Tag: Quality

Reports

Combined Blast and Contact cooling - Effects on physiochemical characteristics of fresh haddock (Melanogrammus aeglefinus) fillets

Published:

01/06/2008

Authors:

Magnea Guðrún Arnþórsdóttir, Sigurjón Arason, Björn Margeirsson

Supported by:

Tækniþróunarsjóður, AVS

Contact

Sigurjón Arason

Chief Engineer

sigurjon.arason@matis.is

Combined Blast and Contact cooling - Effects on physiochemical characteristics of fresh haddock (Melanogrammus aeglefinus) fillets

Skaginn hf. has a patent for new processing technology for the processing of fresh and frozen fillets based on so-called skin cooling before peeling. The purpose of this research project was to compare fillet processing with skin cooling and traditional fillet processing. The project compares fresh fillets and chilled fillets with regard to utilization, quality and shelf life. Two experiments were performed, on the one hand Experiment I where water resistance, quality, boiling efficiency and appearance were examined, and on the other hand Experiment II where these same factors were examined and the effect of erosive cooling on the shelf life of fresh and frozen haddock was examined. The experiments were carried out at Festi ehf. in Hafnarfjörður. The main results of these studies showed that fillet processing with skin cooling has more advantages than traditional fillet processing. The erosive cooling gives higher utilization and more valuable products with a longer shelf life. Increased shelf life of fresh fish provides increased opportunities for export, which is very important for the fishing industry.

The aim of the project was to compare a new processing technique, CBC, with traditional processing of haddock fillets. In the latter the fillets go through the process without additional refrigeration. In the new processing technique, CBC, the fillets, after filleting and pre-trimming, go through pre-cooler / fluid-ice followed by CBC super-chilling. Two trials were performed, a preliminary experiment (I) and a main experiment (II). In the preliminary experiment (I), water holding capacity, quality and cooking yield were examined. In the main experiment (II) these same factors were examined, in addition to the superchilling effect on extended shelf-life of fresh and frozen haddock fillets. After the pre-cooler step, the fillets gained weight with yields of 101.6% to 102.7%. After the CBC super-chilling the fillets had final yields of 100.3% to 101.2%. After skinning, the fillets without refrigeration (traditional processing) lost most weight. The highest value of cooking yield was obtained in CBC super-chilled fillets with skin. Skinless traditional and CBC super-chilled fillets showed similar cooking yield (P> 0.05). CBC super-chilling increased the total yield of the fillets. The difference between the traditional fillets and the super-chilled fillets was significant. The appearance of the CBC super-chilled fillets was much better and with less gaping than the traditional fillets. The traditional fillets had more ragged outlines, and the ratio of cut-offs after fine-trimming was therefore higher for the traditional fillets than the CBC super-chilled fillets. Appearance of the traditional fillets showed a little yellow tinge which increased during the storage time. The CBC super-chilled fillets had a whiter and more "fresh" appearance and were therefore more attractive. Examination of total bacterial count, and amount of TMA and TVN showed that the CBC super-chilling process can extend the shelf life of fresh haddock fillets.

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Reports

Improved quality of herring for human consumption

Published:

01/12/2007

Authors:

Ásbjörn Jónsson, Hannes Hafsteinsson, Irek Klonowski, Valur N. Gunnlaugsson

Supported by:

Nordic Innovation Center

Contact

Valur Norðri Gunnlaugsson

Research Group Leader

valur.n.gunnlaugsson@matis.is

Improved quality of herring for human consumption

Herring is one of the most important fish species in the North Atlantic and the Baltic Sea. Although a large part of the catch goes to human consumption, about 85% of herring is processed into fish oil and flour. There is a general desire to increase the consumption of herring for human consumption. It was important to study the different factors that affect the quality of herring and especially how they are controlled by biological conditions. The main reason for the quality problems in herring is the high content of compounds that promote development, and affect the color and texture changes, as well as the loss of nutrients. Better quality results in increased competition for herring production in the Nordic countries, as well as a positive consumer attitude towards herring products. The main goal of the project was to improve the quality and quantity of herring, for consumption, by researching the quality of the raw material after fishing. Emphasis was placed on quality immediately after fishing and the quality of the raw material after varying periods of frost. Factors such as fishing location and fishing time did not affect the quality of the herring. However, freezing at -20 ° C had a significant effect on the quality of the raw material.

Herring is one of the most important fish species in the North Atlantic and Baltic Sea, with an annual catch exceeding 2 million tonnes. Although a large part of these fish is used for human consumption, as much as 85% of the herring is used for industrial production of fish meal and fish oil. There is a general wish to increase the utilization of herring for human consumption. Thus, it was important to study the various parameters which influence the quality of herring, and in particular how these paramenters are controlled by biological factors. A major reason behind quality problems arising during post-harvest handling of herring is its high content of compounds that efficiently catalyzes the development of rancidity, pigmentation, texture changes and loss of nutritional value. Improved quality will result in increased competitiveness of the Nordic fish processing industry and would improve the attitude among consumers towards herring products. The general objective of the project was to improve the quality and quantity of herring to be used for food production by investigating how natural variation in raw material characteristics affects post-harvest quality. Attention was given to the quality immediately after landing and the quality after period of frozen storage. The results indicated no clear differences in the quality of herring regarding catching place or season. The frozen storage for a prolonged time had the major influence on the quality of herring fillets.

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Reports

Process control for fishing, processing and processing of salted fish. Impact of raw material variables on the utilization and quality of salted fish

Published:

01/08/2007

Authors:

Lárus Þorvaldsson, Þóra Valsdóttir, Sigurjón Arason, Kristín Anna Þórarinsdóttir

Supported by:

AVS, Rannís Technology Development Fund

Contact

Þóra Valsdóttir

Project Manager

thora.valsdottir@matis.is

Process control for fishing, processing and processing of salted fish. Impact of raw material variables on the utilization and quality of salted fish

It was processed from data that has been collected at Vísi hf. and Þorbirni hf and the relationship between utilization and quality with fishing areas, fishing time, fishing vessel, cooling on board and changes in the process of action evaluated. It was found that fishing area had a significant effect on processing efficiency, but the difference between efficiency and quality according to fishing areas was smaller. Fluctuations in efficiency and quality were found to be seasonal and there were also differences between years. Changes to on-board cooling, i.e. the use of liquid ice instead of flake ice on board was not found to have a significant effect in the aforementioned manner. On the other hand, changes in the mechanism of action, ie injection, both utilization and quality. The content of the report was part of the project "Process control of fishing, processing and processing of salted fish".

Analysis of data collected by the fisheries companies Vísir and Thorfish revealed the effects of fishing grounds, season, fishing vessels, chilling methods on board and salting procedure on yield and quality of salted products. Effects of fishing grounds on processing yield were significant but curing yield and quality were less influenced. Variation in curing yield and quality were seasonal and differences between years were observed. Changes in chilling methods on-board, ie use of liquid ice instead of flake ice did not affect yield and quality of salted products. On the other hand, changes in the salting procedure did, when injection was added as the initial step in the process.

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Reports

Process control for fishing, processing and processing of salted fish. Effects of different salting methods on the effect of cod fillets

Published:

01/07/2007

Authors:

María Guðjónsdóttir, Þóra Valsdóttir, Ása Þorkelsdóttir, Kolbrún Sveinsdóttir, Hannes Magnússon, Sigurjón Arason, Kristín A. Þórarinsdóttir

Supported by:

AVS, Rannís Technology Development Fund

Contact

Þóra Valsdóttir

Project Manager

thora.valsdottir@matis.is

Process control for fishing, processing and processing of salted fish. Effects of different salting methods on the effect of cod fillets

A comparison was made of the effects of different salting methods on the utilization, quality and other properties of salted cod fillets. One group was only pre-salted but other groups were pre-salted in different ways, ie. by brine salting, spraying and / or pickling. Injured fish had a higher utilization and came out better in quality assessment than uninjected fish. However, the results indicated that the odor and taste of action were higher in unsprayed fish. The effect of phosphate use and spraying on drying properties due to higher water and salt content in products was investigated. It was found that injected fish lost less weight during drying. For the aforementioned reasons, the water content turned out to be higher after drying than in unsprayed fish. The fillets of the dried products varied according to whether the chemical content was based on drying or weight loss on drying. Therefore, the criteria for new salting processes need to be revised and drying processes need to be adapted to the changed properties of salted products.

The effects of different salting processes on yield, quality and other characteristics of salted and cured products were evaluated. Various combinations of salting steps were tested, one group was only dry salted but other groups were first pickle salted, brine injected and / or brine salted. The injected products had higher yield and higher quality than other products. The results indicated that the curing odor and flavor were stronger in products that were not injected. The water and salt content was higher in injected fillets which is important with regard to continuing processes, like drying and rehydration. Measurements during and after drying showed that injection resulted in lower drying rate and higher water content of the fillets. Dried products have been rated in different classes with regard to water content and weight changes during drying. Due to changes in the salting process and drying properties of the salted fish, these reference values have to be reconsidered.

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Reports

Process control for fishing, processing and processing of salted fish. Impact of post-catch cooling on utilization and quality (2)

Published:

01/07/2007

Authors:

Þóra Valsdóttir, Karl Rúnar Róbertsson, Egil Þorbergsson, Sigurjón Arason, Kristín Anna Þórarinsdóttir

Supported by:

AVS, Rannís Technology Development Fund

Contact

Þóra Valsdóttir

Project Manager

thora.valsdottir@matis.is

Process control for fishing, processing and processing of salted fish. Impact of post-catch cooling on utilization and quality (2)

The purpose of the experiment was to investigate the effect of different cooling methods on board a fishing vessel on the quality and utilization of salted fish in terms of whether the fish was filleted or flattened before processing. There has been different experience with the use of liquid ice, but there have been theories that it has a negative effect on quality and utilization. The use of liquid ice in the train was at least worse in terms of quality and utilization compared to flake ice, whether it was processed fillets or flat fish. Discharge was more pronounced in fillets than in flat fish, but it could not be linked to cooling methods on board.

The aim of the trial was to investigate the effects of different cooling methods onboard a fishing vessel on curing characteristics during heavy salting of cod. The fish was either splitted or filleted before salting. It has been claimed the use of liquid ice for cooling of raw material, may lead to lower yield and quality of the products. The results showed that products from fish stored in liquid ice from catch to processing were similar or better than from fish stored in flake ice. Gaping appeared to be more related to fillets than splitted fish, but this factor could not be linked to chilling methods used onboard.

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Reports

Process control for fishing, processing and processing of salted fish. Effects of different salting methods on the effect of flat fish

Published:

01/07/2007

Authors:

Kristín Anna Þórarinsdóttir, Þóra Valsdóttir, María Guðjónsdóttir, Sigurjón Arason

Supported by:

AVS, Rannís Technology Development Fund

Contact

Þóra Valsdóttir

Project Manager

thora.valsdottir@matis.is

Process control for fishing, processing and processing of salted fish. Effects of different salting methods on the effect of flat fish

Flat cod was processed according to different salting processes in order to assess the effect of pre-salting (injection, pickling and brine salting) and the composition of the injection brine (salt, phosphate, fish protein) on the action properties. Pre-salting improved efficiency and overall utilization at all stages, depending on efficacy, dehydration and drying. Brine was better than brine salting but had the most effect of spraying (followed by brine). All groups were post-salted after pre-salting. Products with added proteins came out best in the quality assessment, ie. higher percentage went in SPIG I than in other groups. Effects on microbial growth and degradation (TVN, TMA, TBA) were not significant. Efficacy characteristics assessed by sensory evaluation were similarly similar for all groups, regardless of the salting method.

Different pre-salting methods (injection, brine salting, pickle salting) were used as the initial step in heavy salting of cod. The effects of brine composition (salt, phosphate, fish proteins) were evaluated. Pre-salting increased yield and quality, brine salting was more effective than pickle salting, but the best results were obtained by injection (followed by brine salting. Dry salted was used as the main salting step for all groups. Higher ratio of products with added proteins were graded as the best class (SPIG I). Effects on microbial growth or formation of degradation compounds (TVN, TMA, TBA) were not significant.Sensory analysis showed that curing characteristics (taste, odor, appearance, texture) were not affected by the salting procedure.

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