Functionsof FatsFlavor:sourceofdesirableandundesirableflavorsdesirableflavors:fromlactonesanddiacetylinbutter,ketonesincheeseundesirableflavors:rancid,tallowy and fishyflavors.2,4-decadienal:atlowlevelsprovidesdesirablefriedfoodflavortopotatochips,butatKagomehighlevelsimpartsundesirablerancidflavorsColor:sheenimpactfromwaxes,yellowcolorfromcarotenoids,greenfromchlorophyilsTexture:mouth feel in butter and margarine,smoothfeelofmilkandicecreamRoles of Fats.EnergysourceChoiceSele.Texture-Adipose tissue?E.g.Marbling of meat.USDAgradingisbased on fatdistribution
6 Functions of Fats • Flavor: source of desirable and undesirable flavors desirable flavors: from lactones and diacetyl in butter, ketones in cheese. undesirable flavors: rancid, tallowy and fishy flavors. 2,4-decadienal: at low levels provides desirable fried food flavor to potato chips, but at high levels imparts undesirable rancid flavors. • Color:: sheen impact from waxes, yellow color from carotenoids, green from chlorophylls • Texture: mouth feel in butter and margarine, smooth feel of milk and ice cream Roles of Fats • Energy source • Texture – Adipose tissue • E.g. Marbling of meat • USDA grading is based on fat distribution Prime Choice Select Standard Utility Cutter
Lipids·MajorlipidcomponentsThe building blocks·Fatty acidsTriacylglycerols (triglycerides)glycerolayacdPhosphoglycerides(phospholipids).Minorcomponents.Hydrocarbons,Sterols,Tocopherols,CarotenoidsDietaryfats福Essentialfattyacids,Eicosanoids,Biological functionsTriglycerideorFattyAcidStructureTriacylglycerols?R-groupsonfattyacidchainsaregenerallylinear hydrocarbons, e.gtriglyceridePCHCHCHCHCHCHCHCH-0-CCH,CH,CH,CH,CH,CH,CH,which may be more simply represented asO0-
7 Lipids • Major lipid components • Fatty acids • Triacylglycerols (triglycerides) • Phosphoglycerides (phospholipids) • Minor components • Hydrocarbons, Sterols, Tocopherols, Carotenoids • Dietary fats • Essential fatty acids, Eicosanoids, Biological functions The building blocks OH OH OH Triglyceride or Triacylglycerols Fatty Acid Structure • R-groups on fatty acid chains are generally linear hydrocarbons, e.g. which may be more simply represented as C O - O - CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH3 CH2 CH2 CH2 CH2 CH2 CH2 CH2 C O - O -