アルギン酸ナトリウム

Origin

Sodium alginate is a naturally occurring polysaccharide derived from brown algae (Phaeophyceae), such as *Laminaria digitata*, *Ascophyllum nodosum*, and *Macrocystis pyrifera*. It is the sodium salt of alginic acid. The extraction process involves harvesting the seaweed, washing it, and then treating it with alkaline solutions to dissolve the alginate. This is followed by precipitation with calcium chloride or hydrochloric acid, and finally, the alginic acid is neutralized with sodium carbonate to form sodium alginate.

Usage

Sodium alginate is widely used in the food industry as a thickening agent, stabilizer, gelling agent, and emulsifier. It is used in products such as ice cream (to prevent crystal formation), sauces, dressings, bakery products, and beverages. Its ability to form gels in the presence of calcium ions makes it useful in creating structured foods and encapsulation. In molecular gastronomy, it is a key ingredient in spherification techniques. Beyond food, it finds applications in pharmaceuticals (as a drug delivery system and wound dressing), textiles (as a printing paste), and paper manufacturing.

Side Effects

Sodium alginate is generally considered safe for consumption. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) has established an Acceptable Daily Intake (ADI) of 'not specified', meaning that, based on available data, the intake of sodium alginate at levels necessary to achieve the desired technological effect in food does not represent a health hazard. Some individuals may experience mild gastrointestinal discomfort, such as bloating or diarrhea, if consumed in very large quantities. Allergic reactions are rare.

Regulatory Status

Sodium alginate (E401) is approved for use as a food additive in many countries, including those in the European Union, the United States, Canada, and Australia. It is regulated under various food additive regulations, which specify the permitted uses and maximum levels in different food categories. In the EU, it is listed under Regulation (EC) No 1333/2008 on food additives. In the United States, it is Generally Recognized As Safe (GRAS) under FDA regulations.