulting in different properties in each stream. Most of the non-protein nitrogen compounds (including BA, TVB-N, TMA, and DMA) followed the liquid streams. However, the concentrate contributed less than 20% to the produced fishmeal quantity. Mixing of this stream into the fishmeal processing again, as currently carried out, should thus be avoided. Furthermore, the cooking, separating, and drying steps should be optimized to improve the water and lipid separation and avoid the formation of undesired nitrogen compounds to produce higher-value products intended for human consumption.

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Tengiliður

Davíð Gíslason

Verkefnastjóri

davidg@matis.is

Resource polymorphism has been proposed as an important phase of diversification and speciation in vertebrates. Studies of fish in young lakes of the Northern Hemisphere indicate variably advanced cases of adaptive trophic diversification. We have previously proposed a scheme describing this variation in terms of a gradient of resource-based polymorphic traits, emphasizing flexible behaviour in early phases and morphological divergence in more advanced phases. Here, we present data on Arctic char (Salvelinus alpinus) in Icelandic lakes exhibiting a variable degree of phenotypic and genotypic segregation. We show that (i) the morphs are at different levels of phenotypic segregation and reproductive isolation and in one case completely reproductively isolated, (ii) morphs within lakes appear to be of intralacustrine origin, and (iii) the morphological and genetic divergence of morphs is correlated, suggesting a role for trophic adaptation as a driving force in morph segregation.

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Tengiliður

Davíð Gíslason

Verkefnastjóri

davidg@matis.is

The biology of Brown trout (Salmo trutta) and Arctic charr (Salvelinus alpinus) was studied in four Faroese lakes in late July – early August 2000. Relative density and condition of Brown trout were lowest in Leynavatn and highest in Saksunarvatn. Arctic charr only occurred in Leynavatn, where it outnumbered Brown trout by a factor of 2.7. For all fish populations, growth rates were slow, fish were small and maximum age of fish was low. The oldest fish in Toftavatn was 5+yr and the oldest fish in the study, in Saksunarvatn, was 9+yr. Asymptotic length was ca. 21 cm for arctic charr in Leynavatn and ca. 25 cm for Brown trout in both Leynavatn and Toftavatn, but for Brown trout in Eystara Mjáavatn andSaksunarvatn, no asymptote was observed. Small butsignificant differences in morphology were observedamong Brown trout populations with corresponding differences in diet. Brown trout in Toftavatn had a more forked caudal fin and the diet was more pelagic/epiben- thic than in the other lakes. In Leynavatn, Brown trout fed more on benthic diet and had a more curved snout than Brown trout in the other lakes, which may be signs of character displacement resulting from interspecific competition with Arctic charr. The Arctic charr in Leynavatn did not show signs of morphological or ecological polymorphism and their diet was both of benthic and planktonic origin. Genetic analyses of Arctic charr showed minor variation at most loci, high homozygosity and genotypic disequilibrium between three loci, indicating extensive inbreeding and random genetic drift in a small, isolated population. It is suggested that the restriction of Arctic charr to one natural lake in the Faroe Islands is primarily due to unfavourable water temperatures. Evidence suggests that the slow growth, small size and short lifespan of Arctic charr and Brown trout in Leynavatn may be due to interspecific competition between the two species along with relatively poor food conditions in the lake.

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Tengiliður

Davíð Gíslason

Verkefnastjóri

davidg@matis.is

To examine the population genetic structure of lake-resident Arctic charr, Salvelinus alpinus from northwest Europe on multiple spatial scales, 2367 individuals from 43 lakes located in three geographical regions (Iceland, the British Isles and Scandinavia) were genotyped at six microsatellite loci. On a large scale, data provided little evidence to support clustering of populations according to geographical region. Hierarchical analysis of molecular variance indicated that, although statistically significant, only 2.17% of the variance in allelic frequencies was partitioned at the among-region level. Within regions, high levels of genetic differentiation were typically found between lakes regardless of the geographical distance separating them. These results are consistent with the hypothesis of rapid postglacial recolonization of all of northwest Europe from a single charr lineage, with subsequent restriction of gene flow. On a smaller scale, there was evidence for close genetic relationships among lakes from within common drainage basins in Scotland. Thus, interlake genetic structure reflects localized patterns of recent (or contemporary) gene flow superimposed onto a larger scale structure that is largely a result of historical processes. There was also evidence for widespread genetic structuring at the within-lake level, with sympatric populations detected in 10 lakes, and multilocus heterozygote deficits found in 23 lakes. This evidence of the Wahlund effect was found in all lakes known to contain discrete phenotypic morphs, as well as many others, suggesting that morphs may often represent separate breeding populations, and also that the phenomenon of polymorphism in this species may be more widespread than is currently realized.

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