Reports

Fæðubótarefni úr íslensk þangi / Functional ingredients from Icelandic seaweed

Published:

01/01/2012

Authors:

Rósa Jónsdóttir, Hólmfríður Sveinsdóttir, Jón Óskar Jónsson, Jóna Freysdóttir, Patricia Hamaguchi, Halldór Benediktsson, Annabelle Vrac, Hörður G. Kristinsson

Supported by:

Fisheries Project Fund

contact

Rósa Jónsdóttir

Group Leader

rosa.jonsdottir@matis.is

Fæðubótarefni úr íslensk þangi / Functional ingredients from Icelandic seaweed

The aim of the study was to develop the processing of dietary supplements from Icelandic seaweed by maximizing the extraction and purification process of biomaterials and measuring their bioactivity. Seaweed was collected monthly for one year and the chemical content and bioactivity were measured in test tubes and in cell systems. The processing of polyphenols was scaled up and the shelf life was studied. The seasonal fluctuation in vitamin C content was very clear and peaked during the summer. There was also a large difference in the amount of iodine, which was much higher during the winter compared to samples taken during the summer. The antioxidant activity of polyphenols was very high, both measured as ORAC and DPPH and in cells. The results of studies in the angiogenesis model strongly indicate the anti-inflammatory effect of polyphenols from seaweed. Fucoxanthin levels were on average lowest in the summer but highest in the winter, although the difference was not significant. Seaweed fucoxanthin collected in January and July measured 90% and 80% antioxidant activity in cells. The results of this project strongly show that it is a good idea to process bioactive substances from seaweed into dietary supplements.

The aim of the project was to develop functional ingredients from brown seaweed (Fucus vesiculosus) for use in nutraceutical and functional foods by optimizing extraction of bioactive compounds and characterizing their properties to demonstrate possible health benefits. Fucus vesiculosus was collected monthly for one year for chemical characterization and to study bioactivity using in ‐ vitro chemical and cellular tests. The polyphenol extraction process was scaled up and shelf life of the extract studied. The seasonal variation in vitamin ‐ C content was clear reaching maximum level during the summer. A large difference was seen in the iodine content which was much higher in the winter compared to the summer. The antioxidant activity of the polyphenols was high, measured as ORAC and DPPH and in cell models. The dendritic cell (DC) model showed indications of anti ‐ inflammatory effect of polyphenols. The amount of fucoxanthin was on average lowest in the summer but highest in the winter. Cellular antioxidant activity of fucoxanthin samples from January and July was 90% and 80%, respectively. The results of this project indicate that it is feasible to produce functional ingredients from Icelandic seaweed.

Report closed until 01.01.2015

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Reports

Evaluation of antibacterial and antioxidant properties of different chitosan products

Published:

01/12/2011

Authors:

Hélène L. Lauzon, Patricia Yuca Hamaguchi, Einar Matthíasson

Supported by:

AVS (contract R 11 074‐11)

Evaluation of antibacterial and antioxidant properties of different chitosan products

In this study, the bactericidal and antioxidant properties of twelve different chitosan substances from Primex ehf. The effect of viscosity / molecular weight (150-360 KDa) and the degree of deacetylation (A = 77‐78%; B = 83‐88%; C = 96‐100%) on the activity of the substances were assessed. The effect of pH (6 and 6.5) and temperature (7 and 17 ° C) on bactericidal activity was also examined. Antioxidant activity was assessed by four methods: oxygen radical absorbance capacity (ORAC), ferrous ion chelating ability, reducing power and DPPH radical scavenging ability. Variable antioxidant activity was found in different chitosan substances. A1 had the highest but actually slight reducing and binding properties, while B3 and B4 had the highest ORAC values. Chitosans with 96-100% deacetylation had the highest in vitro antioxidant activity, regardless of their molecular weight. Similarly, the bactericidal activity of the chitosan substances varied among the bacterial species studied, in addition to which the pH and temperature effects were different. However, some chitosan substances were found to work well on all bacterial species, eg A3 ‐ B2 ‐ B3 ‐ C1.

This report evaluates twelve different types of chitosan products manufactured by Primex ehf and tested for their antibacterial and antioxidant properties in a suitable carrier solution. This study examined the effect of viscosity / molecular weight (150‐360 KDa) and degree of deacetylation (A = 77‐78%; B = 83‐88%; C = 96‐100%) on the properties evaluated, as well as the influence of pH (6 and 6.5) and temperature (7 and 17 ° C) on the antibacterial activity of the chitosan products. The antioxidant activity was evaluated using four assays: oxygen radical absorbance capacity (ORAC), ferrous ion chelating ability, reducing power and DPPH radical scavenging ability. The different chitosan products had different antioxidant properties. A1 had both some reducing and chelating ability, while B3 and B4 had some oxygen radical absorbance capacity. The radical scavenging ability of high DDA (96‐100%) chitosan products was emphasized. Similarly, the antibacterial activity of the different chitosan solutions differed among the bacterial species evaluated as well as pH and temperature conditions. Nevertheless, some products demonstrated antibacterial activity towards all strains tested: mainly A3 ‐ B2 ‐ B3 ‐ C1.

Report closed until 01.01.2014

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