Note: Descriptions are shown in the official language in which they were submitted.
~ WO95/17104 2 1 5 4 6 6 2 PCr/uss4ll4o53
Stable Particulate Sweetener Compositions
Related Ap~lication Information
The present application is a continuation-in-part
of U.S.S.N. 08/163,163 filed on December 7, 1993.
5 Backaroun~ of the Invention
The present invention relates to the preparation
of stabilized particulate high intensity sweeteners for
use in dry foods and powdered beverage applications.
More specifically, the present invention relates to
10 stable dipeptide-based sweetener compositions that are
formulated as stable, free flowing particles for use in
the food and beverage industries.
Aspartame (APM) is a well known dipeptide
sweetener manufactured and sold by The NutraSweet
15 Company of Deerfield, Illinois, as NutraSweet Brand
sweetener. Additionally, there are some foreign
manufacturers of aspartame. When used herein, the term
"aspartame" or "APM" refers to cx-L-aspartyl-L-
phenylalanine methyl ester, its' salts and metal
20 complexes as taught in U.S. Patent Nos. 3,492,131 and
3,714,139 to Schlatter. Salts and metal complexes of
APM are also disclosed in U.S. Patent Nos. 4,448,716
and 4,439,460 to Tsau et. al., 4,029,701 and 4,031,258
to Berg et. al., all of which are incorporated herein
25 by reference.
The major application for aspartame is as a low
calorie sweetener in the food and beverage industries.
Aspartame powder is sold in bulk to the various food
and beverage manufacturers who must then either
30 incorporate the sweetener directly into the final
product (food and dry applications) or repackage the
sweetener and distribute it to the various bottlers
WO 9S/17104 PCT/US94/140S3 ~
21~4~2
--2--
which subsequently mix into the liquid beverage
composition. Aspartame in bulk is commercially
available as both powder and granulated forms.
Aspartame powder Pex se has low bulk density and good
dissolution properties. Yet, due to the very nature of
its lower bulk density and small particle size, the
powder is readily air-borne and oftentimes may have
dusting and flow problems. The granular form has a
higher bulk density and possesses good flow properties
but does not always instantaneously dissolve. These
properties can result in product losses and metering
problems, a need for expensive packaging and overall
shipping and hAn~l;ng inconveniences.
The present invention improves the overall
stability and flowability of aspartame during shipping
and storage. The dipeptide nature of the compound
renders it highly susceptible to degradation by heat
and other chemicals through the hydrolysis of the its
peptide bonds. Long term storage or the storage of APM
powder in areas of high temperatures often results in
the loss of much of its sweetness as these conditions
tend to bring about the cyclization of the molecule
into its diketopiperazine derivative. Moreover, the
powder itself is hard to handle and oftentimes some
becomes lost in the environment as "dust". In the
beverage industry some of the bulk aspartame powder is
lost as dust in the air during hAn~llng and shipping
prior to dissolution of the powder into the beverage
solution during manufacture. When one is dealing in
tons of aspartame per year, these can be considerable
losses if left unchecked and which if reduced will
result in major cost reductions. The present invention
el- ml n~Ates this problem.
Finally, another advantage of the stabilized APM
particulate compositions of the present invention is
~ WO95/17104 21 ~ 4 6 ~ 2 PCT~Sg4/14053
the dissolution and dispersion of the sweetener in
solution as compared with the unprocessed aspartame
powder. During beverage manufacture for example,
aspartame powder when mixed with the soft drink liquid
has a tendency to float on the surface of the liquid
and adhere to the sides of the container in which it is
mixed. In non-acidified liquids, both the powder and
granular forms tend to clump into a sticky mass that is
not easily dispersed and dissolved. Since the high
tech beverage manufacturing facilities of today require
precise metering of the liquid components of the
beverage to be made, such clumping is entirely
unacceptable. This requires the use of equipment for
agitation or stirring to mix the powder into the liquid
resulting in additional processing steps and costs of
manufacture.
In flavored dry mixes, for example flavored teas,
coffees, powdered soft drinks the flavors such as
vanilla, citrus and other similar flavors can interact
with aspartame resulting in the loss of flavor and
sweetness during storage. The aspartame has to be
protected with a physical barrier to prevent contact
and hence interaction with the flavor.
It has been surprisingly and unexpectedly found
that the stability and flow properties of dry aspartame
powder can be dramatically enhanced if the aspartame is
first added to and suspended in water and combined with
a minor amount of a stabilizing flow agent to form an
aqueous suspension which is then mixed with an aqueous
solution of a coating agent, said mixture being
subsequently dried so that the coating agent
encapsulates the aspartame/flow agent blend. Preferably
the suspension is spray dried so as to form a fine,
particulate encapsulated product that protects the
aspartame from reacting with other flavor and chemical
WO95/17104 PCT~S94/14053 ~
2 1 ~ 2
ingredients in dry food and powdered beverage products
and enhances the sweeteners flow properties and other
physical characteristics.
United States Patent No. 4,722,844 to T. Ozawa et.
5 al. teaches the preparation of aqueous APM suspensions
which are asserted to be both chemically and physically
stable. In water, like most crystalline materials, APM
particles sink and settle since APM's specific gravity
is significantly greater than that of water. To obtain
10 physically stable APM suspensions, this patent teaches
the addition of a viscosity or specific gravity
increasing component, such as food gums and
polysaccharides. The patent discloses physically
stable APM suspensions (2.0%-5.0%) in sugar syrups such
15 as isomerized sugar and sorbitol. The aspartame
suspensions of Ozawa et. al. '844 use an a~ueous
vehicle that is high in sugar, polysaccharide or food
gum content, i.e. over 50~, and low aspartame content.
Such a product will not be acceptable however, for use
20 in most food applications.
United States Patent No. 4,007,288 to Glicksman
et. al. discloses a readily soluble sweetening
composition for use in foods and beverages wherein the
aspartame is first solubilized with a bulking agent
25 such as dextran or some other hydrolyzed starch
material and the solution is then vacuum drum dried to
a composite powder of sweetener and bulking agent.
United States Patent No. 4,631,195 to Colliopoulos et.
al. discloses another attempt at stabilizing aspartame
30 for cooking and baking applications whereby the r
aspartame is co-dried with polyglucose or polymaltose.
U.S. Patent No. 4,619,833 to Anderson teaches a rapidly
soluble dry beverage mix in which aspartame is dry
mixed with a dispersion of food acids, flow
35 conditioners and maltodextrin.
~ WO 95/17104 2 ~ 5 4 6 6 2 PCT/US94/14053
Finally, United States Patent No. 4,001,456 also
to Glicksman et. al. teaches sweetening compositions in
which aspartame is ~ A in an aqueous solution of a
bulking agent comprising an organic acid, hydrolyzed
starch materials and sugars wherein the solution is
then spray dried to form a fine, agglomerated
APM/bulking agent powder. None of the prior art
however, teaches a physically stable aspartame
composition with a high APM content that is a highly
flowable particulate powder for easy h~nA11ng and
storage that is useful in a broad range of dry food and
beverage applications.
SummarY of the Invention
The present invention relates to a high intensity
sweetener composition and method for its preparation.
More specifically, the invention comprises a stabilized
dipeptide sweetener that is prepared as an aqueous
suspension and mixed with a minor amount of a water
soluble flow agent comprising food grade polymers,
hydrocolloids and gums to form a suspension. The -
suspension is then mixed with a solubilized
encapsulation agent comprising maltodextrin, gum
arabic, starches and the like, said mixture is then
dried so that the maltodextrin or gum coats and
encapsulates the aspartame/flow agent composition as a
dry particulate powder. The sweetener composition
exhibits superior flow and shelf stable properties and
particularly lends itself to dry food and powdered
beverage applications.
Detailed Description of the Invention
The ingredients and parameters that go into the
preparation of the aspartame suspension which serves as
the starting point in the process of the present
WO 95117104 PCT/US94/140S3
~15~62
--6--
claimed invention is more particularly and fully set
forth in copending application U.S.S.N. 08/163,163
which is hereby incorporated by reference. The
aspartame liquid suspension described therein is a
relatively pure aqueous aspartame suspension with an
APM concentration of from about 10% to 70% by weight
that is physically stable under long term and adverse
storage conditions as well as providing greater ease in
h~n~11ng than bulk aspartame crystalline powder. The
problem with most APM suspensions of high aspartame
concentrations, i.e. >20%, is that they become highly
viscous, sticky and not sufficiently flowable for the
most food and beverage applications, and particularly
those requiring a particulate sweetener in its dry
state. The APM suspensions described therein are less
viscous, free flowing and are particularly suited for
use in the dry, powdered beverage industry.
For purposes of the present disclosure, the term
suspension refers to a system whereby very small
particles (solid, semi-solid or liquid) are more or
less uniformly dispersed in a different liquid or
gaseous medium. If the particles are small enough to
pass through a filter membrane, the system is
colloidal. If the particles are larger than this, they
will tend to precipitate and sink since they are
heavier than the surrounding solution. Naturally, if
they are lighter than the solution however, they will
agglomerate and rise to the surface.
The suspension which serves as a starting point
for the preparation of the sweetener compositions of
the present invention is first prepared through the
incorporation of a small amount of a water soluble flow
agent such as food grade polymers, hydrocolloids or
gums into an aqueous aspartame solution. Suitable flow
agents include, but are not limited to sodium
~ WO9S/17104 21~ 46 6 2 PCT~S94/14053
carboxymethyl cellulose, algin, gum arabic,
carrageenan, xanthan gum, guar gum, hydroxypropyl
methyl cellulose (HPMC), methylcellulose, pectin,
locust bean gum, sodium alginate, propylene glycol
alginate, caramel and mixtures thereof. Trace amount
of an emulsifier or wetting agent such as polysorbate
(polyoxyethylene fatty acid ester) or lecithin may also
be incorporated to improve the suspensions' dissolution
and stability characteristics.
The water soluble food grade polymers,
hydrocolloids, gums and mixtures thereof are
incorporated into the aspartame aqueous suspension in
amounts of from about 0.001~ to about 0.5~ by weight of
the total weight of the suspension. Levels exceeding
0.5~ will continue to reduce the viscosity of the
suspension but this is not critical to the practice of
the present invention and viscosity is reduced to a
less effective degree than the lower levels.
When mixed in a suspension with the stabilizing
flow agent, aspartame levels of from approximately 10%
to about 70~ by weight of the total weight of the
suspension is achievable. Preferably, said aspartame
is incorporated in amounts of from about 20~ to about
55% by weight and most preferably in an amount of from
about 20~ to about 35% by weight of the entire
suspension.
Although aspartame powder is sparingly soluble in
water by itself, suspensions of up to 30~ can be made.
However, this pure aspartame/water suspension is a very
viscous foam or paste which does not lend itself to
most food and beverage processing operations. The
addition of the polymers, hydrocolloids or gums to the
a~ueous suspension of aspartame surprisingly alters the
flow characteristics of the suspension to a more fluid
form exhibiting pseudoplastic flow behavior with
WO 95/17104 PCT/US94/140!;3
B ~
enhanced dissolution properties and stability.
Traditionally, hydrocolloids have been used to
increase the viscosity of fluids. In the present case
however, the addition of the hydrocolloid turns the
foam into fluid, the viscosity decreases, and the APM
suspension becomes fluidized thereby becoming more
manageable. Microscopy data shows that the APM
crystals surround air bubbles in the foam and that the
crystals are floating or moving freely in a liquid
suspension. Without being bound to any theory, this
phenomena may be explained by the fact that APM is a
dipeptide with a hydrophobic group in its structure.
When this is dissolved in water, the water becomes
organized and further addition of the APM crystals
creates the foam by the stabilized aspartame. Addition
of a small amount of a very hydrophilic polymer like
carrageenan or sodium carboxymethyl cellulose (sodium
CMC) frees up the water and allows more APM to be added
to the system.
The aspartame/flow agent suspension is then
combined with an aqueous solution of the encapsulation
agent or agents. Suitable encapsulating agents are
carbohydrates such as the dextrins, gum arabic and
starches. Specifically, maltodextrin with a low
dextrose equivalent (DE) value of from about 5.0 to
about 25.0 is preferred while maltodextrins with a DE
value of from about 10.0 to about 15.0 are most
preferred. Commercially available maltodextrins that
are suitable in the practice of the present invention
include the Maltrin0 series of maltodextrins (Grain
Processing Corp., Muscatine, Iowa).
Gum arabic and any number of food grade starches
will also provide suitable encapsulation functionality.
Whereas native starches provide little emulsification
properties to spray dried flavors and sweeteners, there
~ WO 95/17104 2 ~ ~ 4 ~ ~ ~ PCT/US94/14053
_g _
is a great deal of improvement when the starch is
modified through esterification with a substituted
cyclic dicarboxylic acid anhydride. Commercially
available modified starches include N-Lok and Capsul,
two modified waxy maize starches (National Starch,
Bridgewater, N.J.) and Amylogum CLS, a modified potato
starch.
Hydrolyzed starches also perform well as the
encapsulating agent. Suitable commercially available
hydrolyzed starches include two lipophilic modified
waxy corn starches, Sta-Mist 515 and Mira-Cap (Staley
Inc., Decatur, Ill.). Mixtures of these agents may
also be employed and a commercially available mixture
known as ARS is available which is a blend of dextrins,
carageenans and dextrose. Another excellent blend is
National 46, a combination of dextrin and a hydrolyzed
starch. (Grain Processing Corp., Muscatine, Iowa).
The use of gums with hydrolyzed starch for example,
provides a better product than the hydrolyzed starch
alone in many applications as the blend exhibits
greater emulsification properties. In summary then,
whatever encapsulation agent/agents is selected depends
in part upon what flavor or sweetener is being
encapsulated. In the case of the particulate aspartame
sweetener, maltodextrin is most preferred.
The a~ueous aspartame/flow agent suspension
preferably comprises a 50~ aspartame concentration and
is mixed with the encapsulation agent solution
thoroughly prior to drying. The amount of encapsulation
! 30 agent dissolved in solution and mixed with the
aspartame/flow agent suspension also depends upon the
type of agent used and the application to which the
finished encapsulated particulate product is employed.
Generally, the specifications listed on the packaging
or labeling for each respective encapsulation agent
WO 95/17104 PCT/US94114053
2~ ~4~2
- 1 o -
will provide additional guidance in this area.
Preferably maltodextrin/APM weight ratios of from about
3:7 to 7:3 may be used, and more particularly ratios of
2:3 to 3:2 give best results. However,
maltodextrin/aspartame ratios of 1:99 to about 5:95
respectively, are sufficient to stabilize the aspartame
and prevent "balling" or "pilling" of the sweetener
composition as is known in the art of blending dry,
powdered ice tea and soft drink beverage compositions.
When aspartame powder is gently mixed with dry foods
such as powdered coffee, tea etc. in a "V" type
blender, the aspartame can segregate and form "pills"
or "balls" and is not well distributed in the final
product. This phenomenon occurs only in gentle
bl~n~ng operations when more attrition is used. In a
ribbon blender, this does not occur. The addition of
about 1.0% to 5.0% maltodextrin to the APM liquid
suspension and subsequent spray drying of the mixture
to a powder yields a product with flow properties that
do not cause pill or ball formation in gentle ml ~1 ng
operations. Moreover, aspartame/maltodextrin/gum
arabic mixtures in ratios of about 15:9:1 respectively,
yield an encapsulated dry aspartame particle that
exhibits particularly excellent flow properties.
The encapsulated product may conceivably be made
by any one of a number of the drying methodologies as
is known in the art such as pan drying, spray drying,
spheronized particle air flow drying and the like.
Preferably, the APM suspension and coating solutions
are mixed together and spray dried using a Niro spray
drier or rotary atomizer apparatus.
Prior to spray drying the aspartame flow agent
suspension with the encapsulation agent, th~ viscosity
of the aqueous suspension should range from about 200-
1500 m.P.a. and preferably, 200-1000 m.P.a. at a shear
~ WO95/17104 PCT~S94/14053
~ 1 5~6 2
of 1/100 sec. using a Haake Vlscometer, (Haake Buchler
Instruments Inc., Saddlebrook, N.J.). For optimized
spray drying results, the aqueous suspension and the
encapsuIating agent should be combined in a well mixed
solution wherein the solids comprise from about 20~ to
about 60% of the total mixture. This concentration
range produces the optimum viscosity for atomization
and efficient encapsulation. The temperature of the
blend is also important as it has a direct effect on
the viscosity of the feed suspension. Preferably, the
feed solution should be maintained at a temperature of
from about 60 to about 100F and ideally from about
60 to 80F.
The dry, stable, free flowing aspartame particles
are particularly useful in powdered beverage
compositions which are packaged and sold as a dry
powder and subsequently prepared as an aqueous beverage
by ml~ng a pre-determined amount in water. Powdered
flavored coffees, teas, cocoa, fruit drinks and
powdered dietary beverage formula are particularly
improved through the use of this sweetener.
The following examples are provided to more
specifically describe and set forth several
contemplated embodiments of the present invention.
They are for illustrative purposes only and it is
understood that minor changes and alterations may be
made to the parameters of the process or the
ingredients used therein which are not specifically
detailed. It is to be recognized that such changes
which do not materially alter or affect the final
product are still considered as falling within the
spirit and scope of the invention as recited by the
claims that follow.
WO9S/17104 PCT~S94/14053 ~
~ 2~4~62
Example I
A number of aspartame (APM) liquid suspensions at
50% concentration were prepared using the stabilizing
flow agents of the present invention comprising the
following food polymers, hydrocolloids and gums in an
amount of approximately 0.2% ~0.3~ by weight of the
total weight of the suspension. The flow curves of the
suspensions were generated using the Haake
Rotoviscometer Model VT500 at 25C using a MV1 sensor.
The viscosity at 54 1/s is reported below.
Viscosity at
PolYmer Flow Aaent54 (l/s) shear rate 25C
Carrageenan 32
Sodium Alginate 88
15 Xanthan gum 63
Sodium carboxymethyl cellulose 111
Locust bean gum 519
Guar gum 193
Pectin 1512
20 Gum Arabic 679
Propylene glycol alginate 18
Caramel DS #400 166
A combination of polymer flow agents can also be used
to make fluid 50% APM suspensions in water as shown
25 below:
Viscosity at
Polvmer Flow Aaent54 (l/s) shear rate 25C
0.2% Carrageenan + 0.05% Xanthan 58
0.2% Carrageenan + 0.05% Locust
bean gum 68
0.2% Carrageenan + Guar gum43
0.2% Carrageenan + 0.05%
Sodium carboxymethyl cellulose 64
Samples of the above suspensions (50 ml.) were
placed in test tubes and spun in a table-top centrifuge
for fifteen (15) minutes at 50 g. After this time, all
suspensions exhibited less than 2.0% sedimentation in
the tubes.
~ W O 95/17104 2 1 ~ 4 ~ ~ 2 PCTrUS94/14053
Example II
Two stable, particulate sweetener compositions of
the present invention were prepared as follows:
Sam~le A
4000 gms. liquid APM suspension (50%
concentration)
-0.3~ carboxymethylcellulose as the flow agent
Sample B
6000 gms. liquid APM suspension (50
concentration)
-3.0% carboxymethylcellulose as the flow agent
In two separate containers, 2000 and 3000 gms. of
maltodextrin with a DE value of approximately 15
(Maltrin~ 100) were mixed in 2000 and 3000 gms. of
distilled water respectively. The solutions were
warmed to approximately 38C and stirred until the
maltodextrin was completely dissolved. Sample A was
then added to the 2000 gms. maltodextrin solution while
sample B was added to 3000 gms. solution, and both were
stirred until uniform solutions were obtained. The
mixture was then dried in a Niro spray drier equipped
with a rotary atomizer. The inlet temperature is from
approximately 150C to about 200C and outlet
temperature is from approximately 90C to about 110C.
The rotary atomizer wheel is at about 2000-5000 r.p.m.
The mixture is atomized into fine droplets which are
dried in the drier by air and the resulting powder
consists of spherical particles in which APM is
encapsulated by the maltodextrin. The powder is free
flowing and is readily dissolved in water.
