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.

View report
EN