Constitute a


Sodium alginate (C6H7O8Na) n is mainly composed of the sodium alginate, by a - L - mannose hyaluronic acid unit (M) and b - D - ancient luo uronic acid unit (G) rely on 1, 4 - glycosidic bond connection and by different proportions of GM, MM and GG copolymer composed of fragments.
The molecular weight


Goods with molecular weight of sodium alginate usually like polysaccharide, scattered.Therefore, a kind of sodium alginate average molecular weight of all molecules usually represent the group.The most common form of molecular weight is the number average molecular weight (Mn) and the molecular weight (Mw).The two defined by the following formula:
Mi Ni = here with a specific molecular weight number of molecules, Mi Wi = with specific molecular weight molecular weight.
In the polydispersity of molecular group, usually Mw > Mn.Mw/Mn coefficient of dispersion index, sodium alginate commodity index classic in the range of 1.5 ~ 2.5.The most common way to determine the molecular weight, in order to establish based on viscosity and light scattering measurement calculated out.
Molecular formula




Sodium alginate formula
Formula for (C6H7NaO6) x, such as molecular structure

PH


Sodium alginate slightly soluble in water, insoluble in most organic solvents.It is soluble in alkaline solution, make the solution viscosity.Sodium alginate powder in water wet, hydration make its surface sticky particles.Then the particles together to form a mass quickly, mass slow hydration and dissolve completely.If the water contains other compete with alginate hydrated compound, the sodium alginate is more difficult to dissolve in water.Sugar, starch or protein in the water can reduce the hydration rate of sodium alginate, mixing time is necessary to extend.Monovalent cations of salt (NaCl) on the concentration above 0.5% will also have a similar effect.Sodium alginate in 1% of the distilled water solution pH value of 7.2.
The stability of


Sodium alginate has hygroscopicity, equilibrium moisture content depend on relative humidity.Dry sodium alginate in well sealed container to store below 25 °C and temperature is quite stable.Sodium alginate solution stability in the pH5 ~ 9.Degree of polymerization (DP) and the molecular weight is directly related to the viscosity of sodium alginate solution, the viscosity decreased when the deposit can be used to measure sodium alginate to the degree of polymerization.High degree of polymerization of sodium alginate stability than the low degree of polymerization of sodium alginate.It is reported that sodium alginate by proton catalytic hydrolysis, depends on the hydrolysis time, pH and temperature.Propylene glycol esters algal acid solution at room temperature, pH3 ~ 4 when stability;PH less than 2 or greater than 6, even at room temperature will quickly reduce the adhesive.

In the application of food




Food grade sodium alginate
Food grade sodium alginate
To replace starch, sodium alginate gelatin stabilizer for ice cream, can control the formation of ice crystals, improve the taste of ice-cream, can also be stable sugar water ice fruit sorbet, and frozen milk mixed drinks.Many dairy products, such as refined cheese, whipped cream, dry cheese using sodium alginate stability can prevent food and packaging are even viscous, dairy accessories can be used as the cover, can make its stable and to prevent icing sugar crisp skin cracking.
Sodium alginate is used in salad sauce (a salad), pudding, a dessert, jam, tomato paste and canned products of thickening agent, in order to improve the stability properties of the products, reduce the liquid leakage.
Added in the dry noodles, fans, rice production sodium alginate can improve products group cohesiveness, strong tension, bending, reducing end breakage rate, especially for low gluten flour content, effect is more obvious.In products such as bread, pastry, adding sodium alginate can improve the homogeneity of products within the organization and holding water, extend the storage time.Added in the frozen dessert products can provide heat fusion layer, improve the aroma releasing, improve the performance of melting point.


Adding sodium alginate artificial eggs
Sodium alginate can make various gel food, maintain good colloid form, not the drainage or shrinkage, suitable for frozen food and artificial copy type.Can also be used to cover fruit, meat, poultry and aquatic products as a protective layer, do not direct contact with air, extend the storage time.Also can be used as bread icing, filling packing besmear cover, such as canned food, snack self-curing forming agent.In acid medium high temperature, frozen and can still maintain the original form.Still can replace Joan made with elastic rubber, non-stick teeth, transparent crystal jelly.
In the application of pharmaceutical preparations


Sodium alginate as early as in 1938 has been the United States pharmacopoeia.Alginate in revenue in 1963 the British pharmacopoeia.Alginic acid insoluble in water, but in the water will swell.Therefore, traditionally, sodium alginate is used as adhesive tablets, and alginate ZuoSu interpretation of the basic pieces of the disintegrating agent.However, sodium alginate for tablet properties depends on the effect of prescription in quantity, and in some cases, the sodium alginate can promote the disintegration of tablets.Sodium alginate can join in granulating process, rather than in the form of powder to join after granulating, so the production process more simple.Compared with the use of starch, made into greater mechanical strength.
Sodium alginate is used in suspension, gel, and with the substrate of fats and oils in the production of concentrated emulsion.Sodium alginate used in some of the liquid medicine, can enhance the viscosity, improve solid suspension.Propylene glycol esters algal acid can improve the stability of the emulsion.Controlled release drug delivery system is an important role in health care.Water-soluble drug particles from the colloidal medium to minimize the time before to ensure that the drug is the largest.However, this is not important to water insoluble drugs.They found that the release of drugs related to the solubility of drugs used.
One researcher reported swelling of alginate gel particles with a pH sensitive, such as particle in distilled water or acid medium (pH1.5 KCl - HCl) no change, and in the phosphate buffer of pH7.0 swelling rapidly, size bigger.The properties of sodium alginate is sensitive to acid is very useful to drug, can make the drug from attacks by hydrochloric acid in gastric juice, and in the small intestine dry gel swelling can make release drugs to the desired rate.
Another researcher in acidic conditions by sodium alginate and glutaraldehyde crosslinking and pour into ethanol solution preparation containing diclofenac sodium (slightly soluble in water) of controlled release sodium alginate ball.The embedding rate was 30% ~ 30%, and its value depends on the preparation conditions.Pellets preparation when temperature or with crosslinking material exposed to prolonged, depress the embedding rate, prolonged drug release.
The application of the printing industry


Reactive dyes to dye Sodium alginate used as reactive dye printing ink in the printing and dyeing industry, the better
Food starch and other pulp.Bright printed textile decorative pattern, line is clear, to the high amount of color, color uniformity, good permeability and plasticity.Seaweed gel is the best size for modern dyeing, has been widely applied in cotton, wool, silk, nylon, etc. Various kinds of fabric printing, especially suitable for mixed dye printing paste.
The warp sizing agent. China's textile sector with seaweed gel or mixed with starch instead of starch warp sizing agent, not only can save a lot of food, and can make warp fibers don't fluff, friction resistance, less breakage, thus improve the weaving efficiency.Seaweed gel of cotton and synthetic fibers are effective.
In the application of the pharmaceutical industry


Sulfate alginate dispersant type made of PS gastrointestinal double contrast barium sulfate preparations, has low viscosity, particle size, attached to the wall sex good, stable performance, etc.
PSS is alginate as raw material to develop a kind of brown alga of double sodium acetate, anticoagulant, fall hematic fat and reduce blood viscosity.
With seaweed glue instead of rubber dental impression material, gypsum, not only cheap, easy to operate, and print out the tooth profile of more accurate.
Seaweed gel also can produce all kinds of dosage forms of hemostatic agents, including hemostatic sponge, hemostatic gauze, hemostatic film, scald gauze, spray hemostatic agent, etc.[3]