Reports

Shelf life tests on cod pieces: Effects of supercooling on salt and protein injected cod muscles

Published:

01/12/2007

Authors:

María Guðjónsdóttir, Kolbrún Sveinsdóttir, Hannes Magnússon, Sigurjón Arason

Supported by:

Rannís Research Fund

contact

Kolbrún Sveinsdóttir

Project Manager

kolbrun.sveinsdottir@matis.is

Shelf life tests on cod pieces: Effects of supercooling on salt and protein injected cod muscles

An integrated refrigeration study was performed on the effects of salting, protein injection and subcooling on the quality, chemical and physical properties of salt and protein injected cod muscles. The study shows that by injecting salt and protein into the muscle, utilization can be improved, drip reduced and the boiling efficiency of the muscle increased. On the other hand, the injection of salt and protein into muscles increases microbial growth and the formation of erratic alkalis, thus shortening the shelf life of the product. However, lowering the storage temperature could inhibit the growth of microorganisms and the formation of erratic alkalis. Decreased storage temperature, however, led to cell damage due to ice formation on the surface regardless of the salinity of the muscle. Therefore, it is not considered desirable to store fresh or lightly salted cod muscle at temperatures below -2 ° C. The effect of rinsing the samples in a brine bath after injection was also investigated. Such rinsing did not significantly affect the water and salinity or efficiency of the samples, but showed a reduction in the formation of erratic bases. It is therefore advisable to rinse fillets in brine after injection to prevent damage to the best extent possible. Sensory evaluation results showed that the properties of the muscle changed significantly with the injection of salt and protein into the muscle, but the injected groups lost their freshness characteristics until the fresh untreated control group.

A combined cooling experiment was performed on the effect of salting, protein injection and superchilling on the quality and physicochemical properties of brine and protein injected cod muscle. The study showed that brine and protein injections lead to increased processing and cooking yield, as well as decreased drip. Injection of salt and proteins increase on the other hand microbiological growth and the formation of volatile nitrogen bases, which in turn leads to shorter shelf life. By lowering the storage temperature this growth of microorganisms and volatile nitrogen bases could be decreased. If the storage temperature is kept too low this on the other hand led to cell damages due to ice crystallization on the muscle surface, independent on the salt content of the muscle. It is therefore not recommended to store fresh and light salted cod at temperatures below -2 ° C. The study also viewed the effect of brining the muscle after brine and protein injection. This brining had no significant effect on the salt or water content of the muscle but decreased the amount of volatile bases. It is therefore recommended that cod muscle is always washed in brine after injection to keep damaging processes at a minimum. Sensory analysis showed a significant difference between the characteristics of brine and protein injected samples to unprocessed cod muscle. The injected groups also lost their freshness characteristics earlier than the unprocessed control group.

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Reports

Dried fish as health food

Published:

01/09/2007

Authors:

Ásbjörn Jónsson, Guðrún Anna Finnbogadóttir, Guðjón Þorkelsson, Hannes Magnússon, Ólafur Reykdal, Sigurjón Arason

Supported by:

AVS Research Fund, (AVS-Fund)

contact

Guðjón Þorkelsson

Strategy & Stakeholders

gudjon.thorkelsson@matis.is

Dried fish as health food

One of the main goals of the project was to obtain basic information about the properties of Icelandic dried fish and that the information would be open and thus for the benefit of all dried fish producers in Iceland. The main conclusion of the project is that dried fish is a very rich protein source with 80-85% protein content. The amino acids were measured and compared with amino acids in eggs. The result is that dried fish proteins are of high quality. These results support the marketing of dried fish as both a healthy food and a national food. It is important to look at the salt content in dried fish better and try to reduce it to increase the health of dried fish, especially in hot-dried dried fish, as it was much higher than in other dried fish. Measurements of trace elements showed that their amount in dried fish is well within limits compared to the recommended daily allowance (RDS) except in selenium. Its amount in 100 g is three times the recommended daily dose. However, it is not considered harmful in any way.

The main object of this project was to provide information of the quality in Icelandic dried fish to be of benefit for all producers in Iceland. The main results showed that dried fish was a very rich source of proteins, containing 80-85% protein. Amino acids were measured and compared to the amino acids in eggs. It was concluded that the proteins in the dried fish were of high quality. This supports the marketing of dried fish in the health foods and traditional food markets. It is important to better analyze the salt content in dried fish and reduce it to improve balanced diet in dried fish, especially for indoor produced dried fish, which salt content is rather high. The trace elements in dried fish showed minimal content, except for selen where the content was threefold the recommended daily allowance (RDA). This is not hazardous for people in any way.

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Reports

Dried fish as a health food

Published:

01/05/2007

Authors:

Ásbjörn Jónsson, Guðrún Anna Finnbogadóttir, Guðjón Þorkelsson, Hannes Magnússon, Ólafur Reykdal

Supported by:

AVS Fisheries Research Fund

contact

Guðjón Þorkelsson

Strategy & Stakeholders

gudjon.thorkelsson@matis.is

Dried fish as a health food

The main goal of the project was to obtain basic information about the properties of Icelandic dried fish and that the information would be open and thus to the benefit of all dried fish producers in Iceland. The main conclusion of the project is that dried fish is a very rich protein source with 80-85% protein content. The amino acids were measured and compared with amino acids in eggs. Dried fish proteins proved to be of high quality. These results support the marketing of dried fish, both as a healthy and national food. It is important to look at the salt content of dried fish better and try to reduce it to increase the health of dried fish, especially in hot-dried dried fish as it turned out to be much higher than in other dried fish. Measurements of trace elements showed that their amount in dried fish is well within limits compared to the recommended daily allowance (RDS) outside selenium. Its amount in 100 g is three times the recommended daily dose. However, it is not considered harmful in any way.

The main object of this project was to establish information of the quality of Icelandic dried fish, which could benefit producers in Iceland. The main results showed that dried fish is a very rich source of proteins, containing 80-85% protein. Amino acids were measured and compared with amino acids in eggs. The conclusion was that proteins in the dried fish were of high quality. This supports the marketing of dried fish in the health foods and traditional food markets. However, it is important to analyze better the salt content in dried fish and find ways to reduce it to improve balanced diet in dried fish, especially for indoor produced dried fish, where the salt content is rather high. The trace elements in dried fish were found to be minimal, except for selen, where the content was threefold the recommended daily allowance (RDA). This is not, however, hazardous for people in any way.

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