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Two trials have been carried out with hot-smoking of Atlantic mackerel in order to investigate the effect of different raw material (fillets), on product quality and shelf-life. Fillets produced from trawled, Icelandic mackerel, caught in September, from Norwegian purse-seine caught fish from November, and from trawled mackerel caught in January, were hot smoked, vacuum packaged and stored at 4 °C. After one and seven weeks, the colour was measured instrumentally, and the samples were evaluated by a sensory panel. The results indicate that neither catch season, nor frozen storage time significantly affected the processing yield. The colour of the smoked fillets changed during storage; both the redness and the yellowness decreased over the 6 week storage period, as did the lightness. In the trial, frozen fillets stored for more than eight months were used. None of the smoked samples, however, were characterised as rancid or oxidized. The products from the three different catch-months were, in fact, only significantly different with respect to salty and acid taste. The results show that the smoking process to some degree evens out the differences in raw material freshness and composition. Hot smoked Atlantic mackerel (Scomber scombrus) Effects of catch season, frozen storage time of raw material (fillets) and chilled storage time of finished product, on colour and sensory characteristics Varmrøykt makrell Effekt av fangstsesong, fryselagringstid av råstoff (filet) og kjølelagringstid av ferdig produkt, på farge og sensoriske egenskaper

A model for coupled heat and mass transfer during baking of meat in a convection oven has previously been made using COMSOL Multi-physics. In OPTIMAL, the goal was to investigate whether the model for meat could be converted to the model for fish using data previously collected on Atlantic cod. Liquid loss, the core and surface temperature, water content, and shrinkage of the cod loin was measured and analyzed experimentally. The model was then validated by comparing the experimental and the simulated data. The project OPTIMAL was financed by Stiftelsen NorConserv. Collaboration between Nofima, DTU and University of Stavanger has been established. OPTIMAL - Utvikling av et beslutningsstøtte verktøy for optimalisering av prosess og produktkvalitet

Med støtte fra RFF-Vest og med Pelagia som industriell partner var hovedmålet å avdekke de viktigste sammenhengene mellom sesong, behandling og prosessparametere, på kvalitet og holdbarhet av fryst makrellfilet. Prosjektet ble delt inn i 3 deler. Del 1 kvantifiserte kvalitetsparameterne i dagens fileter som selges i Japan. Del 2 undersøkte kvalitetsvariasjonen i makrellfilet, som følge av fangstsesong og endelig tinetemperatur ved filetering. Del 3 undersøkte lagringsstabiliteten av filetprodukter og effekten av tilsats av en antioksidant. Kina-filet hadde jevn kvalitet, mens norsk filet var preget av stor variasjon innen samme batch, trolig på grunn av manuell filetproduksjon og glasering. Resultatene for farge og gaping samsvarte godt med generell oppfatning om kvalitetsforskjell i råstoff mellom notfanget og trålfanget makrell. Når det gjelder farge, tekstur, gaping og blodflekker var kvaliteten på norsk notfanget septemberfilet ganske lik kvaliteten på Kina-filet. Resultatene tyder på at tining kan ha effekt på filetkvalitet. Dette bør undersøkes nærmere med flere fisk og under mer kontrollert (automatisert) filetproduksjon. Etter 4 måneders fryselagring ble filetene mer gule uavhengig av råstoff, noe som indikerte harskning. De opprinnelige fargeforskjellene observert i starten av lagringen hadde blitt minsket bort, og det ble ikke lenger observert stor fargeforskjell mellom de ulike råstoffene etter 12 måneder. Resultatene tyder på at holdbarheten på norsk makrellfilet er 4–8 måneder på cirka -20 °C fryselagring. Fastheten så ut til å øke med lagring (60 % Kraft) og være bløtere sammenlignet med Kina-filet (Areal 0–90 %). Resultatene viste ikke tydelig antioksidativ effekt av 2 % rosmarinekstrakt. Developing and Optimizing mackerel filleting

A model for coupled heat and mass transfer during baking of meat in a convection oven has previously been made using COMSOL Multi-physics. In OPTIMAL, the goal was to investigate whether the model for meat could be converted to the model for fish using data previously collected on Atlantic cod. Liquid loss, the core and surface temperature, water content, and shrinkage of the cod loin was measured and analyzed experimentally. The model was then validated by comparing the experimental and the simulated data. The project OPTIMAL was financed by Stiftelsen NorConserv. Collaboration between Nofima, DTU and University of Stavanger has been established.

Denne rapporten presenterer resultater fra første fase i et delprosjekt hvor formålet har vært å innhente forskningsbasert markedskunnskap som kan danne grunnlag for strategier for introduksjon av nye sildeprodukter i det tyske og ukrainske markedet. Dette gjøres gjennom å undersøke hvilke muligheter og barrierer såkalte "lead-users" ser for nye sildeprodukter i sine respektive marked. Resultatene viser at sterk konkurranse sammen med lav innovasjonsgrad bidrar til at det tyske sildemarkedet er svært prissensitivt. De to aktørene som ble intervjuet er meget opptatt av å være med på å utvikle genuint nye sildeprodukter. I en produktutviklingsprosess er det viktig for de tyske aktørene å bygge tette og langsiktige relasjoner med sine leverandører. Det ukrainske markedet domineres av hel fryst sild, er svært prissensitivt og import av filet har gått ned det siste året. I prosjektet ble det bare identifisert en "lead-user" i dette markedet, noe som gjør det vanskelig å gi konkrete innspill på hvilke strategier som kan være fornuftig i dette markedet. The aim of this project was to obtain research based market knowledge and to suggest strategies for new herring products in the German and Ukrainian market. The results show that German companies are very interested in new product development. This is due to intense competition, little innovation and a very price sensitive herring market. The Ukrainian herring market was also characterized by intense competition and little innovation. However, only one lead-user was identified making it difficult to suggest strategies for new herring products.

På oppdrag for FHF er holdbarhet på kjølt cluster av kongekrabbe (Paralithodes camtschaticus) studert. Målet har vært å komme frem til en anbefalt holdbarhet og i tillegg vise et grunnlag for en fremtidig QIM-analyse som en alternativ måte å fastsette holdbarhet på. Cluster av kongekrabbe ble produsert ved Storbukt Fiskeindustri AS i Honningsvåg. Deretter ble clusterne lagret i 14 døgn på 4 °C og analysert med hensyn på mikrobiologi, sensorikk, farge, pH og salt. En totalvurdering av resultatene viser at kjøtt i legger har en holdbarhet på 8 døgn, mens kjøtt fra skulder har en holdbarhet på 5 døgn. Det er imidlertid lite praktisk for industrien å operere med to holdbarheter på ett produkt. Derfor anbefales en holdbarhet på 5 døgn for kjølt cluster av kongekrabbe produsert under de samme betingelsene som i dette forsøket. I en fremtidig QIM-analyse, viser resultatene at lukt i skulderdelen gir en klar indikasjon på produktets totale kvalitet. Dette vil være viktig ved bruk av en fremtidig QIM analyse. In this project, shelf-life of clusters of red king crab (Paralithodes camtschaticus) has been studied. A cluster refers to a "half king crab", namely three legs plus one claw attached to a shoulder. The aim of the work has been to determine shelf-life of meat located in shoulders and legs and link this to microbial and chemical analysis. During storage, a deterioration of the meat located in the shoulder occurred faster as compared to the meat of the legs. Based on this, a shelf of 5 and 8 days for meat in shoulder and legs, respectively, is recommended. However, as clusters are sold as one unit, the overall recommended shelf of chilled clusters is 5 days.

Målet med forsøket var å avdekke hvilken betydning stress, pumpetrykk og lagrings temperatur hadde på kvaliteten for Norsk vårgytende sild. For å avklare ulike nivåer av stress ble blod, muskel pH og rigor mortis analysert. Etter levering til landanlegg ble andel av pumpeskader evaluert og filet kvalitet målt ved ulike kvalitetsscore i tillegg til tekstur og farge. Nedbrytning av muskelproteiner ble også evaluert. Resultatene viser at til tross for å være en pelagisk art med mye rød muskulatur, viser sild å ha evne å opprettholde til en viss grad aerob forbrenning under trengings situasjon. Riktignok vil silda over tid slite seg ut, men det går langsommere enn hva en kan forvente, 1030 minutt trengetid for et mindre kast synes å ha mindre effekt med hensyn til tømming av energilagrene. Dette hadde ingen nevneverdig effekt på kvaliteten. Dette kan sees i sammenheng med pumpetrykk da et økt trykk og inntakshastighet vil kunne skade fisken fysisk og medføre økt svinn. Imidlertid er skadene av mer ytre karakter, hvor det økte trykket med biomasse ikke ser ut å skade selve filetkvaliteten. Bløthale er nedbrytning av bindevev som er et sammensatt problem og relateres til sted, tid og temperatur. I dette delforsøket var det ingenting i fangstøyeblikket som skulle tilsi at hovedårsaken til problemet ligger her, hverken med tanke på stress, pumpe, temperatur, lagring, fyllingsgrad eller været. Imidlertid viser forsøket at gaping i sild i likhet med andre næringer er et reelt problem. Ettersom graden av nedbrytning av bindevevsstrukturen alltid vil være en del av den naturlige variasjonen, finnes det en rekke tiltak som kan begrense skadeomfanget. Det gjelder ofte å korte ned på tid mellom fangst og prosessleddet, samt skånsom behandling av fisken frem til prosessering. The influence of stress, pumping and storage temperature on the quality of Atlantic herring (Clupea harengus) was investigated. Results show that herring as a pelagic specie were able to maintain an aerobic metabolism during crowding and pumping, but became exhausted after 30 min. This had minor effect on quality measured by colour, gaping and texture softness. The pump pressure was however important, where the proportion of injured fish correlated with the pressure. Softness and gaping increased with storage temperature. Soft texture and gaping in the tail region was a result of breakdown of muscle proteins and connective tissue, related to seasonal effects. In periods with soft texture the time between harvest and processing is vital.

The papers of this thesis are not available in Munin: 1. Sone, I., Olsen, R.L., Dahl, R. & Heia, K.: 'Visible/near-infrared spectroscopy detects autolytic changes during storage of Atlantic salmon (Salmo salar L.)', Journal of Food Science (2011), vol.76, no.3:203-S209. Available at http://dx.doi.org/10.1111/j.1750-3841.2011.02062.x 2. Sone, I., Olsen, R.L., Sivertsen, A.H., Eilertsen, G. & Heia, K.: 'Classification of fresh Atlantic salmon (Salmo salar L.) fillets stored under different atmospheres by hyperspectral imaging', Journal of Food Engineering (2011), vol.109, no.3:482-489. Available at http://dx.doi.org/10.1016/j.jfoodeng.2011.11.001 3. Sone, I., Olsen, R.L., & Heia, K.: 'Spectral changes of Atlantic salmon (Salmo salar L.) muscle during cold storage as affected by the oxidation state of haem', Journal of Agricultural and Food Chemistry (2012), vol.60, no.38:9719–9726. Available at http://dx.doi.org/10.1021/jf302505y Spectral effects of microbial growth, packaging atmosphere and heme oxidation were investigated with fresh salmon. The presence of microorganisms and their growth have little effect on the development of spectral features in fresh salmon during storage prior to extensive spoilage. Important spectral changes occur at 606 and 636 nm in the spectra of fresh salmon during storage. Heme oxidation is the primary source of spectral changes occurring at 636 nm in fresh salmon fillets during air storage. The origin of the shoulder peak appearing at 606 nm is absorption due to water in the salmon muscle. The spectral variations at 606 nm depend on the dominant oxidation state of heme in the muscle and the change in the visibility of the water shoulder peak in the spectrum.

Hovedfokus i dette arbeidet har vært differensiering av laksefilet basert på objektiv instrumentell måling av kvalitetsparametere. Farge og fargeutvikling er viktige kvalitetsparametere for differensiering, og i dette arbeidet har det fremkommet at både konsentrasjon og oksidasjonsnivå av hemeproteiner (hemoglobin/myoglobin) er viktig å kontrollere for å oppnå en god farge og fargestabilitet. Videre er blod- og melaninflekker ofte årsak til nedgradering av laksefileter. I dette prosjektet er det utviklet en objektiv instrumentell metode for påvisning av blod- og melaninflekker på overflaten og inni laksefileter som kan implementeres i en produksjonslinje. I tillegg til å finne flekkene kan også blod og melanin skilles fra hverandre. Fjerning av pinnebein er en ressurskrevende operasjon i forbindelse med produksjon av laksefileter. I dag gjennomføres den i to operasjoner, første maskinell plukking og deretter manuell etterplukking. Et forsøk gjennomført ved en bedrift bekreftet at etterplukking er påkrevd, men ikke tilstrekkelig for å fjerne alle bein. Når den maskinelle plukkingen tilsynelatende fungerer best kan det stå igjen mange knekte bein som ikke den manuelle etterplukkingen kan fjerne. I en sensorisk test ble det vist at pinnebein tykkere enn ca. 0,35 mm og lengre enn 9 mm blir påvist av konsumenten. I testen med maskinell og manuell plukking ville det tilsvart at 83 % av beinene som sto igjen etter manuell plukking ville blitt påvist av konsumenter. Rapport/Report 7/2012 English Summary Automatisk kvalitetsdifferensiering av laksefilet

During the recent years, environmentally friendly packaging has become increasingly important for the consumer. However, this shift towards a greener alternative should not come as a compromise on the safety of the product being packaged. The main aim of this study was to investigate two different biopolymers and their usage as packaging material for food packaging applications. Films made from natural biopolymers such as chitosan and alginate were made, and their functional properties were studied. However, in order to achieve films with enhanced functional properties (mechanical, barrier, etc.) suitable for food packaging applications, seaweed was added to the film forming solution followed by HPP treatment. Chitosan is typically dissolved in acetic acid, which has a quite pungent smell which might lead to rejection by the consumer. Thus, it was investigated if citric acid as a solvent could compare to the properties of chitosan-acetic acid films. The films made with the two different acids showed similar water vapor transmission rates. However, chitosan-acetic acid films were tougher, more flexible and had a higher concentration of free amino groups. Nevertheless, films made with both citric and acetic acid were observed to have relatively good antioxidant properties. HPP treatment was performed on the film-forming solution prior to casting the films. Generally, HPP treatment at pressures of 200 and 600 MPa either decreased the properties in the chitosan films, or the properties remained unchanged. In addition, seaweed was added in different concentrations to investigate if the properties of the chitosan films could improve. However, no such improvement was seen except for increased antioxidant activity at high seaweed concentrations. Alginate is dissolved in water, so only the effect of HPP treatment and seaweed addition was studied for this polymer. HPP treatment showed some promising effects on the tensile strength of the alginate films at 200 MPa pressure. However, the barrier properties in the films remained unchanged by HPP treatment. Some decrease in antioxidant activity was observed with HPP treatment at 600 MPa pressure. Addition of seaweed showed more promising results. The antioxidant activity of the alginate films increased with added seaweed and some improvement was seen in the WVTR. Nevertheless, the tensile strength of the films was not improved by addition of seaweed, and the elasticity decreased. Both chitosan and seaweed has been reported to have good antimicrobial properties. These properties were investigated by two types of assays: disc diffusion and liquid-based assays. The disc diffusion assay was not successful due to the films curling in on themselves upon contact with the slight wet media. However, two liquid-based assays were performed at both ideal growth temperate of 37 °C, and 10 °C to simulate more realistic storage temperatures. Chitosan made with citric acid or acetic acid showed higher antimicrobial effect against E. coli than S. aureus at both 24 h incubation at 37 °C and 5 and 10 days incubation at 10 °C. The log concentration in the chitosan samples was below the detection limit for E. coli after 5 and 10 days incubation at 10 °C. Seaweed had no antimicrobial effect at 37 °C, however, some effect was seen for S. aureus at 10 °C. The combination of chitosan and seaweed was also studied at 10 °C. Reduction in CFU/mL were observed for both E. coli and S. aureus after 5 and 10 days incubation at 10 °C, however, the effect was biggest for S. aureus with a complete inhibition after 10 days incubation at 10 °C.

Master's thesis in Biological Chemistry Plasma activated water (PAW) has recently gained increased attention as a next generation non-thermal food processing technology. It has promising potential as a eco-friendly alternative to traditional decontamination methods in the food industry, as well as promising applications in agriculture, such as plant growth enhancement. In this MSc thesis, PAW composition and stability during four-week storage at different temperatures, relevant for industry settings, (10, 4 and -20 °C) were assessed as a function of PAW operating conditions (i.e. plasma power and activation time). Increasing plasma power (25 and 35 W) and activation time (10 and 30 min) resulted in a significant drop in pH (up to 2.5 ± 0.1) and significantly higher oxidation reduction potential (ORP) level (up to 284.1 ± 11.5 mV) and concentration of the monitored reactive oxygen and nitrogen species (RONS), i.e. nitrates, nitrites and hydrogen peroxide (up to 342.5 ± 13.6, 1.6 ± 0.1 and 1.1 ± 0.2 mg/L, respectively). Furthermore, the presence of carbonic compounds (carbonic acid, bicarbonate and carbonate ion) in PAW significantly increased with activation time, where the main specie was carbonic acid (maximum of 693.3 ± 131.9 μM), and estimation of the hydronium ion and hydroxide levels increased and decreased, respectively. The nitrous and nitric acid in PAW both increased with increasing plasma power and activation time. Regarding PAW storability, the pH, ORP and nitrates level remained stable during the four-week storage, independently of the temperature. However, nitrites levels were not detectable after 24 h for all operating conditions and storage temperatures, except for the most severe activation settings (36 W for 30 min), where a significant decrease was still detected only at 10 and 4 °C. Hydrogen peroxide levels were also non-detectable after 24 h for all operating conditions and storage temperatures, which was attributed to its instability in acidic environments. The potential of PAW for microbial inactivation, alone or combined with ultrasonication (US), was assessed on planktonic cells of Listeria monocytogenes, with high prevalence in fresh produce, and also on wild harvested macroalgal biomass (Laminaria hyperborea), as a sustainable alternative to current preservation strategies. About 5 log reductions on L. monocytogenes suspensions were achieved after 5 min treatment with PAW, whilst there was no significant difference for the synergistic effect was observed when combined with US. For macroalgae decontamination, the combined effect of PAW and US resulted in about ≈ 2 log reductions of the total viable counts. Thus, the potential of PAW to extended product shelf-life and reduce food waste generation was demonstrated. Assessment of PAW as a nitrogen rich fertilizer and growth enhancement was conducted on Solanum lycopersicum (tomato) cultivar Heinz plants, resulting in significantly longer and heavier plants irrigated with PAW, alone and with the synergistic effect with a nutritional solution. In conclusion, this MSc thesis has demonstrated the potential of PAW as a promising alternative to traditional sanitizers applied in the food industry, as well as to mineral fertilizers in agriculture applications.