CA1050812A

CA1050812A - Methyl ester of l-aspartyl l-phenylalanine in storage-stable-beverages

Info

Publication number: CA1050812A
Application number: CA224,874A
Authority: CA
Inventors: Thomas P. Finucane
Original assignee: General Foods Corp
Current assignee: General Foods Corp
Priority date: 1974-04-25
Filing date: 1975-04-17
Publication date: 1979-03-20
Also published as: JPS5746818B2; DE2518302A1; CH604564A5; IT1037648B; JPS519766A; BE828304A; FR2268472A1; GB1458934A; AU8040975A; NL7504851A; SE7504778L; FR2268472B1

Abstract

ABSTRACT OF THE DISCLOSURE

The dipeptide sweetener, APM, is stabilized in liquid comestibles over a pH flavor range of 2.3-7.0 by concentrating the ester in a solution while freezing the solution to produce discrete water ice crystals, thereby providing a stable water-based edible concentrate having a storage stability in terms of sweetness retention and avoidance of undesirable reactions in excess of 16 weeks when the composition is maintained under frozen storage.

Description

~l~S~ 2 This invention relates to frozen aqueous comestibles.
The dipeptide sweetener APM, that is, ~he methyl es~er of L-aspartyl L-phenylalanine i8 a most attractive æweetening compound having advantages over the more conven-tional sweeteners, for example saccharine or cyclam~tes. The sweetness impact which would be of use dictates the desirabili-ty o using such an ester in a beverage, typically a fruit flavored beveragel having an acid pH. The prior art workers ~ave suggested that APM would have utility and stability in aci aif iea solutions part-cala~ly ~he~ stored u~der r~frigera~e~
conditions, i.e. 35F. However, the stability aforded is limited. Ester solutlons at e~en an optimum pH reported, namely, 2.0-4.0, undergo a distinct loss in sweetness with or without the decomposition of the ester as measured by the presence of diketopiperazine ~KP) or other decomposition products such as the amino acids, aspartic acid and phenyl-alanine; the prior art workers have generally associated de-composit~on with the aatual assay for DKP and have measured the presence of methanol as a means for measurement thereof.
Nevertheless, refrigera~ed storage stability is quit~ limited being in the order of less than a few months and more typically in the order of about 4-5 weeks.
Accordingly, workers prior to the invention have viewed the stability o APM to be such as to require its use in comes-tibles having a reduced moisture content.
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The present invention is founded on the discovery that an aqueous solution of the APM estl_r in beverage comes-tibles, ranging from normal consumable concentrations to di-lutable concentrates, is stabilized by causing the solution to undergo a gradual temperature reduction to the point whereat discrete water ice crystals are formed and ultimately the beverage composition is converted into a solid or semi-solid form.
According to the invention there is provided an aqueous comestible of pH 2.3 to 7.00 in frozen form containing as sweetener methyl ester of L-aspartyl-L-phenylalanine wherein there are two phases o frozen material one of which has a greater concentration o ester than the other.
There is also provided a method of providing a stabilized aqueous comestible o pH 2.3 to 7.00 containing in solution a5 swPetener a methyl ester of L-aspartyl-L-phenylalanine wherein the solution is cooled at a rate which crystallizes part of the a~ueous system to a solid with lower concentration o ester than the solution to increase concen-tration of ester in the unfrozen phase and thereater the entire solution is rozen and is stored at below freezing point.
The APM ester is stabilized almost indefinitely so far as present experimental evidence indicates provided tempera~ures are maintained below the freezing point of the solvent phase in the beverage composition. Experiments to date indicate that fruit flavored bever~ge compositions, optimally having a pH in the range of 3.0-4.4, and generally in the range of 2.3-5.9 are advantageously stabilized for 0 periods of a year when such compositions are stored at tem-~o~ z peratures below 0C.; a broad operable range is believed to range upwardly to pH 7. a.
The mechanism whereby this stabilization occurs i~
not understood. It is theorizdd that the equilibrium of the ester is maintained by causing the a~ueous solution in which it is present to undergo a form of freeze concentration in that the water ice crystals thereof that are formed produce an ever increasing enriched concentrate in terms of the ester content; equilibrium stability occasions a minimal cleviation from the intended form of the ester, i.e. the methyl ester of aspartyl phenylalanine with a minimum generation of de-composition products.
The invention has a number of applications ranging from slush concentrates which normally would contain sucrose but which have substituted therefor concentrations of APM
providing equivalent sweetnesses and such slush beverage com-positions may have a number of freezing point depressing agents added thereto inclualng the natural or artificial acidulents typically in the conventional beverage food acids, phosphoric acid, citric acid, malic acid which serve to depress the freezing point. The invention does not require any speciic critical observance of a formulation to achieve a freezing point so far as is presently determined.
Moreover, the means whereby the ester concentrati~n in the solute phase is affected does not appear to call for any criticality and thus any means may be employed which result in a partial crystallization of the water to discrete water ice crystals with a resultant ester concentration in the unfrozen aqueous solvent; the ester content will be con-0 siderably increased over that in the solute phase initially--4--.

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generated upon reezing. So far as is presently known, the preservative effects of freezing are provided in slush con-centrates as well as solid or semi-solid foxms such as pops and spoonable beverayes.
The most preferred and economical uses of the in-vention will involve the complete substitution of the e~ter for the sweetening saccharides that are normally used in the beverage and thus will provide the ability to reduce caloric values of the beverage.
It is important in retaining the stability of the ester-containing solution that it be maintained during storage in packaging, distribution or preparatory to home consumption at a temperature substantially below 0C., depending upon the freezing point of the solution.
The number of applications in which this invention will find use range from single to multi strer.gth concentrates, either carbonated or non-carbonated, gelatin-containing solu-tions useful as dessert gels, sherbets and even shakes which are based on milk or other proteinacPous by products. Like-wise other compositions such as jams and jellies may be similarly formulated and take advantage of the present inven-tion with a total or partial substitution of the saccharide by the ester.
Accordingly, it will be:understood in accordance with thi~ invention that the term comestible is intended to apply to a wide range o~ alimentary compositions adapted to be consumed in a liquid or semi-liquid state and wherein the ester is a sweetening part o~ the aqueous phase.
EX~MPLE
A spoonable beverage concentrate is formulated as 8~Z
~ollows PREMIX
Ingredient Per cent Water 90,73 Colloidal Thickener 4.5Q
Cottonseed Oil 2.90 Color 0.10 Vitamin A 0.03 Orange Flavor 1.74 100.00 DRY BLEND
~, _ Ingradient Per cent Citric Acid 70.61 Citrate/Phosphate Buffer (1=1) 15.64 ::
Vitamins (A,B,C) 6.78 Sodium Carboxymethyl Cellulose 3.30 APM 3.67 100.00 FINAL MIX
Ingredient Per Cent Sugar Syrup 18.33 Corn Syrup 7.50 Water 37.40 Orange Pulp 8.37 Premix 22.16 Dry Blend 6.24 100.00 lZ
PREPARATION PROCEDURE
1. Weigh out premix ingredients.

2. Make thorough blend of premix ingredients and homogenize at 3500 psi~

3. Weigh dry blend ingredients. Mix in until thoroughly blended.

4. Weigh ingredients for final mix.

5. Mix the dry blend into part of the water from the final mix, then combine all remaining ingredients.

6. Freeæe finished concentrate at a rate initially permitting formation o ice crystals, then grind in commercial meat grinder, Speed No. :L, using 3/8" plate opening. Fill into cans, seal and place in freezer.
Thus, the premix ingredients were thoroughly blended and then homogenized at 3500 psi. The dry blend was then mixed into part of the water for the final mix and then all of the remaining ingredients including the premix were com-bined until an essentially stabilized emulsified solution was produced. This solution was a concentrated oxange flavored sweet preparation. The concentrate was frozen at the specified rate and then ground and charged to cans and sealed. The frozen concentrate was stored for 12 months and evaluated after storage at 0F. and 15F. The product~
versus the control was found to possess an acceptable flavor and did not evidence any substantial loss in swee~ness despite the extended storage under refrigerated conditions.

Claims

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

1. An aqueous comestible of pH 2.3 to 7.00 in frozen form containing as sweetener methyl ester of L-aspartyl-L-phenylalanine wherein there are two phases of frozen material one of which has a greater concentration of ester than the other.

2. A comestible according to claim 1, wherein the pH is from 2.3 to 5.9.

3. A comestible according to claim 2, wherein the pH is 3.0 to 4.4.

4. A comestible according to any one of claims 1 to 3, which is a fruit flavored beverage.

5. A method of producing a stabilized aqueous comestible of pH 2.3 to 7.00 containing in solution as sweetener a methyl ester of L-aspartyl-L-phenylalanine, wherein the solution is cooled at a rate which crystallizes part of the aqueous system to a solid with lower concentration of ester than the solution to increase concentration of ester in the unfrozen phase and there-after the entire solution is frozen and is stored at below freez-ing point.

6. A method according to claim 5, wherein the pH is from 2.3 to 5.9.

7. A method according to claim 5, wherein the pH is from 3.0 to 4.4.