FORM 2
THE PATENTS ACT. 1970
(39 OF 1970)
&
THE PATENT RULES, 2003
COMPLETE SPECIFICATION
[SECTION 10; RULE 13]
"A PROCESS FOR PREPARING FATTY ACIDS"
APPLICANT: GODREJ CONSUMERS PRODUCT LTD.
NATIONALITY: COMPANY INCORPORATED UNDER THE
COMPANIES ACT, 1956
ADDRESS: PIROJSHANAGAR, EASTERN EXPRESS
HIGHWAY, VIKHROLI, MUMBAI- 400 079,
MAHARASHTRA STATE, INDIA
THE FOLLOWING SPECIFICATION DESCRIBES THE NATURE OF THIS
INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED: -


FIELD OF INVENTION:
The present invention relates to a process of preparing fatty acids. Particularly, it
relates to a process for preparing light coloured and heat stable fatty acids. The
invention has been developed primarily for use in premium quality products like
foods, pharmaceuticals and cosmetics and will be described hereinafter with
reference to this application. However it will be appreciated that the invention is
not limited to this particular field of use.
BACKGROUND OF THE INVENTION:
Any discussion of the prior art throughout the specification should in no way be
considered as an admission that such prior art is widely known or forms part of
the common general knowledge in the field.
Fatty acids are used in premium quality products like foods, pharmaceuticals and
cosmetics. Light coloured products signify purity and hence are more attractive to
a customer. Manufacture of consumer products involves a number of processes
that requires application of high temperatures in the presence or absence of air.
High temperatures may lead to the darkening or discolouring of the fatty acids.
This generally leads to the end product becoming darker, which is commercially
undesirable. Since fatty acids are the raw materials to make these light coloured
commercial products, it is necessary that the starting material have light colour
and good heat stability to withstand the manufacturing process.
Vegetable oils are one of the major sources of fatty acids. They contain a number
of naturally occurring coloured and colour forming bodies. In the course of
obtaining a vegetable oil from seed or fruit physical operations such as steaming,
expelling and extraction are involved. Besides these processes, there are natural
biochemical reactions that are simultaneously taking place, such as enzymatic
hydrolysis, oxygenation etc. The combination of the physical operations, as well
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as natural reactions, lead to degradation products of the triglycerides and fatty
acids which are coloured and colour forming molecules. The degradation or
breakaway molecules of the original coloured or colour forming bodies create
newer coloured or colour forming bodies. Normal refining or purification
processes - alkali refining, degumming, adsorptive bleaching, chemical
bleaching, distillation/ deodorization can be used up to a limit to remove colour
forming bodies in vegetable oil. But refining a crude oil is a very expensive
option and can only be affordable for manufacture of edible oil. Oleochemical
manufacturers can only afford to use crude vegetable oil for the manufacture of
ratty acids.
As we progress further downstream, the crude oils undergo typical oleochemical
reactions splitting, hydrogenation, and distillation. These high temperature/ high
pressure or high temperature/ low pressure processes further affect the original
and breakaway coloured and colour forming bodies in crude oil. Only limited
amount knowledge is available on the structures of the original and breakaway
coloured and colour forming bodies.
Prior Art
Our earlier patent application (241/MUM/2000) described the impurities in most
of the crude oils as being saturated and unsaturated, cyclic and acyclic
hydrocarbons, alcohols, esters, aldehydes, ketones and lactones. As can be seen
most of the moieties are functionally unsaturated or carbonyl in nature. Hence the
tendency to further degrade into smaller coloured moieties when subjected to
heat, in the course of carrying out certain chemical reactions. Indian Patent
application No. 241/MUM/2000 describes use of oxidizing agent such as
hydrogen peroxide for bleaching fatty acid so as to get a lighter colour is well
explained. But as can be seen from those examples, the fatty acids were not very
light coloured and were not subjected to any storage or heat stability test. So as a
stand alone process would not be able to deliver heat stability to a fatty acid.
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Sodium borohydride is a well known reducing agent for carbonyl group
aldehydes, ketones and esters. All these functional groups are present in oils and
fatty acids as chromophoric coloured and colour forming bodies. Although
Sodium borohydride as a reducing agent is well documented but its use for oils
and fatty acids is rather limited.
US Patent No. 5,034,509 describes an invention for improving the colour and the
stability of the colour of carboxylic acid or a mixture of the same by treating the
carboxylic acid of its mixture with a hydride-yielding substance at an elevated
temperature of 200 to 250°C and by distilling the mixture thus obtained. The
colour and the stability of the colour of the distillate thus obtained are better than
the corresponding quantities of a distillate of untreated carboxylic acid or an
untreated mixture of the same. Sodium borohydride and lithium aluminium
hydride are preferred hydride-yielding substances. The method according to the
invention can be applied to all carboxylic acids, advantageously to fatty acids and
resin acids.
Our process of using sodium borohydride differs from that described above. But
sodium borohydride reduces only carbonyl moieties not the unsaturated moieties,
hence sodium borohydride treatment alone is not enough to obtain a light
coloured and heat stable fatty acid.
This will also be amply illustrated from the examples to follow.
OBJECT OF INVENTION:
It is an object of the invention to obviate the aforesaid drawbacks by providing a
process to prepare light coloured and heat stable fatty acids.
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The inventive step in the present invention therefore lies in combining the
treatment of fatty acids with an oxidising agent, preferably hydrogen peroxide for
oxidizing the unsaturated moieties in the fatty acids, followed by a treatment with
a reducing agent, preferably sodium borohydride for reduction of carbonyl
moieties in the fatty acids.
The present invention discloses a process to prepare fatty acids obtained from
crude vegetable oils and fats with the following distinct features:
a) Light Colour
b) Stable to Heat-
c) Even chained carbon atoms ranging from C6 to C24
SUMMARY OF THE INVENTION:
The present invention relates to a process for preparing fatty acids comprising the
steps of:
a) Treating the distilled fatty acids with an oxidizing agent;
b) Distilling the resultant mixture under vacuum;
c) Treating the distilled mixture with a reducing agent;
d) Distilling the resultant mixture under vacuum.
DETAILED DESCRIPTION OF THE INVENTION:
The present invention envisages a process for preparing light coloured & heat
stable fatty acids, comprising the steps of:
a. Treating the distilled fatty acid with an oxidizing agent, preferably
hydrogen peroxide;
b. Distilling the treated fatty acid after peroxide treatment;
c. Treating the distilled fatty acid with a reducing agent, preferably Sodium
Borohydride.

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d. Distilling the treated fatty acid, the process conditions being maintained,
depending upon the type of fatty acid in consideration.
The fatty acid is selected from C6 to C24, preferably from C6 to C18 (coconut
fatty acid). Oxidation is carried out between 50°C to 90°C for a period of 1 to 6
hours, when 0.5% - 1% w/v of hydrogen peroxide is used for oxidation.
Preferably, the oxidation is carried out between 80°C to 85°C for a period of 2
hours. The reduction is carried out at temperature of 28°C to 30°C for a period of
2 hours, when 100 ppm of sodium borohydride is used. Distillation is carried out
at 160°C to 210°C at I mm Hg.
The present invention will now be described with reference to the following
examples. However, the examples in no way limit the scope of the invention,
Examples
The following examples are shown in respect of coconut fatty acid. However, any
other fatty acid in the range from C6 to C24 and more particularly C6 to C18 can
be used to show similar results. The examples show how the combination of
oxidation reaction and reducing reaction is inventive.
Example I
The distilled coconut fatty acid is heated to 80 - 85° C and 1 % Hydrogen
Peroxide is added and the fatty acid is stirred continuously for 2 hrs maintaining
the temperature at 80 - 85 °C. The bleached fatty acid is distilled at 210° C at
1mm Hg. The original colour of the fatty acid is read using an automatic
Tintometer. The fatty acid is tested for its heat stability. The heat stability method
is the AOCS Td 3a - 64. After the heat stability test, the colour was read using an
automatic Tintometer.
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Example II
The distilled coconut fatty acid is treated with lOOppm Sodium Borohydride at
room temperature (28 - 30°C) for 3 hrs with constant magnetic stirring in a
sealed flask. After the Borohydride treatment the fatty acid is again distilled by
the above mentioned method of distillation. The original colour of the fatty acid
is read using an automatic Tintometer. The fatty acid is tested for its heat
stability. The heat stability method is the AOCS Td 3a - 64. After the heat
stability test, the colour was read using an automatic Tintometer.
Example III
The distilled coconut fatty acid is treated with lOOppm Sodium Borohydride at
room temperature (28 - 30°C) for 3 hrs with constant magnetic stirring in a
sealed flask. The treated fatty acid is distilled as above. The treated and distilled
fatty acid is heated to 80 - 85°C and 1 % Hydrogen Peroxide is added. The fatty
t
acid is stirred continuously for 2 hrs maintaining the temperature at 80 - 85°C.
After the Peroxide bleaching the fatty acid is again distilled by the above
mentioned method of distillation. The original colour of the fatty acid is read
using an'automatic Tintometer. The fatty acid is tested for its heat stability. The
heat stability method is the AOCS Td 3a -64. After the heat stability test, the
colour was read using an automatic Tintometer.
Example IV showing Inventive Step
The coconut distilled fatty acid is heated to 80 - 85°C and 1 % Hydrogen
Peroxide is added and the fatty acid is stirred continuously for 2 hrs maintaining
the temperature at 80 - 85°C. After the Peroxide bleaching the fatty acid is
distilled by the above mentioned method of distillation. After distillation, the
bleached and distilled fatty add is further treated with lOOppm Sodium
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Borohydride at room temperature (28 - 30°C) for 3 hrs with constant magnetic
stirring in a sealed flask. After the Borohydride treatment the fatty acid is again
distilled by the above mentioned method of distillation. The original colour of the
fatty acid is read using an automatic Tintometer. The fatty acid is also tested for
its heat stability. The heat stability method is the AOCS Td 3a - 64. After the heat
stability test, the colour was read using an automatic Tintometer,

Measurement
Colour values
The Colour Values are expressed in the Lovibond R + Y scale. This scale is the
universal standard for measuring the colour of oils and fatty acids in the
oleochemical industry. These Colour Values are measured by the Lovibond
Tintometer model PFX 990 / 995, manufactured by The Tintometer Limited,
England. This instrument is the standard and approved for automatic reading of
colours in the oleochemical industry. The colour of light coloured products is
measured in a 5.25" long quartz cell. The "Original Colour" represents the colour
bodies present in the fatty acid after treatment described in each of the examples.

The colour developed after subjecting the fatty acid to the Heat Stability Test,
represents the potential colour forming bodies in the fatty acids. The Heat
Stability Test is an accelerated study carried out to establish the potential of a
fatty acid to remain colour stable even at elevated reaction temperatures. A low
original colour represents a very light coloured fatty acid which also means very
small amount of colour bodies in the fatty acid. A small change from the original
colour to the colour developed after heating indicates a smaller amount of
potential colour forming bodies. This therefore indicates a truly heat stable fatty
acid.
Heat Stability Test
This is a standard test, carried out on all fatty acids, measures the ability of fatty
acid to remain colour stable even after being subjected to heat under the specified
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conditions of the test. The Test Method followed by us, is that prescribed by the
American Oil Chemists Society (A. O. C. S.) Official Method Td 3a-64
Since the Iodine Value of the Coconut Fatty Acid, used in the above examples, is
< 15 the Heat Stability Test is carried out for 2 hours at 205C under a blanket of
Nitrogen. After the prescribed time, the sample is taken out of oil bath and is
cooled to a temperature which is about 10-15°C above its solidification point.
t
The sample is then poured in to the 5.25" long quartz cell to measure the colour.
Using Lovibond Tintometer colour is measured and recorded as the "Colour after
Heat Stability".
Results Table

Original Colour
(R+Y)5.25"CeIl Colour after Heat
Stability Test
(R+Y) 5.25" Cell
Example I 0.4+3.0 2.1+9.0
Example II 0,5+4.9 1.4+8.2
Example III 0.3+1.9 2.0+14.0
Example IV 0.1+1.6 0.3+1.9
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We claim:
1. A process for preparing fatty acids comprising the steps of:
a) Treating the distilled fatty acids with an oxidizing agent;
b) Distilling the resultant mixture under vacuum;
c) Treating the distilled resultant mixture with a reducing agent;
d) Distilling the resultant mixture under vacuum.
2. A process as claimed in claim 1, wherein said oxidizing agent used in step
(a) is hydrogen peroxide.
3. A process as claimed in claim 1, wherein said reducing agent used in step
(c) is sodium borohydride.
4. A process as claimed in any of the Claims 1 to 3, wherein said fatty acid
is selected from C6 to C24.
5. A process as claimed in Claim 4, wherein said fatty acid is selected from
C6 to C18.
6. A process as claimed in Claim 2, wherein 0.5% - 1% w/v hydrogen
peroxide is used.
7. A process as claimed in Claim 2, wherein said oxidation is carried out
between 50°C to 90°C for a period of 1 to 6 hours.
8. A process as claimed in Claim 3, wherein said sodium borohydride is
used in an amount of 100 ppm.
9. A process as claimed in Claim 3, wherein the reduction is carried out at
temperature of 28°C to 30°C for a period of 2 hours.
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10. A process as claimed in Claim 1, wherein said distillation is carried out at
160°C to 210°C at 1mm Hg.
11. A process for preparing fatty acids substantially described herein with
reference to examples.
12. Light coloured and heat stable fatty acid obtained by employing the
process as claimed in any of the aforesaid claims.
Dated this 29th day of March 2006.

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