HIGHLY SOLUBLE REBAUDIOSIDE D
PRIOR APPLICATION INFORMATION
This application is entitled to the earlier filing dates of, and claims the benefit of
priority to, U.S. Provisional Application No. 61/422,403, filed on December 13, 2010, and
U.S. Provisional Application Number 61/424,798, filed on December 20, 2010, the
contents of which are incorporated by reference herein in their entirety.
FIELD OF THE INVENTION
The invention relates to a process for producing highly soluble compositions
containing purified steviol glycosides from Stevia rebaudiana Bertoni plant extract, more
particularly Rebaudioside D.
BACKGROUND OF THE INVENTION
High intensity sweeteners possess a sweetness level many times exceeding that of
sucrose. They are essentially non-caloric and used widely in manufacturing of diet and
reduced calorie food. Although natural caloric sweeteners such as sucrose, fructose, and
glucose provide the most desirable taste to consumers, they possess high calorie values.
High intensity sweeteners do not affect the blood glucose level and provide little or no
nutritive value.
Stevia rebaudiana Bertoni is a perennial shrub of the Asteraceae (Compositae)
family native to certain regions of South America. The leaves of the plant contain from 10
to 20% of diterpene glycosides, which are around 150 to 450 times sweeter than sugar.
The leaves have been traditionally used for hundreds of years in Paraguay and Brazil to
sweeten local teas and medicines.
At present there are more than 230 Stevia species with significant sweetening
properties. The plant has been successfully grown under a wide range of conditions from
its native subtropics to the cold northern latitudes.
The extract of Stevia rebaudiana plant contains a mixture of different sweet
diterpene glycosides, which have a single base - steviol - and differ by the presence of
carbohydrate residues at positions C13 and CI9. These glycosides accumulate in Stevia
leaves and compose approximately 10% - 20% of the total dry weight. Typically, on a dry
weight basis, the four major glycosides found in the leaves of Stevia are Dulcoside A
(0.3%), Rebaudioside C (0.6-1.0%), Rebaudioside A (3.8%) and Stevioside (9.1%). Other
glycosides identified in Stevia extract include Rebaudioside B, C, D, E, and F,
Steviolbioside and Rubusoside. Among steviol glycosides only Stevioside and
Rebaudioside A are available on a commercial scale.
Steviol glycosides have zero calories and can be used wherever sugar is used.
They are ideal for diabetic and low calorie diets. In addition, the sweet steviol glycosides
possess functional and sensory properties superior to those of many high potency or high
intensity sweeteners.
Rebaudioside D (CAS No: 63279-13-0), as shown in Fig. 1, is one of the sweet
glycosides found in Stevia rebaudiana. Studies show that highly purified forms of
Rebaudioside D possess a very desirable taste profile, almost lacking the bitterness and
lingering licorice aftertaste typical for other Steviol glycosides.
These properties multiply the significance of Rebaudioside D and attract great
interest for methods of preparation of highly purified forms of Rebaudioside D. However,
highly purified steviol glycosides possess relatively low water solubility. For example
Rebaudioside A thermodynamic equilibrium solubility at room temperature is only 0.8%.
On the other hand, it is well known that Rebaudioside A exhibits so called
polymorphism (Zell T.M., Padden B.E.. Grant D.J.W., Schroeder S.A., Wachholder K.L.,
Prakash I., Munsona E.J. (2000) Investigation of Polymorphism in Aspartame and
Neotame Using Solid-State NMR Spectroscopy, Tetrahedron, 56, 6603-6616).
Rebaudioside A amorphous, anhydrous and solvate forms differ significantly from each
other in terms of solubility, which is one of the main criteria for the commercial viability
of a sweetener. In this regard, as shown in Table 1, the hydrate form of Rebaudioside A
displays the lowest solubility (Prakash I., DuBois G.E., Clos J.F., Wilkens K.L., Fosdick
L.E. (2008) Development of rebiana, a natural, non-caloric sweetener. Food Chem.
Toxicol., 46, S75-S82 ) . It was shown that Rebaudioside A may transform from one
polymorph form to another at certain conditions (US Pat. Appl. 11/556,049).
Table 1
Properties of Rebaudioside A forms (US Pat. Appl. 11/556,049)
Rebaudioside D possesses even lower water solubility compared to Rebaudioside
A. In room temperature it can be dissolved only at 0.05%. When heat is applied, one can
make up to 0.5% solution, but upon cooling to room temperature, Rebaudioside D will
quickly crystallize back out from the solution. Considering high sweetness intensity of
Rebaudioside D, even 0.05% solubility can be sufficient for many applications.
Many food production processes use highly concentrated ingredient mixes prior to
producing final forms of food products. In that case, higher concentrations of dissolved
Rebaudioside D will be required. It has to be noted that using the heat for dissolution of
Rebaudioside D may not be possible in many compositions which contain heat sensitive
components. Also maintaining high temperature of mixture for prolonged time to prevent
premature crystallization of Rebaudioside D can cause thermal degradation of mixture
components or undesirable changes of organoleptic properties.
Therefore there is a need for developing highly soluble forms or compositions of
Rebaudioside D which can provide stable solutions with minimal or no heat treatment.
Furthermore, considering the similar chemical structures of Rebaudioside D and
other steviol glycosides, as well as other terpene glycosides, the developed approaches
may be used in the case of other glycosides as well.
SUMMARY OF THE INVENTION
The invention relates to a process for producing highly soluble compositions
containing purified steviol glycosides from Stevia rebaudiana Bertoni plant extract, more
particularly Rebaudioside D.
Hereinafter the term "steviol glycoside(s)" will mean Rebaudioside A,
Rebaudioside B, Rebaudioside C, Rebaudioside D, Rebaudioside E, Rebaudioside F,
Stevioside, Steviolbioside, Dulcoside A, Rubusoside, or other glycoside of steviol and
combinations thereof.
Hereinafter, unless specified otherwise the solubility of material is determined in
RO (reverse osmosis) water at room temperature. Where the solubility is expressed as "%"
it to be understood as number of grams of material soluble in 100 grams of solvent.
Hereinafter the term "highly purified" will mean purity level of at least 95% (w/w)
on anhydrous basis.
Hereinafter the term "low purity" will mean purity level of less than 95% (w/w) on
anhydrous basis.
Hereinafter the term "TSG content" will mean Total Steviol Glycosides content,
and it will be calculated as sum of all steviol glycosides' content including Rebaudioside
A, Rebaudioside B, Rebaudioside C, Rebaudioside D, Rebaudioside E, Rebaudioside F,
Stevioside, Steviolbioside, Dulcoside A and Rubusoside.
Hereinafter the terms "Reb A, B, C, D, E, F" refer to Rebaudiosides A, B, C, D, E,
F, respectively.
Hereinafter the term "Reb D" refers to Rebaudioside D (CAS No. 63279-13-0).
Hereinafter the term "crystalline Rebaudioside D" will refer to any form of highly
purified Rebaudioside D obtained by crystallization from an aqueous or aqueous alcoholic
solution containing Rebaudioside D and further separating the Rebaudioside D crystals
and drying them by any means known to the art.
Hereinafter the term "amorphous Rebaudioside D" will refer to any form of highly
purified Rebaudioside D obtained by spray drying or freeze drying of aqueous or aqueous
alcoholic solution containing Rebaudioside D.
Hereinafter the terms "non-steviol glycoside fraction" or "non-glycoside fraction"
will mean materials predominantly comprising compounds, other than steviol glycosides,
which are present in the water extracts of Stevia rebaudiana leaves or commercially
available stevia extracts at more than 0.0001% (w/w) on dry basis. Not limiting examples
of such compounds include typical plant materials, such as pigments and saccharides,
phenolic compounds, volatile oil components, sterols, triterpenes, flavonoids, coumarins,
non-glycosidic diterpenes (sterebins) spathulenol, decanoic acid, 8,11,14-ecosatrienoic
acid, 2-methyloctadecane, pentacosane, octacosane, stigmasterol, bsitosterol, a- and bamyrine,
lupeol, b-amyrin acetate, and pentacyclic triterpene or combinations thereof. The
materials designated as "non-steviol glycoside fraction" or "non-glycoside fraction" and
prepared in some embodiments of present invention may also contain small residual
amounts of steviol glycosides.
Hereinafter the term "polyol" refers to a compound that contains more than one
hydroxyl group. A polyol may contain 2 to 7 hydroxyl groups. Non-limiting examples of
polyols include erythritol, maltitol, mannitol, sorbitol, lactitol, xylitol, inositol, isomalt,
propylene glycol, glycerol (glycerine), threitol, galactitol, reduced isomaltooligosaccharides,
reduced xylo-oligosaccharides, reduced gentio-oligosaccharides,
reduced maltose syrup, reduced glucose syrup or combinations thereof.
Hereinafter the term "molasses" refers to sugarcane molasses such as first
molasses, second molasses, US grade "A", "B", "C", and substandard blackstrap molasses,
as well as beet sugar molasses, boil-back molasses, high-test molasses, refiners' molasses,
sweet sorghum syrup. Non-limiting examples of typical constituents of molasses are
sucrose, glucose, fructose, starch, gums, pentosans, hexitols, myoinositols, mannitol,
aminoacids, wax, sterols, phosphatides, aconitic, citric, malic, oxalic, glycolic, succinic,
fumaric acids, melanoidins or mixtures thereof.
Hereinafter the term "caramel" refers to class I (INS No: 150a), Class II (INS No:
150b) class III (INS No: 150c), and class IV (INS No: 150d) caramel colors or mixtures
thereof.
In one embodiment of the invention, crystalline Reb D was dissolved in a water
ethanol mixture and spray dried to obtain amorphous form of Reb D with improved
solubility.
In another embodiment, crystalline or amorphous Reb D is combined with a polyol
at a ratio of 1:100 to 100:1 (w/w) to obtain a composition with improved RebD solubility.
In yet another embodiment, the combination of crystalline Reb D and polyol at a
ratio of 1:100 to 100:1 (w/w) is dissolved in water or aqueous alcohol and spray dried to
provide a composition with improved Reb D solubility.
In another embodiment, the combination of amorphous Reb D and polyol at a ratio
of 1:100 to 100:1 (w/w) is granulated by means of roll compact granulator. The granulated
material made in accordance with the present invention advantageously yields a product
with favorable characteristics such as Reb D solubility and particle size distribution.
In another embodiment, steviol glycosides are separated from Stevia rebaudiana
leaves' water extract to obtain the non-glycoside fraction of Stevia. Any separation
technique known to the art, such as chromatographic separation, crystallization from water
or aqueous alcohol, adsorption on specific resins, membrane separation, or supercritical
fluid extraction may be employed.
In another embodiment, amorphous or crystalline Reb D is combined with a nonglycoside
fraction of stevia at a ratio of 1:100 to 100:1 (w/w) to obtain a composition with
improved RebD solubility.
In yet another embodiment the combination of crystalline Reb D and nonglycoside
fraction of stevia at a ratio of 1:100 to 100:1 (w/w) is dissolved in water or
aqueous alcohol and spray dried to provide a composition with improved Reb D solubility.
In another embodiment, amorphous or crystalline Reb D is combined with
molasses or caramel at a ratio of 1:100 to 100:1 (w/w) to obtain a composition with
improved RebD solubility.
In yet another embodiment, the combination of crystalline Reb D and molasses or
caramel at a ratio of 1:100 to 100:1 (w/w) is dissolved in water or aqueous alcohol and
spray dried to provide a composition with improved Reb D solubility.
It is to be understood that both the foregoing general description and the following
detailed description are exemplary and explanatory and are intended to provide further
explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWING
Fig. 1 shows the chemical structure of Rebaudioside D (CAS No: 63279-13-0).
DETAILED DESCRIPTION OF THE INVENTION
The invention is aimed to provide Rebaudioside D forms or compositions
containing Rebaudioside D with improved solubility in water.
In one embodiment, highly purified crystalline Rebaudioside D, which has a
solubility of 0.05%, was dissolved in aqueous alcohol at a concentration of 0.5 to 50%,
preferably 5-25%, more preferably 10-20%. The alcohol content used in aqueous alcohol
is 0.1-100% (vol/vol), preferably 20-70% (vol/vol), more preferably 30-50% (vol/vol).
The alcohol is selected from the group consisting of alkanols, more particularly methanol,
ethanol, n-propanol, 2-propanol, 1-butanol, 2-butanol or combinations thereof To dissolve
the Reb D, the solution is heated to 30-100°C, preferably 50-100°C, more preferably 60-
100°C. To prevent premature crystallization, the solution is maintained at 20-80°C,
preferably 30-70°C, more preferably 50-60°C. The solution is fed to a spray drier to obtain
a powder of highly purified amorphous Reb D with a solubility of 0.2%.
In another embodiment highly purified amorphous or crystalline Rebaudioside D is
combined with a polyol at a ratio of 1:1 to 1:100 (wt/wt), preferably 1:1 to 1:30 (wt/wt),
more preferably 1:1 to 1:10. The polyol is selected from group consisting of erythritol,
maltitol, mannitol, sorbitol, lactitol, xylitol, inositol, isomalt, propylene glycol, glycerol
(glycerine), threitol, galactitol, reduced isomalto-oligosaccharides, reduced xylooligosaccharides,
reduced gentio-oligosaccharides, reduced maltose syrup, reduced
glucose syrup or combinations thereof. Preferably, the polyol is selected from group
consisting of erythritol, maltitol, mannitol, sorbitol, lactitol, xylitol, inositol, and isomalt,
and more preferably, erythritol, maltitol, sorbitol, and isomalt. When the prepared
compositions containing crystalline Reb D are dissolved in water at room temperature the
solubility of Reb D is 0.1-2.0%. For compositions with amorphous RebD the solubility
under the same conditions is 0.3-2.0%.
In another embodiment, the combination of amorphous Reb D and polyol at a ratio
of 1:1 to 1:100 (w/w), preferably 1:1 to 1:30 (w/w), more preferably 1:1 to 1:10, is
granulated by means of any equipment known to art suitable for granulation of fine
powder into granules, preferably by means of a roll compact granulator. The roll speed
was between about 5-20 rpm, preferably between about 7-10 rpm, and more preferably
about 9 rpm. The roll pressure was between about 20-80 bar, preferably between about 40-
50 bar, and more preferably about 45 bar. The granulator rotors were rotating at a rate of
between about 50-2000 rpm, preferably between about 100-200 rpm, and more preferably
at about 150 rpm. The granulators were equipped with screens which sizes were between
about 0.5-6.0 mm, preferably between about 1-4 mm, and more preferably about 3.1 mm
for the pre-granulator and about 1.6 mm for the fine granulator. When the prepared
compositions are dissolved in water, the solubility of Reb D is 0.1-2.5%.
In another embodiment, the non-glycosidic fraction of stevia is combined with
crystalline Rebaudioside D, at a ratio of 1:1 to 1:100 (wt/wt), preferably 1:2 to 1:20
(wt/wt), more preferably 1:3 to 1:10. The mixture is dissolved in aqueous alcohol at a
concentration of 0.5 to 50%, preferably 5-25%, more preferably 10-20%. The alcohol
content in used aqueous alcohol is 0.1-100% (vol/vol), preferably 20-70% (vol/vol), more
preferably 30-50% (vol/vol). The alcohol is selected from the group consisting of alkanols,
more particularly methanol, ethanol, n-propanol, 2-propanol, 1-butanol, and 2-butanol. To
dissolve the Reb D, the solution is heated to 30-100°C, preferably 50-100°C, more
preferably 60-100°C. To prevent premature crystallization, the solution is maintained at
20-80°C, preferably 30-70°C, more preferably 50-60°C. The solution is fed to a spray
drier to obtain a powder of highly soluble Reb D composition. When the prepared
compositions are dissolved in water at room temperature the solubility of Reb D is 0.3-
5.0%, or 0.1-2.5%.
In another embodiment, molasses are combined with crystalline Rebaudioside D,
at a ratio of 1:1 to 1:100 (w/w), preferably 1:2 to 1:20 (w/w), more preferably 1:3 to 1:10.
The mixture is dissolved in aqueous alcohol at a concentration of 0.5 to 50%, preferably 5-
25%, more preferably 10-20%. The alcohol content in used aqueous alcohol is 0.1-100%
(vol/vol), preferably 20-70% (vol/vol), more preferably 30-50% (vol/vol). The alcohol is
selected from the group consisting of alkanols, more particularly methanol, ethanol, npropanol,
2-propanol, 1-butanol, 2-butanol. The molasses are selected from the group
comprising of US grade "A", "B" and "C" molasses as well as substandard molasses,
preferably grade "A" molasses. To dissolve the Reb D the solution is heated to 30-100°C,
preferably 50-100°C, more preferably 60-100°C. To prevent premature crystallization the
solution is maintained at 20-80°C, preferably 30-70°C, more preferably 50-60°C. The
solution is fed to a spray drier to obtain a powder of highly soluble Reb D composition.
When the prepared compositions are dissolved in water, the solubility of Reb D is 0.1-
3.5%.
In another embodiment, caramel is combined with crystalline Rebaudioside D, at a
ratio of 1:1 to 1:100 (w/w), preferably 1:2 to 1:20 (w/w), more preferably 1:3 to 1:10. The
mixture is dissolved in aqueous alcohol at a concentration of 0.5 to 50%, preferably 5-
25%, more preferably 10-20%. The alcohol content in used aqueous alcohol is 0.1-100%
(vol/vol), preferably 20-70% (vol/vol), more preferably 30-50% (vol/vol). The alcohol is
selected from the group consisting of alkanols, more particularly methanol, ethanol, npropanol,
2-propanol, 1-butanol, 2-butanol. The caramel is selected from the group
comprising of class I, class II, class III and class IV caramel colors, preferably, class I
caramel. To dissolve the Reb D the solution is heated to 30-100°C, preferably 50-100°C,
more preferably 60-100°C. To prevent premature crystallization the solution is maintained
at 20-80°C, preferably 30-70°C, more preferably 50-60°C. The solution is fed to a spray
drier to obtain a powder of highly soluble Reb D composition. When the prepared
compositions are dissolved in water, the solubility of Reb D is 0.3-3.5%.
The following examples illustrate preferred embodiments of the invention. It will
be understood that the invention is not limited to the materials, proportions, conditions and
procedures set forth in the examples, which are only illustrative.
EXAMPLE 1: Preparation of amorphous Rebaudioside D
lOOg of crystalline Rebaudioside D, produced by PureCircle Sdn Bhd, with 98.1%
purity (on anhydrous basis) was dissolved in 500 mL aqueous ethanol, containing 50%
(vol.) ethanol. The solution was maintained at 50°C and dried using a YC-015 laboratory
spray drier (Shanghai Pilotech Instrument & Equipment Co. Ltd., China) operating at
175°C inlet and 100°C outlet temperatures. The obtained amorphous powder was
compared with crystalline material for solubility.
Table 2
Solubility of Rebaudioside D
*Solutions obtained at 50°C and 100°C crystallized after cooling down to room temperature (20°C).
EXAMPLE 2: Preparation of non-glycosidic stevia fraction
500g of commercial stevia extract, containing Rebaudioside A 41.2%, Stevioside
30.6%, Rebaudioside C 9.9%, Rebaudioside F 2.3%, Dulcoside A 0.5%, Rubusoside
0.6%, Rebaudioside D 1.5%, Steviolbioside 0.2% and Rebaudioside B 0.1% were
dissolved in 9.5 liter of RO water and passed through a column packed with 10 liter
Amberlite XAD7HP resin. The column was washed with 10 volumes of RO water. The
collected water fractions were evaporated under vacuum at 55°C and spray dried to yield
45g powder with 9.8% TSG including 7.8% Rebaudioside D, 2.0% Rebaudioside A and
non-detectable amounts of other steviol glycosides.
EXAMPLE 3 : Preparation of Rebaudioside D soluble composition
lOg of crystalline Rebaudioside D, produced by PureCircle Sdn Bhd, with 98.1%
purity (on anhydrous basis) was mixed with different amounts of erythritol (Prima Inter-
Chem Sdn Bhd, Malaysia). The obtained blends were tested for solubility, and solution
stability to crystallization, during storage at room temperature.
Table 3
Solubility of Rebaudioside D blends
* Solubility is calculated for RebD % content in solution
** The material was dissolved at 100°C and cooled down to room temperature (20°C). The reported
concentrations are stable (do not crystallize) for 24hrs storage in room temperature.
EXAMPLE 4: Preparation of Rebaudioside D soluble composition
lOg of amorphous Rebaudioside D prepared according to EXAMPLE 1, was
mixed with different amounts of erythritol (Prima Inter-Chem Sdn Bhd, Malaysia). The
obtained blends were tested for solubility, and solution stability to crystallization, during
storage at room temperature.
Table 4
Solubility of Rebaudioside D blends
* Solubility is calculated for RebD %content in solution
** The material was dissolved at 100°C and cooled down to room temperature (20°C). The reported
concentrations are stable (do not crystallize) for 24hrs storage in room temperature.
EXAMPLE 5: Preparation of Rebaudioside D soluble composition
lOg of crystalline Rebaudioside D, produced by PureCircle Sdn Bhd, with 98.1%
purity (on anhydrous basis) was mixed with different amounts of erythritol (Prima Inter-
Chem Sdn Bhd, Malaysia). The obtained blends were dissolved in 5 volumes of aqueous
ethanol, containing 50% (vol.) ethanol. The solution was maintained at 50°C and dried
using a YC-015 laboratory spray drier (Shanghai Pilotech Instrument & Equipment Co.
Ltd., China) operating at 175°C inlet and 100°C outlet temperatures. The obtained
amorphous powder was tested for solubility, and solution stability to crystallization,
during storage at room temperature.
Table 5
Solubility of Rebaudioside D blends
* Solubility is calculated for RebD %content in solution
** The material was dissolved at 100°C and cooled down to room temperature (20°C). The reported
concentrations are stable (do not crystallize) for 24hrs storage in room temperature.
EXAMPLE 6: Preparation of Rebaudioside D soluble composition
lOg of crystalline Rebaudioside D, produced by PureCircle Sdn Bhd, with 98.1%
purity (on anhydrous basis) was mixed with different amounts of stevia non-glycosidic
fraction prepared according to EXAMPLE 2. The obtained blends were tested for
solubility, and solution stability to crystallization, during storage at room temperature.
Table 6
Solubility of Rebaudioside D blends
* Solubility is calculated for RebD %content in solution
** The material was dissolved at 100°C and cooled down to room temperature (20°C). The reported
concentrations are stable (do not crystallize) for 24hrs storage in room temperature.
EXAMPLE 7 : Preparation of Rebaudioside D soluble composition
lOg of amorphous Rebaudioside D, prepared according to EXAMPLE 1, was
mixed with different amounts of stevia non-glycosidic fraction, prepared according to
EXAMPLE 2. The obtained blends were tested for solubility, and solution stability to
crystallization, during storage at room temperature.
Table 7
Solubility of Rebaudioside D blends
* Solubility is calculated for RebD % content in solution
** The material was dissolved at 100°C and cooled down to room temperature (20°C). The reported
concentrations are stable (do not crystallize) for 24hrs storage in room temperature.
EXAMPLE 8: Preparation of Rebaudioside D soluble composition
lOg of crystalline Rebaudioside D was mixed with different amounts of stevia nonglycosidic
fraction, prepared according to EXAMPLE 2. The obtained blends were
dissolved in 5 volumes of aqueous ethanol, containing 50% (vol.) ethanol. The solution
was maintained at 50°C and dried using a YC-015 laboratory spray drier (Shanghai
Pilotech Instrument & Equipment Co. Ltd., China) operating at 175°C inlet and 100°C
outlet temperatures. The obtained amorphous powder was tested for solubility, and
solution stability to crystallization, during storage at room temperature.
Table 8
Solubility of Rebaudioside D blends
* Solubility is calculated for RebD % content in solution
** The material was dissolved at 100°C and cooled down to room temperature (20°C). The reported
concentrations are stable (do not crystallize) for 24hrs storage in room temperature
EXAMPLE 9: Preparation of Rebaudioside D soluble composition
lOg of crystalline Rebaudioside D, produced by PureCircle Sdn Bhd, was mixed
with different amounts of molasses (Chee Lam Trading, Malaysia). The obtained blends
were dissolved in 5 volumes of aqueous ethanol, containing 50% (vol.) ethanol. The
solution was maintained at 50°C and dried using a YC-015 laboratory spray drier
(Shanghai Pilotech Instrument & Equipment Co. Ltd., China) operating at 175°C inlet and
100°C outlet temperatures. The obtained amorphous powder was tested for solubility, and
solution stability to crystallization, during storage at room temperature.
Table 9
Solubility of Rebaudioside D blends
* Solubility is calculated for RebD % content in solution
** The material was dissolved at 100°C and cooled down to room temperature (20°C). The reported
concentrations are stable (do not crystallize) for 24hrs storage in room temperature
EXAMPLE 10: Preparation of granulated Rebaudioside D soluble composition
lkg of amorphous Rebaudioside D prepared according to EXAMPLE 1, was
mixed with different amounts of erythritol (Prima Inter-Chem Sdn Bhd, Malaysia). The
obtained blends were transferred to an Alexanderwerk WP 50N/75 roller compactor. The
compactor was operating at 9 rpm and 45 bar pressure. The compacted mass was fed to a
pre-granulator and a fine granulator with rotors at rotating at 150 rpm. The screen size for
the pre-granulator was 3.1 mm and for the fine granulator was 1.6 mm. The "overs"
(particles that are too large) and "fines" (particles that are too small) were separated by top
screen having a screen size of US Mesh 10 and bottom screen of US Mesh 40. The % ratio
of "overs":"product":"fines" was 0.9%:78.2%:20.9% respectively. The obtained products
were tested for solubility, and solution stability to crystallization, during storage at room
temperature.
Table 10
Solubility of Rebaudioside D blends
* Solubility is calculated for RebD % content in solution
** The material was dissolved at 100°C and cooled down to room temperature (20°C). The reported
concentrations are stable (do not crystallize) for 24hrs storage in room temperature
While the foregoing has described one or more embodiments of the present
invention, it will be understood by those skilled in the art that various changes and
modifications may be made and equivalents may be substituted for elements or
compositions thereof without departing from the true scope of the invention. Therefore, it
is intended that this invention not be limited to a particular embodiment disclosed, but that
the invention will include all embodiments falling within the scope of the appended
claims.
CLAIMS:
1. A method of preparing a highly soluble steviol glycoside, comprising the steps of:
a. providing a highly purified steviol glycoside;
b. dissolving the highly purified steviol glycoside in a solvent selected
from the group consisting of water or aqueous alcohol to make a
solution;
c. drying the solution to obtain the highly soluble steviol glycoside.
2. The method of claim 1, wherein the steviol glycoside is selected from the group
consisting of Rebaudioside A, Rebaudioside B, Rebaudioside C, Rebaudioside D,
Rebaudioside E, Rebaudioside F, Stevioside, Dulcoside A, and combinations thereof.
3. The method of claim 1 wherein the highly purified steviol glycoside comprises
Rebaudioside D.
4. The method of claim 1 wherein an alcohol content of the aqueous alcohol is about
0.1-100% (vol/vol), preferably about 20-70% (vol/vol), and more preferably about 30-50%
(vol/vol), and a ratio of aqueous alcohol to dissolved steviol glycoside solids (vol/wt) is
about 5:1 to about 10:1.
5. The method of claim 1 wherein drying is performed by a technique capable of
yielding materials with amorphous polymorphic forms.
6. The method of claim 1, wherein the highly soluble steviol glycoside is in an
amorphous powder form.
7. The method of claim 1, additionally comprising the step of blending the highly
purified steviol glycoside with a polyol to form a blend, and the dissolving step (b)
comprises dissolving the blend in the solvent.
8. The method of claim 7, wherein the highly purified steviol glycoside and the
polyol are blended to achieve a ratio (wt/wt) of steviol glycoside to polyol of about 1:100
to about 100:1, preferably about 1:1 to about 1:30, and more preferably about 1:1 to about
1:10.
9. The method of claim 7, wherein the polyol is selected from the group consisting of
erythritol, maltitol, mannitol, sorbitol, lactitol, xylitol, inositol, isomalt, propylene glycol,
glycerol (glycerine), threitol, galactitol, reduced isomalto-oligosaccharides, reduced xylooligosaccharides,
reduced gentio-oligosaccharides, reduced maltose syrup, reduced
glucose syrup, and combinations thereof.
10. The method of claim 7, wherein the polyol comprises erythritol.
11. The method of claim 1, additionally comprising the step of blending the highly
purified steviol glycoside with a non-glycosidic fraction of Stevia to form a blend, and the
dissolving step (b) comprises dissolving the blend in the solvent.
12. The method of claim 11 wherein a ratio (wt/wt) of the non-glycosidic fraction of
Stevia to the highly purified steviol glycoside is about 1:100 to about 100:1, preferably
about 1:2 to about 1:20, more preferably about 1:3 to about 1:10.
13. The method of claim 11 wherein the non-glycosidic fraction of Stevia is prepared
by a process comprising the steps of:
a. providing a stevia extract;
b. dissolving the stevia extract in water or aqueous alcohol to form a
stevia extract solution;
c. passing the stevia extract solution through a chromatographic
system packed with macroporous adsorbent resin capable of adsorbing steviol
glycosides;
d. collecting an effluent from the chromatographic system;
e. drying the effluent to obtain the non-glycosidic fraction of Stevia.
14. The method of claim 13, wherein the stevia extract contains about 10-95%,
preferably about 30-90%, and more preferably about 40-85% total steviol glycosides.
15. The method of claim 13, wherein the water or aqueous alcohol ratio to dissolved
stevia extract solids (vol/wt) is about 1:1 to about 200:1, preferably about 5:1 to about
100:1, more preferably about 10:1 to about 50:1.
16. The method of claim 13 wherein the amount of stevia extract exceeds an
adsorption capacity of the adsorbent in the chromatographic system by about 1-10 times,
preferably by about 1-5 times, and more preferably by about 1-1.5 times.
17. The method of claim 13, wherein the chromatographic system comprises about 1-
20 consecutively connected columns, preferably about 1-10 columns, and more preferably
about 1-6 columns.
18. The method of claim 1, additionally comprising the step of blending the highly
purified steviol glycoside with molasses to form a blend, and the dissolving step (b)
comprises dissolving the blend in the solvent.
19. The method of claim 18, wherein a ratio (w/w) of molasses to steviol glycoside is
about 1:100 to about 100:1, preferably about 1:2 to about 1:20 and more preferably about
1:3 to about 1:10.
20. The method of claim 18, wherein the molasses is selected from the group
comprising sugarcane molasses such as first molasses, second molasses, US grade "A",
"B", "C", and substandard blackstrap molasses; beet sugar molasses; boil-back molasses;
high-test molasses; refiners' molasses; sweet sorghum syrup; and a combination thereof.
21. The method of claim 1, additionally comprising the step of blending the highly
purified steviol glycoside with caramel to form a blend, and the dissolving step (b)
comprises dissolving the blend in the solvent.
22. The method of claim 1, wherein a ratio (w/w) of caramel to steviol glycoside is
about 1:100 to about 100:1, preferably about 1:2 to about 1:20, and more preferably about
1:3 to about 1:10.
23. The method of claim 21, wherein the caramel is selected from the group consisting
of Class I (INS No: 150a), Class II (INS No: 150b), Class III (INS No: 150c), and Class
IV (INS No: 150d) caramel colors and combinations thereof.
24. The method of claim 1, wherein the drying step comprises spray drying the
solution in a spray drier operating at an inlet temperature of about 50-200°C and an outlet
temperature of about 80-120°C.
25. The method of claim 6, further comprising blending the highly soluble amorphous
steviol glycoside with a polyol to form a blend, and granulating the blend to prepare a
highly soluble steviol glycoside composition.
26. A highly soluble steviol glycoside made by the method of claim 1.
27. A product comprising the highly soluble steviol glycoside of claim 26.
28. The product of claim 27, selected from the group consisting of a food product, a
beverage product, a pharmaceutcal composition, a nutraceutical composition, a tobacco
product, an oral hygiene composition and a cosmetic composition.