GB2104369A - Aspartame concentrates stabilised by caramel - Google Patents

Abstract

An aspartame sweetener concentrate for use in sweetened foods and beverages, particularly carbonated beverages comprises a mixture of aspartame and caramel coloring. The dipetide sweetener is soluble and stable (both thermally and to acidic pH's) in the concentrate over prolonged periods of time and in various storage conditions.

Description

SPECIFICATION Aspartame concentrates The present invention relates to a dipeptide sweetener concentrate for use in food products.

More particularly, the invention relates to a stable dipeptide sweetener concentrate for use in foods and beverages, particularly carbonated beverages.

There is a growing preference by diabetic and diet-conscious consumers for a wide variety of food products sweetened with low-calorie sweetners, instead of sucrose or other caloriecontributing carbohydrate sweeteners. This trend has been particularly prevalent with respect to nonalcoholic, sweetened carborated beverages. Accordingly, considerable effort has gone into the formulation of food products and beverages containing low calorie sweeteners, such as saccharin and cyclamates.

The sweetness of aspartame has been reported to be about 1 80 times that of sucrose, yet it is very low in calorie content on an equivalent sweetness basis. Accordingly, this material has been considered as an attractive substitute for sucrose in a wide variety of food products and beverages.

The present invention is concerned with formulations employing dipeptide sweeteners, such as those generally described in United States Patent No. 3,475,403. Such sweeteners include lower alkyl esters of the dipeptide, aspartylphenylalanine. The methyl ester of this dipeptide (1 methyl-N-L-oe-aspartyl-L-phenylalanine) is the most common form of the sweetener, and is generally referred to by its common name, aspartame. As used herein, the term aspartame is intended to include the lower alkyl esters of the dipeptide, as well as the edible soluble salts thereof.

Aspartame suffers from two primary disadvantages as a low-calorie sweetener for food products. First of all, the dipeptide ester is subject to degradation in aqueous systems, particularly at low pH or high temperatures, and secondly, the compound has a very low rate of dissolution in water. For dry preparations, neither of these properties is particularly disadvantageous. But for food products and beverages containing substantial amounts of water, these properties can constitute significant drawbacks. The instability of aspartame is especially apparent in the acidic and highly aqueous environment of carbonated beverages. As aspartame degrades, it has been found to lose its sweetness, resulting in a limited shelf life for aspartamecontaining products.

Previous attempts to stabilize and solubilize aspartame have generally involved fusing the sweetening compound with various food-grade bulking agents. For example. Glickson, et al.

U.S. Patent 3,761,288 describe a composition prepared by co-drying an aqueous solution of an edible bulking agent, such as citric acid, dextrin, or various sugars, with aspartame. Furda, et al., U.S. P'nt 3,934,048 describe a sweetening composition prepared by co-drying a solution of aspartame with an edible, bland polysaccharide. The preferred uses for such compositions are in dry fcod mixes or premixes, rather than liquid concentrates. When such materials are utilized in a food or beverage preparation, the bulking agents may impart their own characteristic flavors, which may be foreign to the original product, and therefore, not acceptable to the consumer.

The present invention involves a stabilized aspartame concentrate, in which the sweetening compound is stabilized both in the concentrate and in the final food or beverage product.

In accordance with the invention, an aspartame concentrate comprises a mixture of from about 1% by weight to about 35% by weight of aspartame and from about 65% by weight to about 99% by weight of caramel coloring. It has surprisingly been found that aspartame has a highly solubility in caramel coloring, thus permitting the preparation of highly concentrated premixes, but also that caramel coloring stabilizes the aspartame to a high degree.

Concentrates prepared in accordance with this invention are especially useful in preparing a variety of food products, because caramel color is already a common ingredient of many such products. For instance, sweetened products, such as carbonated beverages, candies, bakery products, and the like frequently contain caramel coloring to impart a characteristic amber shade. Although the concentrates of the present invention are especially useful for food products and beverages, they may also find application in other materials, such as pharmaceuticals and dentifrices. As used herein, the term "caramel coloring" includes the commonly known amber or brown polymer-containing materials prepared by the partial pyrolysis of sugars.These materials include brown sugar and burned sugar, and preferred materials are the well known, darkly colored, viscous liquid materials produced by heating of saccharides with small amounts of ammonia or ammonium salts.

A number of different types and grades of caramel coloring are known or commercially available, such as beer caramel, baker's caramel, confectioner's caramel and the like. These materials may be of the foaming or non-foaming type and may have various tincturial powers and specific gravities. For the purposes of the present invention, any such types and grades of caramel coloring may be employed, and selection of the appropriate material can be based upon the particular food or beverage application The preferred type of caramel for beverage applications is sulfite-ammonia caramel (SAC). also commonly known as soft drink caramel.

These materials may be Intensely colored, and. therefore, are generally used in low concentrates in food products. For instance. only a few drops of caramel color are usually required to color six ounces of carbonated beverage. For the concentrate to have the desired sweetening power. it therefore must contain a relatively high concentration of aspartame.

The concentration of aspartame in the concentrates of the present invention may generally range from about 1% by weight to abot 35% by weight. Preferred concentrations range from about 5% by weight to about 15% by weight. base on the total weight of the concentrate. The caramel coloring generally has a low pH. e.g. about 2.4. but unlike other aqueous acidic solutions, aspartame has been found to be quite stable In the caramel coloring. For example, after 4 weeks of storage at 70"F (21 'C). only about 3%. of the aspartame is lost from a concentrate having about 30')/o moisture. In contrast. as much as 60% of the aspartame is lost from a 15% acid solution under identical storage conditions.

The aspartame is advantageously dispersed in the caramel coloring with agitation. High speed mixing or homogenization may be employed to accelerate dispersion, but less vigorous procedures may also be used. The caramel coloring can be mildly heated to facilitate dispersion, if desired.

The stability of aspartame may be further improved by dehydrating the concentrates of this invention Such dehydration may be partial. to prepare a very viscous liquid or paste or may be substantially complete. to form a dry mixture. that may be pulverized into a granular form. The solubility of the resulting material in water has been found to closely approximate that of sucrose. permitting its use in dried food products or beverage premixes.

In addition to providing stable concentrates that may be stored over extended periods of time, when aspartame is added to the food product or beverage In the form of such a concentrate, the aspartame is stabilized in the resulting product The manner by which stabilization occurs is not well understood, but. wirhout being bound to any particular theory, it is believed that the aspartame particles or molecules are encapsulated by the materials in the caramel coloring. This encapsulation effectively reduces the water activity In the Immediate surroundings of such aspartame particles or molecules. Reducing the water activity In the surroundings of the aspartame. therefore. inhibits hydrolysis or degradation of the sweetening compound.

Particularly advantagous applications of the aspartame concentrates of the present invention are in preparation of sweetened carbonated beverages and the bottling or fountain syrups from which such beverages are prepared. Because of the low pH and aqueous environment of such beverages. aspartame stability has been an obstacle to the development of suitable formulations.

By utilizing the concentrates of the present invention the problem associated with aspartame solubility has been overcome, and since caramel coloring is a common ingredient of many such beverages no additional ingredients are employed which tend to interfere with the flavor of these products. Moreover, no special processing steps are generally required for making such beverages.

Conventional bottling or fountain syrups are usually prepared by dissolving in water.

appropriate amounts of a sweetening agent. an acidulent, flavoring concentrate, coloring agents.

and preservatives. The concentrations of these Ingredients are adjusted to provide a bottling or fountain syrup which when diluted with carbonated water. results in a carbonated beverage having the desired qualities of flavor, color and sweetness. Acidulents commonly employed in carbonated beverages include phosphoric acid, citric acid, malic acid. fumaric acid, and the like, and these acidulents are employed in concentrations, such that the pH of the bottling or fountain syrup ranges from about 2.2 to 3.5. preferably from about 2.5 to 3.0, as is well known in the art.

A wide variety of flavoring concentrates. such as cola concentrate, essential oils and extracts of various fruits and spices, concentrated fruit juices, and artificial flavors, such as ethyl acetate, amyl butyrate, and caffeine. may be employed. A wide variety of colorings are also available, and these include caramel coloring and the various F D SC. colorings, and combinations thereof.

Flavorings and colors are sometimes combined to form a single component which can be used in the preparation of a bottling or fountain syrup. Standard preservatives, such as sodium benzoate. may also be added to the bottling or fountain syrup in preserving amounts if desired.

The bottling or fountain syrup is generally diluted with water in a ratio of about 1 to about 3 parts by volume of the syrup to about 10 parts by volume of water. and the final product is carbonated to contain from about 3 to about 5 volumes of CO. gas. Carbonation may be accomplished by carbonating the diluted syrup or using carbonated water as the diluent.

In preparing such syrups and beverages with the aspartame concentrates of the present invention. the concentrate may simply be substituted for some or all of the caramel coloring to provide the desired concentration of aspartame. Typically. aspartame concentrations of about 0.2-0.5% w/v, preferably about 0.3% -o 4 4.i w v are employed in the bottling or fountain syrup. Beverages prepared in this manner have been found to have a pleasant flavor, and have a shelf life compatible with the commercial production and scale of such products.

The present invention is further illustrated by the following examples, which are not intended to be limited.

Example I An aspartame concentrate for use in a cola carbonated beverage was prepared by adding 6.0 pounds of aspartame to 2.5 gallons of caramel color in a stainless steel container. This mixture was stirred for about one hour at room temperature until the aspartame was completely dispersed. Portions of the resulting concentrate were stored at 6"C, 25"C and 40"C for six weeks, and samples were taken periodically and analyzed for aspartame by high pressure liquid chromatography (HLPC).

As a control, an identical aspartame concentrate was prepared, except that the phosphoric acid was substituted for caramel color to provide an identical pH. Portions of this concentrate were stored at 6"C, 25"C, and 40"C for six weeks and were also periodically analyzed for aspartame. The pH of both the test concentrates and the controls was about 2.4. The conditions for the HLPC analysis were as follows: Std Aspartame 100 mg Aspartame per 100 ml in distilled water Instrument Water's HPLC with UV Detector A=254 nm Column Partisil PXS 10/25 ODS Solvent 3.0 g NH4NO3 and 0.4 ml HNO3 per 1000 ml distilled water Flow rate 1.0 ml/min.

Wave length 254 nm Sensitivity 0.1 Injection volume 30 its The results of the analyses are shown in graphic form in the drawing, in which the stability of aspartame (expressed as percentage of the initial concentration) is plotted vs. time. (Note: no detectable degradation of aspartame occured up to six weeks in the test concentrate stored at 6"C.) This experiment clearly dernonstrates the substantially greater stability of aspartame in syrups prepared from the aspartame concentrates of the present invention.

Example II A dry besraae premix is prepared by first making an aspartame concentrate. Aspartame (100 g) is dispersed in 400 g of caramel color. This material is completely dehydrated by Iyophilizaoion, and is pulverised in a mortar and pestle. The dry aspartame concentrate (200 g) is blended with citric acid powder (2009) and powdered root beer flavoring (100 g) to make a dry root beer premix. A root beer syrup is prepared by dissolving fifty grams of this premix in 500 ml of water. A root beer soft drink is prepared by dissolving one part of the root beer syrup in five parts of carbonated water.

Claims (14)

1. An aspartame concentrate, comprising a mixture of from about 1% by weight to about 35% by weight of aspartame and from about 65% by weight to about 99% by weight of caramel coloring.

2. The aspartame concentrate of claim 1, wherein the concentration of the aspartame is from about 5% by weight to about 15% by weight of the concentrate, and the concentration of the caramel coloring is from about 85% by weight to about 95% by weight of the concentrate.

3. The aspartame concentrate of claim 1 or 2, wherein the caramel coloring is selected from the group consisting of beer caramel, baker's caramel, confectioner's caramel, brown sugar and burned sugar.

4. The aspartame concentrate of claim 1 or 2, wherein the caramel coloring is a darkly colored, viscous liquid prepared by heating saccharides with ammonia or ammonium salts.

5. A method for making an aspartame-sweetened carbonated beverage bottling or fountain syrup, comprising (a) mixing from about 1 part by wt. to about 35 parts by wt. of aspartame with about 99 parts by wt. to about 65 parts by wt. of caramel coloring, to form an aspartame concentrate; (b) mixing with water, sufficient aspartame concentrate to provide an aspartame concentration of from about 0.2% w/v to about 0.5 w/v, sufficient acidulent to provide a pH of from about 2.2 to about 3.5, and a flavoring amount of a flavoring agent, to form a carbonated beverage bottling or fountain syrup.

6. The method of claim 5, wherein the aspartame concentrate is prepared by mixing from about 5 parts by weight to about 1 5 parts by weight of aspartame with from about 95 parts by weight to about 85 parts by weight of caramel colouring.

7. The method of claim 5 or 6, wherein sufficient aspartame concentrate is employed to provide an aspartame concentration of from about 0.3% w/v to about 0.4% w/v in the bottling or fountain syrup, and sufficient acidulent is employed to provide a pH of from about 2.5 to about 3.0 in the bottling or fountain syrup.

8. The method of claim 7, wherein the acidulent is phosphoric acid, citric acid, malic acid, fumaric acid, or combinations thereof.

9. The method of claim 7, wherein the acidulent is phosphoric acid, and the flavouring is a colour flavouring concentrate.

1 0. The method of claim 5 or 6, wherein the caramel colouring is selected from the group consisting of soft drink caramel, beer caramel, baker's caramel, confectioner's caramel, brown sugar and burned sugar.

11. The method of claim 5 or 6, wherein the caramel colouring is soft drink caramel.

1 2. The method of claim 9, wherein the caramel colouring is a darkly coloured, viscous liquid prepared by heating saccharides with ammonia or ammonium salts.

1 3. An aspartame concentrate according to claim 1 substantially as described herein.

14. A method for making an aspartame-sweetened carbonated beverage according to claim 5 substantially as described herein.

1 5. Carbonated beverages when prepared by the method of anyone of claims 5 to 1 2 or 1 4.