Reports

Chemical composition of silver - Seasonal fluctuations

Published:

26/08/2019

Authors:

Þóra Valsdóttir, Karl Gunnarsson

Supported by:

Fisheries Project Fund, AVS

contact

Þóra Valsdóttir

Project Manager

thora.valsdottir@matis.is

Chemical composition of silver - Seasonal fluctuations

The aim of the study was to examine the amount of nutrients, minerals and trace elements in oats by season to assess when it is best to harvest them from a nutritional point of view. Samples were taken at two locations, Tjaldanes by Saurbær in Dalasýsla and Herdísarvík by Selvogur in Reykjanes in the period from October 2011 to April 2013.

Seasonal fluctuations were detected in the content of nutrients in silver in both Herdísarvík and Tjaldanes and then followed the same process. In early spring, fiber, protein, fat, ash and water levels peaked. Measurements also indicated seasonal fluctuations in some of the minerals and trace elements measured; potassium, phosphorus, iodine, selenium, cadmium and lead. Heavy metals were within the limit limits with the exception of cadmium in winter.

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Reports

Properties of silver. Impact of location and season / Properties of dulse. Influence of location and season

Published:

06/06/2011

Authors:

Þóra Valsdóttir, Karl Gunnarsson

Supported by:

AVS

contact

Þóra Valsdóttir

Project Manager

thora.valsdottir@matis.is

Properties of silver. Impact of location and season / Properties of dulse. Influence of location and season

This report reports on the results of a study of silver collected from June to October 2010 at two different growth sites of silver, on cliffs and boulders (Bolaklettar) and on islands (Fossárvík). The aim was to obtain reliable information on the effect of location and time of year on the appearance, nutritional value, amount of trace elements and minerals in silver in these places. The effect of season and location was measured on most of the measures analyzed, both composition and properties. The degree of variability varies depending on the factor involved. In some cases it can be significant and therefore important to collect silver in the places and time of year that is most favorable.

Dulse was collected from June to October 2010 at two different locations, rocky shore and at sandbank were the sea was mixed with fresh water. The aim was to collect data on the influence of location and season on the appearance and chemical composition of dulse. Significant differences were found on several attributes. Knowledge of the variability in ie color and protein content assist processors in selecting the most favorable raw material for their product.

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Reports

Influence of drying methods on the properties of dulse

Published:

01/06/2011

Authors:

Þóra Valsdóttir, Irek Klonowski

Supported by:

AVS

contact

Þóra Valsdóttir

Project Manager

thora.valsdottir@matis.is

Influence of drying methods on the properties of dulse

Knowledge of the parameters that control the quality and properties of dried silver (Palmaria palmata) is relatively small and little is known. If the utilization of brokers is to be increased and expanded, it is important to study these variables in more detail and document them. This report presents the results of experiments whose main objective was to compare the effects of three different drying methods on the nutritional value and physical properties of dried silver. The drying methods compared were solar drying, oven drying and lyophilization, as well as the effect of the effect on the sun-dried salts was assessed. Comparable changes in nutrients were measured after the drying process. The main difference in terms of drying methods was detected in the amount of vitamin C. There was a noticeable difference in color and texture. Taste properties were not measured but it is believed that there is some difference. Despite the fact that the results gave certain answers, many questions arose when interpreting them. There is therefore a need to acquire more knowledge about the properties of silver and their interaction with different processing factors.

The influence of three different drying methods on selected nutritional and physiochemical properties of dulse were compared; sun drying, oven drying and freeze drying. Similar influence was found on nutritional components. The main difference was found on vitamin C retention. Difference was found as well in color and texture. Flavor characteristics were not analyzed, however some differences are expected. Despite giving some answers, the results raised many questions on their interpretation. There is a need for extended knowledge on the properties of dulse and their interplay with different processing parameters.

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Reports

Processing of dried silver for human consumption. Gæðþættir og gæðaviðmið / Processing of dried dulse for consumption. Quality parameters and requirements.

Published:

01/06/2011

Authors:

Þóra Valsdóttir, Karl Gunnarsson

Supported by:

AVS

contact

Þóra Valsdóttir

Project Manager

thora.valsdottir@matis.is

Processing of dried silver for human consumption. Gæðþættir og gæðaviðmið / Processing of dried dulse for consumption. Quality parameters and requirements.

Many things need to be considered when catching and processing salt and other algae for human consumption. There are different requirements and criteria among processors, buyers and consumers regarding how sales should be and what their desired quality is. This report gathers information on official requirements and known standards for the processing of dried human food for human consumption, which processors and purchasers can use to set product and quality standards for these products. Despite the fact that it is a traditional product, much work remains to be done to gain adequate knowledge of many aspects of the production of dried silver and how to best manage it (such as the storage of fresh ingredients). Guidelines for the processing of dried silver will therefore continue to evolve and change as knowledge advances.

Many things need to be considered when collecting and processing dulse and other seaweed for human consumption. Requirements on how dried dulse should be and their required quality, vary between buyers and consumers. Information was collected on official requirements and known paradigms on the processing of dried dulse. Despite being a traditional product, extended knowledge on the influence of different processing parameters on the properties of dried dulse and how they can be controlled, is needed. Instructions on processing of dried dulse will therefore continue to develop as knowledge on the matter extends.

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Reports

Spicy salt / Pickled dulce

Published:

01/12/2009

Authors:

Þóra Valsdóttir, Irek Klonowski, Eyjólfur Friðgeirsson

Supported by:

AVS Fisheries Research Fund

contact

Þóra Valsdóttir

Project Manager

thora.valsdottir@matis.is

Spicy salt / Pickled dulce

Íslensk hollusta ehf got Matís to collaborate with them to complete product development on spicy silver. Tests were performed on marinating in several common materials, ie. oil, soy sauce, vinegar, whey and brine. Marinating similar to that used by Íslensk hollusta ehf turned out to be the best, but tests showed that the processing process could be significantly improved to the best product in terms of appearance, taste and shelf life. Spicy salts are now an interesting product with a beautiful look and delicious taste. It will be interesting to see how the market responds to this innovation.

The project focused on finalizing product development of pickled dulse developed by Íslensk hollusta ehf. Tests were executed with various curing media; oil, soy, vinegar, whey and salt brine. The curing media selected was similar to the one already developed by Íslensk hollusta. However, improvements in the processing were obtained, especially with regard to optimization of appearance, flavor and storage time or shelf life. Pickled dulse is now an interesting product with attractive appearance and taste. It will be interesting to see how the market will respond to this new product.

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