What is sodium alginate and its application?
Sodium alginate is a by-product of extracting iodine and mannitol from brown algae kelp or Sargassum. Its molecule is composed of β-D-mannuronic acid (β-D-mannuronic, M) and α-L-gul Uronic acid (α-L-guluronic, G) is connected by (1→4) key. It is a natural polysaccharide with the stability, solubility, viscosity and safety required for pharmaceutical excipients. Sodium alginate has been widely used in the food industry and medicine.
Sodium alginate is a by-product of extracting iodine and mannitol from brown algae kelp or Sargassum. Its molecule consists of β-D-mannuronic acid (β-D-mannuronic, M) and α-L-guluo. Uronic acid (α-L-guluronic, G) is connected by pressing (1→4). The aqueous solution of sodium alginate has high viscosity and has been used as a thickener, stabilizer, emulsifier, etc. for food. Sodium alginate is a non-toxic food and has been included in the United States Pharmacopoeia as early as 1938. Sodium alginate contains a large amount of -COO-, which can exhibit polyanionic behavior in aqueous solution, has a certain degree of adhesion, and can be used as a drug carrier for the treatment of mucosal tissue. Under acidic conditions, -COO- is transformed into -COOH, the ionization degree decreases, the hydrophilicity of sodium alginate decreases, the molecular chain shrinks, and the pH value increases, the -COOH group is continuously dissociated, and sodium alginate becomes hydrophilic Sex increases, and the molecular chain stretches. Therefore, sodium alginate has obvious pH sensitivity. Sodium alginate can quickly form a gel under extremely mild conditions. When there are cations such as Ca2+ and Sr2+, the Na+ on the G unit reacts with divalent cations, and the G unit stacks to form a cross-linked network structure, thus forming Hydrogels. Sodium alginate gel is formed under mild conditions, which can avoid the inactivation of active substances such as sensitive drugs, proteins, cells and enzymes. Due to these excellent properties, sodium alginate has been widely used in the food industry and medicine.
As a thickening agent for beverages and dairy products, sodium alginate has unique advantages in thickening: the good fluidity of sodium alginate makes the added beverage taste soft and smooth; and it can prevent the viscosity drop during product disinfection. When using sodium alginate as a thickening agent, products with larger molecular weight should be used as much as possible, and Ca should be added in an appropriate amount. Can greatly increase the viscosity of sodium alginate.
Sodium alginate is a high-end stabilizer for cold drinks such as ice cream. It can make ice cream and other cold food and drink products have a smooth appearance and smooth taste. Because calcium alginate can form a stable thermally irreversible gel, it will not become rough (ice crystal growth) during transportation and storage, and ice cream deformation caused by temperature fluctuations will not occur; at the same time, this ice cream has no peculiar smell when eaten. Both the expansion rate and the melting point are increased, so that the quality and efficiency of the product are significantly improved. The product tastes smooth, delicate and tastes good. The addition amount is relatively low, generally 1-3%, and the foreign addition amount is 5-10%.
Sodium alginate is used as a stabilizer for dairy products and beverages. Stable frozen milk has a good taste, no stickiness and stiffness, stickiness when stirring, and a sense of lag.