Physical Properties:
1.Physical properties of lipids depends up on length of and degree of unsaturation of hydrocarbons.
2.Saturation means absence of double bonds means compound with single bond .Then they rotate freely .They pack tightly so saturated lipids are in solid state. Saturated lipids means
The simplest fatty acids are unbranched, linear chains of CH2 groups linked by carbon-carbon single bonds with one terminal carboxylic acid group.
3.Unsaturated means presence of double bonds ,cis double bond force to kick in the hydrocarbon chain.so they are not pack tightly ,means liquid state.Unsaturated fatty acids have one or more carbon-carbon double bonds. The term unsaturated indicates that fewer than the maximum possible number of hydrogen atoms are bonded to each carbon in the molecule. The number of double bonds is indicated by the generic name—monounsaturated for molecules with one double bond or polyunsaturated for molecules with two or more double bonds.
4.Lipids have low specific gravity than water ,so oil floats on the aqueous phase.
5.All triacyl glycerol are in L forms.
6.Carbon atom of triacyl glycerol's more reduced than the carbon atom of carbohydrates..so oxidation of fatty acids gives more energy.
7.Lipid rich food expose to oxygen in air they spoil and gives rancidity,carbon dioxide double bond of unsaturated fatty acids to produce aldehyde and carboxylic grou of short chain length and higher volatility.
8.Animal fat heating with NaOH or KoH gives glycerol plus salts of Na+/K+.
9.Fatty acids synthesis takes place in Cytosol of cell.
10. The melting temperatures of saturated fatty acids of biological interest are above 27 °C (81 °F) and rise with increasing length of the hydrocarbon chain.
11.Monounsaturated and polyunsaturated molecules melt at substantially lower temperatures than do their saturated analogs, with the lowest melting temperatures occurring when the carbon-carbon double bonds are located near the center of the hydrocarbon chain. As a result, these molecules form viscous liquids at room temperature.
12.Soaps :adding an equal number of molecules of a base such as sodium hydroxide (NaOH). This effectively replaces the H+ with Na+ to give the salt of the fatty acid, which is a soaps.
Chemical properties:
1. Acid number indicates the number of free fatty acids present in the fats, high acid number indicates how much fat stored in improper conditions.that is important in rancidity of hydrogen.
2.Iodine number refers the unsaturation of fatty acids.that means number of double bonds present.
3.Peroxide value represents the degree of oxidation state.
4.The Reichert value (or more fully, the Reichert-Meissl-Wollny value or Reichert-Meissl-Wollny number) is a value determined when examining fatty acids. The Reichert value is an indicator of how much volatile fatty acid can be extracted from fat through saponification. how much fat soluble in water.
5.The Polenske value is an indicator of how much volatile fatty acid can be extracted from fat through saponifications,used for identification of water insolube fats.
6.Hydrogenation, addition of hydrogens to the fats to make prepare unsaturated fats to saturated.Vegetable oils which have been partially hydrogenated, are now partially saturated so the melting point increases to the point where a solid is present at room temperature. hydrogenated oil gives food structure and does not feel or taste oily.The hydrogen makes the fat harder, which is why it sticks to your arteries.
7.Halogenations:addition of halogens to the double bond fatty acids
8.Esterification:
Fatty acid esters (FAEs) are a type of ester that result from the combination of a fatty acid with an alcohol. When the alcohol component is glycerol, the fatty acid esters produced can be monoglycerides, diglycerides, or triglycerides. Dietary fats are chemically triglycerides.
1.Physical properties of lipids depends up on length of and degree of unsaturation of hydrocarbons.
2.Saturation means absence of double bonds means compound with single bond .Then they rotate freely .They pack tightly so saturated lipids are in solid state. Saturated lipids means
The simplest fatty acids are unbranched, linear chains of CH2 groups linked by carbon-carbon single bonds with one terminal carboxylic acid group.
3.Unsaturated means presence of double bonds ,cis double bond force to kick in the hydrocarbon chain.so they are not pack tightly ,means liquid state.Unsaturated fatty acids have one or more carbon-carbon double bonds. The term unsaturated indicates that fewer than the maximum possible number of hydrogen atoms are bonded to each carbon in the molecule. The number of double bonds is indicated by the generic name—monounsaturated for molecules with one double bond or polyunsaturated for molecules with two or more double bonds.
4.Lipids have low specific gravity than water ,so oil floats on the aqueous phase.
5.All triacyl glycerol are in L forms.
6.Carbon atom of triacyl glycerol's more reduced than the carbon atom of carbohydrates..so oxidation of fatty acids gives more energy.
7.Lipid rich food expose to oxygen in air they spoil and gives rancidity,carbon dioxide double bond of unsaturated fatty acids to produce aldehyde and carboxylic grou of short chain length and higher volatility.
8.Animal fat heating with NaOH or KoH gives glycerol plus salts of Na+/K+.
9.Fatty acids synthesis takes place in Cytosol of cell.
10. The melting temperatures of saturated fatty acids of biological interest are above 27 °C (81 °F) and rise with increasing length of the hydrocarbon chain.
11.Monounsaturated and polyunsaturated molecules melt at substantially lower temperatures than do their saturated analogs, with the lowest melting temperatures occurring when the carbon-carbon double bonds are located near the center of the hydrocarbon chain. As a result, these molecules form viscous liquids at room temperature.
12.Soaps :adding an equal number of molecules of a base such as sodium hydroxide (NaOH). This effectively replaces the H+ with Na+ to give the salt of the fatty acid, which is a soaps.
Chemical properties:
1. Acid number indicates the number of free fatty acids present in the fats, high acid number indicates how much fat stored in improper conditions.that is important in rancidity of hydrogen.
2.Iodine number refers the unsaturation of fatty acids.that means number of double bonds present.
3.Peroxide value represents the degree of oxidation state.
4.The Reichert value (or more fully, the Reichert-Meissl-Wollny value or Reichert-Meissl-Wollny number) is a value determined when examining fatty acids. The Reichert value is an indicator of how much volatile fatty acid can be extracted from fat through saponification. how much fat soluble in water.
5.The Polenske value is an indicator of how much volatile fatty acid can be extracted from fat through saponifications,used for identification of water insolube fats.
6.Hydrogenation, addition of hydrogens to the fats to make prepare unsaturated fats to saturated.Vegetable oils which have been partially hydrogenated, are now partially saturated so the melting point increases to the point where a solid is present at room temperature. hydrogenated oil gives food structure and does not feel or taste oily.The hydrogen makes the fat harder, which is why it sticks to your arteries.
7.Halogenations:addition of halogens to the double bond fatty acids
Hydrogenation of fatty acids is the process by which the C=C double bonds in
the alkane chains of fats are reduced to C-C single bonds by adding one
hydrogen atom to each carbon atom in the bond. The reason this is done is
that it makes the fats exist in a solid state at room temperature rather
than a liquid state. The reason this is done in food science is that it
allows various vegetable oils/fats to be used as spreads (butter
substitutes) in their solid form. The disadvantage to this is that, if you
reduce more than one double bond, there is evidence that this increases your
risk of fat deposition in your arteries, ie, heart disease.
8.Esterification:
Fatty acid esters (FAEs) are a type of ester that result from the combination of a fatty acid with an alcohol. When the alcohol component is glycerol, the fatty acid esters produced can be monoglycerides, diglycerides, or triglycerides. Dietary fats are chemically triglycerides.
