Reports

Development of food imaging methods - Part B. Use of image analysis in research on the composition of muscle fibers in lambs / Development of analytical methods - The use of image analysis for analyzing lamb muscle

Published:

01/10/2009

Authors:

Eyrún Harpa Hlynsdóttir, Jónína Þ Jóhannsdóttir, Rannveig Björnsdóttir

Supported by:

Matvælasetur Háskólinn á Akureyri

Development of food imaging methods - Part B. Use of image analysis in research on the composition of muscle fibers in lambs / Development of analytical methods - The use of image analysis for analyzing lamb muscle

Research has shown that there is a great difference in the quality of food according to its origin and different treatment, and therefore it is important to be able to monitor the quality of processed raw materials and food in the easiest and most reliable way. Imaging is an interesting option that can provide information that is accessible and shows well the structure of tissues and the effect of different factors on the composition and properties of products. The report is a summary of methods for the analysis of different types of muscle cells in lambs. In summary, it can be said that the dyeing was successful and that it was possible to clearly separate the different types of muscle fibers in the spinal and thigh muscles of lambs. However, the method that has been used to differentiate type II muscle fibers into subtypes IIA and IIB is excluded, but it was found that the response with that method was not decisive and it is therefore appropriate to point out the use of other and more precise methods.

Research reveal variable quality of food products, depending on the origin, processing and other treatment of the product. Hence, it is considered of importance to be able to easily monitor the quality of the raw material. Image analysis is considered an interesting choice of analytical method which allows detection of tissue structures and analysis of the effects of various factors on tissue structure and various quality parameters. The report compiles methods used for identifying different types of cells in the muscle of lambs. The main results show that it is possible to distinguish different types of muscular fibers in lambs. Classification of the Type II fibers, based on their oxidative activity using the NADH ‐ TR method, however, proved inaccurate. More accurate methods such as the SDH method are therefore recommended.

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Reports

Development of analytical methods for food imaging - Use of imaging to assess spinal defects immediately at the larval stage of cod farming / Development of analytical methods - The use of image analysis for detection of spinal deformities of fish larvae

Published:

01/01/2009

Authors:

Jónína Þ Jóhannsdóttir, Rut Hermannsdóttir, Rannveig Björnsdóttir

Supported by:

Matvælasetur Háskólinn á Akureyri

Development of analytical methods for food imaging - Use of imaging to assess spinal defects immediately at the larval stage of cod farming / Development of analytical methods - The use of image analysis for detection of spinal deformities of fish larvae

Research has shown that there is a great difference in the quality of food according to its origin and different treatment, and therefore it is important to be able to monitor the quality of processed raw materials and food in the easiest and most reliable way. Imaging is a very interesting option that can provide information that is accessible and shows well the structure of tissues and the effect of different factors on the composition and properties of products. Various defects are common problems in cod farming and it is believed that this can, among other things, limit growth potential and cause increased losses. Skeletal defects such as skulls do not appear until the later stages of larval rearing and it is therefore important to develop an easy method of diagnosis earlier in the process. Imaging of cod and halibut larvae was based on a staining method with a double staining solution in which bones and cartilage are stained (Alazarin red and Alcian blue). Various versions were tested during the adaptation of the method, which proved necessary in order to get the clearest picture of the appearance of the spine. It turned out to be best to dye over a longer period of time (overnight), but the bleaching time needs to be extended from the original method description to reduce the color in the flesh. The results indicate that imaging is a good way to assess the quality of larvae and it is best to stain only the bones as cartilage in the fins and face can shade the upper part of the spine.

Research reveal variable quality of food products, depending on the origin, processing and other treatment of the product. Hence, it is considered of importance to be able to easily monitor the quality of the raw material. Image analysis is considered an interesting choice of analytical method which allows detection of tissue structures and analysis of the effects of various factors on tissue structure and various quality parameters. Various deformities are commonly observed in aquacultured fish and may limit growth and contribute to reduced survival. Spinal deformities do not appear until late during the larval stages and therefore it is important to develop an accessible method for early detection of these deformities. Cod and halibut larvae were analyzed using image analysis following double staining of bone and cartilage (Alazarin red and Alcian blue). Various adjustments of the method were tested in order to get a clear view of the spinal cord. The most successful results were obtained when staining was carried out overnight and the bleaching time extended in order to minimize staining of the flesh. The results indicate that image analysis using staining is practical for detection of spinal deformities of fish larvae. The most successful results were obtained using staining of only the bone tissue as staining of the cartilage as well would predominate the uppermost part of the spine.

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Reports

Comparison of microstructure between farmed and wild cod

Published:

01/12/2008

Authors:

Valur Norðri Gunnlaugsson, Guðrún Anna Finnbogadóttir

Supported by:

AVS R26-06 / AVS R&D Fund of Ministry of Fisheries in Iceland

contact

Valur Norðri Gunnlaugsson

Group Leader

valur.n.gunnlaugsson@matis.is

Comparison of microstructure between farmed and wild cod

The aim of this project was to build up knowledge through image analysis to facilitate the processing and product development of farmed cod. In the project "Future cod", imaging revealed remarkable results where a large difference was found in the structure of the flesh in wild cod and farmed cod. The purpose of this project was to examine this difference in more detail and try to find reasons for it. The results of the project confirmed this large difference in intercellular space, as had been seen before, but it was only seen in samples taken from live fish. There was little difference in pre-rigor samples taken, whether farmed or wild. After post-rigor, only wild fish were sampled, as the processing properties of farmed cod were weak after freezing. It was found that the extracellular space increased again in wild fish during death. Numerous other measurements were made on these samples in step 4 of this project and a close connection could be seen with the results for the proportion of intercellular cells in these samples. The mobility of water molecules was lower in wild cod muscles, which was consistent with the greater intercellular space than in farmed fish. On the other hand, the water content of the wild cod was higher. The results indicated that the structure and properties of the muscle were quite different in these groups. The research was part of the project "Processing and quality control of farmed cod, more specifically a summary for work component 3.

In previous project there was much difference in gap between cells samples from wild and farmed cod. In this project phase the aim was to confirm this difference and try to identify the reason for it. The results showed a difference in microstructure between wild cod and farmed one, when samples were taken from live fish. This difference was not a distinct, when samples from pre-rigor and post rigor fish where analyzed. In project phase 4 these samples where used for number of measurement. The results from the microstructure analysis were in harmony with results from measurement of water content and water mobility.

Report closed until December 2011 / Report closed until December 2011

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Reports

Process control for fishing, processing and processing of salted fish. Effect of cooling after fishing on the muscular structure of cod

Published:

01/08/2007

Authors:

Valur N. Gunnlaugsson, Jónína Ragnarsdóttir, Þóra Valsdóttir, Kristín Anna Þórarinsdóttir

Supported by:

AVS, Rannís Technology Development Fund

contact

Valur Norðri Gunnlaugsson

Group Leader

valur.n.gunnlaugsson@matis.is

Process control for fishing, processing and processing of salted fish. Effect of cooling after fishing on the muscular structure of cod

This report describes the results of a cod image analysis. The effect of cooling methods after fishing on the muscular cod stock was assessed. It was not possible to detect differences in fillets depending on whether the fish had been stored in liquid ice or flake ice in a train or had been cooled separately on deck. Muscle changes during salt fish processing were monitored and the effect of injection was assessed. During salting, cells contracted and the extracellular space increased. There was a clear difference in the fillets depending on whether they were injected or not. During dehydration, the difference due to injection decreased again.

Results from image analyzes on cod are discussed in this report. The effects of chilling methods after catch on microstructure of cod fillets were also evaluated. No significant effects were observed, neither when extra chilling was added on deck nor with regard to different ice types (liquid ice / flake) used for storage of the fish. Changes in the fish muscle during heavy salting were examined and the effects of injection as the initial step in the process studied. During salting muscle cells shrank and the ratio of extracellular fluid increased. Significant effects of injection were observed after salting but during rehydration the difference decreased again.

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