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Seaweeds on Stamps |
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seaweed curiosities |
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seaweed extracts
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Agar, carrageenan and alginate
are seaweed
extracts and their properties are mainly gelling
and thickner agent. |
Agar is extracted from Gelidium, Pterocladiella, Gelidiella and Gracilaria.
Agarophytes are used as gelling agent
for the elaboration in great amount of foods.
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Gelidium corneum
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Chondrus crispus |
The original source of carrageenan is Chondrus crispus although other
species are used nowadays like Mastocarpus stellatus,
Kappaphycus, Euchema sp., this last one is cultivated
in the Philippines and Indonesia and contribute around
80% of the world-wide production. The carrageenophytes
are |
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used as emulsifier, stabiliser, gelling agent and thickner
in elaboration of food, cosmetics, aerosol. There are several
carrageenans, differing in their chemical structure and properties,
and therefore in their uses. The carrageenans of commercial
interest are called iota, kappa and lambda.
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Alginate, sometimes shortened
to "algin" is
present in brown seaweeds. For the extraction of alginates
more than 300 species could be used but actually Macrocystis,
Laminaria, Ascophyllum and Fucus sp. are the
most utilized. Alginates and its derivatives are used first
to increase the viscosity of aqueous solutions, their second
ability is to form gels. The third property of alginates is the
ability to form films of sodium or calcium |
Ascophyllum nodosum
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alginate and fibres
of calcium alginates.
Algin has numerous applications specially in food (re-structured or
re-formed food products) and in textile printing as thickeners for the
paste containing the dye.
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