CHAPTER 5

• Fixed Oils, Fats, Waxes and Fatty Acids

  Esters of long-chain fatty acids and alcohols or of closely related derivatives
• Fixed Oils and Fats

  Soluble in non-polar organic solvents and generally insoluble in water
• Medical/Pharmaceutical uses of Lipids

  • Emollient
  • Vehicles for medications
  • Therapeutic property
  • Enteral and Parenteral Nutrition
• Industrial uses of Lipids

  • Soaps
  • Paints
• Fixed Oils and Fats

  Glycerol combined with Fatty Acids
• Waxes

  High mol. wt. alcohol (Cetyl alcohol) combined with Fatty acids
• Sources of Fixed Oils and Fats

  • Plants: peanut oil, olive oil
  • Animal: Lard
• Primary function of Fixed Oils and Fats

  For food (energy) storage
• Sources of Vegetable Oils and Fats

  • Castor seed
  • Cotton seed
  • Sesame seed
  • Hemp seed
  • Linseed
  • Almond Seed
  • Coconut
• Classification of Fixed Oils

  Drying Oils, Semi-drying Oils, and Non-Drying Oils
• Waxes

  May also be of plant and animal origin
• Fixed Oils and Fats

  Liquid at normal temperature
• Waxes

  Semi-solid to solid at ordinary temperature
• There are no chemical differences of Fixed Oils and Fats of plants or animal origin
• Most Vegetable Oils are liquid at ordinary temperature except Cocoa butter – Solid vegetable oil
• Most Animal Fats are solid except Cod Liver Oil – Liquid animal fat
• Extraction of Fixed Oils and Fats

  1. Cold – Virgin/Cold Pressed Oil

  2. Hot – Hot-pressed Oil

  3. Organic solvents used for extraction
• Extraction of Animal Fats


  Separated from other tissues by rendering with steam or without steam
• Classification of Fixed Oils

  • Saturated: Coconut Oil, Palm Oil, Palm Kernel Oil
  • Monounsaturated: Castor Oil, Olive Oil, Peanut Oil, Rapeseed Oil
  • Polyunsaturated: Almond Oil, Corn Oil, Cottonseed Oil, Cod Liver Oil, Linseed Oil, Persic Oil, Soybean Oil, Sesame Oil, Safflower Oil, Sunflower Oil
• Fats and Related Compounds

  • Theobroma Oil – Cacao Butter/Cocoa Butter
  • Lanolin – Hydrous Woolfat
  • Anhydrous Lanolin – Woolfat
  • Hydrogenated Vegetable Oils
  • Lard
• Waxes


  Esters resulting from the condensation of high molecular weight, straight-chain acids and alcohols
• Well-known Waxes

  • Beeswax
  • Carnauba wax
  • Spermaceti
• General Uses of Waxes

  • Hardens ointments and creams
  • Preparation of Cerates
  • Protective coatings in industry and art
• Sources of Waxes

  • Plants: Carnauba Wax, Bayberry Wax
  • Insects: Beeswax, Lacwax
  • Other Animals: Spermaceti
• Saturated Fatty Acids

  • No C-C double bonds
  • Presence of double bonds lowers melting point
  • Saturated fatty acids of less than eight carbon atoms are liquid at physiological temperature, whereas those containing more than ten are solid
• Examples of Saturated Fatty Acids

  • Lauric acid
  • Myristic acid
  • Palmitic acid
  • Stearic acid
  • Arachidic acid
• Unsaturated Fatty Acids

  • With double bonds
  • Oxygen saturates the double bonds to form oxides that may polymerize to form hard films
  • Double bonds also take up hydrogen in the proper conditions producing semi-solid fats that are used extensively as cooking fats and shortening
• Classification of Fixed Oils based on oxygen absorption

  Drying oils, Semi-drying oils, and Non-drying Oils
• USP Tests for Fatty Acids

  • Ester Value
  • Saponification Value
  • Acid Value/Acid Number
  • Iodine Number