1. INTERESTERIFICATION

2. Interesterification
Interesterification involves an exchange of acyl group among triglycerides.
Acyl groups may exchange positions within a triglyceride or among triglyceride molecules.

3. Interesterification

4. Probablity of Different Triglycerides Formation
If A, B, and C are the molar percentages of fatty acids A, B, and C for a commercial oil,
Then, molar percentage of glycerides containing only 1 acid is:
% AAA = A3 : 10,000
Molar percentage of glycerides containing 2 acids is:
% AAB = 3A2B : 10,000
And molar percentage of glycerides containing 3 acids is:
% ABC = 6ABC : 10,000

5. Intraesterification, Interesterification and Equilibrium Mixture.
Catalyst O O L L S O S L S
Continued reaction S S S S S S S O L S S O L S S L O S L S O S L O O L S L L O O O O L O L L O O L L L O L O
SSS
(SUS
SSU) (SUU
USU)
UUU

6. Random Interesterification
A S (Stearic acid 35%) B S (50%)
O (Oleic acid 30%) O (40%)
L (Linoleic acid 35%) L (10%)
After random interesterification, the triglyceride compositions are:
Sample A
Sample B
Triglyceride %
Triglyceride %
SSS
= 4.3
SSS
= 12.5
OOO
= 2.1
OOO
= 6.4
LLL
= 4.3
LLL
= 0.1
SSO
= 11.0
SSO
= 30.0
SSL
= 12.8
SSL
= 7.5
OOS
= 9.5
OOS
= 24.0
OOL
= 9.5
OOL
= 4.8
LLS
= 12.8
LLS
= 1.5
LLO
= 11.0
LLO =
1.2
SOL*
= 22.0
SOL*
= 12.0
*Total triglycerides containing 3 different fatty acids.

7. Catalysts High temperature catalysts: KOH and NaOH 3 )
Low temperature catalysts: Sodium Methoxide (NaOCH

8. Reaction Mechanisms The formation of enolate ion
2. The formation of Beta-Keto ester
3. Interesterification

9. Catalyst Function in Interesterification
Initial removal of an -proton by the base catalyst leads to the charge delocalized enolate anion. O + -
H2O + O H C H C C H 3 3 - O O - C H C C H C H C C H 3 2 3 2 O - C H C C H 3 2

10. Enolate Ion Formation - - - - + CH3OH O C O C H R O C O C H R + O C H2 1 -
CH3OH + O C O C H R + 2 2 O C H 3 O C O C H R 2 3 O O - - O C C R O C C R 1 1 H H O C O C H R O C O C H R 2 2 2 2 O C O C H R O C O C H R 2 3 2 3 - O O C C R 1 H O C O C H R 2 2 O C O C H R 2 3

11. Mechanism for Intramolecular Ester-Ester Interchange_ _ O O O H O O C CH R O C O C C C C H R 1 H 2 2 C R - R 1 1 O C O C H R O C C H R O 2 2 2 2 O O C O C H 2 R 3 O C O C H 2 R 3 O C O C H 2 R 3
I II III
Enolate ion formation
Beta-Keto ester formation
Intraesterification _ _ O H O _ O C C C C H R O 2 2 O C O C H R 2 2 R O H O 1 O O O C C C C H R 2 2 O C C R 1 R 1 H O C O C H R O C O C H R 2 3 2 3 O C O C H R 2 3
III IV V

12. Mechanism for Intermolecular Ester-Ester Interchange_ O O C C R O C C H R 1 2 4 H + O C O C H R O C O C H R 2 2 2 5 O C O C H R O C O C H R 2 3 2 6
I VI _ O H O O C C C O
VII R C H R 1 2 4 O C O C H R O C O C H R 2 2 2 5 O C O C H R O C O C H R 2 3 2 6

13. Mechanism for Intermolecular Ester-Ester Interchange
Interesterification _
Beta-Keto ester formation R R 4 1 O H O + R R _ 2 5 O C C C C H R R R 6 2 4 6 R 3 R 1 IX _ R R C O O 2 5 R R R O 1 5 3 R + R
VIII 2 4 R R 3 6 X

14. Random Esterification
Interesterification can be carried out to an equilibrium condition, at which point the fatty acids assume an almost random distribution among triglycerides.

15. Intraesterification, Interesterification and Equilibrium Mixture.
Catalyst O O L L S O S L S
Continued reaction S S S S S S S O L S S O L S S L O S L S O S L O O L S L L O O O O L O L L O O L L L O L O
SSS
(SUS
SSU) (SUU
USU)
UUU

16. Direct Interesterification
Interesterification can be directed away from its usually random end-point if the fat is allowed to crystallize during reactions.
The trisaturated glycerides crystallize first.

17. Intraesterification, Interesterification and Equilibrium Mixture
Catalyst O O L L S O S L S
Continued reaction S S S S S S S O L S S O L S S L O S L S O S L O O L S L L O O O O L O L L O O L L L O L O
SSS
(SUS
SSU) (SUU
USU)
UUU

18. Directed InteresterificationL
1. Stearic-Stearic-Stearic mole % solid
2. Oleic-Oleic-Oleic mole % liquid
3. Linoleic-Linoleic-Linoleic mole % liquid
4. Oleic-Oleic-Linoleic mole % liquid
5. Oleic-Linoleic-Linoleic mole % liquid

19. Effects of Different Interesterification of Lard on Triglycerides
__________________________________________________________________ S
(%) S
U(%) SU
(%) U
(%) 3 2 2 3
__________________________________________________________________
Natural Lard
2.0
27.0
47.0
24.0
Completely Random
4.3
23.8
44.4
27.5
Directed Random
8.4
17.4
41.4
32.9
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20. Intraesterification, Interesterification and Equilibrium Mixture.
Catalyst O O L L S O S L S
Continued reaction S S S S S S S O L S S O L S S L O S L S O S L O O L S L L O O O O L O L L O O L L L O L O
SSS
(SUS
SSU) (SUU
USU)
UUU

21. Benefits of Interesterification
Lard may be given different properties by varying the method of interesterification.
One set of conditions favors intramolecular interchange and results in a crystal-modified lard (CML).
Conditions favoring random distribution can be controlled to yield a partially modified lard (PML).
Conditions favoring directed interesterification can be used to control the GS3 content of direct interesterified lard (DIL).

22. Baking Evaluation of Modified Lards Stored at Different Temperatures
Pound cake volume (ml)
Storage temperature (ºC ) 24 30 38
Storage time (weeks) 2 16 1 9 1 4
Lard (Natural)
1475
1435
1400
1190
1400
1100
PML
1500
1445
1470
1335
1400
1295
CML
1525
1565
1535
1550
1510
1555
DIL
1505
1455
1595
1305
1440
1355

23. Applications
Shortenings: The proportion of palmitic acid in the 2-position is reduced from about 64% to 24% on random interesterification.
Natural lard beta
Randomized lard beta’
Randomization of lard improves its plastic range and thus makes it a better shortening than natural lard.

24. Plasticity and Consistency
Plasticity is the changes in consistency as a function of temperature.
Consistency is the apparent hardness at a temperature

25. Margarines – High Stability Margarine Blends
1. 75 % (co-randomized 40 % coconut oil / 60 % palm oil),
2. 10 % (co-randomized 50% coconut oil / 50 %
hydrogenated canola oil) and
3. 15 % hydrogenated soybean oil
Good spreadability, high temperature stability, and good eating qualities.

26. Nutritional Margarine Blends
High polyunsaturated content and low-to-zero trans-acid containing margarines are produced by interesterifying a blend of liquid oil and a fully hydrogenated oil.

27. Confectionary Fats
Hydrogenated palm kernel oil is a hard butter melting at 46C and produces a waxy feel in the mouth.
On randomization, its melting point is reduced to 35C. By blending hydrogenated palm kernel oil and its randomized product, a whole series of hard butters with highly desirable melting qualities (rapid melt in mouth) are obtained

28. Confectionary Fats from Blend of Hydrogenated and Interesterified Hydrogenated Palm Kernel Oil
SCI
Fat
M.P .( C) 10 20 35 38
Hydrogenated palm
46.8
74.2
67.0
15.4
11.7
kernel oil (PKO)
Int. hydrogenated
35.0
65.0
49.9
1.4
1.1
PKO
50% hydrogenated
41.7
70.0
57.4
8.7 5. 2
50% int. hydrogenated

29. Effect of Randomization on SCI of an 80:20 Mixture of Lightly Hydrogenated Soybean Oil and Palm Stearine

30. Solid Content Index of Cocoa Butter before and after Interesterification

31. Changes in SCI of Lard by Interesterification

33. Cross-Sectional Structures of Triglycerides
Freedom of molecular motion
Alpha
Beta Prime
Beta

34. Double Chain Length Structures of Triglycerides
Alpha Beta-Prime Beta
(Vertical tuning fork) (Tilted tuning fork) (Stacked chair)

35. Characteristics of Triglygeride Polymorphs
________________________________________________________________________
Alpha Beta-Prime Beta
________________________________________________________________________
Platelet
Fine needle
Long needle 5 m 1 m
25-50 m
Most loosely packed
More closely packed
Most closely packed
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