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    Lecithin

    Uploaded by

    Michael Urrutia
    The document describes several tests that can be used to analyze the components of lecithin. The Acrolein test is used to detect the presence of glycerol by heating lecithin in the presence of potassium bisulfate, which dehydrates glycerol to form the aldehyde acrolein. The Iodine Absorption test detects unsaturated fatty acids by their reaction with iodine. The Phosphorus test identifies phosphate ions through their reaction with ammonium molybdate to form a yellow precipitate. Lecithin functions in the body as a precursor to acetylcholine and as a component of lung surfactant. The Liebermann-Burchard test uses ac

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    Lecithin

    Uploaded by

    Michael Urrutia
    222 views14 pages
    The document describes several tests that can be used to analyze the components of lecithin. The Acrolein test is used to detect the presence of glycerol by heating lecithin in the presence of potassium bisulfate, which dehydrates glycerol to form the aldehyde acrolein. The Iodine Absorption test detects unsaturated fatty acids by their reaction with iodine. The Phosphorus test identifies phosphate ions through their reaction with ammonium molybdate to form a yellow precipitate. Lecithin functions in the body as a precursor to acetylcholine and as a component of lung surfactant. The Liebermann-Burchard test uses ac

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    Lecithin

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    The document describes several tests that can be used to analyze the components of lecithin. The Acrolein test is used to detect the presence of glycerol by heating lecithin in the presence of potassium bisulfate, which dehydrates glycerol to form the aldehyde acrolein. The Iodine Absorption test detects unsaturated fatty acids by their reaction with iodine. The Phosphorus test identifies phosphate ions through their reaction with ammonium molybdate to form a yellow precipitate. Lecithin functions in the body as a precursor to acetylcholine and as a component of lung surfactant. The Liebermann-Burchard test uses ac

    Copyright:

    © All Rights Reserved
    Download as PPTX, PDF, TXT or read online from Scribd
    Download as pptx, pdf, or txt
    222 views14 pages

    Lecithin

    Uploaded by

    Michael Urrutia
    The document describes several tests that can be used to analyze the components of lecithin. The Acrolein test is used to detect the presence of glycerol by heating lecithin in the presence of potassium bisulfate, which dehydrates glycerol to form the aldehyde acrolein. The Iodine Absorption test detects unsaturated fatty acids by their reaction with iodine. The Phosphorus test identifies phosphate ions through their reaction with ammonium molybdate to form a yellow precipitate. Lecithin functions in the body as a precursor to acetylcholine and as a component of lung surfactant. The Liebermann-Burchard test uses ac

    Copyright:

    © All Rights Reserved
    Download as PPTX, PDF, TXT or read online from Scribd
    Download as pptx, pdf, or txt
    of 14

    Lecithin

    Tests on Lecithin
    Acrolein Test
    Acrolein Test
    Purpose:
    - used to test for the presence of glycerol
    Principle
    - Glycerol decomposes slowly at a boiling temperature.
    - When a fat is heated strongly in the presence of a dehydrating
    agent such as potasium bisulfate (KHSO4). The glycerol portion
    of the molecule is dehydrated to form the aldehyde Acrolein
    - Acrolein, an aldehyde is easily recognized by its penetrating and
    irritating odor.

    Acrolein Test

    CH
    2
    OH CH
    2


    CH OH CH + 2H
    2
    O

    CH
    2
    OH CHO

    Glycerol Acrolein
    Heat

    KHSO
    4

    IODINE ABSORPTION
    LECITHIN TEST RESULT
    in IODINE ABSORPTION
    Purpose:
    - test for unsaturated fatty acids that would cause
    decolorization of the solution.
    Principle:
    - Halogens such as Iodine will interact with the double bonds
    of the unsaturated fatty acids thus becoming saturated
    - a change in color will indicate that it contains unsaturated
    fatty acids which reacted to iodine through halogenation
    reaction.
    H
    3
    C(CH
    2
    )
    16
    COOH + I
    2
    no reaction

    H H H H

    H
    3
    C(CH
    2
    )
    7
    C =C (CH
    2
    )
    7
    COOH + I
    2
    H
    3
    C(CH
    2
    )7C C (CH
    2
    )
    7
    COOH

    I I



    Test For Phosphorus
    Purpose:
    - To test for the presence of phosphorus
    Principle:
    - Phosphate ions react with ammonium molybdate to produce a
    characteristic yellow precipitate, ammonium phosphomolybdate


    ((NH
    4
    )
    3
    PO
    4
    12 MoO
    3
    ).
    Function of Lecithin in the Body
    Precursor of Acetylcholine
    A major component in lung surfactant

    Test for Cholesterol
    Liebermann-Burchard Test:

    Liebermann-Burchard Test:
    A test for unsaturated steroids

    Liebermann-Burchard Reaction:
    - Acetic anhydride reacts with cholesterol in a chloroform solution
    to produce a characteristic blue-green color.

    +
    H2SO4
    polymer containing a chromophore
    (blue-green color)
    - H2O
    3,5-cholestadiene
    Liebermann-Burchard Reaction

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