Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to the art of preparing
artificially s~eetened comestibles and more particularly to
means whereby the class of L-aspartic acid derivatives that
are sweet are effectively converted to a free flowing mixable
and highly soluble sweetening composition.
The members of the sweetening class of L-aspartic
acid derivatives such as the dipeptide L-aspartic acid ester
of L-phenylalanine, i.e., APM a~oresaid, are characteristically
less soluble than would be preferred for a so-called "instant" ~
comestible like a beverage mix containing the artificial ~`
sweetener. Accordingly, means have been pursued to render ~-
the compounds in this class more readily dispersible and
sGluble as by subdividing them and thus improving their rate
of solubility as well as their rate of dispersibility.
Attempts at subdivision of the crystalline particles of such
compounds to enhance the rate of solubility have not been too
successful and alternative means have been employed to ~ ~
effectively improve the rate of dispersion and hence the - ;
overall rate of solubility. One common problem of such
compounds appears to be their electrostatic properties; as ~ ;
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recovered in crystalline form, they possess an inherent
Zwitterion capacity; indeed as long as the compounds retain
their identity as sweeteners it appears that they possess
this capacity. Comestibles like beverage mixes containing
food acids and powderous flavors and colors when commingled
with the artificially sweetened compound will have erratic
flow properties due the electrostatic properties of the ~;
compound. Also, such mixes are prone to dusting and are not
free flowing relative to the more flowable active ingredients
which characterize the mix; the consequence are irregularities
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or even inoperative beverage and like comestible recipes.
Attempts at ammeliorating these effects as by screening are
not effective since such attempts at subdivision are not
pexmanent; the sweetening compound particles will reaggregate
under the influence of their inherent electrostatic charges.
It would be desirable to have a form of L-aspartic
acid-derived sweetening compound which is readily blendable
and flowable and which has a high rate of solubility and
dispersibility. Preferably, such a compound should be
blendable with characterizing flavoring and coloring in-
gredients or should lend itself to flavoring and coloring
while at the same time being a stable sweetening compound.
A procedure has now been identified whereby discrete
crystals of L-aspartic acid derivative compounds meeting the
foregoing requisites is produced by employing a minor amount
of the compound per se in solution as a medium to aggregate
the crystals thereof in an immobilized state, the crystals
being assembled randomly at spaced points of contact by the
dried solution of APM or like sweetening material.
In a typical subgeneric embodiment of this in-
vention, indeed the preferred form thereof, the sweetening
compound crystals are subdivided by hydromilling them to a
uniform particle size incident to which some crystals will be
dissolved and form agglutinating solutes; this hydromilled
slurry, preferably at a reduced temperature whereat solution
is minimized, is then dried as by spray drying droplets
produced by pumping the slurry through an atomizing nozzle;
the droplets advantageously dry in a form whereby the sub-
divided discrete crystals nest with one another while a part
of the droplet and are permanently bound to one another by
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the solute sweetening compound at their points of contact
such that when the droplet is recovered as a dry powder a
permanent agglomerate of sweetening compound in a free
flowing, rounded form.
S Another subgenus of the invention involves the
conversion of the sweetening compound into a semi-moist meal
or dough consistency produced by combining limited quantities .
of water and the sweetening compound in crystalline form, :
whereby the water partially dissolves a portion of the
sweetening compound forming an agglutinating solution which
enables the moist mixture of crystalline solids to be converted~
into an handleable mass, as by extruding at room temperature,
which extrudate or otherwise-shaped mass can be dried and
subsequently ground; the aggregated particles will possess ~;.
the same characteristic random nesting of crystalline sweeten- ~ ~
ing compounds adhering at their spaced points of contact . .`
through the intermediation of redried sweetening compound
acting to bridge the crystalline particles into i~mobilized .~ :
granules.
The processes of this invention and the products, ~
that is the compositions produced.thereby, will be chosen ::
dependent upon the intended advantageous use to be made of
the product. In the case of the preferred spray dried form ; ~ `
of particl~ having a very free flowing, high rate of solubil-
ity, this application will be preferred for beverage uses
whereas in other applications than in dry beverage mixes it
may be practical to resort to the dough-forming techniques to
be hereinafter described wherein a more granular form of
particulate structure will be suitable. :
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The invention will he useful in the effective
fixation of a broad class of L-aspartic acid derivatives
which will be categorized as follows-
(1) The methyl esters of L-aspartyl-2,5-
Dihydro-L-phenylalanine; L-aspartyl-L-(l-cyclohex-1-en)-
alanine; L-aspartyl-L-phenylglycine; L-aspartyl-L-2,5-di-
hydro-phenylglycine; ,
(2) methyl-L-aspartyl-L-alpha~phenylglycinase
and its salts.
(3) Lower alkyl esters of L-asparty~-L-(beta-
cyclohexyl)-alanine disclosed in South A~rica Patent No.
6,695,910 issued February 18, 1971 to Imperial Industries
Ltd.;
~4) Those alkyl esters classed as alpha-L or
DL-aspartyl-L or DL-substituted glycines described in Nether-
lands Patent No. 7,007,176 issued May 19, 1970 preparation of
aspartyl compounds and issued to Stamicarbon, N~
(5) Those hydrogenated dipeptide ester ~
sweeteners such as L-asparagio O-etherified serine methyl ~ ;
esters described in French Patent No. 2,105,896 issued April
28, 1972 for Dipeptide Ester Sweeteners to Takeda Chemicai
Industries Ltd.;
(6) Those aspartic acid peptide est~rs having
the formula:
H2CC(CH2COOH)HCONHC (Rlj(R2)COOR
where R and Rl are CH3 or C2H5 and R2 is C4-7 alkyl having
the stereo chemical form L-L, DL-L, L-DL, or DL-DL;
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(7) Those s~eetening agents haviny the ,~: -
formula: ~,
~N - CH - CONH - CH - COOR
C~I2 CH2
COOH pH
shown in British Patent 1,339,101 issued November 28, 1973
to G.D. Searle and Co., wherein R is a lower alkyl such as
methyl and is prepared by reacting an N-protected-L-aspartic
anhydride with L-phenylalanine lower alkyl esters, and
(8) Those sweetening preparations having the ,~
formula L-aspart~l-L-1,4-dimethyl-pentyl amide disclosed in , ,
German Patent No. 2,306,909 issued August 23, 1973 to
Proctor and Gamble. ,
In the preferred spray drying process, the L-
aspartic acid derivative crystal solids at a minor weight ~,~
percent are admixed with water and converted into,a slurry
maintained at a temperature much below 150F and typically
at ambient room temperature conditions, whereby a minimum of ,~
the sweetening compound is allowed to go into solution, the ~
vast majority of the derivative crystalline mate.rials being . : '
undissolved and at most hydrated. This slurry is thereafter
subjected to a hydromill processing wherein it will be force
hydromilled or otherwise.colloidally milled under pressure , '~
between a narrow orifice operative to subdivide.the crystal~
line material,to a uniform particle size distribution as by
passage.between a mill having an opening less than 125 ,~
microns intermediate the working mill faces. ~'
The hydromilled slurry is thereafter spray dried
into the intended form. The partial solution of the sweeten- ~
ing compound will be just sufficient to provide the ~'
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agglutenating adhesion intermediate the undissolved crystalline
sweetening compound solids whereby when a droplet is caused
to undergo evaporation the crystals will be randomly aggregated
at their spaced points of contact through the intermediation
of the redried compounds per se.
As indicated, the slurry may be dried by means
other than spray drying, spray drying being most preferred
in that by the formation of a droplet and the surface
tension effects produced thereby the crystals are caused to ~ -
be assembled into a spherical aggregated condition whence
they may be permanently bonded.to one another in the structure
intended to provide a substantial immobilization and reduction
of the effects of the electrostatic charges thereof. A ~ :
slurry may be dried by any one of a number of well known
drying methods of use in accordance with the food arts such
as drum.drying, oven drying, freeze drying, etc.; in all of
these applications, a slurry form that is relatively cool .
will be employed and if the slurry is dried in this unitary
condition en masse,. it will be subsequently subdivided into
the granular state of use.
In lieu of a slurry form, a dough may be produced
which takes advantage of the glutinous character of the
peptide and equivalent hydrated crystals which is generated
by the addition of a minor weight percent of water thereto, :~
whence a suitable dough or meal that is moist will be
produced and converted into a shape-retaining form.as by the
preferred step.of extrusion subsequent to.which the shape
will be redried and incident to which redxying the individual
crystals will be permanently bonded to one another through
the intermediation of thé redried dissolved sweetening
compounds.
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The slurry or dough practices do not preclude the
presence in the aqueous phase of compatible inert or ad-
junctive agents such as colors and even flavors provided
they are sufficiently incapable of entering into unstabiliz-
ing reactions with the L-aspartic acid derivative; thus, the
aqueous medium used to produce the slurry or meal may have
the coloring matter dissolved in the aqueous solvent; e.g. a
spray dried form can be advantageously colored requiring no
blending for this purpose. Likewise, water insoluble
materials may be emulsified or homogenized in the aqueous
medium forming a slurry or the dough for efficacious combina-
tion with the sweetening compound, the remaining water
present being operative to effect the partial dissolution of ; ?
the compound and form the agglutenating bridging solution.
Moreover, other artificial sweeteners such as
saccharin and/or cyclamates may be blended at minor weight
percents of the total composition to provide a balanced
organoleptic sweetening impact by forcs of the uniformity of
their distribution throughout the slurry or dough matrices
depending upon the particular process employed; in this~
application, it will be desired to employ the cyclamate at a
very minor weight percent of the saccharin which in turn
will be a very minor weight percent of the total L-aspartic
acid compound solids used whereby a preferred balanced
organoleptic sweetness will be afforded when the total
sweetening compounds are rendered soluble and used in
beverage or other food applications. In these applications,
the artificial sweeteners may be either dissolved in the ;` ~ -
aqueous phase or dry blended in the non-aqueous phase and -
will be effectively fixed through the random aggregation of
the crystalline L aspartic acid derivative compound per se.
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All of the~e applications will produce a most
flowable and blendable, ~table, highly soluble composition
which avoids the disadvantages stemming ~rom the electro-
static properties still possessed by the compound it~elf.
The invention will now be more fully understood by
reference to the accompanying operative best modeQ thereof.
Example I: APM crystals (30%) and room temperature tap
water (70%) are admixed; the admixture is then charged to a ..
Fryma* mill wherein the particles are caused to pas~ an
opening having a gap setting of about 75 microns operative
to reduce the particle size of the APM crystals and sub-
divide any clusters thereof resulting in a fluid, pumpable,
creamy slurry which at room temperature is pumped to a spray
drying, atomizing nozzle which charges, under a spray
pressure of 425 p~ig, the droplets into a vertical, spray
drying tower having an inlet drying air temperature.of 410F
and an outlet air temperature of about 235F with an air
flow of approximately 2600 cubic feet per minute. The dried
droplets charge was recovered at a moisture content of 1~07%
20 and a density of 0.248 grams per cc and 0.304 grams per cc
packed - the density resulting from tapping a charge of the
material until it approache~ asymptotic density reduction
under the influence o~ tapping per se with no overt positive
mechanical displacement force,
The dried particles had the following particle ~.
size distribution:
Sieve ~umber (U.S.. S.) % on Sieve,
+60 0.60
-60,+70 25.4
-17,+120 58,03
-120,+140 11.80
-140,+200 3.80
-200,+300 0.30
-300 0.07
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The dried product will be noted to have a very
uniform particle size distribution wherein 99% of the
particles are between 60-200 mesh size; advantageously the ; ;~
composition has a narrow particle size distribution such
that the particles are an amount of 1.10 grams of the spray
dried APM agglomerates, dry blended with 3.60 grams of
anhydrous citric acid can be spoon-stirred in 1892 milli-
meters of water at 45F for 40 seconds and will form a
complete solution; a like mixture of APM-acid mix that is
unprocessed will take between 60 and 90 seconds to go into
solution depending upon particle distribution and size of ~.
the sweetening compound therein.
A complete beverage:mix of color, flavor and
citric acid, blended with the processed APM particles of .;~
this invention, had a free flow capacity which was quite .
acceptable to food manufacturing processes. ` `~
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