FORM 2
THE PATENTS ACT, 1970
(39 OF 1370)
&
PATENTS RULES, 2006
COMPLETE SPECIFICATION
(SECTION 10; RULE 13)
Title
GREEN OIL EXTRACTION PROCESS FOR EFFICIENT RECOVERY OF OIL
FROM POMEGRANATE SEEDS
Applicant : IITB MONASH RESEARCH ACADEMY Nationality : INDIAN Address : IIT Bombay
Powai, Mumbai 400 076, India
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER, IN WHICH IT IS TO BE PERFORMED

FIELD OF INVENTION
The present invention generally relates to food processing industry for making functional foods rich in omega-3 and omega-6 fatty acids, e.g. pomegranate oil. In particular, the present invention relates to the method of extraction of pomegranate oil from pomegranate seeds. More particularly, the present invention relates to an efficient recovery of pomegranate oil from seeds thereof by using a green fractionation process.
BACKGROUND OF INVENTION
Pomegranate seed, a by-product of the pomegranate juice industry, is an excellent source of oil which is rich in omega-3 fatty acid and omega-6 fatty acid. The omega fatty acids are synthesized very little in human body and mainly obtained from diet. The conventional sources of omega-3 and omega-6 fatty acids are mainly fish oils, such as salmon and cod liver oil. Amongst vegetarian sources, flax seeds and soybean oil are the two traditional sources (Candela, Rabaneda, Dassen, Borje & Lobo, 2007). Thus, pomegranate seed oil can be a non-conventional source for these fatty acids. As per various studies, pomegranate seed oil is reported to have anti-cancer, anti-asthmatic, anti-oxidant and anti-obesity properties (A. M. Goula, 2013; Schubert, Lansky, & Neeman, 1999).
In last few years, various methods have been developed and investigated by
researchers to improve the extraction of seed oil from pomegranate juice industry waste. The general scheme of oil extraction from pomegranate seeds is shown in a flow chart in Figure 1. It includes three major steps, which decide the yield and quality of the product, i.e. pomegranate oil.
These steps are: a) Drying, b) Size reduction, and c) Method of extraction. The various issues associated with these steps are as follows: a) DRYING - As shown in the flowchart, pomegranate seeds are separated from the pomace with initial moisture content (wet basis or w. b.) of about 55-60% and dried to 3-5% moisture content (w.b.). It is important to have low

moisture content in dried seeds for efficient recovery of oil. Therefore, drying is an indispensable but expensive unit operation. Since major component of pomegranate seed oil is poly unsaturated fatty acids (PUFA), its exposure to higher temperatures for longer time may degrade the quality of oil. The effects of the drying conditions on the quality of seed oil has not been evaluated. In the research community, the real focus has been only on the extraction efficiency, while overall economics with respect to drying process has not generated enough interest.
b) SIZE REDUCTION - In order to improve the extraction efficiency of oil
from the pomegranate seeds, the researchers have tried to reduce the seed size
to open up more surface area, which would ideally improve mixing between the
extraction medium and oil.
Eikani et al (2012) reported a seed oil yield of 22.2%, 18.7% and 11.2 % for average particle sizes of 250 µm, 500 µm and 1000 µm respectively. Therefore, it was concluded that finer the solid particles in the feed, better will be the extraction due to a better mass transfer mechanism. Other researchers were also in agreement with the aforesaid Eikani results (Tian et al 2013, Goula 2013).
The present inventors carried out the compositional analysis of pomegranate seeds and observed that the seeds are rich in not only oil, but also in proteins and structural carbohydrates.
This led them to believe that optimal fractionation of dried pomegranate seeds could give concentrated oil and protein fractions separately and the use of non~ green solvents such as hexane (which is commonly used as a solvent for oil extraction) could be significantly reduced or avoided. To avoid non-green solvents, fractionated dried seeds can be enzymatically treated to extract and recover oil and proteins.
c) EXTRACTION - At present, the extraction is carried out by using
traditional methods including cold press and solvent extraction. The
disadvantages associated with these methods are low yield in case of cold press

method and high solvent consumption in case of solvent extraction process. There is also a risk of thermal degradation of heat-labile components, and longer extraction times.
Soxhlet extraction process is the most widely used conventional method of extraction at the lab scale. Several novel extraction techniques have been sought to completely remove or reduce the disadvantages associated with conventional methods. Some of these novel methods include, microwave, supercritical fluid extraction (SFE), ultrasound-assisted extraction (UAE). Amongst all these methods, UAE and SFE method were found to be better in terms of seed oil extraction efficiency.
For a green process, (considering reduction or replacement of solvent e.g. hexane), SFE and UAE can be the most promising options (Liu et al 2009, Tian et al 2013). However, both processes are energy intensive and therefore, expensive. Detailed techno-economic analysis has not been conducted by researchers for both these processes.
Other alternative for a greener process could be enzymatic extraction. There is only one study available on enzymatic treatment to recover pomegranate seed oil which demonstrated the potential of enzymatic treatment to improve oil yield (Mirzaakhmedov et al 2011), however, this study was not conducted exhaustively, and the yield was poor.
Therefore, there is an existing need to develop a green process for minimizing the amount of energy required to dry pomegranate seeds, to reduce or avoid non-green solvents for obtaining higher oil yields and other value-added fractions such as proteins without compromising with the quality attributes of oil (for example, punicic acid).
OBJECTS OF THE INVENTION
Some of the objects of the present invention - satisfied by at least one embodiment of the present invention - are as follows:

An object of the present invention is to provide a cost-effective, efficient and green process for extracting oil from pomegranate seeds.
Another object of the present invention is to provide a cost-effective, efficient and green process for recovery of oil from pomegranate seeds.
Still another object of the present invention is to provide a cost-effective, efficient and green fractionation process for recovery of oil from pomegranate seeds.
Yet another object of the present invention is to provide an efficient and green fractionation process for recovery of oil from pomegranate seeds without drying.
A still further object of the present invention is to provide a green fractionation process for recovery of oil from pomegranate seeds, requiring minimum energy.
A yet further object of the present invention is to provide a green fractionation process for recovery of high-quality oil from pomegranate seeds with high yield.
These and other objects and advantages of the present invention will become more apparent from the following description, when read with the accompanying figures of drawing, which are however not intended to limit the scope of the present invention in any way.
SUMMARY OF THE INVENTION
In accordance with the present invention, a cost-effective, efficient and green process for extracting oil from pomegranate seeds, comprising the following four method steps:
(i) Drying of pomegranate seeds using microwave assisted drying method was evaluated to minimize drying time and maintaining quality attributes of oil;

(ii) Conducting optimum fractionation of pomegranate seeds to obtain several
fractions thereof to concentrate oil bearing seed component for oil seed extraction;
(iii) Using green solvent extraction process to extract seed oil from oil bearing fractions by completely eliminating hexane and to obtain high quality oil which is
as good as cold press oil; and
(iv) Using green solvent extraction process to extract seed oil from ground pomegranate seed in 'as is' condition, by undertaking 'No fractionation and no drying' method for oil extraction, i.e. processing pomegranate seeds (as is) by an enzymatic extraction process using a host of enzymes.
STATEMENT OF THE INVENTION
In accordance with the present invention, there is provided a green oil extraction process for efficient recovery of oil from pomegranate seeds, comprising the steps of:
• separating pomegranate seeds from pomace;
• washing the separated pomegranate seeds;
• pulverizing separated seeds in a hammer mill;
• sieving pulverized seeds in a gyratory screen having a plurality of sieves of predefined sizes; and
• extracting oil from different oil bearing seed sizes by using a green solvent extraction process;
wherein the extraction process reduces/eliminates non-green solvents like hexane to obtain high oil-yield and other value-added components like proteins, without compromising with the oil quality attributes like punicic acid. Typically, the pulverized seeds are dried by a microwave-assisted drying process using different power levels/wattages for different drying times depending on punicic acid contents of pulverized seeds.

Typically, the microwave drying process is conducted between 180W to 720W
for 0 to 50 minutes for reducing punicic acid content in pulverized seeds from 70 to 66%.
Typically, the microwave drying process is conducted at 360W for 20 minutes for
reducing punicic acid content in pulverized seeds to 72%.
Typically, the oil extraction process involves complete elimination of hexane from oil bearing seed fractions to obtain a high-quality pomegranate oil and separated protein fractions.
In an embodiment of the present invention, the oil extraction process is conducted by extracting and recovering oil and proteins from dried seeds in 'as is' condition without drying and using a wet enzymatic oil extraction process by
treatment of pulverized seeds with a host of enzymes.
Typically, the wet enzymatic oil extraction process extracts oil from pomegranate seeds by using protease enzymes and a cocktail of protease and cellulase enzymes.
In another embodiment of the present invention, the drying process of pomegranate seeds is conducted in a convective hot-air dryer using different combination of temperatures and time periods for obtaining the targeted reduction in the moisture content of the pulverized seeds depending on punicic acid contents thereof.
Typically, the inlet air temperature is controlled by a proportional integral derivative controller (PID) to obtain the targeted moisture content of dried pulverized pomegranate seeds.
Typically, the time required for reducing the moisture content of dried pulverized seeds is a function of the hot-air temperature, preferably the required time is between 105 minutes for the hot-air temperature of 105°C for the lowest moisture

content of pulverized seeds to the required time of 1320 minutes for the hot-air temperature of 40°C for the highest moisture content of pulverized seeds.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The present invention will be briefly described with reference to the accompanying drawings.
Figure 1 shows the flow chart of a conventional 3-step process for extracting oil from pomegranate seeds.
Figure 2 shows a schematic diagram of the unit used for fractionation of pomegranate seeds by the four-step method developed in accordance with the present invention.
Figure 3 shows a flow chart of a green extraction of the pomegranate seed oil without drying in accordance with the present invention.
Figure 4 shows a graphical representation of the conventional pomegranate seed oil extraction process using convective hot air-drying (AD).
Figure 5 shows a graphical representation of the conventional pomegranate
seed oil extraction process using microwave-assisted drying (MD).
Figure 6 shows a graphical representation of the effect of conventional drying methods on punicic acid concentration which methods are used for oil extraction.
Figure 7 shows a bar chart for the optimized fractions obtained from the dried seeds after milling and sieving at 17000 rpm for 10-30 seconds.
Figure 8 shows a bar chart for oil yields of different fractions.
Figure 9 shows a comparative bar chart for oil recovery by using the cold press,
conventional (Soxhlet extraction) and enzymatic process.

DETAIL DESCRIPTION OF THE ACCOMPANYING DRAWINGS
In the following, the efficient, green, high-yield process for extracting oil from
pomegranate seeds developed in accordance with the present invention will be described in more details with reference to the accompanying drawings without limiting the scope and ambit of the present invention in any way.
Figure 1 shows the flow chart of a conventional 3-step process for extracting oil from pomegranate seeds. These steps include drying pomegranate seeds obtained as a by-product from the pomegranate juice industry, reducing the seed-size and extracting oil by a mechanical method or a chemical method involving solvent extraction. At step 10, pomegranate seeds, a by-product preferably obtained from pomegranate juice plants is taken for washing at step 20, which is subsequently dried at step 30. Thereafter, seed size reduction is taken up at step 40 for extracting oil therefrom at step 50. This oil extraction can be done either by a mechanical method at step 60 to recover oil 70 or by a chemical method, e.g. a solvent extraction method at step 80, in which dried seeds containing oil are mixed with a solvent at step 85 and oil 90 is finally extracted thereby.
Figure 2 shows a schematic diagram of the unit used for fractionation of pomegranate seeds by the four-step method in a unit developed in accordance with the present invention. It includes pomegranate seeds are dried by using microwave-assisted drying (MD) for minimizing drying time and maintaining the quality attributes of oil therein. Subsequently, these dried pomegranate seeds 110 are supplied to a hammer mill 120 (preferably operating between 17000 to 19000 rpm) from the open top thereof for crushing to obtain seed powder in a gyratory screen 130 by using various sieve sizes for optimum fractionation of milled seeds (time 10 to 150 seconds) into different fractions (F1, F2, F3, F4, see Figure 7) and concentrating oil bearing seed components for oil seed extraction (Figure 3).

Figure 3 shows a flow chart of a green process of extraction of pomegranate
seed oil without drying and developed in accordance with the present invention,
Here, the seed oil seed extraction at step 140 is used to extract pomegranate oil by separating dried seed powder 150 from various oil-rich fractions 160 and wet ground mass 170, This green process requires reduced energy input and provides higher yield over the existing processes.
Figure 4 shows a graphical representation of a pomegranate seed oil extraction process using convective hot air-drying (AD), which shows that the time required to reduce the moisture content of pomegranate seeds to the desired level depends on hot air temperature, i.e. highest at 40°C (after 1320 minutes) and lowest at 105°C (after 105 minutes).
Figure 5 shows a graphical representation of the pomegranate seed oil extraction process using microwave-assisted drying (MD), which shows that by microwave drying under 180W, 360W, 540W and 720W, the time taken to dry
the same sample were 50, 23, 20 and 14 minutes respectively (Figure 5). These graphs clearly demonstrate that the microwave drying times (Figure 4) are about 50 to 99% shorter than the convective hot air-drying time (Figure 5).
Figure 6 shows a graphical representation of the effect of conventional drying methods on punicic acid concentration which methods are used for oil extraction. Here, points d1, d2 and d3 represent hot-air drying at 40°C, 75°C and 105°C respectively, whereas points d4, d5, d6 and d7 represent microwave drying at 180W, 360W, 540W and 720W respectively. It is known that punicic acid is the most important component of the pomegranate seed oil. The results indicated that higher convective temperatures are not ideal for punicic acid stability. For example, punicic acid concentration decreased from 70 to 66 (%) on drying the seeds at 105°C. Similarly, on exposing pomegranate seeds to microwave at various power levels, a clear trend of punicic acid degradation was observed with increase in wattage (power level). Seed exposure at 180W has shown minimal effect (about 74%) on punicic acid. Seed exposure at 720W has significantly reduced (62%) punicic (C18:3) acid content. Thus, it could be safely arrived at that

appropriate drying conditions are important for maintaining the oil quality
attributes. Here, out of 7 different drying conditions evaluated, microwave drying
at 360W was found to be the best, which had a drying time of 20 minutes and punicic acid of 72%. However, except this 720W exposure for drying, no other drying condition has shown any significant effect on oil yields (Table 1).
Figure 7 shows a bar chart for the optimized fractions obtained from the dried seeds after milling and sieving at 17000 rpm for 10-30 seconds. Different seed sizes were obtained (Figure 2) as different fractions, fraction F1 (>1100 µm) in green colour, fraction F2 (between 1100 pm and 850 µm) in blue colour, fraction F3 (between 850 pm and 500 µm) in yellow colour and fraction F4 (< 500 µm) in red colour.
Figure 8 shows a bar chart for oil yields of different fractions F1, F2, F3, F4 as well as dried seed powder. Here, oil bearing fraction F4 had concentrated oil sacs (about 40% oil, dry basis) for processing through cold press with higher extraction efficiency. The combination of F2, F3 and F4 fractions yield overall about 95% of total oil and co-products like high value proteins can also be recovered and concentrated for other food applications. The same oil rich fraction is processed in Soxhlet process by using organic solvent for extracting oil by utilizing just a third to half the solvent as compared to the existing Soxhlet extraction process. Removing the non-oil bearing fractions also helps in improving the mass transfer mechanism between the solute and solvent, thereby obtaining an improved oil yield in less time and using a reduced solvent volume.
Figure 9 shows a comparative bar chart for oil recovery by using the cold press, conventional (Soxhlet extraction) and enzymatic process. This shows that the non-solvent extraction process yields about 12% oil, conventional extraction method as well as enzymatic extraction process yield about 20% oil.

EXPERIMENTS
DRYING
Pomegranate seeds were dried in a convective hot air dryer at an inlet air temperature of 50°C, 75°C and 105°C, which was controlled by a proportional integral derivative (PID) controller. During this experiment, the air velocity was maintained at 1.5 m/s and measured by using METRAVI- AVM 02 anemometer. The sample weight was recorded at regular intervals. Whereas, microwave drying of pomegranate seeds was carried out in a microwave oven (LG, MC3283FMPG) of 900 W rated capacity at 2.45 GHz. Seed drying was done at four different power levels, i.e. 180W, 360W, 540W and 720W. 3 petri-plates containing 15 gm of seed sample were placed inside the microwave oven. The sample weight was recorded after every 10 seconds until the desired moisture content was reached,

RESULTS:

During convective hot air drying, the time required to reduce the moisture content of pomegranate seeds to the desired level was dependant on the hot air temperature, being the highest at 40°C (1320 minutes) and the lowest at 105°C (105 minutes) (Figure 4).Whereas, during microwave drying under 180W, 360W, 540W and 720W,
thetime taken to dry the same samples was 50, 23, 20 and 14 minutes respectively (Figure 5), which shows that microwave drying times were about 50 to 99% shorter than the convective hot air-drying times.Punicic acid is the most important component of
the pomegranate seed oil. The results indicated that higher convective temperatures are not ideal for punicic acid stability. For example, punicic acid concentration decreased from 70 to 66% when seeds were dried at 105°C. Similar trends were observed when pomegranate seeds were exposed to microwave at various wattages (Figure 6). With increase in wattage, punicic acid degradation was clearly noticed.

While lowest wattage (180W) had minimal effect on punicic acid (~74%), the highest wattage (720W) significantly reduced the punicic (C18:3) acid content
(62%).
Thus, appropriate drying conditions are important for maintaining the oil quality attributes. Out of 7 drying conditions evaluated for drying time and punicic acid, microwave drying at 360W was found to be best (drying time 20 minutes and punicic acid 72%).
However, except for microwave drying at 720W, other drying conditions did not have any significant effect on the oil yields (Table 1), as illustrated by ANOVA analysis at different drying conditions (Tukey Method).
Table 1

Drying method N Mean (% dry basis) Grouping
d5 3 21.7 + 0.5 r\
d6 q 21.1 ±0.2 A B
d2 3 20.7 ±0.3 A B
d3 3 20.0 ± 0.5 A B
d4
3 19.9±03 A B
d1 3 19.6 ±0.2 A B
d7 3 19.1 ±0.8 B
*Means that do not share the same letter are significantly different.
FRACTIONATION
By using the hammer mill, aforesaid dried pomegranate seeds were pulverized into several fractions (Figure 2). A gyratory screen or sieve-shaker was used to collect these different fractions. The rationale behind this milling and sieving process is to collect at the top, the larger particles not passing through the sieve, as relatively pure fibres (fraction rich in cellulose, hemicellulose and lignin). Smaller sieved particles are rich in protein and/or lipid content.

The optimization of this fractionation process was done to concentrate oil rich fractions. The variables considered for maximizing the oil bearing fractions were
the rpm and time of operation of the hammer mill, Each fraction is analysed for
its proximate composition (Moisture, carbohydrate, fat/oil, protein and ash
content).
RESULTS:
The cold press extraction process is the most popular process out of the existing methods used for oil extraction. Since cold pressed oils are produced at lower temperatures and they retain flavor, aroma, and nutritional value. However, the cold press efficiency is not high (~60-70%), so significant oil quantity ends up in the residue. Especially, when oil bearing seeds have a low oil content (≤ 20-22% oil, dry basis), the extraction efficiency reduces significantly in cold pressed oil (max. achievable is about 60-70%).
In accordance with the present invention, the microwave-assisted drying process is used for drying of pomegranate seeds. Two hammer mill parameters, i.e. time and rpm are used for fractionation of dried seeds and for maximizing oil recovery in oil bearing fractions. Moreover, main and interaction effects of these parameters are also evaluated. Accordingly, the fractionation process was optimized to obtain maximum oil yield from the oil bearing fractions.
In accordance with the present invention, pomegranate seeds are fractionated into oil bearing and non-oil bearing components (Figure 7) and each fraction is analyzed for its proximate composition (Table 2 showing the composition of each fraction obtained by using milling and sieving).
Figure 8 shows an oil bearing fraction F4 having concentrated oil sacs (-40% oil, dry basis), which could be processed through cold press with higher extraction efficiency. A combination of F2, F3 and F4 fractions yields about 95% of total oil and co-products such as high value proteins could be recovered and concentrated for other food applications.

Same oil rich fraction could also be processed in the conventional Soxhlet extraction process using organic solvents to extract oil by utilizing only 1/3rd to
1/2 of the solvent as compared to the existing Soxhlet extraction process.
The removal of non-oil bearing fractions helped in improving the mass transfer mechanism between the solute and solvent. Thus, an improved oil yield is achieved in less time and using a reduced solvent volume.
Table 2

Fraction % w/w Protein Ash Oil
F1 (37.6%) 1.8 ±0.2 2.7 ±0.6 1.4 ±0.2
F2(15.4%) 26.4 ±4.3 2.2 ± 1.1 7.6 ±1.3
F3(12.6%) 33.7 + 7.6 1.8 ±0.5 18.4 ±0.7
F4 (34.4%) 27.5 + 6.2 1.3+1.2 39.7 ±6.5
Unprocessed 21.2 ± 2.1 2.1+1.1 17.7 + 2.1
EXTRACTION THROUGH ENZYMATIC PATHWAY
The organic solvents could be completely eliminated by recovering oil from oil rich fractions. About 98% oil yield could be recovered without using any organic solvent. The wet fractionation of pomegranate seeds (without drying) also helps in reducing the costs associated with drying of the raw material, since drying is one of the costly unit operations. Significant savings could be realized by removing this drying operation from the overall fractionation process. The improved recovery of purified proteins and fibers from pomegranate seeds has specific applications in food and pharma industries.
RESULTS :
Recently, enzymatic hydrolysis techniques have attracted the attention of researchers for extracting oil from oil bearing seeds. Generally, oil inside the seed is partly bound to proteins and complex carbohydrates. Therefore, this technique involves the treatment of these seeds with cell-wall degrading enzymes and protease enzymes for enhancing oil recovery in the oil extraction

process. The enzymatic activity is affected by several parameters such as enzyme concentration, incubation temperature, pH of the medium, substrate
concentration and incubation time. Therefore, this experiment included
identifying the optimal conditions for extracting oil from pomegranate seeds by
using protease enzyme and a cocktail of protease and cellulase enzyme and to compare the oil yield % with those obtained by the conventional Soxhlet extraction process.
For protease enzyme, optimum enzyme load (E) was 68 uL, solid to liquid ratio (T) was 1:10 and incubation time was 14 h respectively for obtaining the maximum average oil yield of 20.2%. Figure 9 shows the comparison of oil yields from the processes of cold press, Soxhlet extraction and enzymatic hydrolysis.
Almost all the oil could be recovered by using enzymatic hydrolysis process.
Since some oil (about 30%) was not available in free form (in emulsion), the emulsion was further treated with enzymes and centrifuged to recover the remaining oil therein. The final yield of oil is about 98% of the theoretical value.
TECHNICAL ADVANTAGES AND ECONOMIC SIGNIFICANCE
The green process of extraction of oil from pomegranate seeds without drying and developed in accordance with the present invention has the following technical and economic advantages:
• Offers cost-effective, green process to extract oil from seeds without drying.
• Provides an efficient process for recovery of oil from pomegranate seeds.
• Provides a green fractionation process for pomegranate seed oil recovery.
• Provides a fractionation process requiring minimum energy.
• Reduces or avoids used of non-green solvents.
• Offers a high-yield fractionation process for recovery of high-quality oil.

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications Such Specific
embodiments without departing from the generic concept. Therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments,
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Therefore, while the embodiments herein have been described in terms of preferred embodiments, the skilled person will recognize that the embodiments herein can be practiced with modification within the spirit and scope of embodiments described herein.
The description provided herein is purely by way of example and illustration. The
various features and advantageous details are explained with reference to this non-limiting embodiment in the above description in accordance with the present invention. The descriptions of well-known components and manufacturing and processing techniques are consciously omitted in this specification, so as not to unnecessarily obscure the specification.
Innumerable changes, variations, modifications, alterations and/or integrations can be made in terms of materials and method used to configure, manufacture and assemble various constituents, components, subassemblies, assemblies and in terms of the size, shapes, orientations and interrelationships without departing from the scope and spirit of the present invention.
The numerical values given of various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher or lower than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the disclosure unless there is a statement in the specification to the contrary.

Throughout this specification the word "comprise", or variations such as
"comprises" or "comprising", shall be understood to implies including a described
element, integer or method step, or group of elements, integers or method steps, however, does not imply excluding any other element, integer or step, or group of elements, integers or method steps.
The use of the expression "a", "at least" or "at least one" shall imply using one or more elements or ingredients or quantities, as used in the embodiment of the disclosure in order to achieve one or more of the intended objects or results of the present invention.

We claim:
1. A green oil extraction process for efficient recovery of oil from
pomegranate seeds, comprising the steps of:
• separating pomegranate seeds from pomace;
• washing the separated pomegranate seeds;
• pulverizing separated seeds in a hammer mill;
• sieving pulverized seeds in a gyratory screen having a plurality of sieves of predefined sizes; and
• extracting oil from different oil bearing seed sizes by using a green solvent extraction process;
wherein the extraction process reduces/eliminates non-green solvents like hexane to obtain high oil-yield and other value-added components like proteins, without compromising with the oil quality attributes like punicic acid.
2. Process as claimed in claim 1, wherein the pulverized seeds are dried by a microwave-assisted drying process using different power levels/wattages for different drying times depending on punicic acid contents of pulverized seeds.
3. Process as claimed in claim 2, wherein the microwave drying process is conducted between 180W to 720W for 0 to 50 minutes for reducing punicic acid content in pulverized seeds from 70 to 66%.
4. Process as claimed in claim 3, wherein the microwave drying process is conducted at 360W for 20 minutes for reducing punicic acid content in pulverized seeds to 72%.
5. Process as claimed in claim 2, wherein the oil extraction process involves complete elimination of hexane from oil bearing seed fractions to obtain a high-quality pomegranate oil and separated protein fractions.

6. Process as claimed in claim 1, wherein the oil extraction process is
conducted by extracting and recovering oil and proteins from dried seeds in 'as
is' condition without drying and using a wet enzymatic oil extraction process by
treatment of pulverized seeds with a host of enzymes.
7. Process as claimed in claim 6, wherein the wet enzymatic oil extraction
process extracts oil from pomegranate seeds by using protease enzymes and a cocktail of protease and cellulase enzymes,
8. Process as claimed in claim 1, wherein drying process of pomegranate seeds is conducted in a convective hot-air dryer using different combination of temperatures and time periods for obtaining the targeted reduction in the moisture content of the pulverized seeds depending on punicic acid contents thereof.
9. Process as claimed in claim 8, wherein the inlet air temperature is controlled by a proportional integral derivative controller (PID) to obtain the targeted moisture content of dried pulverized pomegranate seeds.
10. Process as claimed in claim 9, wherein the time required for reducing the moisture content of dried pulverized seeds is a function of the hot-air temperature, preferably the required time is between 105 minutes for the hot-air temperature of 105°C for the lowest moisture content of pulverized seeds to the required time of 1320 minutes for the hot-air temperature of 40°C for the highest moisture content of pulverized seeds.