Alginic Acid

Alginic acid is a naturally occurring hydrophilic colloidalimproving the texture or stability of many processed
polysaccharide obtained from several species ofproducts like ice cream, fruit drinks, pie filling and as
brown seaweed (Phaeophyta). It is a linear copolymertablet disintegrate. Its also used as plastic material for
consisting meanly (beta) B-1, 4 linked mannuronic acid.taking dental impressions, in paper industry as a
Although the theoretical equivalent weight of thissurface sizing and coating agent, as a thicker in textile
structure is 176.13, actual equivalent weight of purifiedprinting particularly with fiber reactive dyes as an
products varies from 195 to 215.effective flocculants for water treatment, for imparting
Mostly all larger brown seaweed as well as smallglaze  on ceramics and for the suppression of
brown seaweed contains algin compounds. It occursintestinal absorption of 90 Sr.
as a white to yellowish brown filaments, grainy,About 25,000t of alginic acid per annum are extracted
granular or powdered for ins. Recently the intercellularworld wide. The main producers are Scotland, Norway,
has been regarded as the main sites of algin butChina and USA with smallest being produces in
sometime it is present in cell wall also Kylin suggestedCanada, Japan, Chile, France and Spain. A recent
the alginic acid occurs in the cell wall in the form of anstudy suggests that China now has 50% of the
insoluble calcium salt.European market for alginates and may have similar
The most obvious property of alginic acid, acid is itspercentage of North American market. Due to its
insolubility in water but has a high water absorptioncommercial value lots of work has been done through
capacity. It is readily soluble in aqueous solution of alkaliout the world.
metals hydroxide or carbonates and gives highlyAlginic acid is extracted from seaweed and marketed,
viscous solution of the alginates salts. The physicalgenerally as sodium or calcium alginate for a variety of
property vary according to the proportions ofuses perhaps the most important of which in recent
D-mannuronie acid and L-guluronic acid present. Theyear’s at least is for the manufacturess of what
pH of alginic acid ranges from 2.0 to 3.5.has been called “Seaweed rayon”.
The estimation of actual alginic acid content of theseBrown seaweeds are potential wealth from the sea.
seaweeds was carried out by the method describedHowever the exploitation of the marine resources in
by Cameronetal in 1948. But a modified method ofPakistan is still in its elementary stage and very little is
Stanford described by Tressler in 1951 was applied.known about alginic acid content of brown seaweeds
Alginic acid is used widely in foods andof the productive North Arabian sea abordering
pharmaceuticals not only for its nutritional value but forPakistan.