Varmebehandling av pre-rigor filetert laks: sensorisk analyse og prediksjon av varmetransport

Norsk fiskerinæring har i dag utfordringer når det gjelder å øke videreforedling av rund fisk. Utvikling av nye produkter vil kunne være viktig med hensyn på å øke økonomisk gevinst og for å skape konkurransefortrinn. SALMA-laks er et nisjeprodukt og består av pre rigor-filetert oppdrettslaks av superior kvalitet. SALMA har lenge vært anerkjent for sin egnethet i retter hvor rå fisk er hovedingrediensen, spesielt i retter som sushi og sashimi. Fordi det i Norge er lange tradisjoner for varmebehandling av laks, er det imidlertid også ønskelig å bestemme hvordan SALMA-laks bør varmebehandles for best mulig å bevare råvarens gode kvalitet. Forsøkene i denne oppgaven har hatt til hensikt å kartlegge om og hvordan den sensoriske profilen i SALMA-laks vil påvirkes ved bruk av ulike kombinasjoner av tid og temperaturtid ved varmebehandling i dampovn. Til den sensoriske vurderingen er et profesjonelt panel ansatt ved Nofima Mat benyttet. Panelet bestod av 9 dommere som tidligere har jobbet med råvarer av samme type i ulike sammenhenger. I forsøksprosessen er også varmegjennomgang i råvaren undersøkt ved å konstruere en matematisk modell. Modellen er vurdert i forhold til evne til å predikere kjernetemperatur, og den er deretter benyttet som hjelpemiddel for å fastsette forsøksparametere for varmebehandling av prøver som inngikk i det sensoriske forsøket. Resultatene fra forsøkene indikerer at ulike kombinasjoner av tid og temperatur vil resultere i ulike sensoriske profiler. De fleste egenskapene det er testet for, viser systematiske resultater i forhold til temperatur og oppholdstid i ovn hvor de mildest og hardest varmebehandlede prøvene viser flest forskjeller. Det er også vist at det er mulig å predikere varmegjennomgang i SALMA-laks ved hjelp av en matematisk modell. One of the main challenges of the Norwegian fish industry today is to increase development of new fish-based products. An increase in production of more raffined fish products would provide a competitive edge and might give increased income for the industry. SALMA-salmon is an example of a Norwegian fish product that has been a success in the Norwegian and foreign markets recent years. This is pre-rigor filleted farmed Atlantic Salmon, and is considered an unique product. SALMA-salmon has experienced great success as an ingredient in typically raw fish dishes such as sashimi and sushi. However traditionally, salmon is often served in a cooked manner, and it is therefore of interest to examine the effect of heat treatment on SALMA-salmon and how to heat treat the fish to maintain the surperiore quality. The trials in question have been conducted to examine the effects of different time and temperature combinations on the sensory profile of SALMA-salmon. A sensory panel consisting of 9 trained pannellists was included to discuss and validate the sensory attributes of cooked salmon. In addition, a mathemathical model for describing heat transfer in the salmon samples during and after heat treatment was constructed. The model was assessed by a serial of heat treatment trials and used to construct trial parameters for the sensory experiments. The results of the trials indicate significant differences between samples heat treated by different time and temperature combinations in respect to sensory attributes. The results also imply that a mathematical approximation and simulation might predict core temperatures of salmon samples during and after heat treatment. One of the main challenges of the Norwegian fish industry today is to increase development of new fish-based products. An increase in production of more raffined fish products would provide a competitive edge and might give increased income for the industry. SALMA-salmon is an example of a Norwegian fish product that has been a success in the Norwegian and foreign markets recent years. This is pre-rigor filleted farmed Atlantic Salmon, and is considered an unique product. SALMA-salmon has experienced great success as an ingredient in typically raw fish dishes such as sashimi and sushi. However traditionally, salmon is often served in a cooked manner, and it is therefore of interest to examine the effect of heat treatment on SALMA-salmon and how to heat treat the fish to maintain the surperiore quality. The trials in question have been conducted to examine the effects of different time and temperature combinations on the sensory profile of SALMA-salmon. A sensory panel consisting of 9 trained pannellists was included to discuss and validate the sensory attributes of cooked salmon. In addition, a simple mathemathical model for describing heat transfer in the raw material during and after heat treatment was constructed. The model was assessed by a serial of heat treatment trials and used to construct trial parameters for the sensory experiments. The results of the trials indicate significant differences between samples heat treated by different time and temperature combinations in respect to sensory attributes. The results also imply that a mathematical approximation and simulation might predict core temperatures of salmon samples during and after heat treatment.