OIA2007 LIPIDS

Definition of Lipids

Hydrophobic organic compounds composed of C, H, O, sometimes P and N.

Solubility of Lipids

Soluble in organic solvents (e.g., chloroform, ether), insoluble in water.

Basic Units

Lipids are made up of fatty acid monomers.

Biological Importance

Energy storage, membrane structure, vitamins, hormones, nervous system support.

Simple Lipids

Fats, oils, waxes (esters of alcohol and fatty acids).

Compound Lipids

Phospholipids, glycolipids, lipoproteins.

Derived Lipids

Steroids, carotenoids, fat-soluble vitamins (A, D, E, K).

Saturated Fatty Acids

No double bonds; e.g., Octanoic acid.

Unsaturated Fatty Acids

Have one or more C=C double bonds (e.g., oleic acid).

Cis vs. Trans Fats

Cis: same side; natural fats

Trans: opposite sides; formed in processed foods

Structure of Triglycerides

Made of glycerol + 3 fatty acids.

Hydrophilic vs. Hydrophobic Ends

Head = polar (hydrophilic); tail = non-polar (hydrophobic)

Cold Pressing

Produces virgin or cold-pressed oils (e.g., virgin olive oil).

Hot Pressing

Yields higher amounts, but may degrade compounds.

Solvent Extraction

Uses organic solvents for high-efficiency oil extraction.

Animal Fat Extraction

Separated by steam rendering, fat floats and is decanted.

Fixed Oils

Non-volatile, fatty oils obtained from seeds/nuts (e.g., castor oil).

Applications of Fixed Oils

Used in soap, paints, ointments, dietary supplements.

Main Component

Ricinoleic acid triglyceride (≈80%).

Medicinal Use

Cathartic (purgative) action due to ricinoleic acid.

Other Uses

Lubricant, cosmetic ingredient, contraceptive base.

Toxic Content

Contains ricin (toxic protein) and ricinine (alkaloid).

Definition

Monohydroxy alcohols with a steroid nucleus (4-ring structure).

Types of Sterol

Phytosterol (plants), Zoosterol (animals - e.g., cholesterol), Mycosterol (fungi).

Examples of Sterol

Vitamin D, bile acids, sex hormones, corticosteroids

Definition of Waxes

Esters of long-chain fatty acids + high MW alcohols (not glycerol).

Function in Nature (Waxes)

Water retention on leaves, fruits, and insect secretions.

Examples of Waxes

Beeswax, Jojoba wax, Carnauba wax.

Synonym Beeswax (Apis mellifera)

Cera flava (Yellow beeswax)

Main Component Beeswax

Myricin (myricyl palmitate) ≈ 80%

Uses of Beeswax

Ointments, candles, lipsticks, dental prep, water-resistant polishes.

Purification Methods (Beeswax)

Boiling water/sulfuric acid, then natural or chemical bleaching.

Key Nutrients Cod Liver Oil (Gadus morrhua)

Rich in Vitamin A & D

Contains EPA, DHA

Medicinal Uses Cod Liver Oil

Treats rickets, TB, improves immune health.

Extraction Steps Cod Liver Oil

Refining → Drying → Winterization → Deodorization → Standardization

Vitamin Content Shark Liver Oil

Very high in Vitamin A (up to 30,000 IU/g)

Uses Shark Liver Oil

Burn ointments, eye health, deficiency of vitamin A.

Identification Tests Shark Liver Oil

Violet or blue color when treated with sulfuric acid or antimony trichloride (for Vit A detection).

Source Wool Fat (Lanolin, Adeps Lanae)

Secreted by sebaceous glands of sheep (Ovis aries).

Uses of Lanolin

Absorbable ointment base, cosmetic creams, lip balms.