![]() It has a strongly alkaline taste, and forms a moderately basic solution in water. Pure sodium carbonate is a white, odorless powder that is hygroscopic -absorbs moisture from the air. It most commonly occurs as a crystalline decahydrate, which readily effloresces to form a white powder, the monohydrate. Sodium carbonate: Sodium carbonate, Na2CO3, -also known as washing soda, soda ash and soda crystals, and in the monohydrate form as crystal carbonate- is the water-soluble sodium salt of carbonic acid. ![]() In chemical terms, agar is a polymer made up of subunits of the sugar galactose. For commercial purposes, it is derived primarily from ogonori. Agar can be used as a laxative, an appetite suppressant, a vegetarian substitute for gelatin, a thickener for soups, in fruit preserves, ice cream, and other desserts, as a clarifying agent in brewing, and for sizing paper and fabrics.The gelling agent in agar is an unbranched polysaccharide obtained from the cell walls of some species of red algae, primarily from tengusa -Gelidiaceae- and ogonori -Gracilaria. These algae are known as agarophytes, and belong to the Rhodophyta -red algae- phylum.Agar has been used as an ingredient in desserts throughout Asia, and also as a solid substrate to contain culture media for microbiological work. It forms the supporting structure in the cell walls of certain species of algae, and is released on boiling. In cooking, it is sometimes used as an emulsifier and to prevent sticking, for example in nonstick cooking spray.Īgar: Agar -pronounced, sometimes - or agar-agar is a jelly-like substance, obtained from red algae.Agar is a mixture of two components: the linear polysaccharide agarose, and a heterogeneous mixture of smaller molecules called agaropectin. Lecithin is sold as a food additive and dietary supplement. This results in a type of surfactant that usually is classified as amphipathic. In aqueous solution, its phospholipids can form either liposomes, bilayer sheets, micelles, or lamellar structures, depending on hydration and temperature. ![]() It has low solubility in water, but is an excellent emulsifier. It is usually available from sources such as soybeans, eggs, milk, marine sources, rapeseed, cottonseed, and sunflower. Lecithin can easily be extracted chemically using solvents such as hexane, ethanol, acetone, petroleum ether, benzene, etc., or extraction can be done mechanically. Gobley originally isolated lecithin from egg yolk-λέκιθος lekithos is "egg yolk" in Ancient Greek-and established the complete chemical formula of phosphatidylcholine in 1874 in between, he had demonstrated the presence of lecithin in a variety of biological matters, including venous blood, in human lungs, bile, human brain tissue, fish eggs, fish roe, and chicken and sheep brain. In 1850, he named the phosphatidylcholine lécithine. Lecithin: Lecithin -UK:, US:, from the Greek lekithos, "egg yolk"- is a generic term to designate any group of yellow-brownish fatty substances occurring in animal and plant tissues, which are amphiphilic – they attract both water and fatty substances -and so are both hydrophilic and lipophilic-, and are used for smoothing food textures, dissolving powders -emulsifying-, homogenizing liquid mixtures, and repelling sticking materials.Lecithins are mixtures of glycerophospholipids including phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, and phosphatidic acid.Lecithin was first isolated in 1845 by the French chemist and pharmacist Theodore Gobley.
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