Reports

Enriched seafood

Published:

01/04/2012

Authors:

Emilia Martinsdóttir, Rósa Jónsdóttir, Kolbrún Sveinsdóttir, Margrét Geirsdóttir, Aðalheiður Ólafsdóttir, Helga Helgadóttir, Gísli M. Gíslason

Supported by:

AVS

Contact

Rósa Jónsdóttir

Research Group Leader

rosa.jonsdottir@matis.is

Enriched seafood

The project Enriched Seafood, which was carried out in collaboration with the company Grím kokk in the Westman Islands and Iceprotein in Sauðárkrókur, is now being completed. There, several prototypes of products from Icelandic seafood were developed and added to them, such as algae concentrate with defined bioactivity, hydrolysates to increase protein content and fish oil to increase omega-3 fatty acids. The results show that it is possible to increase the amount of omega-3 fatty acids in fish balls without compromising the taste quality. The same can be said about the addition of algae powder and also succeeded in increasing the amount of protein in the fish balls. Consumer surveys were conducted to examine consumers' tastes for prototypes compared to traditional products already on the market. Information on the bioactive substances and their activity influenced how people liked the products. The effect of the information depended on various factors, such as attitudes towards health and food and attitudes towards the ingredients of the product tested. An online consumer survey of more than 500 people showed that people are generally more positive about enrichment in the case of known health products such as omega-3. It is also better to provide information on effectiveness even if it is a known substance, as it enhances people's positive experience of the product. Enrichment with kelp also seems to be a viable option as information on the use value of kelp in the product was given and the same can be said regarding fish protein. These products generally appeal more to people who focus on food hygiene, which is a fairly large group according to these findings. In general, it can be concluded from these results that the enrichment of seafood is a realistic possibility, but labeling and information to consumers must be considered. Based on these results, it can be concluded that the enrichment of seafood is a realistic possibility, but labeling and information to consumers must be considered.

Prototypes of seafood dishes enriched with bioactive compounds from the ocean, such as seaweed, fish proteins and fish oil to increase omega-3 fatty acids have been developed to meet market demand. The results show that it is possible to increase the content of omega ‐ 3 fatty acids in fishcakes without negatively affecting the flavor. Also the enrichment of seaweed and fish proteins to increase protein content was successful. Consumers were asked about liking of various prototypes compared to traditional fish dishes. Information on the added compounds and their bio ‐ activity affected the liking of the consumers. Influence of information depended on various factors like attitudes towards health, food and the added ingredients. Web ‐ based consumer survey (500 respondents) showed that consumers were more positive towards enrichment of seafood if well ‐ known ingredients like omega ‐ 3 were used. The information on health ‐ effect and bio ‐ activity was also positive regarding the consumer experience. even though the ingredients were well ‐ known. Enrichment using seaweed or proteins also seems to be a realistic option based on information of the health effect given. These kinds of products appeal more to consumers emphasizing health benefits of their food. It can be stated from the results of the project that enrichment of seafood is a realistic option but labeling and information to consumers is important.

Report closed until 01.04.2015

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Reports

Bioactive products in the production of halibut and cod larvae / Bioactive products in production of halibut and cod larvae

Published:

01/12/2008

Authors:

Jónína Þ. Jóhannsdóttir, Rannveig Björnsdóttir, Eydís Elva Þórarinsdóttir, Kristjana Hákonardóttir, Laufey Hrólfsdóttir

Supported by:

AVS, Matvælasetur HA

Bioactive products in the production of halibut and cod larvae / Bioactive products in production of halibut and cod larvae

The aim of the project was to find ways to improve the survival and quality of cod and halibut larvae and to use environmentally friendly methods. The aim was also to open up the possibility of utilizing saithe peptides that could increase the value of saithe. The results of a previous project in halibut farming were promising and indicated that it was most convenient to treat larvae with peptides through feed animals, in addition to which it was necessary to further investigate the concentration of treatment. In connection with the project, new facilities for animal husbandry have been developed and set up at Fiskey hf. for research into the different treatments of feed animals and thus contribute to increased stability in the production of halibut juveniles. Repeated experiments with bioactive substances in the cultivation of equidae have been carried out and they seemed to tolerate a certain concentration of the substances. The main results of experiments in the early stages of cod farming indicate that treatment with saithe peptides results in good growth, noticeably faster development of internal organs and a much lower incidence of larval defects. However, it is clear that the effects of different levels of treatment need to be further investigated. There is strong evidence that IgM and lysozyme are present in cod larvae soon after hatching or much earlier than previously claimed, and that treatment appeared to stimulate their production. Treatment with saithe peptides does not appear to affect the bacterial flora of larvae, but a specific species composition was detected in the gastrointestinal tract of larvae in pots where larval survival and quality were optimal. This gives evidence that a certain species composition of bacterial flora is favorable for cod larvae.

The main goal of this project was to increase viability and quality of cod and halibut larvae before and during the first feeding period by using bioactive products. The aim was also to increase the exploitation and value of pollock. The findings of previous projects in halibut culture were promising and indicated that treating live feed is a suitable method to carry bioactive products to the larval intestines during first feeding but the intensities of treatment needed to be further investigated. New facilities have been developed in relation to the project for research in the live feed culture at Fiskey Ltd. to promote increased stability in the production of halibut fingerlings. Repeated experiments have been conducted in the culture of rotifers and results indicate good tolerance towards treatment with bioactive products in certain intensities. The overall results of the project indicated that pollock peptides may promote increased growth and quality of cod larvae during first feeding. The results also indicate the presence of IgM and lysozyme early post hatching, but it has not been observed in cod larvae of this size before. Furthermore, results also indicate that hydrolysates from pollock can stimulate the production of these factors in cod larvae. Treatment using pollock peptides, did not affect the bacterial community structure of live feed or cod larvae, however a similar structure was observed in larvae from the most successful production units different from other tanks. The results therefore indicate a bacterial community structure that may be preferable to the cod larvae.

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Reports

Use of bioactive substances in halibut farming

Published:

01/12/2007

Authors:

Jónína Þ. Jóhannsdóttir, Heiðdís Smáradóttir, Jennifer Coe, Rut Hermannsdóttir (MS student), María Pétursdóttir, Rannveig Björnsdóttir

Supported by:

Líftækninet HA (2005-2007), KEA University Fund (2006)

Use of bioactive substances in halibut farming

The main goal of the project was to promote the increased performance of halibut in fire and use environmentally friendly methods. Bioactive substances were used that were easy to obtain, contributed to the increased value of seafood and also had some of the desired activity, ie. bactericidal / inhibitory, prebiotic or immunostimulatory activity. Experiments were made with various materials in the project, ie. chitosan derivatives as well as peptides derived from blue whiting, cod and saithe. The effect of treatment with the substances was assessed in terms of the growth and performance of larvae and forage animals as well as in terms of the composition of the bacterial flora and the stimulation of a non-specific immune response in larvae. The main results indicate that the most suitable method for introducing substances into larvae is to use feed animals (Artemia) and a method was developed in the project to treat them. The bioactive substances did not appear to have a bactericidal effect in the rearing environment of the feed animals, but did contribute to a change in the composition of the bacterial flora. Bioactive substances seemed to be used primarily as supplements as feed animals were plump and playful. The performance and quality of larvae in the breeding units of Fiskey hf. is very different and there is no obvious relationship between the performance of the peritoneal stage and the performance and quality of the larvae at the end of the initial feeding. The composition of bacterial flora was also found to be very different in peritoneal larvae and larval feeding larvae. Three separate experiments were carried out in the Fiskey juvenile farm where the larvae in the initial feeding were treated with bioactive substances. The main results showed that it is important to treat with the right concentration of substances and for a reasonably long time as too much concentration can have a negative effect on the growth and metamorphosis of larvae. Treatment with blue whiting peptides was thought to give promising results and have a beneficial effect on larval metastasis. Bioactive substances did not appear to have a decisive effect on the number of bacterial bacteria in the gastrointestinal tract of larvae, but treatment with blue whiting and cod peptides could potentially alter the composition of the flora. Studies on the non-specific immune response of halibut larvae revealed the presence of C3 and Lysozyme from the end of the peritoneal stage, but IgM production does not begin until about 28 days after the start of feeding. Higher levels of IgM were detected during the first weeks in larvae treated with saithe peptides and this may indicate an immunostimulatory effect. The results of the project as a whole indicate that the bioactive substances studied did not have a decisive effect on the bacterial flora of the farm, but the treatment of larvae in starter feeding with the right concentration of bioactive substances could have a good effect on larval performance and stimulate larval immune response. of the farm when they have not yet developed a specialized immune response.

The aim of this project was to promote increased survival of halibut larvae during first feeding by using bioactive products. The bioactive products were selected by the criterion that they were easily accessible and induced any of the desired effects ie inhibiting bacterial growth, prebiotic effects or immunostimulants. The products studied are chitosan and peptide hydrolysates from blue whiting, cod and saithe. The effects of treatment were evaluated with respect to growth and survival of larvae and the live feed (Artemia) as well as effects on bacterial numbers or the community structure of the intestinal microbiota of larvae and stimulation of the innate immune system of the larvae. The results indicate that treating live feed (Artemia) is a suitable method to carry the bioactive products to the larval intestines during first feeding and a new technique has been standardized for treatment of the live feed with the products. The bioactive products did not affect the total bacterial count in the Artemia but the composition of the bacterial community may be changed as a result of the treatment. The Artemia seems to use the bioactive products as a food supplement and was well suited to be used as live feed. A significant variation in overall success of larvae was observed without any obvious correlation between survival of larvae at the end of the yolk sac stage and at the end of first feeding. A different bacterial pattern was observed in the intestine at the yolk sac stage compared to first feeding larvae. Three separate experiments were carried out in the halibut production units at Fiskey Ltd. where larvae were treated with various bioactive products. The results emphasize the importance of treating larvae with the appropriate concentrations of the products, as elevated concentrations can negatively affect growth and metamorphosis of the larvae. Treatment with peptides from blue whiting resulted in relatively good survival of larvae with similar success of metamorphosis compared to control units. The bioactive products did not affect bacterial growth but there were indications that peptides from blue whiting and cod may affect the composition of the intestinal community of bacteria in the larvae. Results from studies of the immunological parameters indicate the presence of C3 and Lysozyme already from the end of the yolk sac stage and the initialization of IgM production after approximately 28 days in feeding. Production of IgM was stimulated in larvae treated with peptides from saithe, indicating immunostimulating effects of this product. The overall results indicate that the bioactive products studied did not affect the bacterial flora during the first production stages of halibut larvae. However, if used in the appropriate quantities and at the right time, the products may promote survival and growth and stimulate the innate immunity of larvae.

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