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
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 Major lipid components The building blocks ·Fatty acids Triacylglycerols(triglycerides) glycerol Phosphoglycerides(phospholipids) fat的y acids ·Minor components HO Hydrocarbons,Sterols,Tocopherols,Carotenoids Dietary fats Essential fatty acids,Eicosanoids, Biological functions Triglyceride or Fatty Acid Structure Triacylglycerols R-groups on fatty acid chains are generally linear hydrocarbons,e.g. triglyceride O.C CE CIC CIC which may be more simply represented as
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 -