CA1086559A

CA1086559A - Sweetening composition and method

Info

Publication number: CA1086559A
Application number: CA274,833A
Authority: CA
Inventors: Myron D. Shoaf; Lamonte D. Pischke
Original assignee: General Foods Corp
Current assignee: General Foods Corp
Priority date: 1976-04-05
Filing date: 1977-03-28
Publication date: 1980-09-30
Also published as: NL186736C; IT1077484B; SE420377B; FR2346988B1; NL7703645A; FR2346988A1; DE2713951A1; CH603076A5; IE44797L; IE44797B1; JPS52122677A; DE2713951C2; NL186736B; JPS5820588B2; SE7703713L

Abstract

ABSTRACT OF THE INVENTION L-aspartic acid derivatives typified by L-aspartyl, L-phenylalanine methyl ester (APM) in crystalline form are agglom-erated by a minor weight percent of a like solution serving as a permanent aggregating matrix at the spaced points of contact in a random distribution of the crystals whereby they are assembled and immobilized to a free flowing form for use in dry food mixes.

Description

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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 --l--' ', ' ': ' ~ , ' :~
.' . ' . ~ j . , , ~6~Si~3 , 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.

, 8~59 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 B *Trademark - 8 ~

i5s9 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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Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A process for producing a flowable dry sweetening composition which comprises forming an admixture consisting essen-tially of crystalline particles of a dipeptide L-aspartic acid ester sweetening compound and an amount of water sufficient to form an admixture of undissolved compound particles to be dis-solved by the water to form agglutenating solute, wherein the compound particles admixed with water are milled to a particle size less than 125 microns to form a uniform, cluster-free slur-ry, causing the resulting solute solution to be distributed throughout the remaining undissolved particles of the compound while causing said particles to be assembled randomly with res-pect to one another, and spray drying the solution to immobilize -the particles in the random arrangement thereof at spaced points of contact through the intermediation of redried compound, said sweetening composition consisting essentially of said particles immobilized by redried compound.

2. The process of Claim 1 wherein the amount of water is a major percent by weight of the admixture of compound and water.

3. The process of Claim 1 wherein the slurry is main-tained below 150°F prior to drying.

4. The process of Claim 1 wherein the compound parti-cles are distributed in that amount of water which forms a doughy, shape-retaining meal having the solution of sweetening compound distributed throughout to agglutinate said particles in said random arrangement.

5. The process of Claim 4 wherein the meal is milled to form particles of meal.

6. The process of Claim 1 wherein the compound is an alkyl ester of L-aspartyl-L-phenylalanine.

7. A free-flowing highly water soluble powdery sweet-ening composition comprising a nested random aggregation of immo-bilized crystalline particles of a dipeptide L-aspartic acid ester sweetening compound having a particle size of less than 125 microns aggregated to one another at spaced points of contact through intermediate aggregating bonds formed by redried quantities of the compound, said dissolved and redried form of the compound at said spaced contact points being a minor amount of the dipep-tide L-aspartic acid ester sweetening compound present, said sweetening composition consisting essentially of said dipeptide L-aspartic acid ester sweetening compound particles immobilized by redried compound.

8. The composition of Claim 7 wherein the compound is an alkyl ester of L-aspartyl-L-phenylalanine.

9. The composition of Claim 8 wherein the compound is L-aspartyl L-phenylalanine methyl ester.