Freezing and thawing of fish - Effect of storage temperature and thawing method on protein denaturation and lysosomal enzymes
Atlantisk laks er en lett bedervelig matvare som fraktes over store avstander. På grunn av dette trengs det det gode konserveringsmetoder. Generelt sett oppnås dette ved frysing, som gir lang holdbarhet. For å få tilnærmet fersk kvalitet på fryst laks, må både frysing- og tiningsprosessen være optim...
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Format: | Master Thesis |
Language: | English |
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NTNU
2021
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Online Access: | https://hdl.handle.net/11250/2823133 |
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NTNU Open Archive (Norwegian University of Science and Technology) |
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Atlantisk laks er en lett bedervelig matvare som fraktes over store avstander. På grunn av dette trengs det det gode konserveringsmetoder. Generelt sett oppnås dette ved frysing, som gir lang holdbarhet. For å få tilnærmet fersk kvalitet på fryst laks, må både frysing- og tiningsprosessen være optimalisert. Tre normale tinemetoder, i vannbad, i kjølerom på 4°C og i romtemperatur ble undersøkt med tanke på hvor godt egnet de var til å bevare tilnærmet fersk kvalitet i Atlantisk laksefilet. De innledende forsøkene indikerte at temperaturen i vannbadsgruppen var for høy til å oppnå tilnærmet fersk kvalitet, og at tiden til gruppen som ble tint i romtemperatur var for kort til å oppnå fullstendig tining. Som følge av dette, ble forholdene for vannbadsgruppen ble endret fra 30°C til 25°C, og tiden gruppen som ble tint i romtemperatur ble økt fra 2,25 til 3 timer. Drypptap og lysosomal enzymlekkasje var signifikant forhøyet i laks som ble tint i vannbad ved 30°C i 1,25t, sammenlignet med tining i romtemperatur og i kjølerom. Proteinløselighet var signifikant lavere (10,97-12,95%) for tining i vannbad ved 30°C i 1,25t, sammenlignet med tining i vannbad ved 25°C, for to tidslengder på 1t (22,27%) og 1,25t (19,48%). Reduksjon av temperaturen i vannbadsgruppen indikerte lavere proteindenaturering, bedre vannbindingsevne (WHC) og minimalisert lysosomal enzymlekkasje, sammenlignet med vannbadstining ved 30°C. Resultatene i denne studien indikerte at vannbadstining ved 25°C ga signifikant lavere lysosomal enzym lekkasje (0,079 for 1t) og drypp tap (1,72% for 1,25t), mens proteinløselighet (23,27% for 1t) var forhøyet, men ikke signifikant høyere sammenlignet med tining i luft (i rom temperatur og i kjølerom ved 4°C). Basert på de tre tinemetodene som ble testet, var vannbadstining ved 25°C i 1t best egnet til å oppnå tilnærmet fersk kvalitet i frossen Atlantisk laksefilet. Atlantic salmon is a highly perishable commodity that is traded over large distances and therefore, necessitate the need for good preservation systems. In general, this is often achieved by freezing, which gives long shelf life. While there are many studies that cover the effect of freezing, few exist about thawing of seafood. To achieve fresh-like quality in fish, the freezing and thawing process must be optimized. Three common thawing methods, immersion in water, thawing in cold room at 4°C and in room temperature was tested for their ability to retain fresh-like quality in Atlantic salmon fillets. The preliminary experiments gave indication that the temperature in the immersion thawing group was too high to achieve fresh-like quality, and the room temperature thawed group’s duration was too short to achieve complete thawing of the fillets. Subsequently, the conditions for the water immersion group were changed from 30°C to 25°C and the room temperature group duration was changed from 2,25h to 3h. Drip loss and lysosomal enzyme leakage was significantly elevated in salmon thawed by immersion at 30°C for 1,25h compared with thawing in room temperature and in cold room. Protein solubility was significantly lower (10,97-12,95%) when thawed by immersion at 30°C for 1,25h compared with immersion thawing at 25°C, for two durations at 1h (22,27%) and 1,25h (19,48%). Reduction of temperature in the immersion group indicated lower protein denaturation, better retention of liquid and minimized lysosomal enzyme activity compared with immersion thawing at 30°C. The results in this study indicated that immersion thawing at 25°C gave significantly lower lysosomal enzyme leakage (0,079 for 1h) and drip loss (1,72% for 1,25h), while protein solubility (23,27% for 1h) was elevated but not significantly higher compared with thawing in air (room temperature and in cold room at 4°C). Based on the three thawing methods tested, immersion thawing at 25°C for 1h is best suited to achieve fresh-like quality in frozen Atlantic salmon fillets. |
author2 |
Rustad, Turid |
format |
Master Thesis |
author |
Hansen, Henning Ottar |
spellingShingle |
Hansen, Henning Ottar Freezing and thawing of fish - Effect of storage temperature and thawing method on protein denaturation and lysosomal enzymes |
author_facet |
Hansen, Henning Ottar |
author_sort |
Hansen, Henning Ottar |
title |
Freezing and thawing of fish - Effect of storage temperature and thawing method on protein denaturation and lysosomal enzymes |
title_short |
Freezing and thawing of fish - Effect of storage temperature and thawing method on protein denaturation and lysosomal enzymes |
title_full |
Freezing and thawing of fish - Effect of storage temperature and thawing method on protein denaturation and lysosomal enzymes |
title_fullStr |
Freezing and thawing of fish - Effect of storage temperature and thawing method on protein denaturation and lysosomal enzymes |
title_full_unstemmed |
Freezing and thawing of fish - Effect of storage temperature and thawing method on protein denaturation and lysosomal enzymes |
title_sort |
freezing and thawing of fish - effect of storage temperature and thawing method on protein denaturation and lysosomal enzymes |
publisher |
NTNU |
publishDate |
2021 |
url |
https://hdl.handle.net/11250/2823133 |
genre |
Atlantic salmon |
genre_facet |
Atlantic salmon |
op_relation |
no.ntnu:inspera:75129783:37369031 https://hdl.handle.net/11250/2823133 |
_version_ |
1766362805213069312 |
spelling |
ftntnutrondheimi:oai:ntnuopen.ntnu.no:11250/2823133 2023-05-15T15:32:17+02:00 Freezing and thawing of fish - Effect of storage temperature and thawing method on protein denaturation and lysosomal enzymes Hansen, Henning Ottar Rustad, Turid 2021 application/pdf https://hdl.handle.net/11250/2823133 eng eng NTNU no.ntnu:inspera:75129783:37369031 https://hdl.handle.net/11250/2823133 Master thesis 2021 ftntnutrondheimi 2021-10-20T22:35:38Z Atlantisk laks er en lett bedervelig matvare som fraktes over store avstander. På grunn av dette trengs det det gode konserveringsmetoder. Generelt sett oppnås dette ved frysing, som gir lang holdbarhet. For å få tilnærmet fersk kvalitet på fryst laks, må både frysing- og tiningsprosessen være optimalisert. Tre normale tinemetoder, i vannbad, i kjølerom på 4°C og i romtemperatur ble undersøkt med tanke på hvor godt egnet de var til å bevare tilnærmet fersk kvalitet i Atlantisk laksefilet. De innledende forsøkene indikerte at temperaturen i vannbadsgruppen var for høy til å oppnå tilnærmet fersk kvalitet, og at tiden til gruppen som ble tint i romtemperatur var for kort til å oppnå fullstendig tining. Som følge av dette, ble forholdene for vannbadsgruppen ble endret fra 30°C til 25°C, og tiden gruppen som ble tint i romtemperatur ble økt fra 2,25 til 3 timer. Drypptap og lysosomal enzymlekkasje var signifikant forhøyet i laks som ble tint i vannbad ved 30°C i 1,25t, sammenlignet med tining i romtemperatur og i kjølerom. Proteinløselighet var signifikant lavere (10,97-12,95%) for tining i vannbad ved 30°C i 1,25t, sammenlignet med tining i vannbad ved 25°C, for to tidslengder på 1t (22,27%) og 1,25t (19,48%). Reduksjon av temperaturen i vannbadsgruppen indikerte lavere proteindenaturering, bedre vannbindingsevne (WHC) og minimalisert lysosomal enzymlekkasje, sammenlignet med vannbadstining ved 30°C. Resultatene i denne studien indikerte at vannbadstining ved 25°C ga signifikant lavere lysosomal enzym lekkasje (0,079 for 1t) og drypp tap (1,72% for 1,25t), mens proteinløselighet (23,27% for 1t) var forhøyet, men ikke signifikant høyere sammenlignet med tining i luft (i rom temperatur og i kjølerom ved 4°C). Basert på de tre tinemetodene som ble testet, var vannbadstining ved 25°C i 1t best egnet til å oppnå tilnærmet fersk kvalitet i frossen Atlantisk laksefilet. Atlantic salmon is a highly perishable commodity that is traded over large distances and therefore, necessitate the need for good preservation systems. In general, this is often achieved by freezing, which gives long shelf life. While there are many studies that cover the effect of freezing, few exist about thawing of seafood. To achieve fresh-like quality in fish, the freezing and thawing process must be optimized. Three common thawing methods, immersion in water, thawing in cold room at 4°C and in room temperature was tested for their ability to retain fresh-like quality in Atlantic salmon fillets. The preliminary experiments gave indication that the temperature in the immersion thawing group was too high to achieve fresh-like quality, and the room temperature thawed group’s duration was too short to achieve complete thawing of the fillets. Subsequently, the conditions for the water immersion group were changed from 30°C to 25°C and the room temperature group duration was changed from 2,25h to 3h. Drip loss and lysosomal enzyme leakage was significantly elevated in salmon thawed by immersion at 30°C for 1,25h compared with thawing in room temperature and in cold room. Protein solubility was significantly lower (10,97-12,95%) when thawed by immersion at 30°C for 1,25h compared with immersion thawing at 25°C, for two durations at 1h (22,27%) and 1,25h (19,48%). Reduction of temperature in the immersion group indicated lower protein denaturation, better retention of liquid and minimized lysosomal enzyme activity compared with immersion thawing at 30°C. The results in this study indicated that immersion thawing at 25°C gave significantly lower lysosomal enzyme leakage (0,079 for 1h) and drip loss (1,72% for 1,25h), while protein solubility (23,27% for 1h) was elevated but not significantly higher compared with thawing in air (room temperature and in cold room at 4°C). Based on the three thawing methods tested, immersion thawing at 25°C for 1h is best suited to achieve fresh-like quality in frozen Atlantic salmon fillets. Master Thesis Atlantic salmon NTNU Open Archive (Norwegian University of Science and Technology) |