Brown and red algae are salt water organisms. These plants grow on rocky shores or in oceans with a rocky bottom. In quiet areas free of excessive waves they can live for up to 15 years. These can be utilized for the special polysaccharides in their bodies. That’s why they are commercially significant. For example, alginic acid and alginates obtained from brown algae can be used in many fields, from the food industry to the medical field, from cosmetics to paper and textiles. An algae species (Macrocystis Pyrifera) that can be found both in North and South America, New Zealand, Australia, and off the African coast is the primary source for the world’s production of alginic acid and alginate. In 2009, 26500 tons of alginate was produced, primarily by the countries of Scotland, Norway, China, and the USA.
Alginic acid is a macro molecule synthesized from mannuronic and gluronic acid molecules. Because of its hydrophilic property, the Na and K salts of alginic acid are used in providing homogeneity to frozen food during defrosting, preventing food decay related to instant temperature spikes, increasing viscosity, preparing jelly like deserts, and stabilizing fruit juices and ice cream. For similar reasons, Alginates are utilized in paper quality enhancement, and the advanced application of ink in glues and in pressed textile products, where they improve the flow of dye. Alginates are also used in cosmetic products, in production of waterproof or fireproof textiles, and in some synthetic dyes because they improve viscosity..
One of the most important uses of alginates is in the medical field. Many people suffer from stomach burn and acid reflux disease. In these treating these symptoms, the percentage of a prescribed medicine containing alginic acid content is 100 %, because in the case of acid reflux, alginic acid contains a preventive property, and antacids. This antacid neutralizes stomach acid. Alginic acid, however, reacts with saliva and Na Bicarbonate ion to produce foam in the upper stomach. In the case of a reflux, this foam barrier prevents the escape of acidic stomach content into esophagus.
According to a study conducted in England in 2010 about obesity treatments, alginic acid added natural fiber and was found to reduce lipid intake 75% in the intestines.
The absorption and removal of drugs in the stomach and intestines plays an important role in ensuring drugs act as intended. For instance a blood clog in a pulmonary vein can be transported to the lungs and may have fatal consequences (a pulmonary emboli). In order to prevent that, low molecular weight, heparin containing, drugs are used. The polymeric alginate beads in these drugs have been found to improve drug efficiency up to 80-90 %. In this kind of controlled release of drugs and enzymes, the use of polymeric alginate additives provides high efficiency.
A new kind of antimicrobial textile that does not stick to wounds is made from the silver coated fibers of an Alginate-carboxymethyl cellulose mixture. This fabric not only provides protection against infections but also, with its non-stick property, prevents traumas; and its high hydrophillic feature allows open wounds to heal faster.
Everything in the universe is beautiful, either directly, by itself, or indirectly, by its consequences. Algae, which many of us dislike, is in fact a great work of art as it is a source of food, a decoration of the seas, and is used to cure various diseases.
Figure 1. The chemical structure of Alginic acid
The main source of alginic acid Macrocystis pyrifera -1-2-3
Gels made from alginates:
HighM: Composition with high density of mannuronic acid.
Standard: Composition with equal amounts of mannuronic and gluronic acid.
High G: Composition with high density of gluronic acid.