1. NOMENCLATURE OF FATTY ACIDS AND THEIR CLASSIFICATION.
Group C. Roll#12, 13, 16, 18, 20 B.Sc.(Hons.) Food Science and Technology 5th Semester
INSTITUTE OF FOOD SCIENCE AND NUTRITION UNIVERSITY OF SARGODHA, SARGODHA-PAKISTAN

2. TABLE OF CONTENTS Introduction Definition Categories of fatty acids
Classification of fatty acids
According to the chain length
According to the body requirement
According to the degree of unsaturation
According to the position of H-atoms

3. TABLE OF CONTENTS… Nomenclature of fatty acids Delta nomenclature
Omega nomenclature
Systematic nomenclature
Telegraphic nomenclature
Common names

4. INTRODUCTION
Fatty acids are the organic acids consisting of a chain of alkyl group containing between 4 and 22 or more carbon atoms with a terminal carboxyl group.
(Merryweather, 2005).
Basic building units of lipids and principal constituents of body fat.
There are more than 100 different fatty acids occurring naturally.
90% of the fatty acids in our body occur in the form of esters of triglycerides, glycolipids, phospholipids, sphingolipids, etc.
Most of the fatty acids contain an even no of carbon atoms, (because of the process of biosynthesis and concentration of C2 units.

5. INTRODUCTION…
Fatty acids are also called “Carboxylic acids” due to the presence of carboxyl group (-COOH)
Degree of unsaturation of fatty acids depend upon the no. of double bonds present in the hydrocarbon chain of the fatty acid.
Fatty acids may be Saturated or Unsaturated depending upon the degree of unsaturation. Greater the degree of unsaturation in a fatty acid, more would be the chances of Lipid oxidation.
Fatty acids are “Amphipathic” in nature. It contains both, non-polar hydrocarbon chain and a polar carboxyl group, therefore, act as Hydrophilic as well as Hydrophobic.
(Dokkum, 1990)

6. INTRODUCTION…
3 different categories of fatty acids are:
Major fatty acids are present in large quantities and are very common. Constitutes for about 95% of fatty acids present in most commonly used fats and oils.
Minor fatty acids occur as the secondary constituents of fats and oils. These are present as either Homologues of major fatty acids or are Isologous to them.
Uncommon fatty acids are usually isolated from scarce sources containing them as their major constituents. These are most commonly from plant origin.
(Zonta et al., 1983).

7. CLASSIFICATION OF FATTY ACIDS
Properties of fatty acids varies due to the difference in chain length, chain structure, degree of unsaturation, position of double bonds, etc.
On the basis of various characteristics, fatty acids are classified into different categories, i.e.
According to the chain length
According to the body requirement
According to the degree of unsaturation
According to the position of H-atoms

8. CLASSIFICATION OF FATTY ACIDS…
According To the Chain Length
Short chain fatty acids Fatty acids with <6 C-atoms in their hydrocarbon chain are called, “Short chain fatty acids.” Short chain fatty acids are liquid at room temperature. By the hydrolysis of triglycerides, fatty acids produced, give a rancid butter flavor. For example, Butyric acid (C-4)
Medium chain fatty acids Fatty acids with 6-12 C-atoms in their hydrocarbon chain are called, “Medium chain fatty acids.” For example, Caproic acid (C- 6), Caprylic acid (C-8)

9. CLASSIFICATION OF FATTY ACIDS…
Long chain fatty acids Fatty acids with C-atoms in their hydrocarbon chain are called, “Long chain fatty acids.” Found as a major part of a few vegetable oils. For example, Myristic fatty acid (C-14), Palmitic acid (C-16), etc.
Very long chain fatty acids Fatty acids with 22 or more C-atoms in their hydrocarbon chain are called, “Very long chain fatty acids.” These fatty acids can’t be metabolize by mitochondria, they are metabolized in peroxisomes. These may be physio pathologically harmful for human. For example, Erucic acid (C-22)
(Harrison, 1990).

10. CLASSIFICATION OF FATTY ACIDS…
According To The Body Requirement
Essential fatty acids Essential fatty acids are the fatty acids that cannot be prepared by the body and are obtained from diet. Our body is not capable to synthesize them. For example, linoleic acid, linolenic acid, arachidonic acid.
Non-Essential fatty acids Fatty acids that can be synthesized by our body and are not required from diet. For example, Palmitic acid, Stearic acid.

11. CLASSIFICATION OF FATTY ACIDS…
According to the degree of unsaturation
Saturated fatty acids Saturated fatty acids are the fatty acids that contain no double bond their hydrocarbon chain. They are solid at room temperature. Saturated fatty acids can increase the risk of coronary heart diseases. Examples, Butyric acid, Caproic acid.
(Rogers, 2005).

12. CLASSIFICATION OF FATTY ACIDS…
Unsaturated fatty acids Unsaturated fatty acids are the fatty acids that contain one or more double bond in their aliphatic chain. These may either be Monounsaturated fatty acids (MUFA) or Poly unsaturated fatty acids (PUFA). They are liquid at room temperature. Abundant in fish and vegetable oils and reduce the risk of coronary heart diseases. Examples, Stearic acid, oleic acid, etc.
(Rogers, 2005).

13. CLASSIFICATION OF FATTY ACIDS…
According To the Configuration of H-atom (adjacent to the double bond)
Cis-Fatty acids Cis- fatty acids are the fatty acids in which the adjacent hydrogen atoms are attached on the same side of the double bond. The chain with a significant no. cis-bonds, tend to be slightly curved.

14. CLASSIFICATION OF FATTY ACIDS…
Trans-Fatty acid Trans-Fatty acids are the fatty acids in which H-atoms are attached on the opposite sides of the double bond. The chain with a significant no. of Trans-fatty acids, don’t bend much and maintain the shape.
(Whitfield et al., 2004).

15. NOMENCLATURE OF FATTY ACID
Types Of Nomenclature
Delta nomenclature
Omega nomenclature
Systematic nomenclature
Telegraphic nomenclature
Common names

16. NOMENCLATURE OF FATTY ACIDS…
Delta nomenclature
For delta nomenclature, there are 3 things we need to know:
Total carbon atoms present in the fatty acids.
Total double bonds present in fatty acids.
No. of carbon atoms starting from the carboxylic acid end (also called the alpha carbon end) to the carbon with first double bond(s).
(Gropper, Smith, 2008).

17. NOMENCLATURE OF FATTY ACID…
Total no. of carbon atoms= 18
Total no. of double bonds= 1
No. of carbon atoms starting from the carboxylic acid end to the carbon with first double bond= 9

18. NOMENCLATURE OF FATTY ACID…
Omega nomenclature
Similar to delta nomenclature.
Carbon atoms are counted from the methyl end.
Symbol used is omega instead of delta.
For omega nomenclature we need to know 3 things.
Total carbon atoms in the fatty acids.
Total double bonds in the fatty acids.
Number of carbon atoms are counted from the methyl end to the carbon with first double bond.
(Gropper, Smith, 2008).

19. NOMENCLATURE OF FATTY ACID…
Total no. of carbon atoms= 18
Total no. of double bonds= 1
No. of carbon atoms starting from the methyl end to the carbon with first double bond= 9
In case of saturated fatty acid, we don’t write the omega nomenclature at the end of the name but if there is a saturated fatty acids with 18 carbon atom, then the name would be 18:0.

20. NOMENCLATURE OF FATTY ACID…
Systematic nomenclature
Systematic nomenclature is similar to the IUPAC nomenclature.
In this system we use –oic (in case of saturated fatty acids) and – enoic (in case of unsaturated fatty acids with single double bond), - dienoic ( for unsaturated fatty acids with two double bonds) and – trienoic (for unsaturated fatty acids with three double bonds) along with the total number of carbon atoms.
For example:
If the total number of carbon atoms is 18 and it is saturated fatty acid then its name will be written as octadecanoic acid.
If the total number of carbon atoms is 18 and it is unsaturated fatty acid with:
one double bond, octadecanoic acid.
two double bonds, octadecadienoic acid.
three double bonds, octadecatrienoic acid.

21. NOMENCLATURE OF FATTY ACID…
Telegraphic nomenclature
In telegraphic nomenclature we use different ways to name saturated fatty acids and unsaturated fatty acids.
For saturated fatty acids: We use the formula CN:M for naming where C = Carbon, N = number of carbon atoms and M = number of double bonds (which will always be zero as there are no double bonds in saturated fatty acids). For example, Butyric acid C4:0 where C is the carbon atom, 4 is the number of carbon atoms and 0 is the number of double bonds.
(Gropper, Smith, 2008).

22. NOMENCLATURE OF FATTY ACID…
For unsaturated fatty acids we use two methods:
Carboxylic end reference In this we start numbering from the carboxyl end and name the fatty acids using the formula CN:M (a,b,c) where C = Carbon, N = number of carbon atoms, M = number of double bonds and (a,b,c) = the positions of the double bonded carbon atoms starting from carboxyl end.

23. NOMENCLATURE OF FATTY ACID…
Methyl end reference In this method we start numbering from the methyl end, the methyl carbon is denoted by n or ω and the formula used for naming is CN:M ω a where C = carbon, N = number of carbon atoms, M = number of double bonds, ω = indicates that the counting is starting from the methyl end and a = the position of carbon with first double bond.

24. NOMENCLATURE OF FATTY ACID…
Common names
The common names of the fatty acids are mostly to be memorized.
They cannot be derived from the structure of fatty acids.
Derived from different languages or words related to the sources of fatty acids.
Examples:
Butyric acid is derived from Butter.
Oleic acid is derived from Aloe (olive).
(Gropper, Smith, 2008).

25. References (L.M.Merryweather, 2005) (Zonta et al., 1983)
(Harrison, 1990).
(F.C. Rogers, 2005).
(Whitfield AJ et al., 2004).
(Gropper SS, Smith JL, Groff JL, 2008).
(Jiří Jonák, Lenka Fialová, 2004).
(Ed Ayers, 1913).

26. THE END.