Acronym NA
Category
Seafood Processing
Title Fryseskader på tørrfisk - Freezing damage to stockfish Programme National Programme
Instrument (FP6)
Contact Type (FP7)
Strand (Interreg)
NA
Theme (FP7)
Activity Area (FP6)
Regional Area (Interreg)
Action (COST)
NA
Specific Programme (FP7)
NA
Funding source National Coordinator Sjurdur Joensen Coordinator email sjurdur.joensen@nofima.no
Coordinator institution
NOFIMA - Norwegian Institute of Food, Fisheries and Aquaculture Research (Norway)
Institutions involved
NA
Start year 2011 End year 2012 Funding (€) € 196,800 Website https://www.fhf.no/prosjekter/prosjektbasen/900692/ Summary Stockfish hang out and are therefore affected by the weather and temperature conditions that occur during the hanging period. Although it is known that the quality of stockfish is greatly affected by the weather, there is a clear attitude from the players in the stockfish industry that traditional outdoor drying should be continued. In recent years, several seasons have experienced somewhat poorer drought conditions at the end of the hanging period. In practice, therefore, one has not hung much with fish in the month of April, as the quality is often poor due to the heat. There is great agreement that March is the safest month to hang in Lofoten. In order to have a larger time window to hang the fish in, there are therefore more people hanging fish in February. This gives some years significant problems with frost-damaged fish, while another year gets good quality of this fish.
When the fish hangs out in the frost, the fish will get frostbite. After experience in previous trials and conversations with some of the players, some information has been gathered related to frost-damaged stockfish. Frost damage to stockfish is shown in many ways depending on how much, for how long and when in the hanging process the fish was frozen. The damage to the fish is generally shown by the fact that the fish as stockfish is more round in the shape where the frost damage is. The muscle that is dry can be more white or yellow than on ordinary stockfish, and that the neck can be ""fos"", ie the muscle will be porous and look like freeze-dried fish muscle. After soaking, frost-damaged fish has a more "spongy" consistency and the color can become more red / brown. Taste and smell become different and often more neutral. If lye fish is produced from such a product, it is easier to dissolve.
There is little systematic documentation of frost damage to stockfish. The causes of freezing damage to stockfish are probably very complex as there are so many factors that affect where in the fish and how much damage the fish gets. After the fish is hung, it loses water reasonably quickly in the groin and abdomen, but late in the middle of the fish. The fish is probably most prone to frostbite in the part of the muscle that contains the most water. The time after hanging the fish is exposed to frost therefore probably has an impact on where and how much damage the fish gets. The temperature, the time it is frozen or the time periods will also determine how much damage the fish gets. The fish can freeze several times to varying degrees, at different times in the hanging process, or for example only once over a period.
The damage to the muscle comes from the fish drying in the frozen state, it freezes to dry. It is therefore important to be able to register the temperature, humidity, wind speed and time during the hanging period.
The main objective of this project was to investigate the effect of low temperatures during production of dried cod, stockfish. It is known that freeze temperatures during drying cause quality damages to the product. In this study we investigated the effect of variation in temperatures as well as temperature fluctuation during drying. The consequence of low temperatures during drying is change in texture and color of the stockfish. The effect of freeze damages is also a reduced capacity for rehydration, and thus giving lesser product value during further processing.
Keywords
Fish;
Fish products;
Process efficiency;
Cod;
Fish quality;
Marine Region
76
Not associated to marine areas
0
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