The present invention generally relates to the preparation of saponin extract
from soap nuts, and more particularly to a process for organic preparation of saponin
extract from soap nut without using excessive chemicals in a reduced lead time.
Background of the Invention
[0002] Soapberry (Sapindus mukorossii) is a species of tree in the family
Sapindaceae. The fruit of soapberry tree is known as soap nut or soapberry nut or
Reetha. Soap nut, essentially the pericarp of soap nut is used in a variety of
formulations including, but not limited to, cleansers, insecticides, medicinal soaps,
and surfactants. Saponin extract is one of the most important ingredient prepared
from soap nut pericarp which is required for the aforementioned formulations.
Therefore, it is of prime importance to prepare the saponin extract using the most
effective method in terms of usefulness and economic efficiency.
[0003] Existing process for preparation of saponin extract includes washing a
selected weight of soap nuts, drying the washed soap nuts, separating pericarp and
seed part of the soap nuts, soaking the separated pericarp in ethanol, refluxing the
soaked pericarp in a solution comprising ethanol, filtering and distilling the solution
comprising ethanol and pericarp, and extracting a brown mass of saponin from the
distilled solution using ethyl acetate and sodium sulphate. However, it has been
observed that the use of chemicals such as ethyl acetate and sodium sulphate even
after heating require significantly longer duration of time for extraction of saponin,
thereby increasing lead time and incurring higher cost. Further, it has been observed
that the overall productivity of the existing process is low, and more importantly the
amount of saponin extract obtained from a preselected weight of soap nuts is low.
[0004] In light of the aforementioned drawbacks, there is a need for an eco-friendly
process for preparation of saponin extract from soap nuts. Further, there is a need
for a process which improves the efficacy of prepared saponin extract by retaining
relatively higher quantity of saponin. Yet further, there is a need for a process which
significantly reduces lead time and cost of extraction.
3
Summary of the invention
[0005] In various embodiments of the present invention, a process for organic
preparation of saponin extract from soap nuts is disclosed. The process yields
increased amount of the saponin extract in a reduced lead time. The process
comprises removing impurities and moisture from a selected weight of soapnuts.
The process further comprises cutting into pieces a pericarp portion separated from
the selected weight of soapnuts. Further, the process comprises soaking a
predetermined weight of the cut pericarp portion in a predetermined volume of ethyl
alcohol for 24 hours to obtain a solution, where the ratio of weight of the cut pericarp
portion to the volume of ethyl alcohol is 1:3. Furthermore, the process comprises
refluxing the solution comprising ethyl alcohol and the cut pericarp portion at 78ᵒC
for 42-48 hours. Finally, the process comprises obtaining a gummy brown mass of
saponin extract from the refluxed solution by cooling the refluxed solution to room
temperature, followed by filtration and distillation to remove ethyl alcohol.
[0006] In various embodiments of the present invention, a saponin extract exhibiting
dark brown colour and a thick gummy texture is disclosed. The saponin extract is
prepared from a process comprising the steps of removing impurities and moisture
from a selected weight of soapnuts. The process further comprises cutting into
pieces a pericarp portion separated from the selected weight of soapnuts. Further,
the process comprises soaking a predetermined weight of the cut pericarp portion in
a predetermined volume of ethyl alcohol for 24 hours to obtain a solution, where the
ratio of weight of the cut pericarp portion to the volume of ethyl alcohol is 1:3.
Furthermore, the process comprises refluxing the solution comprising ethyl alcohol
and the cut pericarp portion at 78ᵒC for 42-48 hours. Finally, the process comprises
obtaining a gummy brown mass of saponin extract from the refluxed solution by
cooling the refluxed solution to room temperature, followed by filtration and
distillation to remove ethyl alcohol.
Brief Description of the Drawings
[0007] The present invention is described by way of embodiments illustrated in the
accompanying drawings wherein:
[0008] Fig. 1 is a flowchart illustrating a process for organic preparation of saponin
extract from soap nuts, in accordance with various embodiments of the present
invention.
4
[0009] Fig. 1a is an FTIR spectrum for detection of saponin in the prepared saponin
extract, in accordance with various embodiments of the present invention.
Detailed Description of the Invention
[0010] The disclosure is provided in order to enable a person having ordinary skill
in the art to practice the invention. Exemplary embodiments herein are provided
only for illustrative purposes and various modifications will be readily apparent to
persons skilled in the art. The general principles defined herein may be applied to
other embodiments and applications without departing from the spirit and scope of
the invention. The terminology and phraseology used herein is for the purpose of
describing exemplary embodiments and should not be considered limiting. Thus, the
present invention is to be accorded the widest scope encompassing numerous
alternatives, modifications and equivalents consistent with the principles and
features disclosed herein. For purposes of clarity, details relating to technical
material that is known in the technical fields related to the invention have been
briefly described or omitted so as not to unnecessarily obscure the present invention.
It is to be noted that, as used in the specification by the term “substantially” it is
meant that the recited characteristic, parameter, or value need not be achieved
exactly, but that deviations or variations, including for example, tolerances,
measurement error, measurement accuracy limitations and other factors known to
those skilled in the art, may occur in amounts that do not preclude the effect the
characteristic was intended to provide. Additionally, definitions of a few terms as
used in the specification are provided below for ease of understanding. The term
“air drying” as used in the specification refers to the drying at room temperature
with surrounding air.
[0011] The present invention discloses a process for organic preparation of saponin
extract from soap nuts. The process of the present invention provides for preparation
of saponin extract from soap nuts by eliminating the use of chemicals such as ethyl
acetate and sodium sulphate. Further, the process of the present invention provides
improved production of saponin extract in a significantly reduced lead time, said
saponin extract is in the form of gummy brown mass which significantly reduces
the viscosity of heavy crude oil having significant resin content. In operation, the
present invention provides for removing impurities from a selected weight of soap nuts
by washing. Further, the invention provides for air drying the washed soap nuts at room
temperature. Furthermore, the invention provides for separating the pericarp portion
5
and seed portion of the soap nuts. The pericarp portion is cut into small pieces and a
predetermined weight of the cut pericarp is soaked into a predetermined volume of
ethyl alcohol for 24 hours. Yet further, the invention provides for refluxing the solution
of ethyl alcohol comprising pericarp at 78 ᵒC for 48 hours. Yet further, the solution of
ethyl alcohol comprising pericarp is cooled to room temperature and filtered to obtain
a mass of saponin extract. Finally, the mass of saponin extract is distilled to evaporate
any ethyl alcohol to obtain a gummy brown mass comprising saponin.
[0012] The present invention would now be discussed in context of embodiments as
illustrated in the accompanying drawings.
[0013] Fig. 1 is a flowchart illustrating a process for organic preparation of saponin
extract from soap nuts, in accordance with various embodiments of the present
invention.
[0014] At step 102, impurities and moisture are removed from a selected weight of
soap nuts. In an embodiment of the present invention, a predetermined quantity of
soap nuts are collected. The soap nuts are obtained from the soapberry tree
(Sapindus mukorossi) and are readily available in the market. In an exemplary
embodiment of the present invention, a selected weight of soap nuts from the
collected predetermined quantity of soapnuts are washed with clean water in a flask
or the like to remove impurities. Further, the washed soap nuts are air dried at room
temperature in a petri dish or the like to remove moisture.
[0015] At step 104, pericarp portion is separated from the soap nuts and cut into small
pieces. In an embodiment of the present invention, the pericarp portion and the seed
portion of the soap nuts are separated. In an exemplary embodiment of the present
invention, the pericarp portion is separated from the selected weight of soap nuts by
peeling. Further, the pericarp portion is cut into small pieces.
[0016] At step 106, cut pericarp is soaked in ethyl alcohol to obtain a solution. In an
embodiment of the present invention, a predetermined weight of cut pericarp is soaked
into a predetermined volume of ethyl alcohol for 24 hours. The ratio of weight of cut
pericarp to the volume of ethyl alcohol is selected, such that the cut pericarp is
completely immersed in ethyl alcohol to facilitate improved soaking. In an exemplary
embodiment of the present invention, the ratio of weight of cut pericarp to the volume
of ethyl alcohol is 1:3. In operation, a predetermined weight of cut pericarp is
transferred to a flask comprising predetermined volume of ethyl alcohol for soaking.
6
In an experiment, substantially 80 grams of pericarp was transferred to a 500 ml conical
flask comprising substantially 240 ml of ethyl alcohol.
[0017] At step 108, the solution comprising ethyl alcohol and cut pericarp is refluxed.
In an embodiment of the present invention, the solution of ethyl alcohol comprising
cut pericarp is refluxed at 78ᵒC for 42-48 hours. In a preferred embodiment of the
present invention, the solution of ethyl alcohol comprising cut pericarp is refluxed at
78 ᵒC for 48 hours. In a preferred embodiment of the present invention, the refluxing
temperature is the boiling point of the solvent i.e. ethyl alcohol.
[0018] At step 110, the refluxed solution of ethyl alcohol and cut pericarp is cooled to
room temperature and filtered to obtain a mass comprising saponin extract. In
operation, the solution of ethyl alcohol comprising cut pericarp is filtered using
Whatman filter paper 42.
[0019] At step 112, a gummy brown mass comprising saponin extract is obtained by
distilling the filtered mass of saponin extract. In an embodiment of the present
invention, the filtered mass of saponin extract is distilled to evaporate all the ethyl
alcohol until a gummy brown mass of saponin extract is obtained. In an exemplary
embodiment of the present invention, the distillation apparatus comprises a distillation
flask, a condenser and a collection vessel. In operation, the filtered mass of saponin
extract is heated in the distillation flask to volatise any ethyl alcohol present in the
filtered mass of saponin extract. Further, the volatised ethyl alcohol is condensed in the
condenser back to liquid state. Finally, the ethyl alcohol is collected in the collection
vessel, and a brown mass of saponin extract is obtained after separating the ethyl
alcohol. In an experiment, 20 grams of gummy brown mass of saponin extract was
obtained from 80 grams of cut pericarp which is higher than the conventional process.
The obtained brown mass of saponin was dark brown in colour with a thick gummy
texture. Further, it was observed that the obtained brown mass of saponin extract
formed foam when dissolved in water. The obtained gummy brown mass of saponin
extract comprises relatively higher amount of saponin along with other constituents.
[0020] An experiment was conducted to establish the presence of saponin in the
obtained brown mass of saponin extract. In the experiment FTIR (Fourier transform
infrared) spectroscopy was used. During the experiment peaks as shown in Fig. 1a
were observed at wave numbers 1046.17 and 1077.84 cm-1 in the FTIR spectrum
depicting the presence of glycosidic linkages. Further, peak was observed at wave
7
number 1727.84 cm-1 depicting the presence of carbonyl bond in the brown mass of
saponin extract. The presence of glycosidic linkages as well as carbonyl (C=O) bonds
are characteristic molecular bonds of saponin, thereby establishing the presence of
saponin in the obtained brown mass of saponin extract.
[0021] Advantageously, the process of the present invention is organic and eliminates
the use of chemicals such as ethyl acetate and sodium sulphate. Further, the process
of the present invention provides more weight of saponin extract from a
predetermined weight of pericarp portion in comparison to the conventional method.
It has been observed that the process of the present invention yields up to 25% of
saponin extract from the predetermined weight of pericarp portion, whereas the
conventional process yields 20% of saponin extract from the predetermined weight
of pericarp portion. Further, the process of the present invention provides saponin
extract with improved efficacy by retaining higher quantity of saponin in a
significantly reduced lead time. Furthermore, the saponin extract in the form of
gummy brown mass obtained using the process of the present invention significantly
reduces viscosity of crude oils. It has been observed that a selected concentration of
saponin extract obtained using the present invention provides significant viscosity
reduction in crude oil in comparison to the same concentration of saponin extract
obtained by the conventional methods.
[0022] Table 1 below illustrates results of an experiment conducted to observe
viscosity reduction in crude oil using various additives.
S. No. Crude oil
characteristics
Additive Concentrat
ion of
Additive
Temperatur
e Range
%
Reduction
in
viscosity
1. 19.32ᵒ
API(American
Petroleum
Institute) Gravity
Saponin
extract
obtained
from
conventional
process
4% 40 ᵒC 81%
8
2. 13.09ᵒ API
(Heavy Crude
Oil), Crude Oil
with API gravity
13.09ᵒ is heavier
and has higher
viscosity than the
crude oil with
API gravity
19.32ᵒ.
Saponin
extract
obtained
from the
process of
the present
invention
4% 40 ᵒC 95%
3. API Gravity:
13.09 ᵒ API;
Asphaltene
content: 2.84
wt%;
Resin: 31.45
wt%;
Wax content:
3.31wt%
Chemical
additive
2500ppm
+2%
xylene
20ᵒC 46%
4. Crude oil havingAPI Gravity:
13.09 ᵒ API;
Asphaltene
content: 2.84
wt%;
Resin: 31.45
wt%;
Wax content:
3.31wt%
Saponin
extract
obtained
from the
process of
the present
invention
0.3% 20ᵒC 97%
9
[0023] As can be observed from table 1, the viscosity reduction in two varieties of
crude oil (Both being heavy, 13.09 ᵒ API gravity crude oil being heavier than 19.32ᵒ
API gravity crude oil) has been compared using the saponin extract obtained from
the present invention, the chemical additive and the saponin extract obtained from
the conventional methods. The results in item number 1 and 2 of table 1 show that
the saponin extract obtained from the conventional method at 40ᵒC reduces the
viscosity of crude oil (19.32ᵒAPI) by 81% while saponin extract obtained from the
process of the present invention reduces the viscosity of crude oil (heavy-13.09ᵒ
API) at the same temperature of 40ᵒ
C by 95% indicating improved efficacy. Further,
the results in item numbers 3 and 4 show viscosity reduction in the crude oil having
13.09 ᵒAPI, Asphaltene content: 2.84 wt%, Resin: 31.45 wt%; Wax content:
3.31wt% at 20ᵒ
C using the chemical additive supplied by a vendor and the saponin
extract obtained from the process of the present invention. As can be observed from
the table the chemical additive supplied by the vendor reduces the viscosity by 46%
and saponin extract obtained from the process of the present invention reduces the
viscosity of the same crude oil by 97%. In view of the above results it may be
concluded that the saponin extract obtained from the process of the present invention
is more effective in preventing the formation of clusters of heavier molecules i.e.
resins & asphaltenes which are responsible for high viscosity and heavy nature of
crude oil. Thus, the saponin extract of the present invention shows improved
efficacy at least in relation to crude oil viscosity reduction, in comparison to saponin
extract obtained from the conventional methods.
[0024] Various other experiments were conducted to observe viscosity reduction in
crude oil using predetermined concentrations of saponin extract obtained from the
present invention. As shown in table 2 and graph 1 below, it was observed, more is
the concentration of saponin extract more is the reduction in viscosity of crude oil.
Further, it can be observed that a predetermined concentration of the obtained saponin
extract of the present invention provides up to 98% of viscosity reduction in heavy
crude oils at 20ᵒC.
S. No. Sample Viscosity (cP) at
20 ᵒC
% Reduction in
viscosity
1. Neat crude oil 82700 ----
10
2. Crude oil + 4% saponin
extract
1227 98
3. Crude oil + 0.3% saponin
extract
2875 97
Table 2
Graph 1
[0025] It is to be noted that the efficacy of saponin extract obtained from the process
of the present invention is not limited to crude oil viscosity reduction. The obtained
mass of saponin extract may be used in other formulations as well, such as, but not
limited to cleansers, insecticides, and medicinal soaps.
[0026] While the exemplary embodiments of the present invention are described
and illustrated herein, it will be appreciated that they are merely illustrative. It will
be understood by those skilled in the art that various modifications in form and detail
may be made therein without departing from the scope of the invention except as it
may be described by the following claims.

We claim:
1. A process for organic preparation of saponin extract from soap nuts,
said process yielding increased amount of the saponin extract in a reduced lead
time, said process comprising the steps of:
removing impurities and moisture from a selected weight of soapnuts;
cutting into pieces a pericarp portion separated from the selected weight
of soapnuts;
soaking a predetermined weight of the cut pericarp portion in a
predetermined volume of ethyl alcohol for 24 hours to obtain a solution, wherein
the ratio of weight of the cut pericarp portion to the volume of ethyl alcohol is 1:3;
refluxing the solution comprising ethyl alcohol and the cut pericarp portion
at 78ᵒC for 42-48 hours; and
obtaining a gummy brown mass comprising saponin extract from the
refluxed solution by cooling the refluxed solution to room temperature, followed
by filtration and distillation to remove ethyl alcohol.
2. The process as claimed in claim 1, wherein removing impurities and
moisture from the selected weight of soapnuts comprises collecting a
predetermined quantity of soap nuts, washing a selected weight of soap nuts
from the collected predetermined quantity of the soapnuts with clean water, and
air drying the washed soapnuts at room temperature.
3. The process as claimed in claim 1, wherein the pericarp portion is
separated from the selected weight of soap nuts by peeling.
4. The process as claimed in claim 1, wherein 25% of the brown gummy
mass of saponin extract is obtained from the predetermined weight of cut pericarp
portion.
5. The process as claimed in claim 1, wherein the step of distillation
comprises: heating the filtered solution comprising a mass of saponin extract and
ethyl alcohol in a distillation flask to volatise ethyl alcohol; condensing the
volatised ethyl alcohol in a condenser to liquid state; collecting the ethyl alcohol in
a collection vessel, and obtaining the brown mass of saponin extract after
separating the ethyl alcohol.
12
6. The process as claimed in claim 1, wherein the obtained saponin extract
is dark brown in colour, has a thick gummy texture, and forms foam when
dissolved in water.
7. The process as claimed in claim 1, wherein a predetermined
concentration of the obtained saponin significantly reduces viscosity of crude oils
upto 98%.
8. A saponin extract exhibiting dark brown colour and a thick gummy
texture, said saponin extract prepared from a process comprising the steps of:
removing impurities and moisture from a selected weight of soapnuts;
cutting into pieces a pericarp portion separated from the selected weight
of soapnuts;
soaking a predetermined weight of the cut pericarp portion in a
predetermined volume of ethyl alcohol for 24 hours to obtain a solution, wherein
the ratio of weight of the cut pericarp portion to the volume of ethyl alcohol is 1:3;
refluxing the solution comprising ethyl alcohol and the cut pericarp portion
at 78ᵒC for 42-48 hours; and
obtaining a gummy brown mass of the saponin extract from the refluxed
solution by cooling the refluxed solution to room temperature, followed by
filtration and distillation to remove ethyl alcohol.
9. The saponin extract as claimed in claim 8, wherein a predetermined
concentration of saponin extract provides upto 97% viscosity reduction in crude
oils having significant resin content.