Tag: Protein

Peer-reviewed articles

Protein Recovery of Tra Catfish (Pangasius hypophthalmus) Protein-Rich Side Streams by the pH-Shift Method

Contact

Sigurjón Arason

Chief Engineer

sigurjon.arason@matis.is

Increasing protein demand has led to growing attention being given to the full utilization of proteins from side streams in industrial fish processing. In this study, proteins were recovered from three protein-rich side streams during Tra catfish (Pangasius hypophthalamus) processing (dark muscle; head-backbone; and abdominal cut-offs) by an optimized pH-shift process. Physicochemical characteristics of the resulting fish protein isolates (FPIs) were compared to industrial surimi from the same raw material batch. The pH had a significant influence on protein extraction, while extraction time and the ratio of the extraction solution to raw material had little effect on the protein and dry matter recoveries. Optimal protein extraction conditions were obtained at pH 12, a solvent to raw material ratio of 8, and an extraction duration of 150 min. The resulting FPI contained <10% of the fat and <15% of the ash of the raw material, while the FPI protein recovery was 83.0−88.9%, including a good amino acid profile. All FPIs had significantly higher protein content and lower lipid content than the surimi, indicating the high efficiency of using the pH-shift method to recover proteins from industrial Tra catfish side streams. The FPI made from abdominal cut-offs had high whiteness, increasing its potential for the development of a high-value product.

Reports

Production of valuable products from viscera / Production of valuable products from viscera

Published:

01/03/2014

Authors:

Sigrún Mjöll Halldórsdóttir

Supported by:

AVS

Production of valuable products from viscera / Production of valuable products from viscera

Fish stew is rich in many different substances such as protein, fish oil and minerals, which can be good in all kinds of valuable products. The purpose of the project was to investigate the possibility of using material from slag for pet food and / or fertilizer for plants. Cod processing with and without liver was performed with enzymes: on the one hand Alkalase and on the other hand a mixture of Alkalasa and cod enzymes. Attempts were made to collect fat phase from the slag. The fatty phase was analyzed for fatty acids and peroxide values were measured to assess the degree of development. The protein component was then spray dried and the following measurements were performed: protein content, amino acid analysis, trace element measurement, antioxidant activity (metal chelating ability, DPPH, ORAC, reducing ability and antioxidant activity in the cellular system) and antihypertensive activity. The main results are that the enzymatic slag has an excellent ability to bind to metal and can thus maintain metals (minerals) in a form that both plants and animals can use. The amino acid composition was also very suitable as nutrition for dogs and cats.

Fish viscera is rich in many different materials, such as protein, oil and minerals that can be good in all kinds of valuable products. The purpose of this project was to investigate the possibility of utilizing materials of viscera in pet food and / or fertilizer for plants. Viscera from cod processing with and without liver was processed with the following enzymes: Alcalase and a mixture of Alcalase and cod enzymes. Attempts were made to collect the lipid phase of the viscera. Fatty acids were analyzed in the lipid phase and measured peroxide values to assess the degree of rancidity. The remaining protein solution was spray dried and the following measurements performed: protein content, amino acid analysis, measurement of trace elements, antioxidant (metal chelating, DPPH, ORAC, reducing ability and antioxidant activity in cell systems) and blood pressure lowering activity. The main conclusion is that hydrolysed viscera protein has excellent ability to metal chelation and can thereby maintain metals (minerals) in the form that both plants and animals can utilize. Amino acid composition was also very suitable as nutrition for dogs and cats.

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Reports

Peeling and marketing of surimi and surimi products from bone marrow

Published:

01/01/2014

Authors:

Margrét Geirsdóttir

Supported by:

AVS Fisheries Research Fund, V 026‐12

Contact

Margrét Geirsdóttir

Project Manager

mg@matis.is

Peeling and marketing of surimi and surimi products from bone marrow

In recent years, MPF Ísland and Matís have developed a process in the factory of isolated proteins from bone marrow. In this project, an upscaling of the production of surimi and the production of a surimi product, Fiskitófa, was completed. The quality and shelf life of products were examined. A market research on the surimi market was also carried out and marketing of fish tofu began. A market study revealed that there have been large fluctuations in the prices of surimi and surimi products on the world market in recent years. The product produced in this project, Fiskitófa, fits in very well with the growing part of the market for new and innovative products. Shelf life research showed that the shelf life for prepared Fiskitófa is over 4 weeks in the refrigerator and for surimi at least 6 months in the freezer. Following the presentation of the fish tofu, restaurants have requested a sample for further inspection, which is currently underway.

MPF Iceland and Matis finished scale up for the production of surimi and surimi seafood - FishTofu. Quality parameters and shelf life of products were evaluated, market analysis performed and marketing of products was started. Marketing analysis showed that for the past few years there have been drastic price swings in the surimi and surimi seafood products. There is an increasing opportunity for high quality surimi seafood with health promoting properties and novel products like FishTofu. Shelf life analysis showed that the fish tofu has at least 4 weeks shelf life at cold temperatures and surimi at at least 6 months shelf life in a freezer. Marketing of fish tofu started well and several restaurants have asked for samples for trying.

Report closed until 01.02.2016

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Reports

Fish proteins in baked goods

Published:

01/01/2014

Authors:

Margrét Geirsdóttir, Aðalheiður Ólafsdóttir

Supported by:

AVS - V 11 025‐11

Contact

Margrét Geirsdóttir

Project Manager

mg@matis.is

Fish proteins in baked goods

The aim of the project was to develop a new product at MPF Iceland in Grindavík from extra raw materials that can be used in bread products. MPF aims to sell the protein to bakery producers, both domestically and abroad, thereby ensuring employment and innovation in its home area. Three different types of dried protein products were developed. Tests were performed by mixing them in varying amounts in bread where up to 20% of flour was replaced by protein. Good products were obtained but were not considered good enough for marketing. Next, crispbread was developed with fish proteins that were considered exceptionally good and received positive reviews in consumer surveys. The drying process to complete the marketing of the new protein product is still unfinished.

The aim of the project was to develop new protein product for use in baked goods including bread from by ‐ products from fish production. The goal is to sell protein to producers of bakery goods both in Iceland as well as abroad and in so doing strengthening the seafood industry in Grindavík the hometown of MPF Iceland and thereby in Iceland. Three different fish protein products were developed. They showed good results when used instead of wheat in bread. Good bread was developed but the quality was not of that caliber that was aimed for. On the other hand, good quality rye ‐ crisp bread was developed that received good reviews in consumer research. A good drying process is though still lacking before marketing of the protein product can start.

Report closed until 01.02.2016

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Reports

FiltreX water purifier / RoteX Water filtering

Published:

01/12/2013

Authors:

Gunnar Þórðarson, Albert Högnason, Albert Haraldsson.

Supported by:

Westfjords Growth Agreement

Contact

Gunnar Þórðarson

Regional Manager

gunnar.thordarson@matis.is

FiltreX water purifier / RoteX Water filtering

The most important product of 3X Technology is RoteX equipment, which is used in food processing around the world as a bleeding device, for cooling and thawing fish for processing. The equipment is water-intensive and customers have contacted 3X Technology about the possibility of recycling processing water, as water costs are significant in many food production. Increased emphasis on environmental issues is also having an effect, and increased requirements can be expected regarding the utilization of processing water and its discharge after use into the environment. To solve this problem, the company has designed a prototype of cleaning equipment, FiltreX, as no suitable equipment has been found on the market to meet these needs. The equipment was tested in Kampa Ísafjörður's shrimp processing plant and HG fish processing plant in Hnífsdalur. The equipment worked well to purify effluent from these factories and a significant amount of protein was captured before the water was released into the sea. Measurements of organic substances were disappointing as it was not possible to show a significant reduction with COD measurements. There is a great deal of contradiction in these results and it is clear that further research is needed on the effects of filtration on wastewater with regard to environmental impact, ie organic matter before and after filtration. An application has been made for a grant to TÞS which will be used for further research if the result is positive. It is clear, however, that capturing proteins with FiltreX can generate significant revenue for shrimp fish processing.

3X Technology's most important product is the RoteX machine, used mainly in food production around the world as bleeding equipment, for cooling and thawing of fish for processing. The machine is water intensive and customers have urged 3X Technology's to find a solution for recycling processing water, as use of water is becoming more expensive, as well as the intensive environmental concern for disposal of waste water. To solve this problem, the company has developed a prototype of filtration equipment, FiltreX, since a suitable solution to meet these needs has not been found on the market. The device was tested in Kampishrimp ‐ factory in Isafjordur and HG fish ‐ factory in Hnifsdalur. The equipment functioned well for filtering effluent water from these plants, and a significant amount of protein was captured before the water was discharged into the sea. Measurements of organic offscouring gave a disappointing disillusionment and failed to significantly reduce COD measurements. A major contradiction liesin these results and it is clear that there needsto be further research on these matters, ie to lower organic material between before and after filtration. Application for further subsidy to TÞS will be used for further research if the results will be positive. It is clear, however, that the capture of proteins with FiltreX can provide significant revenue for the shrimp ‐ processing plants.

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Reports

Protein requirements of Arctic charr / Protein requirement of char

Published:

01/05/2013

Authors:

Jón Árnason, Ólafur Ingi Sigurgeirsson, Jónína Jóhannsdóttir, Aðalheiður Ólafsdóttir, Joseph Ginindza

Supported by:

AVS Fund (AVS Project R10011‐10)

Protein requirements of Arctic charr / Protein requirement of char

Five different feed types with protein content from (29) 30 - 40% were given in two size groups (100 g and 600 g) in both fresh and salt water. The effects of different feeds were assessed on the basis of their effects on digestibility, weight development, daily growth (SGR), feed utilization (FCR), chemical composition of fillets (in the larger fish) and sensory evaluation. Final weight and daily growth were lowest in the fish fed the lowest protein, but no effect of protein, in excess of 37% in the feed, was found on final weight and SGR. The minimum protein requirements for growth are therefore between 33% and 38% in the feed. There was no significant difference in feed response between size groups, even though the effect of reduced protein was greater in the larger fish. It was also not possible to see a single decisive effect of salinity on the protein requirement. The protein content of the feed also did not have a decisive effect on the fillet composition or sensory evaluation of the products.

Four (five) different diets with protein varying from (29) 30 - 41% were fed ad libitum to two size groups of Arctic charr (100 gram and 600gram) in fresh‐ as well as seawater. The effect of the different diets was evaluated by digestibility, weight development, SGR, FCR, chemical composition of filet (in the bigger size groups) and sensory evaluation. The lowest final weights and SGR were found when fed the diets with lowest protein but here was no effect final weight and final weight between 38% and 41% protein in the diet, indicating that the minimum need for protein is between 33 and 38% protein in the diet . The same trend was shown in both size groups but the effect was more pronounced in the bigger fish than in the smaller fish. The results regarding size and growth were also the same in fresh‐ and seawater. The protein content in the diet did not have any marked effect on either chemical composition of filets or the sensory quality of the product.

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Reports

Bioactive properties of whey proteins

Published:

01/02/2009

Authors:

Patricia Y. Hamaguchi, Sigrún Mjöll Halldórsdóttir, Hörður G. Kristinsson, Arnljótur B. Bergsson, Guðjón Þorkelsson

Supported by:

The Agricultural Production Fund & Growth Agreement in North West

Bioactive properties of whey proteins

The research described in this report is part of the project Utilization of cheese whey in health-related foods. The project is about improving the utilization and increasing the value of whey that is generated during cheese production at Mjólkursamlag KS in Sauðárkrókur by using both protein and lactose for the production of health drinks and dietary supplements. With improved utilization of milk, for example through the use of whey proteins, unnecessary release of biological substances into the environment can be avoided. Ostamysa from Mjólkursamlag KS was separated into four parts by membrane filtration equipment (Membrane Pilot Plant Type MEM11) in the processing hall of the Matís Biotechnology Center in Sauðárkrókur by Iceprotein employees, on the one hand through a 10 kDa membrane and on the other hand a 200 Da membrane. Chemical composition (moisture, protein, salt, minerals) and bioactivity (ACE inhibitory activity and antioxidant properties) were analyzed in Matís' laboratory in these four samples and the whey itself was measured unchanged. The results are promising and show that there is bioactivity in the whey, which can be used in target foods.

The experiment described in this report is part of the project Utilization of Cheese whey in health-based food products which aims are to improve utilization and increase value of whey that is discarded during the cheese production at KS Sauðárkrókur, by using proteins and lactose to produce health drink and nutritional supplements. With better utilization, unnecessary disposal of bioactive components can be avoided. Cheese ‐ Whey samples from KS were fractionated with membrane filtration equipment (Membrane Pilot Plant Type MEM11) at Matís Biotechnology center in Sauðárkrókur with molecular weight cut ‐ offs 10 kDa and 200 Da. Chemical composition and bioactivity properties were analyzed at Matís Laboratory. Results show that whey contains promising bioactive compounds that could be used as functional food.

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Reports

Fat tolerance of cod

Published:

01/07/2008

Authors:

Jón Árnason, Rannveig Björnsdóttir, Helgi Thorarensen, Ingólfur Arnarson

Fat tolerance of cod

The purpose of this study was to investigate the effect of fat content in feed on the growth and cleaning of cod of different sizes. Knowledge of the nutritional needs of fish is a necessary prerequisite for the preparation of feed for them. Two-size cod (120 g and 600 g) were fed (in triplicate) for 12 weeks on feed containing 10.0%, 13.5%, 21.2%, 24.5% and 27.7% fats in dry matter. Different fat content did not affect growth (SGR), body mass index (CF), fillet utilization, liver fat content or fillet fat content. In the smaller fish, the feed index (FCR) decreased with increased fat in the feed. The feed fat did not affect the fat content of offal without liver in the smaller fish (120g) but in 600 g fish the fat in the intestines increased with increased fat content of the feed. The fat content did not affect the proportion of gutted weight of the total weight in the 600 g fish, but in the smaller fish the proportion decreased with increased fat in the feed. Liver ratio (HSI) in 600g fish was not dependent on the fat content of the feed, but there was a positive correlation between feed fat and HSI in the 120 g fish. This means that the fat tolerance of cod in terms of liver ratio depends on the size of the fish.

Detailed knowledge of the nutritional requirements of fish is essential for feed formulation. The aim of this research was to investigate the effects of different lipid content in diets for Atlantic cod of different size. Cod of two size groups (initial weight 120 grams and 600 grams) were fed, in triplicate, for 12 weeks diets containing 10.0%, 13.5%, 21.2%, 24.5% and 27.7% lipid in dry matter. Different lipid content in the diet did not affect growth (SGR), condition factor (CF), fillet yield, lipid content in liver or lipid content in fillet. In the smaller fish, FCR was reduced with increased diet lipid. The lipid content in the diet did not affect the lipid content of intestines in the 120 grams fish but in the 600 grams fish there was a positive correlation between lipid content in diet and intestines. Dietary lipid did not affect gutted weight (calculated as the percentage of round weight) in the 600 grams fish but in the 120 grams fish, the percent gutted weight decreased with lipid content of the diet. The Heposomatic index (HSI) in the 600 gram fish was not affected by the lipid content of the diet but dietary lipid content significantly affected the HSI in the smaller fish. This indicates that the lipid tolerance of Atlantic cod, with respect to the effect on HSI, is size dependent.

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Reports

Plant raw materials in charr feed instead of fishmeal and fish oil

Published:

01/05/2008

Authors:

Jón Árnason, Ólafur Ingi Sigurgeirsson, Bjarni Jónasson, Helgi Thorarensen, Rannveig Björnsdóttir

Supported by:

AVS

Plant raw materials in charr feed instead of fishmeal and fish oil

The aim of the project was to produce cheap feed for char so that production costs can be reduced and profitability in char farming can be increased. The project consisted of testing different raw materials (especially plant raw materials) instead of fishmeal and fish oil and finding out how large a proportion of them can be in the feed. The condition for success was that the feed was healthy, utilized well by the fish and led to a growth comparable to the current farmed feed and that the feed did not have a negative effect on the quality of the product, in terms of chemical content (fatty acid, color) and physical properties (taste, color, density). Different types of feed were tested as a starter feed for charr juveniles, which is a new approach, in order to get an overview of the possible amount of different raw materials. The most interesting types of feed from those experiments were then tested in experiments on larger chars to confirm the results and to examine the effect on the quality of the products. The results of the experiments with different protein ingredients confirmed that high quality fishmeal (Superior) is a very good source of protein in feed for char. The charr's possibilities of utilizing soybean meal seem to be limited, as in the case of salmon, ie. ≤ 15% incorporation into the feed. The possible use of maize gluten meal appears to be ≤ 18% in starter feeding but could not be tested on larger fish. The reaction of char to rapeseed meal as a protein source, however, was positive and in fact better than expected considering that there has not been a good word for this raw material in feed for other salmonids. Regarding fat sources in charr feed, the results of the project show that different fat sources can be used with acceptable results. Juveniles, on the other hand, seem to have somewhat stricter requirements for fat sources than larger fish. This is especially evident in the effect on growth rate. The results of the experiments with fat sources also show that the composition of the fat source has a decisive effect on the fat composition of the fish as well as various sensory evaluation factors in the product. The main conclusion, however, is that it is possible, within certain limits, to use different fat sources in charr feed. In particular, it seems that palm oil can be used extensively.

The objective of the project was to produce economic feed for Arctic charr to decrease production cost and increase profitability in Arctic charr farming. The project investigated the possibilities of replacing fishmeal and fish oil with raw materials of plant origin, and to find out the limits for their use as feed ingredients. The criteria was that the feed should ensure maximum health, optimize utilization of feed and growth should be comparable to growth obtained by feed currently used. Neither should the feed have adverse effects on product quality, especially regarding fatty acids composition and physical properties (taste, flesh-color, texture). Effect of different raw materials was screened in start feeding trails using Arctic charr larvae. The most interesting raw material combinations were thereafter tested in trials with bigger fish in order to confirm the results of the start feeding trials and investigate the effect of the combinations on slaughter quality of the Arctic charr. The results of the trials with different protein raw materials confirmed that high quality fishmeal (Superior) is a very good protein source for Arctic charr. Arctic charr seems to have limited ability to utilize soybean meal and the inclusion should be limited to ≤ 15% in the diet, similar to the limits that are common for Atlantic salmon diets. The limits for use of Corn gluten meal in starter diets seem to be ≤ 18% but this raw material was not tested in bigger fish. The response of Arctic charr to the use of rapeseed meal as a protein source was positive and even as high inclusion as 30% in the diet did not have negative effect on growth. The main findings of the project regarding use of lipid sources is that it is possible to use different sources with reasonable effect in feed for Arctic charr. Of particular interest is the effect of palm oil. Arctic charr larvae seem to be more demanding, regarding use of lipid sources, than bigger fish. The results clearly demonstrate the effect of fatty acid (FA) composition of the lipid sources on the FA composition of the fish and it is possible to change the FA profile with different lipid sources. Different lipid sources also have marked effects on different sensory traits in the farmed Arctic charr.

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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

Strategic Scientist

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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