Fats and oils are often modified through various methods like blending, fractionation, hydrogenation, interesterification, and genetic improvement in order to achieve desired compositions and properties for different applications. Interesterification is a chemical reaction that rearranges fatty acids within and between triglycerides. It can be done chemically or enzymatically using lipases and is used to modify crystallization behaviors and make products like margarine and cocoa butter equivalents. Optimization of reaction conditions like surfactant mixtures and concentrations can influence interesterification yield.

4. O i l s a n d F a t s
M o d i f i c a t i o n M e t h o d s
 Different functionalities (nutritional and physical) require specific
compositions that are usually not found in a single natural fat or oil
 For this reason, fats and oils are often modified in order to achieve these
desired compositions and thus physical and nutritional properties.
 For example, melting behaviour, solid fat content and crystal habit are
important factors in the formulation of shortening and margarine, while
decreasing PUFAs to increase oxidative stability is important in frying oil
formulations

5. Following are the methods used to modify fats and oils;
 Blending
 Fractionation
 Hydrogenation
 Interesterification (chemical or enzymatic)
 Genetic Improvement (GIO)
O i l s a n d F a t s
M o d i f i c a t i o n M e t h o d s

6. B l e n d i n g
Different base-stocks are mixed together to obtain a specific composition,
consistency, and/or stability in the final product
These base-stocks may include:
 Partially or fully hydrogenated oils
 Interesterified oils and fats
 Fractions from winterized or fractionated oils

7. F r a c t i o n a t i o n
 Fractionation (solvent or dry) leads to the separation of fats and oils
into two or more fractions with different melting points
 Also it could be used to remove an undesirable minor component such
as waxes in oils during de-waxing and winterization processes to
produce salad oil

8. H y d r o g e n a t i o n
Partially hydrogenated fats:
Semi- solid
Stable during deep-frying
Long shelf-life
Excellent functionality
Partially hydrogenated vegetable oils = trans fatty acids
H2
Ni
Heat

9. G e n e t i c
I m p r o v e m e n t
 New mutants can produce oils with specific compositions such as
high saturated, high monounsatuared or low polyunsaturated fatty
acid contents
 These GI oils and fats can be used in the formulation of shortening,
margarine and frying oils

10. Interesterification is a chemical reaction that induces the
rearrangement of fatty acids within and between triacylglycerols
Why to do this?

12. In the presence of catalyst or some enzyme

14. Used since;
 The late 40’s to modify the crystallization behavior
of lard (induce beta prime tendencies)
 Used successfully to make products such as;
 Becel margarine (Unilever) for several decades
Now, used since;
 The early 80’s with enzymatic catalysts
 To make cocoa butter equivalents and other
structured lipids

15. It has following types:
 Chemical Interesterification
 Enzymatic Interesterification

16.  It is done in the presence of basic catalysts, e.g. sodium
methoxide
 It results in non-selective or random rearrangements of fatty
acids

17.  It is done using immobilized lipases
 Commonly done in the industry
 Selective modification of fatty acids

18. Chemical
Interesterification
Enzymatic
Interesterification
Low processing cost (batch reactor)
High processing cost (continuous plug-
flow reactor, lipase)
High processing loss (oil saponification) Minimum processing loss
Low oxidative stability (tocopherol loss) No change in oxidative stability
High levels of reaction by-products
(MAG, DAG, glycerol)
Low levels of reaction by-products
Flavor reversion problem No flavor reversion

20.  Milk was firstly interesterified with oleic acid by catalysis of an
immobilized lipase
 Done in a micro-aqueous two-phase system

21.  A commercial lipase from Rhizopus oryzae and a controlled
pore glass carrier is selected for preparation of an immobilized
lipase
 The prepared immobilized lipase showed a Michaelis
constant of 77 mM and a maximum velocity of 40 U/g of
carrier on the hydrolysis of triolein

22.  Conditions for Interesterification catalyzed by the immobilized lipase
were optimized by the reaction between trimyristin and oleic acid under
various conditions
 The Interesterification of milk fat with oleic acid was performed in
isooctane with .3% (vol/vol) water content
 The fatty acid composition and thermal characteristics of the triglycerides
of the interesterified milk fat were investigated
 The interesterified milk fat had about 50% more oleic acid and a
significantly lower palmitic acid content than those of the original milk fat

23.  The crystallization and melting curves obtained by
differential scanning calorimetry analysis showed that the
transition temperature of the major milk fat peaks decreased
by 7.6 and 5.4°C, respectively
 The results suggest that the prepared immobilized lipase can
induce rather specific Interesterification between oleic acid
and palmitic acid in the milk fat triglycerides, which
produces a lower melting milk fat, without losses of the
short-chain fatty acid composition

24.  It was done in cosurfactant-free micro-emulsion system containing
nonionic and ionic surfactants
 Using commercial lipase obtained from Rhizopus niveus, at different
concentrations of surfactant mixtures and hydrophilic-lipophilic balance
(HLB) values

25.  The results indicated that the Interesterification yield (IY) of lipase
catalyzed interesterified butter fat reached its maximum in the micro-
emulsion system prepared with the surfactant mixture of HLB value of 9,
followed by that of HLB value of 10
 In addition, increasing concentrations of surfactant mixtures, from 3 to 6
mM, resulted by an increase in the IY
 The Interesterification of butter fat in the micro-emulsion prepared with 3
mM of surfactant mixture of HLB value of 10 showed a minimum
hydrolytic activity

26.  Chemical and enzymatic interesterification have
different applications in the food industry, from
formulation of shortenings and margarines to
synthesis of structured lipids for special medicinal
and nutritional applications
 Lipase-catalyzed interesterification reactions for the
synthesis of functional lipid products will remain an
area of interest for many years to come