SODIUM ALGINATE
SODIUM ALGINATE
CAS Number: 9005-32-7
EC Number: 232-680-1
E number: E400 (thickeners, …)
Chemical formula: (C6H8O6)n
Molar mass: 10,000 – 600,000
Sodium alginate is one of the best-known members of the hydrogel group.
The hydrogel is a water-swollen, and cross-linked polymeric network produced by the simple reaction of one or more monomer.
The ability of hydrogels to absorb water arises from hydrophilic functional groups attached to the polymeric backbone, while their resistance to dissolution arises from cross-links between network chains.
Sodium alginate is a naturally occurring anionic polymer typically obtained from brown seaweed, Sodium alginate consists of mannuronic (M) and guluronic (G) acids arranged in different combinations such as blocks rich in either M or G units, or blocks of alternating G and M units.
In the presence of divalent Ca2+ cations, the guluronic acids from nearby chains form ionic crosslinks resulting in alginate hydrogel.
The ratio of M and G units defines the physicochemical properties of the hydrogel.
Sodium alginate, also known as algin, is a carbohydrate product of a seaweed, Macrocystis pyrifera.
Sodium alginate is used as a gel in pharmaceutical preparations.
Sodium alginate is also used as a stabilizer, thickener and emulsifier for food products such as ice cream, yogurt, cream, and cheese.
Sodium alginate acts as a thickener and emulsifier for salad, pudding, jam, tomato juice, and canned products.
Sodium alginate is a hydration agent for noodles, bread, cool and frozen products.
Sodium alginate is a cold gelling agent that needs no heat to gel.
Sodium alginate is most commonly used with calcium lactate or calcium chloride in the spherification process.
Sodium alginate is a polysaccharide distributed widely in the cell walls of brown algae that is hydrophilic and forms a viscous gum when hydrated.
With metals such as sodium and calcium, its salts are known as alginates.
Sodium alginates colour ranges from white to yellowish-brown.
Sodium alginate is sold in filamentous, granular, or powdered forms.
Sodium alginate is a significant component of the biofilms produced by the bacterium Pseudomonas aeruginosa, a major pathogen found in the lungs of some people who have cystic fibrosis.
The biofilm and P. aeruginosa have a high resistance to antibiotics, and are susceptible to inhibition by macrophages.
Sodium alginate (CAS Reg. No. 9005-38-3) is the sodium salt of alginic acid, a natural polyuronide constituent of certain brown algae.
Sodium alginate is prepared by the neutralization of purified alginic acid with appropriate pH control agents.
Uses of Sodium alginate
Alginate absorbs water quickly, which makes it useful as an additive in dehydrated products such as slimming aids, and in the manufacture of paper and textiles.
Sodium alginate also is used for waterproofing and fireproofing fabrics, in the food industry as a thickening agent for drinks, ice cream, cosmetics, and as a gelling agent for jellies.
Sodium alginate is mixed with soybean flour to make meat analogue.
Alginate is used as an ingredient in various pharmaceutical preparations, such as Gaviscon, in which Sodium alginate combines with bicarbonate to inhibit reflux.
Sodium alginate is used as an impression-making material in dentistry, prosthetics, lifecasting, and for creating positives for small-scale casting.
Sodium alginate is used in reactive dye printing and as a thickener for reactive dyes in textile screen-printing.
Alginates do not react with these dyes and wash out easily, unlike starch-based thickeners.
As a material for micro-encapsulation.
Calcium alginate is used in different types of medical products, including skin wound dressings to promote healing, and may be removed with less pain than conventional dressings.
Description
Alginates are extracts derived from certain Brown Seaweeds (Kelp or Macrocystis).
Kelp is commonly found in the northern Atlantic and Pacific Oceans and off the coast of California down through Chile.
Alginic Acid exists naturally in the seaweed.
Through the extraction and refining process alginic acid is converted to commercially functional Sodium Alginates.
Sodium Alginates are used to produce heat-stable gels and to generate viscosity in a variety of fabricated foods, heat-stable fruit fillings, and cheese sauces.
Properties
Sodium alginates are soluble in both hot and cold water and are available in a variety of viscosity ranges with various gelling properties.
Sodium Alginate solutions are converted, in the presence of calcium ions (calcium chloride or other soluble calcium salt), to Calcium Alginate, the heat-stable gelled form.
Sodium Alginate is extracted from naturally occurring seaweed, which is classified into four main groups: Chlorophyceae (green algae); Phaeophyceae (brown algae); Rhodophyceae (red algae); and Cyanophyceae (blue-green algae).
Chlorophyceae and Cyanophyceae, which live in salt water, fresh water, soil, and tree trunks are used primarily in food.
Phaeophyceae and Rhodophyceae, salt water plants available in large quantities, are important commercially because of their specific polysaccharide content.
Agar and carrageenan are extracted from various types of Rhodophyceae.
Sodium alginate reduces appetite and glycemia, when consumed in water- and sugar-based drinks.
But, Sodium alginates effects when added to other commonly consumed beverages have not been reported.
Because chocolate milk (CM) is criticized for raising blood glucose more than unflavored milk, the aim of our study was to investigate the effect of adding a strong-gelling sodium alginate to CM on glycemia, insulinemia, appetite and food intake.
Where is sodium alginate found?
Sodium alginate is a thickener found in the textile screen-printing and carpet jet-printing industry.
Sodium alginate is also a food additive found in gel-like foods such as jam and pimento stuffing in prepared cocktail olives.
How can you avoid contact with sodium alginate?
Avoid products that list any of the following names in the ingredients:
-AI3-19772
-Algiline
-Algin
-Algin (Laminaria spp. and other kelps)
-Algin (polysaccharide)
-Alginate KMF
-Alginic acid, sodium salt
-Algipon L-1168
-Amnucol
-Antimigrant C 45
-Cecalgine TBV
-Cohasal-IH
-Darid QH
-Dariloid QH
-Duckalgin
-FEMA No. 2014
-HSDB 1909
-Halltex
-Kelco Gel LV
-Kelcosol
-Kelgin
-Kelgin F
-Kelgin HV
-Kelgin LV
-Kelgin XL
-Kelgum
-Kelset
-Kelsize
-Keltex
-Keltone
-L’-Algiline
-Lamitex
-Manucol
-Manucol DM
-Manucol KMF
-Manucol SS/LD2
-Manugel F 331
-Manutex
-Manutex F
-Manutex RS 1
-Manutex RS-5
-Manutex SA/KP
-Manutex SH/LH
-Manutex rS1
-Meypralgin R/LV
-Minus
-Mosanon
-Nouralgine
-OG 1
-Pectalgine
-Proctin
-Protacell 8
-Protanal
-Protatek
-Snow algin H
-Snow algin L
-Snow algin M
-Sodium alginate
-Sodium polymannuronate
-Stipine
-Tagat
-Tragaya
What are some products that may contain sodium alginate?
Carpets
Food Products
-Jams
-Jellies
-Preserves
Textiles
Forms
Alginates are refined from brown seaweeds.
Throughout the world, many of the Phaeophyceae class brown seaweeds are harvested to be processed and converted into sodium alginate.
Sodium alginate is used in many industries including food, animal food, fertilisers, textile printing, and pharmaceuticals.
Dental impression material uses alginate as Sodium alginates means of gelling.
Food grade alginate an approved ingredient in process and manufactured foods.
Brown seaweeds range in size from the giant kelp Macrocystis pyrifera which can be 20–40 meters long, to thick, leather-like seaweeds from 2–4 m long, to smaller species 30–60 cm long.
Most brown seaweed used for alginates are gathered from the wild, with the exception of Laminaria japonica, which is cultivated in China for food and its surplus material is diverted to the alginate industry in China.
Alginates from different species of brown seaweed vary in their chemical structure resulting in different physical properties of alginates.
Some species yield an alginate that gives a strong gel, another a weaker gel, some may produce a cream or white alginate, while others are difficult to gel and are best used for technical applications where color does not matter.
Commercial grade alginate are extracted from giant kelp Macrocystis pyrifera, Ascophyllum nodosum, and types of Laminaria.
Alginates are also is produced by two bacterial genera Pseudomonas and Azotobacter, which played a major role in the unravelling of its biosynthesis pathway.
Bacterial alginates are useful for the production of micro- or nanostructures suitable for medical applications.
Sodium alginate (NaC6H7O6) is the sodium salt of alginic acid.
Sodium alginate is a gum.
Potassium alginate (KC6H7O6) is the potassium salt of alginic acid.
Calcium alginate (C12H14CaO12), is made from sodium alginate from which the sodium ion has been removed and replaced with calcium.
What is Sodium alginate?
Sodium alginate, also known as algin, is a carbohydrate product of a seaweed, Macrocystis pyrifera.
Sodium alginate is used as a gel in pharmaceutical preparations.
Sodium Alginate (E401) is extracted from brown seaweed.
Sodium alginate is also used as a stabilizer, thickener and emulsifier for food products such as ice cream, yogurt, cream, and cheese.
Sodium alginate acts as a thickener and emulsifier for salad, pudding, jam, tomato juice, and canned products.
Sodium alginate is a hydration agent for noodles, bread, cool and frozen products.
Sodium alginate is a cold gelling agent that needs no heat to gel.
Sodium alginate is most commonly used with calcium lactate or calcium chloride in the spherification process.
Sodium alginate is a substance that the Food and Drug Administration has listed as generally recognized as safe.
In production, sodium alginate is extracted from brown algae and is the sodium salt of alginic acid.
Sodium alginate is highly viscous and is often used as an emulsifier and a gelling agent.
These properties give sodium alginate a variety of uses in many industries.
Sodium alginate is a neutral salt in which the carboxyl groups of alginate are bonded with a sodium ion.
Alginic acid is not soluble in water but sodium alginate is soluble in both cold and hot water to produce a smooth viscous solution.
When calcium ions are added to a sodium alginate solution, calcium ions react instantly with alginate to form a gel.
The time taken to form a gel can be controlled by controlling the calcium ions.
These unique properties result in sodium alginate being used as a thickener, gelling agent and stabilizer in a wide range of industries.
Applications of sodium alginate
Alginate is used in many foods and biomedical applications, due to its biocompatibility, low toxicity, relatively low cost, and mild gelation.
In the food industry, alginate is used as a thickening agent, gelling agent, emulsifier, stabilizer, texture-improver. Nowadays, alginate is added to numerous kinds of food, such as ice cream, jelly, acid milk drinks, dressings, instant noodles, beer, etc.
Sodium alginate is used in pharmaceutical applications, Sodium alginate is added into tablets as a carrier to accelerate tablet disintegration for a faster release of the medicinal component, in cosmetics due to its functionality as a thickener and moisture retainer.
For example, alginate helps retain the color of lipstick on the lip surface by forming a gel-network.
General description
Sodium alginate is the sodium salt of alginic acid, a natural polysaccharide found in brown algae.
Sodium alginate is generally used as a stabilizer and thickener in the food industry.
Sodium alginate may undergo cross-linking in the presence of divalent cations such as Ca2+ to form biodegradable stable gels, which finds applications as a material for cell encapsulation and immobilization.
Application
Sodium alginate can be used to prepare:
Cationized casein-based polyelectrolyte complex for fragrance-controlled release applications.
Apple aroma microcapsules for cosmetic applications.
Sodium alginate
“Alginate” is the term usually used for the salts of alginic acid, but it can also refer to all the derivatives of alginic acid and alginic acid itself; in some publications the term “algin” is used instead of alginate.
Alginate is present in the cell walls of brown algae as the calcium, magnesium and sodium salts of alginic acid.
The goal of the extraction process is to obtain dry, powdered, sodium alginate.
The calcium and magnesium salts do not dissolve in water; the sodium salt does.
The rationale behind the extraction of alginate from the seaweed is to convert all the alginate salts to the sodium salt, dissolve this in water, and remove the seaweed residue by filtration.
The alginate must then be recovered from the aqueous solution.
The solution is very dilute and evaporation of the water is not economic.
There are two different ways of recovering the alginate.
The first is to add acid, which causes alginic acid to form; this does not dissolve in water and the solid alginic acid is separated from the water.
The alginic acid separates as a soft gel and some of the water must be removed from this.
Sodium Alginate is a natural polysaccharide product extracted from brown seaweed that grows in cold water regions.
Sodium alginate is soluble in cold and hot water with strong agitation and can thicken and bind.
In presence of calcium, sodium alginate forms a gel without the need of heat.
In modernist cuisine, sodium alginate is mostly used with calcium salts to produce small caviar-like and large spheres with liquid inside that burst in the mouth.
Sodium Alginate is also used in the food industry to increase viscosity and as an emulsifier.
Sodium alginate is also used in indigestion tablets and it has no discernible flavor.
What is alginate? Alginate is a polysaccharide, made up of chains of sugar units that can be thousands of sugars long.
Sugars in alginate consist of guluronate (G), mannuronate (M) or guluronate-mannuronate blocks, and the proportion of the different sugars determines how strong a gel is formed.
An excellent, illustrated reference to the structure, discovery (late 1800s), history of use, and chemistry of alginate can be found at here.
FMC (Fine Marine Colloids) is a major world wholesaler of two algal polysaccharides, alginate from brown seaweeds and carrageenan from certain red seaweeds.
Description
Sodium alginate is the sodium form of alginate.
Alginate is a linear, anionic polysaccharide consisting of two form of 1, 4-linked hexuronic acid residues, β-d-mannuronopyranosyl (M) and α-l- guluronopyranosyl (G) residues.
Sodium alginate can be arranged in the form of blocks of repeating M residues (MM blocks), blocks of repeating G residues (GG blocks), and blocks of mixed M and G residues (MG blocks).
Commercially available alginate currently originates from algae. Alginate has wide applications.
For example, one of its most important role is being used as wound dressing materials for the treatment of acute or chronic wounds.
The use of alginate crosslinking to make hydrogels for cell encapsulation is also quite valuable.
The emergence of various kinds of its derivatives recently has further extended its application.
Chemical Properties
Colorless or slightly yellow solid occur- ring in filamentous, granular, and powdered forms.
Forms a viscous colloidal solution with water; insoluble in alcohol, ether, and chloroform. Com- bustible.
Chemical Properties
Sodium alginate occurs as an odorless and tasteless, white to pale yellowish-brown colored powder.
History
Sodium alginate is a natural polysaccharide product that was first described in a patent application by the British chemist Edward C C Stanford in 1881.
To this day brown algae are still the main source used to extract sodium alginate from.
This group includes many of the seaweeds, like kelps, found in chilly northern seas.
In addition to the food industry, the gelling properties of sodium alginate have been used in medical, dental and cosmetic applications for years.
Uses
Sodium alginate can be used as a flavorless gum.
Sodium alginate is used by the foods industry to increase viscosity and as an emulsifier.
Sodium alginate is also used in indigestion tablets and the preparation of dental impressions.
Sodium alginate (NaAlg) and its modified forms have been widely used as membranes in pervaporation (PV) separation of aqueous‐organic solutions because of the hydrophilic nature and versatility to modify/tune their structures to achieve the desired separation.
Sodium alginate is a polymer which can be extracted from brown seaweed and kelps.
Sodium alginate is one of the structural polymers that help to build the cell walls of these plants.
Sodium alginate has some unusual properties and a wide variety of uses.
What seaweeds contain alginate?
Alginate is found in the cells walls of brown marine algae such as kelps and rockweeds; photos of kelps are on the PSA’s “Algae and Biodiversity” and “Algae and People” bookmarks (also on this webpage).
What do alginates do in brown seaweeds?
Different parts of the same seaweed often contain different types and quantities of alginate in their cell walls.
These alginates provide flexible, mechanical structure to the seaweeds and cushion them from possible injury when the seaweeds are subjected to strong water motion (waves, currents).
What products use alginate?
Alginate is used to keep ingredients in foods from separating from each other (i.e., Sodium alginate is used as an emulsifier or stabilizer) and to create a tasty, smooth texture from “creamy foods” to “gelled foods”.
For example, alginate is commonly found in ice creams, salad dressings, fruit juices, and yogurt.
Alginate is also used as an emulsifier or gelling agent in the manufacture of papers, textiles, pet foods, and pharmaceuticals.
Alginate touches nearly every person’s life, nearly every day.
How do I make a gel with alginate for fun?
If you are a teacher or professor, the information in this exercise and its links will let you use alginate to teach students about hydrocolloids, polymers, diffusion, and the power of a chemical transformation (i.e., calcium bridges formed between alginate chains) to alter the shape and texture of a material.
After this has been done, alcohol is added to the alginic acid, followed by sodium carbonate which converts the alginic acid into sodium alginate.
The sodium alginate does not dissolve in the mixture of alcohol and water, so Sodium alginate can be separated from the mixture, dried and milled to an appropriate particle size that depends on its particular application.
The second way of recovering the sodium alginate from the initial extraction solution is to add a calcium salt.
This causes calcium alginate to form with a fibrous texture; Sodium alginate does not dissolve in water and can be separated from it.
The separated calcium alginate is suspended in water and acid is added to convert Sodium alginate into alginic acid.
This fibrous alginic acid is easily separated, placed in a planetary type mixer with alcohol, and sodium carbonate is gradually added to the paste until all the alginic acid is converted to sodium alginate.
The paste of sodium alginate is sometimes extruded into pellets that are then dried and milled.
The process appears to be straightforward, certainly the chemistry is simple: convert the insoluble alginate salts in the seaweed into soluble sodium alginate; precipitate either alginic acid or calcium alginate from the extract solution of sodium alginate; convert either of these back to sodium alginate, this time in a mixture of alcohol and water, in which the sodium salt does not dissolve.
The difficulties lie in handling the materials encountered in the process, and to understand these problems a little more detail of the process is required.
Sodium Alginate Function
Sodium alginate is used to gel in presence of calcium, as shear-thinning thickener in absence of calcium, to stabilize emulsions or foams and to form films.
In modernist cuisine, sodium alginate is mostly used with calcium salts to produce small caviar-like and large spheres with liquid inside that burst in the mouth.
There are two main processes to create spheres, basic spherification and reverse spherification.
To extract the alginate, the seaweed is broken into pieces and stirred with a hot solution of an alkali, usually sodium carbonate.
Over a period of about two hours, the alginate dissolves as sodium alginate to give a very thick slurry.
This slurry also contains the part of the seaweed that does not dissolve, mainly cellulose.
This insoluble residue must be removed from the solution.
The solution is too thick (viscous) to be filtered and must be diluted with a very large quantity of water.
After dilution, the solution is forced through a filter cloth in a filter press.
However, the pieces of undissolved residue are very fine and can quickly clog the filter cloth.
Therefore, before filtration is started, a filter aid, such as diatomaceous earth, must be added; this holds most of the fine particles away from the surface of the filter cloth and facilitates filtration.
However, filter aid is expensive and can make a significant contribution to costs.
To reduce the quantity of filter aid needed, some processors force air into the extract as it is being diluted with water (the extract and diluting water are mixed in an in-line mixer into which air is forced).
Fine air bubbles attach themselves to the particles of residue.
The diluted extract is left standing for several hours while the air rises to the top, taking the residue particles with it.
This frothy mix of air and residue is removed from the top and the solution is withdrawn from the bottom and pumped to the filter.
Alginate hydrogels
Alginate may be used in a hydrogel consisting of microparticles or bulk gels combined with nerve growth factor in bioengineering research to stimulate brain tissue for possible regeneration.
In research on bone reconstruction, alginate composites have favorable properties encouraging regeneration, such as improved porosity, cell proliferation, and mechanical strength, among other factors.
Chemical formula: (C6H8O6)n
Molar mass: 10,000 – 600,000
Appearance: White to yellow, fibrous powder
Density: 1.601 g/cm3
Acidity (pKa): 1.5–3.5
Description
Stabiliser, emulsifier, thickener, formulation aid [DFC] The chemical compound sodium alginate is the sodium salt of alginic acid.
Sodium alginate is a gum, extracted from the cell walls of brown algae.
As a flavorless gum, Sodium alginate is used by the foods industry to increase viscosity and as an emulsifier.
As a food additive, sodium alginate is used especially in the production of gel-like foods.
For example, bakers’ “Chellies” are often gelled alginate “jam.”
Production of Sodium alginate:
The manufacturing process used to extract sodium alginates from brown seaweed fall into two categories:
1) calcium alginate method and 2) alginic acid method.
Chemically the process is simple, but difficulties arise from the physical separations required between the slimy residues from viscous solutions and the separation of gelatinous precipitates that hold large amounts of liquid within the structure so they resist filtration and centrifugation.
Sodium alginate is a natural gelling agent taken from the cell walls of brown algae.
Sodium alginate only gels when Sodium alginate comes in contact with calcium.
Sodium alginate also has many uses other than spherification such as thickening, general gelling, and foaming. Whether or not you know it, each of us have eaten sodium alginate in many types of commercial foods such as ice cream or the pimento portion of stuffed cocktail olives!
Sodium Alginate is used for increasing the viscosity of animal glue when applying metal leaf.
Add 0.1ml of「Fungicide」to 99g of water, then add 1g of「Sodium Alginate」and stir well.
There will be lumps left behind, but leave Sodium alginate in the refrigerator overnight to allow the lumps to dissolve completely.
Other names
Alginic acid; E400; [D-ManA(β1→4)L-GulA(α1→4)]n
Sodium alginate (NaC6H7O6) is a linear polysaccharide derivative of alginic acid comprised of 1,4-β-d-mannuronic (M) and α-l-guluronic (G) acids.
Sodium alginate is a cell wall component of marine brown algae, and contains approximately 30 to 60% alginic acid.
The conversion of alginic acid to sodium alginate allows its solubility in water, which assists its extraction.
Bacterial alginates are synthesized by only two bacterial genera, Pseudomonas and Azotobacter, and is used for protection from the environment and the synthesis of biofilms in order to adhere to surfaces.
This method of synthesis allows the bacteria to produce alginates with a well-defined monomer composition, which may allow the production of “tailor-made” bacterial alginates.
Sodium alginate‚ which is a substance taken from brown algae‚ can be used to remove toxins and heavy metals from your body.
Sodium alginate binds to several types of metals—such as strontium‚ cadmium‚ arsenic‚ and aluminum—in order to pull them.
Sodium alginate can also be used to get rid of harmful environmental fumes.
This is why supplements like Seroyal’s Sodium Alginate vegetarian capsules are helpful to many.
CAS Number: 9005-32-7
ChemSpider: None
ECHA InfoCard: 100.029.697
EC Number: 232-680-1
E number: E400 (thickeners, …)
UNII: 8C3Z4148WZ
CompTox Dashboard (EPA): DTXSID601010868
Alginate-based hydrogels are highly promising candidates for use as drug delivery systems and as biomedical implants as they are structurally similar to the macromolecular-based components in the body, and can often be delivered into the body via minimally invasive administration.
Alginate is an excellent candidate for delivery of protein drugs, since proteins can be incorporated into alginate-based formulations under relatively mild conditions that minimize their denaturation, and the gels can protect them from degradation until their release.
Sodium alginate gels are increasingly being utilized as a model system for mammalian cell culture in biomedical studies.
These gels can be readily adapted to serve as either 2-D or more physiologically relevant 3-D culture systems.
The lack of mammalian cell receptors for alginate, combined with the low protein adsorption to alginate gels allows these materials to serve in many ways as an ideal blank slate, upon which highly specific and quantitative modes for cell adhesion can be incorporated.
Further, basic findings uncovered with in vitro studies can be readily translated in vivo, due to the biocompatibility and easy introduction of alginate into the body.
As a flavorless gum, Sodium alginate is used by the foods industry to increase viscosity and as an emulsifier.
Sodium alginate is also used in indigestion tablets and the preparation of dental impressions.
A major application for sodium alginate is in reactive dye printing, as thickener for reactive dyestuffs (such as the Procion cotton-reactive dyes) in textile screen-printing and carpet jet-printing.
Alginates do not react with these dyes and wash out easily, unlike starch-based thickeners.
Sodium alginate is a good chelator for pulling radioactive substances from the body, such as iodine-131 and strontium-90, that have taken the place of their non-radioactive counterparts.
Sodium alginate is also used in immobilizing enzymes by inclusion.
Weight: 0.5 lbs
Dimensions: 3 × 3 × 3 in
Contents: 50 g vial
Storage: Room temperature
Sodium and potassium alginate are intended to be used as technological additives (functional groups: emulsifiers, stabilisers, thickeners, gelling agents and binders).
Sodium alginate is intended to be used in feedingstuffs for pets, other non food-producing animals and fish, with no maximum recommended use level.
Potassium alginate is intended to be used in feedingstuffs for cats and dogs at levels up to 40,000 mg/kg feed (on dry matter).
Since the functional properties of the additives are determined by the alginate content, sodium and potassium alginate were considered equivalent.
The maximum dose considered safe for cats, dogs, other non food-producing animals, salmonids and other fish is 40,000 mg alginates (sodium and potassium salts)/kg complete feed.
The use of alginates in feedingstuffs for fish is of no concern for the consumer.
Alginates are reported not to be irritant to the skin but mildly irritant to the eyes.
They are considered as potential sensitisers to the skin and the respiratory tract.
Alginates are high-molecular-weight polymers naturally occurring in brown algae.
Their use in feedingstuffs for fish does not pose a risk for the aquatic environment.
Alginates are effective as stabilisers, thickeners, gelling agent and binders.
No conclusion could be drawn on the efficacy of alginates as emulsifiers.
Sodium alginate gelation process
Alginate hydrogels can be prepared by various cross-linking methods, and their structural similarity to extracellular matrices of living tissues allows wide applications.
The most common method to prepare hydrogels from an aqueous alginate solution is to combine the solution with ionic cross-linking agents, such as divalent cations (i.e., Ca2+).
Calcium chloride (CaCl2) is one of the most frequently used agents to ionically cross-link alginate.
Sodium alginate typically leads to rapid and poorly controlled gelation due to its high solubility in aqueous solutions.
One approach to slow and control gelation is to utilize a buffer containing phosphate (e.g., sodium hexametaphosphate), as phosphate groups in the buffer compete with carboxylate groups of alginate in the reaction with calcium ions, and delay gelation.
Calcium sulfate (CaSO4) and calcium carbonate (CaCO3), due to their lower solubilities, can also slow the gelation rate and widen the working time for alginate gels.
The gelation rate is a critical factor in controlling gel uniformity and strength when using divalent cations, and slower gelation produces more uniform structures and greater mechanical integrity.
Finally, thermo-sensitive hydrogels have been widely investigated to date in many drug delivery applications, due to their adjustable swelling properties in response to temperature changes, leading to on-demand modulation of drug release from the gels.
Alginate micro particles
Sodium alginate-based particles have emerged as one of the most searched drug delivery platforms due to their inherent properties, including good biocompatibility and biodegradability for improved delivery, stabilization and prolonged release of encapsulated drugs.
They are also extensively used for the encapsulation of living cells in pharmaceutical research, tissue engineering, and regenerative medicine.
Such microgels act as micrometer-sized 3D culturing units, allowing individual cells to be independently monitored or manipulated, for example to study the role of confinement on cell fate or to deliver cells for the repair of damaged tissue.
Sodium Alginates
Nalgin ULV Very low viscosity
Nalgin MV-120 Medium viscosity / medium gel
Nalgin 600 & Nalgin 800 High viscosity
Nalgin 1000 Very high viscosity
Nalgin HG High gel / medium viscosity
Applications and typical use levels:
Sodium alginate is a neutral salt in which the carboxyl groups of alginate are bonded with a sodium ion.
Alginic acid is not soluble in water but sodium alginate is soluble in both cold and hot water to produce a smooth viscous solution.
Bakery and Dessert Gels 0.10% to 0.20%
Dry Mixes 0.10% to 0.30%
Frozen Desserts 0.10% to 0.30%
Icings 0.10% to 0.30%
Milk Puddings 0.50% to 0.80%
Pie Fillings 0.25% to 0.50%
Restructured Foods 0.75% to 1.50%
Sauces 0.20% to 0.35%
Syrups and Toppings 0.10% to 0.25%
Processed Cheese 0.10% to 0.25%
Salad Dressings 0.10% to 0.50%
Beverages 0.10% to 0.50%
Structure
Alginic acid is a linear copolymer with homopolymeric blocks of (1→4)-linked β-D-mannuronate (M) and α-L-guluronate (G) residues, respectively, covalently linked together in different sequences or blocks.
The monomers may appear in homopolymeric blocks of consecutive G-residues (G-blocks), consecutive M-residues (M-blocks) or alternating M and G-residues (MG-blocks).
Note that α-L-guluronate is the C-5 epimer of β-D-mannuronate.
What is Sodium Alginate Used For?Top
There are two main ways to use sodium alginate to create spheres.
The first is direct spherification, where the sodium alginate is blended into a flavorful liquid, which is then added by the spoonful into a calcium lactate or calcium chloride bath.
The second is reverse spherification, where the calcium is added to the flavorful liquid and then spoonfuls of the liquid are added to a sodium alginate bath.
Sodium alginate works best in non-acidic mixtures.
If you are trying to use Sodium alginate in something acidic you can usually add sodium citrate to alter the pH before adding the sodium alginate.
If you want to gel a thicker substance such as a puree, add water to thin it down until the mixture reaches a better liquid consistancy.
Sodium alginate also has many uses other than spherification such as thickening, general gelling, and foaming.
Sodium alginate
9005-38-3
D-Galacturonic acid sodium salt
sodium;3,4,5,6-tetrahydroxyoxane-2-carboxylate
natriumglucuronat
Alginic acid monosodium salt
SCHEMBL20919851
EBD39195
FT-0621962
FT-0670280
K-4769
sodium;(2S,3R,4S,5R)-3,4,5,6-tetrahydroxyoxane-2-carboxylate
Sodium alginate (a food product derived from brown algae or seaweed) is a thickening and gelling agent that forms heat stable gels in the presence of calcium.
This property allows cooks to make gelled spheres, in a technique known as spherification.
Sodium alginate has been used in the food industry for many years for the production of gel-like foods – for example, the pimento stuffing in prepared cocktail olives.
Sodium alginate is composed of long strands made up of carbohydrate units – these long stands allow it to act as a very efficient thickening agent at low concentrations (e.g. 1%).
Gels formed from alginates have the amazing ability of withstanding heating to temperatures as high as 150ᵒC without melting, allowing them to be used in hot applications such as broths.
When alginate is added to a liquid, it will act as a thickener.
In the presence of calcium ions, a mixture containing alginate will form a gel.
The calcium ions insert themselves between individual alginate strands and will allow them to interlock and form a gel.
SPHERIFICATION METHODS
There are two main methods for creating such spherification, which differ based on the calcium content in the product to be encapsulated in the gel bubble.
For substances containing no calcium, a flavoured liquid is mixed with sodium alginate, and droplets of this mixture are dropped into a room temperature solution made up of water and calcium lactate or calcium gluconate (both are less bitter than other forms of calcium).
‘Reverse’ spherification, is a technique for use with substances which are rich in calcium, in this case additional calcium (if necessary) is blended into a flavoured liquid, and while the sodium alginate is blended into the water.
Both methods give a similar result: a sphere of liquid held by a thin gel membrane, texturally similar to caviar.
Basic spherification is easier & ideal for obtaining spheres with an ultra thin membrane.
The spheres are often referred to as caviar.
Chemical Formula C6H9NaO7
IUPAC name sodium 3,4,5,6-tetrahydroxyoxane-2-carboxylate
InChI Identifier InChI=1S/C6H10O7.Na/c7-1-2(8)4(5(10)11)13-6(12)3(1)9;/h1-4,6-9,12H,(H,10,11);/q;+1/p-1
InChI Key MSXHSNHNTORCAW-UHFFFAOYSA-M
Isomeric SMILES [Na+].OC1OC(C(O)C(O)C1O)C([O-])=O
Average Molecular Weight 216.1212
Monoisotopic Molecular Weight 216.024597317
biological source: synthetic
Quality Level: 400
grade: Halal
reg. compliance:
FDA 21 CFR 117
FDA 21 CFR 150.161
FDA 21 CFR 173.310
Documentation: see Safety & Documentation for available documents
Featured Industry: Flavors and Fragrances
Organoleptic: odorless
food allergen: no known allergens
THE SCIENCE
The flavoured spherification liquid cannot be too high in calcium or acidic (pH level must be above 3.6).
A concentration of about 0.5% (approx. 5g to 1tr) sodium alginate is dispersed into the flavoured liquid (this will vary depending on the properties of the liquid being used).
A concentration of around 1% (approx. 10g to 1ltr) calcium (either gluconate or lactate are advised – due to lack of perceivable bitter taste) is dissolved in water and is called a ‘water bath’.
Melting point:99 °C
Density 1.0 g/cm3(Temp: 25 °C)
FEMA 2014 | ALGIN (LAMINARIA SPP. AND OTHER KELPS)
storage temp. Store at RT.
solubility Slowly soluble in water forming a viscous, colloidal solution, practically insoluble in ethanol (96 per cent).
form powder
color White to Off-white
PH6.0-8.0 (10mg/mL in H2O)
Water Solubility Soluble in water. Insoluble in alcohol, chloroform and ether.
Sensitive Hygroscopic
Merck 14,241
Stability:Stable. Incompatible with strong acids, strong bases, strong oxidizing agents.
Substances Added to Food (formerly EAFUS)ALGINATE, SODIUM
SCOGS (Select Committee on GRAS Substances)Sodium alginate
CAS DataBase Reference9005-38-3(CAS DataBase Reference)
FDA 21 CFR184.1724; 582.7724; 173.310
FDA UNIIC269C4G2ZQ
EPA Substance Registry SystemSodium alginate (9005-38-3)
What is Sodium Alginate?Top
Sodium alginate is a natural polysaccharide product that was first described in a patent application by the British chemist Edward C C Stanford in 1881.
To this day brown algae are still the main source used to extract sodium alginate from.
This group includes many of the seaweeds, like kelps, found in chilly northern seas.
In addition to the food industry, the gelling properties of sodium alginate have been used in medical, dental and cosmetic applications for years.