Benders'dictionary of nutrition and food technology

282linoleic acid, conjugated Isomers of linoleic acid in which two ormore of the double bonds are conjugated (i.e. alternating withsingle bonds) rather than separated by a methylene bridge.a-linolenic acid An essential polyunsaturated fatty acid (C18:3ω3).g-linolenic acid A non-essential polyunsaturated fatty acid(C18:3 ω6), which has some pharmacological actions. Foundin oils from the seeds of evening primrose, borage andblackcurrant.linseed See flaxseed.liothyronine Obsolete name for the thyroid hormone triiodothyronine(T3).lipaemia Increase in blood lipids, as occurs normally after a meal.lipase Enzyme (EC 3.1.1.x) that hydrolyses triacylglycerols tofree fatty acids and 2-mono-acylglycerol. Lipase secreted by thetongue and in gastric and pancreatic juice is EC 3.1.1.3; lipasesare also present in many seeds and grains. Final hydrolysis toyield glycerol is catalysed by acylglycerol lipase (EC 3.1.1.23).Most lipases have low specificity and will hydrolyse anytriacylglycerol. Sometimes responsible for the development of(hydrolytic) rancidity in stored foods, and the development offlavour in cheese.See also acid number; interesterification.lipase, clearing factor See lipase, lipoprotein.lipase, hormone-sensitive lipase in adipose tissue that is activatedin response to adrenaline, and inactivated in response toinsulin, so controlling release of free fatty acids as a metabolicfuel.lipase, lipoprotein lipase (EC 3.1.1.34) in muscle and adiposetissue that is responsible for the uptake of free fatty acids fromtriacylglycerols in lipoproteins. Also known as clearing factorlipase, since it removes triacylglycerol from chylomicrons after ameal, resulting in reduction in their size, and clearing of the milkyappearance of chylomicron-rich plasma.lipectomy Surgical removal of subcutaneous fat.lipidema Condition in which fat deposits accumulate in the lowerextremities, from hips to ankles, with tenderness of the affectedparts.lipids (also sometimes lipides, lipins) A general term for fats andoils (chemically triacylglycerols), waxes, phospholipids,steroids and terpenes.Their common property is insolubility inwater and solubility in hydrocarbons, chloroform and alcohols.Fats are solid at room temperature, while oils are liquids.Non-saponifiable lipids are not hydrolysed by treatment withsodium or potassium hydroxide and therefore cannot be