| 释义 |
lecithin Chem.|ˈlɛsɪθɪn|
Also -ine.
[F. lécithine (N. T. Gobley 1850, in Jrnl. de Pharm. et de Chim. XVII. 411), f. Gr. λέκιθος yolk of egg: see -in1.]
a. Any of a group of phospholipids found in plants and animals which are esters of a phosphatidic acid with choline and on hydrolysis yield choline, phosphoric acid, glycerol, and two fatty acids; also used as a generic name for these compounds.
b. A commercial mixture of lecithin with other phosphatides and often other lipids obtained from natural products and used industrially, esp. that from soya beans.
1861Hulme tr. Moquin-Tandon ii. iii. ii. 86 Helicine..consists..of oleine,..lecithine, and cerebrine. 1873C. H. Ralfe Phys. Chem. 75 Lecithin hydro⁓chlorate. 1896Allbutt's Syst. Med. I. 165 A phosphoretted fat termed lecithin. 1923[see lysolecithin s.v. lyso-]. 1926G. D. Elsdon Chem. & Exam. Edible Oils & Fats iii. 15 Lecithin is a complex compound..and may be looked on as a tri⁓glyceride in which one of the fatty acid radicles has been replaced by a complex organic base containing phosphoric acid. Ibid. xii. 205 Maize oil contains 1·1 to 1·5 per cent. of lecithin. 1951M. B. Jacobs Chem. & Technol. Food & Food Products (ed. 2) III. xlii. 2155 The addition of lecithin to chocolate results in a saving of cacao butter, counteracts moisture, and stabilizes the chocolate. 1951K. S. Markley Soybeans II. xvi. 600 It has become customary in industrial circles to call the phosphatide residue obtained in the commercial manufacture of soybean oil soybean lecithin or simply lecithin. The commercial product contains roughly two-thirds phosphatides and one-third soybean oil. Ibid. 601 The term commercial lecithin or lecithin is applied almost exclusively to soybean lecithin, whereas 20 years ago it would have referred to egg lecithin. 1954Thorpe's Dict. Appl. Chem. (ed. 4) XI. 47/2 Lecithins and cephalins, about 2%, are present in the oil [from soya beans] and have been widely used as emulsifiers in the food, textile, cosmetic, soap, and other industries. 1961H. F. Payne Organic Coating Technol. II. xxiii. 970 Lecithin..is a balanced polar–non-polar compound and will concentrate at the interface between polar pigments and less polar oils and resins to reduce the interfacial tension and facilitate wetting. 1967Martindale's Extra Pharmacopoeia (ed. 25) 293 Lecithins occur in all animal and vegetable cells and vary in composition according to the source from which they are obtained. The two chief commercial varieties are egg lecithin (ovolecithin).., and vegetable lecithin..from various vegetable sources, particularly leguminous seeds. 1970Ambrose & Easty Cell Biol. viii. 272 The main lipid constituents of plasma membranes are phospholipids (in particular phosphatidylcholine or lecithin), and cholesterol, a steroid. 1973Sci. Amer. Apr. 85/1 The alveolar fluid contains trace amounts of various large molecules; among them are the two principal lipids—lecithin and sphingomyelin—that represent the bulk of the pulmonary surfactant. |