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Dekontaminering av Listeria på laks og ørret
Full text linkListeria er en alvorlig matbåren patogen. Til tross for god produksjonshygiene har det vist seg at det kan være utfordringer knyttet til det å sikre fravær av Listeria i laks og lakseprodukter. Dette påfører norsk laksenæring betydelige økonomiske utfordringer hvert år. Formålet med prosjektet har vært å undersøke effekten av ulike dekontamineringsregimer. Mild dekontaminering vil kunne tas i bruk som forebyggende tiltak mot Listeria (0,5–2 log reduksjon). Ved behov for høy inaktivering av Listeria, er det i prosjektet undersøkt potensialet for å benytte metoder og teknologier som gir 5 log inaktivering eller mer. Det er et stort potensial med mange av metodene og teknologiene som er undersøkt i prosjektet. Flere av metodene vil det være behov for å utrede nærmere i forhold til ‘novel foods’-direktivet og søke om godkjenning før de eventuelt kan tas i bruk i Norge.Dekontaminering av Listeria på laks og ørretpublishedVersio
Enhanced fish performance and biosecurity by manipulation of the natural microbiome of Atlantic salmon
Full text linkThe project aimed to enhance Atlantic salmon's performance and biosecurity by manipulating their microbiome. The study investigated whether specific seawater bacteria from healthy salmon skin could improve smolts' survival after seawater transfer. Scale-explants were used to study host-bacterial interactions. Although some bacteria showed probiotic potential, they did not significantly reduce mortality or improve fish health and welfare when challenged with Moritella viscosa or after seawater transfer. The study emphasized the importance of removing fish with winter ulcer disease and the complexity of skin mucus layer colonization.Enhanced fish performance and biosecurity by manipulation of the natural microbiome of Atlantic salmonpublishedVersio
Sammensetning og potensiale for bruk av fiskeslam uten fôrrester
Full text linkFôrrester (uspist fôr) og faeces samles opp til fiskeslam fra oppdrettsanlegg på land. Det er også aktuelt å samle opp fiskeslam fra semilukkede anlegg i sjø, og teknologi for oppsamling av fiskeslam fra merdanlegg er under utvikling. Fôr til laks har høyt innhold av fett og protein, som begge er godt fordøyelige, og derfor i liten grad finnes igjen i faeces. Karbohydrat og mineraler/tungmetall i fôret er mindre fordøyelig, og blir derfor oppkonsentrert i faeces. Laksens faeces går lett i oppløsning og er vanskelig å samle opp på mekaniske filter, mens fôrpellets kan samles opp mer effektivt. Oppsamlet fiskeslam kan derfor inneholde betydelige mengder fôr, og variasjoner i sammensetning av fiskeslam skyldes i stor grad varierende andel fôr i slammet. Mengden fôrrester i fiskeslam har derfor stor betydning for bruken av slammet. I denne rapporten ble det modellert seks ulike situasjoner, basert på to fôr med ulik fordøyelighet, og tre ulike filtereffektiviteter. Den laveste filtereffektiviteten liknet forhold målt i et kommersielt anlegg, den mellomste hadde bedret oppsamling av faeces, og den høyeste filtereffektiviteten samlet opp faeces effektivt og uten innslag av fôrrester. Mengde og sammensetning av fiskeslam ble beregnet. Mengde oppsamlet fiskeslam øker ved økende filtereffektivitet og ved redusert fordøyelighet av fôret, og det ble vist hvordan sammensetningen av fiskeslammet henger sammen med fôrets fordøyelighet, filtereffektivitet og andel fôr i slammet. Godt fordøyelig fôr, høy filtereffektivitet og ingen fôrrester er forbundet med god ressursutnyttelse, men dette ga fiskeslam med det laveste innholdet av energi og nitrogen, og det høyeste innholdet av kadmium i modellen, som begrenser videre bruk av slammet. Fiskeslam brukes til produksjon av biogass og til gjødsling av landbruksareal og andre grøntareal. Fôrrester i fiskeslammet bedrer slammets egenskaper, men god ressursutnyttelse forutsetter at fôret spises av fisken, og ikke ender i slam. Egenskapene til modellert fiskeslam fra de ulike scenariene ble evaluert, og i tillegg ble biogasspotensialet i tre fiskeslamprøver samlet opp uten fôrrester målt. Etter nytt gjødselregelverk gjeldende fra 2025 var alle modellerte fiskeslammene tillatt brukt som gjødsel på landbruksareal, og bruksmengde var begrenset av fosforinnhold, ikke av sink- og/eller kadmiuminnhold. Det tyder på at det er mulig å lage organiske gjødselprodukter også av fiskeslam som kun består av faeces, forutsatt kombinasjon med andre gjødselkomponenter.publishedVersio
Visible near-infrared hyperspectral imaging as a tool to characterise chicken breasts with myopathies and their durability
Full text linkThe surgency of myopathies has posed challenges for the industry as well as researchers, making relevant the use of objective and non-destructive technologies to inspect and discriminate these disorders. In this context, hyperspectral imaging (HSI) provides special properties that allow for an accurate selection of the affected region(s). Two experiments were conducted to evaluate the feasibility of visible and near-infrared (VIS-NIR) HSI to (1) discriminate between myopathies and (2) assess their evolution during refrigerated storage. Hyperspectral images of 98 and 77 chicken breasts, for experiment (1) and (2), respectively, were analysed dividing the breast in 3 regions to precisely assign each one a myopathy or the absence of one. Support vector machine models were employed for classification. Differences between myoglobin content and water binding detected in the VIS-NIR range (386–1016 nm) were relevant enough to accurately discriminate between myopathies (76.1 % accuracy), especially spaghetti meat (94.0 % balanced accuracy). Discrimination was also successful for storage days, detecting spoilage through spectral myoglobin isoform fingerprints (99.3 % accuracy) in the short-wave NIR region (800–1015 nm). These findings suggest a potential industrial use of hyperspectral systems to sort chicken breasts based on myopathy presence by region, and to predict the evolution of their quality traits during refrigerated storage, ultimately tailoring the breast destination for each case and avoiding food waste.publishedVersio
Hyperspectral detection of blood and melanin defects in salmon fillets
Full text linkThis study investigates the use of hyperspectral imaging (HSI) and neural network classification for detecting blood and melanin spots in salmon fillets. Hyperspectral images were collected and categorized into training (100 fillets), cross-validation (28 fillets), and test (229 fillets) groups to develop and evaluate a neural network classification model. Model classification performance was assessed at both pixel-level and at the object level by using a connected component analysis to detect connected regions in the classification maps. Blood spots were detected with higher recall (0.81 at pixel level and 0.92 at object level) than melanin spots (0.71 at pixel level and 0.86 at object level) in the holdout cross validation set, likely due to the distinctive absorption spectrum of hemoglobin compared to eumelanin. The corresponding F1 score, reflecting the harmonic mean of recall and precision, was 0.76 for blood and 0.68 for melanin at the pixel level. The F1 scores at the object level were higher, with scores of 0.85 for blood and 0.84 for melanin, since mismatch in the exact boundary of the defects affects the pixel level scores more than the object level scores. In general, the model effectively separated between blood and melanin defect types, although transient states between pure blood and pure melanin were also observed, particularly in the predicted class probabilities, in line with observations made by previous studies. Directly analyzing the modelled probabilities of blood and melanin may better resolve these transient states, rather than simply classifying the most probable class. The model maintained robust performance across different test sets, with an F1 score of 0.86 achieved for melanin spot detection in an image set (120 fillets) acquired at a different facility, indicating its ability to generalize to new data. Spatial registration of all images with a single reference fillet allowed a common spatial reference to be established. Spatial mapping of defect locations and analysis of trends is a promising means of gaining further insight into production conditions contributing to quality deviations. The contribution of the present study is largely a proof of concept, but the automated and rapid, non-invasive methodology employed is highly suited to the collection of big data sets that can contribute to better understanding the multifactorial development of blood and melanin defects. This study highlights the potential of HSI and neural network classification in enhancing quality control processes in salmon production.publishedVersio
Oppdrettstorsk – status og utfordringer
Full text linkStatus og utfordringer i verdikjeden i dagens oppdrett av torsk er kartlagt gjennom intervju med oppdrettere og undersøkelse av ulike velferds- og kvalitetsparametere på oppdrettstorsk. Målet var å etablere et faktabasert grunnlag for videre forskning og forsøk, med sikte på å forbedre produksjonsbetingelsene, velferden og produktkvaliteten for oppdrettstorsk helt frem til forbruker. Resultatene i dette prosjektet viser at det er uløste utfordringer både når det gjelder deformiteter, tarmhelse og muskelkvalitet på oppdrettet torsk. I det videre arbeid med å løse disse utfordringene er det viktig å ta en flerfaglig tilnærming der både genetikk, produksjonsbetingelser og fôrsammensetning optimaliseres samtidig, og der fiskens velferd og kvalitet som sluttprodukt inkluderes som seleksjonskriterier.Oppdrettstorsk – status og utfordringerpublishedVersio
Genetic and phenotypic validation of whole body fat content measured across production phases of Atlantic salmon using dielectric and near infrared Interactance spectroscopy
Full text linkAccurate and repeated whole-body fat (WBF) measurements across production phases are important for optimizing feed utilization, reducing production waste, safeguarding fish health, ensuring product quality and improving overall salmon production. However, the chemical extraction (reference) methods for WBF recording, although precise and accurate, are costly, destructive and have limited applicability for repeated measurements on live fish. This study validates two digital phenotyping technologies: Dielectric spectroscopy (DS) and Near-infrared spectroscopy (NIR) against the reference Soxhlet chemical extraction method. DS is a fast and non-destructive commercial fat meter, whereas the specially designed NIR interactance allows deep penetration (up to 10 mm) through the fish skin into the body. Approximately 2800 fish belonging to 35 full sibs fish families were recorded for WBF at mean body weight (BW) of ∼110, 300 and 750 g in parr, pre-smolt and post-smolt phases, respectively. The WBF percentage changed across the studied production phases: with parr having a mean of 11.3 % and coefficient of variation (CV = 11 %), pre-smolt decreasing slightly in both mean 10.9 – 11.1 % and CV (5.5 – 8.8 %) and post-smolt with an increase to 14.9 % and CV (8.5 %). Both methods performed well relative to the reference, with NIR (R2 = 0.77 – 0.91) slightly outperforming the DS (R2 = 0.61 – 0.71). Significantly high genetic estimates for NIR (h2 = 0.57 ± 0.04 – 0.62 ± 0.06) and DS (h2 = 0.38 ± 0.07 – 0.56 ± 0.10) signify the potential use of these digital technologies for improving WBF in future selective breeding. The low genetic correlations (rg = 0.22 ± 0.13 – 0.33 ± 0.14) across fresh and seawater phases raise questions about the generalizability of metabolic, lipid and feed efficiency research conducted in parr and pre-smolt phases in freshwater, to the post-smolt stage in seawater. The study highlighted the unexplored detail of the genetic regulation of WBF as fish undergoes production phases. Overall, these results will add to our understanding of genetic architecture for WBF and pave the way for digital phenotyping technologies to record complex but economically important traits and refine breeding strategies.publishedVersio
Upcycling Food Chain Side Streams into Wholly Biobased Surfactants
Full text linkThe production of food entails the formation of a significant amount of side streams. In particular, the meat industry produces fatty acids, while sugars such as glucose and maltose are byproducts of the cereal one. On the other hand, there is a growing demand for more sustainable surfactants, either produced through biotech methods or using renewable raw materials. Here we report the synthesis of amphiphilic glucose and maltose polyesters (BGE and BME). A two-step process involving lipophilization of sugar through formation of an acetal (glycoside) is followed by esterification using sulfonic acid resins as catalysts. The commercial Lewatit GF-101 provided the best performances in the esterification step as far as the conversion is concerned, that is, 57% and 70% for n-butyl d-glucoside (BG) and n-butyl d-maltoside (BM), respectively, along with the highest degree of polyesterification, that means up to 87% for BGE and 78% for BME. The resulting esters exhibit interesting surfactant properties and are capable of forming stable emulsions. As these surfactants are fully biobased and can be derived from a side stream of the agri-food industry, they represent a sustainable alternative, aligning well with circular economy principles.publishedVersio
Laksvel - A standardised, operational welfare monitoring protocol for Atlantic salmon held in sea cages
Full text linkTo measure and record fish welfare in a consistent manner, a detailed protocol is necessary for how measurements and scores should be conducted. This report describes three environmental based (oxygen, temperature, and salinity), three group based (behavior, appetite, and mortality), and fourteen individual based operational welfare indicators for use in salmon grow-out facilities. All indicators are divided into four levels that indicate increasing welfare burden at each level. The protocol includes instructions on how the indicators should be measured or scored, and for the individual-based welfare indicators, there is a guide with a description of each indicator and three example images for each of the three levels indicating deviations (scoring levels 1-3).Laksvel - A standardised, operational welfare monitoring protocol for Atlantic salmon held in sea cagespublishedVersio
