单词 | lecithin |
释义 | lecithinn. Chemistry. (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. ΚΠ 1861 R. T. Hulme tr. C. H. Moquin-Tandon Elements Med. Zool. ii. iii. ii. 86 Helicine..consists..of oleine,..lecithine, and cerebrine. 1873 C. H. Ralfe Outl. Physiol. Chem. 75 Lecithin hydro~chlorate. 1896 T. C. Allbutt et al. Syst. Med. I. 165 A phosphoretted fat termed lecithin. 1923 Levene & Rolf in Jrnl. Biol. Chem. 55 743 Thus the product was a mixture of several substances, which we propose to name lysolecithin and lysocephalin. Inasmuch as lecithins differ in the nature of their saturated fatty acids, it is probable that there exist several lysolecithins. 1926 G. 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15 Lecithin is a complex compound..and may be looked on as a tri~glyceride in which one of the fatty acid radicles has been replaced by a complex organic base containing phosphoric acid. 1926 G. D. Elsdon Chem. & Exam. Edible Oils & Fats xii. 205 Maize oil contains 1·1 to 1·5 per cent. of lecithin. 1951 M. 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. 1951 K. 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. 1951 K. S. Markley Soybeans II. xvi. 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. 1954 Thorpe'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. 1961 H. F. Payne Org. 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. 1967 Martindale'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. 1970 E. J. Ambrose & D. M. Easty Cell Biol. viii. 272 The main lipid constituents of plasma membranes are phospholipids (in particular phosphatidylcholine or lecithin), and cholesterol, a steroid. 1973 Sci. 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. This entry has not yet been fully updated (first published 1902; most recently modified version published online March 2022). < |
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