Fats and oils organic chemistry b. pharm.

Fats and oils and its measurement

1. Amit Z Chaudhari FATs & OILs

2. 2 INTRODUCTION Biomolecules, Fat is extracted from animal vegetables and liquid form is referred to as oils 2018

3. REACTIONS Hydrolysis 3 2018

4. REACTIONS 1. Hydrolysis Soap solution – carboxylate salts 4 2018

5. REACTIONS 1. Hydrolysis Soap solution – micelle formation 5 2018

6. REACTIONS Hydrogenation  mechanism: 6 2018

7. REACTIONS Hydrogenation 7 2018

8. REACTIONS 8 Hydrogenation  E.g. 2018

9. PROPERTIES 2018 Rancidity of oils 9

10. PROPERTIES 2018 1. Rancidity of oils Radical chain reaction of fat rancidity 10

11. PROPERTIES 2018 Drying oils 11 cobalt-catalyzed drying process

12. ANALYTICAL CONSTANTS 2018 Acid number Synonym:  neutralization number, Acid value 12

13. ANALYTICAL CONSTANTS 2018 13 Acid number Principle:

14. ANALYTICAL CONSTANTS 2018 Acid number 14

15. ANALYTICAL CONSTANTS 2018 2. Saponification Number Synonym:  Saponification value, Koettstorfer number 15

16. ANALYTICAL CONSTANTS 2018 2. Saponification Number Principle 16

17. ANALYTICAL CONSTANTS 2018 2. Saponification Number 17

18. ANALYTICAL CONSTANTS 2018 2. Saponification Number Significance: 18

19. ANALYTICAL CONSTANTS 2018 3. Iodine Number Synonym: iodine value 19

20. ANALYTICAL CONSTANTS 2018 3. Iodine Number (iodine value) Principle : 20

21. ANALYTICAL CONSTANTS 2018 3. Iodine Number (iodine value) Significance : 21

22. ANALYTICAL CONSTANTS 2018 4. Ester Number (Ester value) is the number of mg of KOH required to saponify the esters present in 1 g of the substance. Ester value = Saponification value - Acid value. 22

23. ANALYTICAL CONSTANTS 2018 4. Ester Number (Ester value) Method: Weigh accurately about 2 g of the sample. Add 25ml of 0.5M ethanolic KOH And boiled under reflux condenser on a water-bath for1hour. Add 20ml of water and titrate the excess of alkali with 0.5 M HCl using a further 0.2ml of phenolphthalein indicator. Repeat the operation without sample. (Blank reading) The difference between the titrations represents the alkali required to saponify the esters. 23

24. ANALYTICAL CONSTANTS 2018 4. Ester Number (Ester value) Significance: Ester value = Saponification value - Acid value. The ester value shows the amount alkali consumed in the saponification of the esters and is possible identify and differentiate the fats with this value. 24

25. ANALYTICAL CONSTANTS 2018 5. Reichert-Meissl number [Reichert Meissl (RM) value ] It is defined as the ml of 0.1 N KOH required to completely neutralize the soluble volatile fatty acids distilled from 5 g fat. RM number is useful in testing the purity of butter since it contains a good concentration of volatile fatty acids (butyric acid, caproic acid and caprylic acid). Butter has a RM number in the range 25-30, while it is less than 1 for most other edible oils. Thus any adulteration of butter can be easily tested by this sensitive RM number. 25

26. ANALYTICAL CONSTANTS 2018 5. Reichert-Meissl number [Reichert Meissl (RM) value ] Principle: Fat is saponified using glycerol-alkali solution & acidified by sulphuric acid to liberate free fatty acids. the liberated fatty acids are steam distilled and the steam volatile fatty acids are collected (as condensate). The cooled condensate of the volatile fatty acids is filtered for separation of water soluble and water insoluble fatty acids. The water soluble fatty acids is titrated with alkali to give RM value , water - insoluble fatty acids is titrated to give the polenske value . 26

27. ANALYTICAL CONSTANTS 2018 5. Reichert-Meissl number [Reichert Meissl (RM) value ] Significance: It is a measure of water soluble steam volatile fatty acids chiefly butyric and caproic acids present in oil or fat. No other fat contains butyric acid glycerides, and therefore, the Reichert Meissl value of the butter fat is higher than that for any other fat. These determinations have been used principally for analysis of butter and margarines . 27

28. ANALYTICAL CONSTANTS 2018 28 6. Acetyl Number (Acetyl value) is the number of mg of KOH required to acetic acid liberated by the hydrolysis of 1 g of the acetylated substance. Method: Boil the 10g of sample with 20 ml of acetic anhydride for 2 hr. Add 600 ml water and boil for 30 min. Separate and wash the acetylated product Determine the saponification value of the acetylated substance(b ml). Determine the saponification value of the substance(a ml).

29. ANALYTICAL CONSTANTS 2018 29 6. Acetyl Number (Acetyl value) Significance: Is the measure of hydroxy acids in lipids. Increased number of acetyl value indicates more amount of free fatty acids.

30. of the topic End Reference: Organic Chemistry– Morrison & boyd Textbook of org. chem. – Bahl & Bahl IP – 2010 vol.1 Web source