Reports

Value adding technique - Drying of pelagic fish

Published:

13/12/2017

Authors:

Ásbjörn Jónsson, Cyprian Ogombe Odoli, Sigurjón Arason

Supported by:

AVS Fisheries Research Fund

contact

Sigurjón Arason

Chief Engineer

sigurjon.arason@matis.is

Value adding technique - Drying of pelagic fish

The aim of the project was to improve the processing process and the quality and safety of dried sardines produced in Kenya. Like looking at new products such as dried capelin from Iceland for possible export to Kenya. The results showed that it was possible to ensure the quality of dried products such as capelin in Iceland. During indoor drying, conditions such as temperature can be controlled, thus preventing protein deformation and fat development. The results also showed that sardines, which were dried outdoors in Kenya at higher temperatures compared to indoor drying, were of poorer quality, as protein deformation occurred along with evolution. On the other hand, market surveys in Kenya showed that a certain group of consumers liked dried capelin from Iceland and were willing to buy the product.

The objective of the project was to improve the process and quality and safety of dried sardines produced in Kenya. As well as introduce new products from Iceland like dried capelins a possible export to Kenya. Results showed that it was possible to control the quality of dried products like capelin in Iceland. By indoor drying, the conditions can be controlled, like temperature and providing denaturation of proteins and oxidation of fat. Results also showed that sardines dried in open air in Kenya with higher temperature compared with indoor drying, had lower quality, were denaturation of proteins and oxidation of fat occurred. Market research indicated that certain social groups of consumers in Kenya liked indoor drying capelin from Iceland, and were willing to by such product.

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Reports

Shrimp - brine based on characteristics

Published:

01/07/2013

Authors:

Arnljótur B. Bergsson, Ásbjörn Jónsson, Gunnar Þórðarson, Lárus Þorvaldsson, María Guðjónsdóttir, Minh Van Nguyen, Sigurjón Arason

Supported by:

AVS Fisheries Research Fund

contact

Gunnar Þórðarson

Regional Manager

gunnar.thordarson@matis.is

Shrimp - brine based on characteristics

The volume of imported frozen shrimp requires good care in the thawing of the raw material, as shrimp pickling is particularly important for the processing of the product produced from the raw material. Efforts were made to ensure that the best procedures for thawing and pre-packaging were shrimp in terms of raw material properties. Raw material properties were mapped using traditional certified measurement methods as well as low-range nuclear measurements and enhanced with near-infrared spectroscopy. Changes in shrimp that occurred during shrimp pickling were monitored. Processing conditions were mapped using alternate models. The effects of using phosphate as a technical aid were investigated. The correct proportions of shrimp and brine, as well as the temperature of the brine, are prerequisites for stability in pre-pickling so that the desired results are achieved. With proper application, phosphate increases the efficiency of shrimp processing but does not accompany shrimp in the packaging of consumer products. Maladjusted brine reduces utilization.

The volume of imported frozen shrimp demands optimal processes for defreezing the raw material. Brining is most important for the processing of the product that is produced from the raw material. Efforts were made to optimize defreezing and brining of shrimp depending on raw material quality attributes. Quality attributes of shrimp were mapped by accrecated methods as well as NMR and NIR measurments. Changes in shrimp were observed during the brining process. Processing conditions were charted with thermo ‐ models. Effect of usages of phosphate as technological adjuvants was observed. Porpotions of shrimp and brine, as well as temperature of brine are presumptions of stability during brining for expected results to be achieved. With correct application, phosphate increases processing performance and does not accompany shimp into packaged consumer product. Uncontrolled brining reduces product / raw material yield.

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Reports

The role and fate of added phosphates in salted cod products / Role and fate of added phosphate in salted fish

Published:

01/07/2010

Authors:

Kristín Anna Þórarinsdóttir, Sigurjón Arason, Guðjón Þorkelsson

Supported by:

AGS, AVS

contact

Sigurjón Arason

Chief Engineer

sigurjon.arason@matis.is

The role and fate of added phosphates in salted cod products / Role and fate of added phosphate in salted fish

The aim of the project was to evaluate the fate of added phosphate in salted fish. It is clear that its amount decreases with effect and dehydration. The same goes for phosphates that are naturally present in fish muscle. Therefore, the total amount of phosphate in dehydrated products is usually lower than in fresh fish. However, it has been shown that added phosphates (di- and triphosphates) are found in both processed and dehydrated fish. However, it depends on the amount of phosphate added to the product and the salting processes used, ie. whether phosphate was added to the fish by injection or brine. Little or nothing is detected in dehydrated products if brine is used. Differences between processes can be due to the method of salting (spraying / pickling), the type and initial amount of phosphate added and the duration of action. Further research is needed to evaluate the effect of different salting processes on the fate of phosphate in salted cod muscles.

The aim of this study was to investigate the fate of added phosphates in salted cod products. The content of both added phosphates and naturally occurring phosphates, decreases during salting and rehydration. The final content in rehydrated fish (approx. 1-2.5% NaCl) is usually below values in the raw fish. However, di- and triphosphates are present both in salted and rehydrated products. The amount depends on the quantity of added phosphates in the product and on the salting procedures applied. It seems that lower contents are present in brined products than in injected products. Differences may depend on the method used for adding phosphates (injection / brining), phosphate type and, initial content of added phosphates in the muscle after pre-salting and finally on the curing time. Further studies are needed to get accurate information on the effects of different salting procedures on the fate of phosphates in salted cod products.

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Reports

Injection and brining of tilapia fillets

Published:

01/12/2009

Authors:

Kristín Anna Þórarinsdóttir, Kolbrún Sveinsdóttir, Þóra Valsdóttir, Irek Klonowski, Aðalheiður Ólafsdóttir, Hannes Magnússon, Arnljótur Bjarki Bergsson, Ragnar Jóhannsson, Emilia Martinsdóttir

Supported by:

Tækniþróunarsjóður Rannís / Technology Development Fund, RANNIS - Icelandic Center for Research

contact

Kolbrún Sveinsdóttir

Project Manager

kolbrun.sveinsdottir@matis.is

Injection and brining of tilapia fillets

The aim of the project was to investigate the effect of spraying and pickling on the utilization, shelf life and properties of tilapia fillets. Three product categories were produced: chilled products, frozen products (with insignificant changes in salt content) and lightly salted, frozen products. During the processing of chilled products, red fillets were injected with a weak brine (1% salt) containing a reduced cod base (2% brine protein). Lightly salted fillets were initially sprayed with 4% brine, then pickled overnight. Part of the fillet was frozen after pickling but a similar amount was injected with the protein solution after pickling. Utilization increased during spraying and pickling, there was a significant difference in weight changes in frozen fillets and lightly salted fillets due to differences in the salt content of these two product categories. The waterproofness of fillets was poorer after freezing than after storage in the refrigerator. The shelf life of products was short and possible reasons for this are discussed in the report. Microbial growth and degradation processes were largely independent of injection and brine.

The objective of the project was to study effect of injection and brining on the yield, storage life and characteristics of tilapia fillets. Three different product groups were produced: chilled. Frozen (with small salt changes) and lightly salted products. During processing of chilled products fillets with skin were injected with brine containing minced cod (2%) protein in brine. Lightly brined fillets were initially injected with 4% brine and then brined overnight. A part of the fillets was frozen after brining but similar part was injected with protein solution after brining. The yield increased with injection and brining, distinct difference was in the weight changes of frozen and lightly salted fillets because of the difference of the salt content of these two product groups. Water holding capacity of the frozen fillets was lower than for chilled fillets and the storage life was very short. Microbial growth was mostly not depending on the injection and brining.

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