Merge CamScanner 10-15-25 05

LIPIDS

TYPES OF LIPIDS

  • Triglycerides

    • Most common lipid in food & body

    • Composed of 3 fatty acids + glycerol

  • Phospholipids

    • Form cell membranes

    • Function as emulsifiers

  • Sterols

    • Include cholesterol and hormones

  • General Characteristics of All Lipids

    • Composed of carbon, hydrogen, and oxygen

    • Insoluble in water

TRIGLYCERIDES

  • Definitions

    • Triglyceride: Composed of 3 fatty acids + a glycerol backbone

    • Diglyceride: Triglyceride that has lost one fatty acid

    • Monoglyceride: Triglyceride that has lost two fatty acids

  • Esterification

    • Process of forming ester bonds through a condensation reaction

    • Water (H2OH_2O) is released when fatty acids bond to glycerol

  • De-esterification

    • Process of hydrolysis where free fatty acids are released from glycerol using water

FATTY ACIDS

  • Basic Structure

    • Long chains of carbon-hydrogen (C-H) bonds

    • Free fatty acids consist of a hydrocarbon chain with an acid (carboxyl) group at one end and a methyl group at the other

  • Variability of Carbon Chains

    • Vary by: Number of carbons, extent of saturation with hydrogen, and shape (saturated vs. unsaturated)

  • Classification by Chain Length

    • Long-chain fatty acids: 12+ carbons (found in beef, pork, lamb, most plant oils)

    • Medium-chain fatty acids: 6-10 carbons (found in coconut and palm oil)

    • Short-chain fatty acids: < 6 carbons (example: 3% of fat in butter)

SATURATION (NUMBER OF DOUBLE BONDS)

  • Saturated Fatty Acids

    • All bonds are single C-C bonds with maximum hydrogen saturation

  • Monounsaturated Fatty Acids

    • Contains one double bond (missing 2 hydrogens)

    • Solid at room temperature

    • Liquid at room temperature when unsaturated

  • Polyunsaturated Fatty Acids

    • Contains 2 or more double bonds (missing hydrogen at double bonds)

  • Trans Fatty Acids

    • Created via hydrogenation, converting unsaturated fats into saturated configurations

    • Solidifies fat and increases shelf stability

VARIATION OF CARBON CHAIN SHAPE

  • Shape Classifications

    • Bent (kinked) carbon chains: Unsaturated cis fatty acids

    • Straight carbon chains: Trans and saturated fatty acids

HYDROGENATION

  • Process of adding hydrogen to liquid oils

  • Results of Hydrogenation

    • Increased saturation of fatty acids

    • Alteration of double bond configurations

    • Increased solidity and shelf stability

    • Common in margarine, shortening, and processed foods

NAMING FATTY ACIDS

  • Determined by:

    • Number of carbons

    • Location of double bonds

  • Omega System

    • Identifies first double bond closest to the methyl end

    • Notations: omega-3, Ω-3, ω-3, or n-3
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