MXPA01005139A - Reduced molecular weight native gellan gum - Google Patents

Abstract

This invention provides reduced molecular weight gellan gums. The reduced molecular weight gellan gums of this invention generally have a weight average molecular weight less than about 1.7 X 106, and typically in a range of about 1.2 X 106 to about 9.3 X 105. This invention also provides compositions, e.g., solutions and gels, comprising reduced molecular weight gellan gums. The reduced molecular weight gellan gums of this invention may be prepared by any method which reduces the molecular weight of polymers. Such methods include homogenization, sonication, radiation, oxidation and hydrolysis.

Description

PURE GELANUM RUBBER WITH REDUCED MOLECULAR WEIGHT BACKGROUND OF THE INVENTION FIELD OF THE INVENTION This invention relates to a pure gelano gum with reduced molecular weight.

DESCRIPTION OF THE PREVIOUS TECHNIQUE Gellan gum is a high molecular weight polysaccharide produced by fermentation. The substituent sugars of gellan gum are glucose, glucuronic acid and rhamnose in the molar ratio of 2: 2: 1. These sugars are linked to give a primary structure consisting of a linear tetrasaccharide repeat unit as shown below: In the pure form or with high acyl content of the gellan gum, the acyl, acetate and glycerate substituents are present. Both substituents are located in the same glucose residue, and on average, there is one glycerate per unit of repetition and one acetate every two units of repetition. Gums are mainly used to thicken or gel water and are often classified into two groups: thickening and gelling agents. Traditional thickeners include starches, guar gum, carboxymethylcellulose, alginate, methylcellulose, karaya gum and tragacanth gum. Common gelling agents include gelatin, starch, alginate, pectin, carrageenan, agar and methylcellulose. The gelling agents are used in the food industry in a variety of applications, including jellies for confectionery, jams and jellies, dessert gels, frostings and dairy products. The gelling agents differ in the conditions under which they can be used, as well as in the texture of gels they form. These distinctive properties have led to the exclusive use of certain gelling agents in a number of products (for example, starch in confectionery jellies, gelatin in capsules, glazed agar, and alginate in pepper strips). in a number of ways. Gels which are formed by cooling a hot solution of the gelling agent are classified as thermally settable gels. Traditional thermally forgeable gels include gelatin, xanthan gum and locust bean gum combinations, and agar. Gels that require addition of ions to the gelling agent solution in order to set are classified as gels for ion setting. Common ion setting gels include alginate, kappa carrageenan, pectin with low methoxy content and gellan gum. Generally, gels for ion setting are ion-specific. For example, alginate and pectin with low methoxy content require the presence of Ca2 + ions in order to gel, while kappa carrageenan will gel only in the presence of K + ions. Gellan gum is unique among ionic gelling agents because it forms gels with most ions, which include hydrogen ions. Perhaps the most familiar gelling agent is gelatin, which is used to prepare, among other products, dessert gels that are popular in many parts of the world. Unlike polysaccharide gelling agents, gelatin is a protein derived from animal sources. Gelatin has many desirable characteristics, including a melting temperature lower than body temperature. As a result, gels made from gelatin melt in the mouth, this feature provides improved organoleptic properties. However, many consumers are currently interested in food products which are free of ingredients derived from animal sources. Therefore, it would be advisable to provide a gelling agent, derived from a non-animal source, which could be used in place of gelatin in selected food products. The pure gellan gum, which is produced by bacterial fermentation, forms gels that have a texture similar to that of gelatin gels. But solutions prepared with pure gelano gum are highly viscous even at elevated temperatures. In addition, these solutions gel at high temperatures.BRIEF DESCRIPTION OF THE INVENTION This invention provides reduced molecular weight gellan gums of the formula: which has a weight average molecular weight less than or equal to about 1.7 X 106 measured according to SEC / MALLS (Size Exclusion / Light Angle Chromatography by Multiple Angle Laser.

This invention further provides compositions comprising reduced molecular weight gellan gums, as well as a process for making such compositions.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a graph showing the effect of decreasing the molecular weight of gellan gum at the gel setting temperature of 0.5% gellan gum solutions. Figure 2 is a graph showing the effect of decreasing the molecular weight of gellan gum in the viscosity of gellan gum solutions at 95 ° C.

DETAILED DESCRIPTION OF THE INVENTION As used herein, the term "gellan gum" (with reduced molecular weight) refers to a gellan gum which has a lower molecular weight than that of pure gelano gum. The term "pure gelano gum" refers to gelano gum produced by bacterial fermentation which has not been modified by physical or chemical means. The term "gelling salt" refers to any salt which induces gellan gum solutions to form a gel. The gellan gums with a reduced molecular weight of this invention generally have a weight average molecular weight of less than about 1.7 X 106, and usually on a scale of about 1.4 X 106 to about 4.0 X 105. Gellan gums with molecular weight The reduced amount of the present invention provides different advantages over pure gelano gum. When compared to solutions of pure gelano gum, solutions of gelano gum with reduced molecular weight provide reduced viscosity at elevated temperatures. This feature is especially advantageous in solutions having a high sugar concentration where high viscosity is a problem during processing. The compositions of the present invention comprise a gellan gum with reduced molecular weight and water. Normally, the concentration of gellan gum with reduced molecular weight in water will vary from about 0.05 weight percent to about 1.0 weight percent. Preferably, the compositions are gels or solutions in which gellan gum with reduced molecular weight is completely hydrated. The present invention also provides compositions comprising a gellan gum with reduced molecular weight, water, a gelling salt and a sequestrant. The concentration of gelling salt in the compositions will vary depending on the particular gelation salt used. For example, the sodium and potassium gelling salts are generally used in concentrations ranging from about 0.020M to about 0.200M, while the calcium and magnesium gelation salts are normally used at concentrations ranging from about 0.002M to approximately 0.015M. The amount of sequestrant used in the compositions is typically in the range of about 0.05 percent to about 0.25 percent by weight. When fully hydrated, the gelano gums with reduced molecular weight of the present invention will form gels with many different ions. Preferably, the gelling salt is a calcium salt, a sodium salt or a potassium salt. Preferably, the gelling salt is CaCl2. Sodium citrate is the preferred sequestrant. The solutions of gellan gum with reduced molecular weight gel at a lower temperature than the solutions of pure gelano gum. Thus, pure gelano gum solutions normally gel at about 80 ° C to 95 ° C, while solutions of gelano gum with reduced molecular weight normally gel between about 60 ° C and about 85 ° C. By reducing the temperatures to set the gel, the gellan gums with reduced molecular weight of the present invention facilitate the manufacturing process. Another advantage of the reduced molecular weight gellan gums of the present invention is that they provide gels with improved organoleptic properties. In comparison with gels made with pure gelano gum, gels made with gellan gum with reduced molecular weight have reduced adhesion, elasticity and firmness. Consequently, these gels have a better mouth feel than gels prepared from pure gelano gum. Reduced molecular weight gellan gums of the present invention can be prepared by any method that reduces the molecular weight of polymers. Such methods include homogenization, sound treatment, radiation, oxidation and hydrolysis. Preferably, the gellan gums with reduced molecular weight of the present invention are prepared by homogenization. Pure gellan gum is available as Kelcogel LT-100 from the NutraSweet Kelco Company (San Diego, CA). In homogenization, the sample containing the polymer is forced under high pressure (eg, greater than 35.15 kg / cm2) through a small hole. This procedure causes the polymer to break into smaller segments. The homogenization process can be repeated to achieve further reduction in the molecular weight of the polymer. Sound treatment can also be used to reduce the molecular weight of water-soluble polymers. This method involves exposing the polymer sample to high frequency waves. The use of gamma radiation, either from cobalt or electron sources, can also reduce the molecular weight of water-soluble polymers. Molecular weight reduction occurs more easily when the polymer is in the hydrated form, rather than the dry one. For liquid samples, radiation levels of 0.25 to 5 Mrad provide significant reductions in molecular weight. The molecular weight of some polymers, which include gelano gum, can be reduced by exposing the polymer to an oxidizing agent such as hydrogen peroxide. This degradation of oxidation is improved by transition metal cations, such as iron. This is inhibited by oxygen and free radical scavengers, such as ascorbate or propyl gallate. Acid hydrolysis is a well-known technique for reducing the molecular weight of polymers. It is commonly used in clinical analysis of polisácaridos to decompose them in their constituent sugars. Although many different acids can be used, it is generally easier to work with weak acids than with strong acids. Reduced molecular weight gellan gums of the present invention can be used as gelling agents in a variety of fluid food products including confectionery jellies, jams and jellies, dessert gels, frostings and dairy products, such as, for example, ice cream, frozen yoghurt, cottage cheese, sour cream, frozen non-dairy covers and bakery fillings. The following examples are intended to illustrate certain preferred embodiments of the invention, and no limitation thereof is implied.

EXAMPLE 1 (Preparation of qelano gum with reduced molecular weight -1X homogenization) 4 g of pure gelano gum was added to 400 ml of deionized water during mixing at 800 rpm with a 5.08 cm 3-blade propeller mixer in an electronically heated metal beaker. The sample was stirred for 10 minutes before being heated to 95 ° C. The sample was stirred at 95 ° C until the gellan gum was completely hydrated. The hydrated sample was then homogenized at 80 ° C-90 ° C using APV Gaulin homogenizer equipment in a single stage at a pressure of 597.55 kg / cm2. While the homogenated gellan gum solution was still at more than 60 ° C, gellan gum with reduced molecular weight was precipitated using isopropyl alcohol. The precipitation step was completed by adding 3 volumes of isopropyl alcohol to 1 volume of gum solution with reduced molecular weight. The precipitated reduced molecular weight gellan gum fibers were dried under mild heat (ca. 45 ° C) for 12 to 24 hours before being ground to approximately 60 to 80 meshes using a mechanical mill.

EXAMPLE 2 (Preparation of qelano gum with reduced molecular weight -4X homogenization) The pdure used was that described in Example 1, except that the gellan gum sample was passed through the homogenizer 4 times. Further homogenizations produced further reductions in the molecular weight of gellan gum.

EXAMPLE 3 (Preparation of gellan gums with reduced molecular weight - 1X homogenization) Sufficient gelano gum with reduced molecular weight, prepared as described in Example 1, was added to deionized water during rim at 800 rpm with a helix mixer to produce a gel with a gum concentration of 0.5%. After stirring for 10 minutes, the sample was heated to 95 ° C. After the gum was completely hydrated, a 0.5 M CaCI2 solution was added in a sufficient amount so that the final gel had a Ca2 + ion concentration of 6 mM. The solution was then poured into disk molds producing gels approximately 7 mm thick and 25 mm in diameter on cooling.

EXAMPLE 4 (Preparation of gellan gums with reduced molecular weight - 4X homogenization) The pdure used was that described in example 3, except that gellan gum with reduced molecular weight was prepared as described in example 2 (ie, homogenized 4 times), and the final concentration of gum in the gel was of 0.5%.

COMPARATIVE EXAMPLE 1 (Preparation of pure gellan gum gel) The pdure used was that described in example 3, except that the pure gellan gum, instead of gellan gum with reduced molecular weight, was used to prepare the gel, and the final concentration of gum in the gel was 0.5%. .

Analysis of qel The texture indicates how a gel will deform under an applied force. The texture profile of a gel can be obtained by subjecting a gel sample to an increasing force and measuring the resulting deformation. Samples prepared as described in Examples 3, 4 and Comparative Example 1, were evaluated for texture profile analysis using the pdure described in Szczesniak, AS, Classification of Textural Characteristics, J. Food Sci., 28 (1963) 390, the entire contents of which are incorporated herein by reference. The disk gel samples were compressed using an Instron test machine at a rate of 5.08 cm per minute and at a tension level of 80%. The modulus, hardness, brittleness, elasticity, and adherence of the samples were calculated. The results of these calculations are presented in Tables 1A and 1B. The modulus, often referred to as firmness, indicates how firm the gel appears when pressed lightly. Hardness is a measure of the force required to break the gel. Fragility is a measure of how much you can squeeze the gel before it breaks. The elasticity is a measure of how much the gel takes its original possession after the first compression cycle. Adherence is an indication of the difficulty in breaking down the gel in the mouth. As shown in tables 1A and 1B, gels prepared from gellan gum with reduced molecular weight are less adherent, elastic and firm than gels prepared from pure gelano gum.

TABLE 1A Parameters of textures of gels prepared with pure gelano gums and with reduced molecular weight TABLE 1B Texture parameters of gels prepared with pure gellan gums with reduced molecular weight EXAMPLE 5 (Preparation of Gel for dessert) Dessert gels were prepared using untreated pure gelano gum, gelano gum with reduced molecular weight homogenized one time, and gelano gum with reduced molecular weight homogenized 4 times in gum concentrations of 0.5%, 0.75% and 1.0%, respectively. The gels were prepared as described in examples 3, 4 and comparative example 1, except that sugar, adipic acid, sodium citrate, disodium phosphate, fumaric acid, flavoring and coloring were added to the solution before adding CaCl2 at 0.5M. . The amount of each added ingredient present in the final solution considering a percent weight basis was as follows: sugar (13.48%), adipic acid (0.40%), sodium citrate (0.13%), disodium phosphate (0.13%), fumaric acid (0.11%), flavoring (0.02%), and color (0.01%).

Qele Analysis for Desserts Dessert gels prepared as described in Example 5 were evaluated to determine texture profile as described for gel analysis. The modulus, hardness, brittleness, elasticity, and adhesion were calculated. The results of these calculations are presented in tables 2A and 2B.

As shown in tables 2A and 2B, dessert gels prepared from gelano gum with reduced molecular weight homogenized only once are almost as adherent, elastic and firm as dessert gels prepared from pure gelano gum. However, gels for desserts prepared from gellan gum with reduced molecular weight homogenized 4 times is less adherent, elastic and firm than dessert gels prepared from pure gelano gum.

TABLE 2A Texture parameters of dessert gels prepared with pure gelano gums and with reduced molecular weight TABLE 2 B Texture parameter of gels for desserts prepared with pure gelano gums and with reduced molecular weight EXAMPLE 6 Temperatures for gel setting The temperature for gel setting of a solution of pure gellane gum and two solutions of gellan gum with reduced molecular weight was measured using a Rheometric Scientific SR-200 controlled tension rheometer (Piscataway, N.J.). The instrument was placed in parallel plate mode with a 50 mm top plate and a Peltier temperature controlled bottom plate. The sample was placed on the lower plate which had been preheated to 95 ° C, and the upper plate was lowered to provide a space of 1 mm. Evaporation was controlled using the solvent evaporation fitting supplied. During measurement at a frequency of 10 radians per second with an applied voltage of 2 to 5%, the sample was cooled from 95 ° C to 50 ° C and the viscoelastic properties were measured. The elastic modulus, G ', was measured to determine the setting temperature. When the value of G 'exceeded 10 dynes per cm2, it was considered that the sample began to set. This temperature is referred to as the "setting temperature". Gellan gums with reduced molecular weight were prepared as described in example 1. One of the gellan gum solutions with reduced molecular weight was prepared from gellan gum which had been homogenized once, while the other Reduced molecular weight gellan gum solution was prepared using gellan gum which had been homogenized four times. Reduced molecular weight gellan gum solutions were prepared by hydrating sufficient gellan gum with reduced molecular weight in deionized water to produce a solution of gelano gum with reduced molecular weight of 0.5%, followed by addition of sufficient CaCl2 at 0.5 M to produce a solution with a concentration of Ca2 + ions of 6 mM. The solution of pure gelano gum was prepared by hydrating enough gellan gum in deionized water to produce a gellane gum solution of 0.5%, followed by addition of sufficient CaCl2 at 0.5 M to produce a solution with a Ca 2+ ion concentration of 6 mM. The results of these measurements are presented in figure 1. As shown in figure 1, the solutions prepared from gellan gum with reduced molecular weight have a gel setting point lower than the solutions prepared from gellan gum pure without trying.

EXAMPLE 7 (Hot viscosity measurements) The viscosity of a solution of pure gelano gum and the viscosity of two gellan gum solutions with reduced molecular weight at 95 ° C were measured using a Rheometric Scientific SR-200 controlled tension rheometer. The placement of the instrument is as described in example 6. The test protocol used was the uniform voltage sweep test. Tension values were selected to provide maximum coverage of shear rate on the scale of 10 to 1000 s "1. The pure gelano gum solution was prepared by hydrating enough gum in deionized water to produce a gum solution. 0.5% gellan gel solutions with reduced molecular weight were prepared by hydrating enough gellan gum with reduced molecular weight in deionized water to produce a solution of gellan gum with reduced molecular weight of 0.5%. of gellan gum with reduced molecular weight was prepared from gellan gum which had been homogenized once, while the other gelano gum solution with reduced molecular weight was prepared using gellan gum which had been homogenized four times. The results of these measurements are presented in Figure 2. As shown in Figure 2, the solutions prepared from gellan gum with a low molecular weight Reduced viscosity have lower viscosities at elevated temperatures, than solutions prepared using pure gelano gum.

EXAMPLE 8 (Measurement of molecular weight of pure gelano gum) A pure gelano broth was clarified as follows: to about 4 liters of a solution of 1.5% gellan gum broth was added enough sodium hypochloride to produce a solution having a sodium hypochloride concentration of 1000 ppm. The solution was stirred for two hours at 40 ° C, followed by addition of sufficient lysozyme (Genencor, Palo Alto, California) to produce a solution having a lysozyme concentration of 50 ppm. The resulting solution was stirred for two hours at 40 ° C, followed by addition of sufficient HT protease (Miles Enzymes, Elkhart, Indiana) to produce a solution having an HT protease concentration of 500 ppm. The resulting solution was stirred for two hours at 40 ° C, followed by addition of sufficient ethylenediaminetetraacetate (EDTA) and sodium dodecylsulfate (SDS) to produce a solution having EDTA and SDS concentrations of 1000 ppm and 500 ppm, respectively. The resulting solution was stirred for two hours at 40 ° C. The resulting clarified pure gellan broth was then precipitated with two parts by volume of isopropyl alcohol. The precipitated gum fiber was then pressed between muslin cloth for 33% solids, and then dried at 60 ° C for 12. Then the fiber was milled at approximately 250 μm particle size using a Brinkmann knife mill (Westbury , New York). The dried powdery gum was rehydrated to a polymer concentration of 1% in deionized water at 90 ° C. The solution of 1% pure gelano gum was then added to a molecular porous dialysis tube (Spectra / Por® Membrane MWCO 6-8000). The solution was dialyzed against deionized water for 72 hours. The dialyzed gellan gum was precipitated with isopropyl alcohol before being dried and milled. The polymer was then rehydrated in deionized water to polymer concentration of 0.05% at 90 ° C. Tetramethylammonium chloride (TMAC) was added to produce a 10 mM solution. This purification procedure was repeated. The resulting solution was cooled to room temperature. The polymer solution was filtered through Acrodisc filters of 0.45 μm and 0.50 μm. The molecular weight of the pure gellan gum polymer was measured using a SEC / MALLS unit (Size Exclusion / Multi-Angle Laser Light Spray Chromatography). The SEC / MALLS unit was fitted with a 410 water differential refractometer, a Wyatt Technology-Dawn DSP laser photometer and two Waters Hydrogel (2000 and linear series) columns. The data was analyzed using an Astra 21 program. Table 3 shows that pure gelano gum had a weight-average molecular weight (PMpeSo) and a number-average molecular weight (PMnumber) of 2.5 x 106 and 2.2 x 106, respectively .

EXAMPLE 9 (Measurement of molecular weight of gellan gum with reduced molecular weight - 1X homogenization) The procedure used was as described in example 8, except that before the dialysis step, the solution of pure gellan gum of 1% was passed once through a pressure drop homogenizer APV Gaulin at 597.55 kg / cm2 . Table 3 shows that the homogenized gelano gum once had a weight average molecular weight (MWO) and a number average molecular weight (MW number) of 1.7 x 106 and 1.6 x 10d, respectively. _ * __, __, _.- • EXAMPLE 10 (Measurement of molecular weight of gellan gum with reduced molecular weight -2X homogenization) The procedure used was that described in Example 9, except that the gellan rubber sample passed through the homogenizer 2 times. Further homogenization resulted in further reduction in the molecular weight of gellan gum. Table 3 shows that twice-homogenized gelatin gum had a weight-average molecular weight (PMpeSo) and a number-average molecular weight (MWnumber) of 1.2 x 106 and 1.1 x 106, respectively.

EXAMPLE 11 (Measurement of molecular weight of gellan gum with reduced molecular weight -4X homogenization) The procedure used was that described in Example 9, except that the gellan gum sample was passed through the homogenizer 4 times. Further homogenization produced further reductions in the molecular weight of gellan gum. Table 3 shows that gelano gum homogenized 4 times had a weight average molecular weight (Mpeso) and a number average molecular weight (MW number) of 9.3 x 105 and 7.6 x 105, respectively.

TABLE 3 Molecular weights of gelano rubber polymers Other variations and modifications of this invention will be obvious to those skilled in the art. This invention is not limited except to that set forth in the claims.

Claims (27)

NOVELTY OF THE INVENTION CLAIMS

1. - A gellan gum with reduced molecular weight represented by the formula: which has a weight average molecular weight less than or equal to about 1.7 X 106 measured according to Size Exclusion / Light-Spray Chromatography by Multiple Angle Laser.

2. The gellan gum according to claim 1, further characterized in that the weight average molecular weight of said gellan gum is less than or equal to approximately 1.2 X 106 measured according to Size Exclusion Chromatography / Laser Light Spray of Multiple Angles.

3. - The gellan gum according to claim 1, further characterized in that the weight average molecular weight of said gellan gum is between approximately 1.2 X 106 and approximately 9.3 X 105 measured according to Size Exclusion Chromatography / Laser Light Spray of Multiple Angles.

4. A composition comprising: (a) a gellan gum with reduced molecular weight represented by the formula: having a weight average molecular weight less than or equal to about 1.7 X 106 measured according to Size Exclusion Chromatography / Light Spray by Multiple Angle Laser; and (b) water

5. The composition according to claim 4, further characterized in that the weight average molecular weight of said gellan gum is less than or equal to about 1.2 X 106 as measured by Size Exclusion Chromatography. Aspersion of Light by Multiple Angles Laser.

6. - The composition according to claim 4, further comprising a gelling salt.

7. The composition according to claim 6, further characterized in that said gelling salt is selected from the group consisting of a calcium salt, a potassium salt and a sodium salt.

8. The composition according to claim 7, further comprising a sequestrant.

9. The composition according to claim 8, further characterized in that said sequestrant is sodium citrate.

10. The composition according to claim 7, further characterized in that said gelling salt is a calcium salt.

11. The composition according to claim 7, further comprising a fluid food product.

12. The composition according to claim 11, further characterized in that said fluid food product is selected from the group consisting of confectionery jellies, jams, jellies, dessert gels, frostings, non-dairy frozen covers, bakery fillings and products. dairy products.

13. A process for preparing a gellan gum with reduced molecular weight represented by the formula: having a weight average molecular weight less than or equal to about 1.7 X 106 measured according to Size Exclusion / Light Suction Chromatography by Multiple Angle Laser; said process comprises: (a) hydrating pure gelano gum in water; and (b) reducing the molecular weight of said pure gelano gum, whereby gellan gum with reduced molecular weight was produced.

14. The process according to claim 13, further characterized in that the weight average molecular weight of said gellan gum with reduced molecular weight is less than or equal to about 1.2 x 106 measured according to Size Exclusion / Light Spray Chromatography by Multiple Angles Laser.

15. The process according to claim 13, further characterized in that the molecular weight of said pure gellan gum is reduced by a treatment selected from the group consisting of homogenization, sound treatment, radiation, oxidation and hydrolysis.

16. - The method according to claim 15, further characterized in that said treatment is homogenization.

17. The process according to claim 13, further comprising the step of reducing the molecular weight of said gellan gum with reduced molecular weight.

18. The method according to claim 17, further characterized in that the molecular weight of said gellan gum with reduced molecular weight is reduced by a treatment selected from the group consisting of homogenization, sound treatment, radiation, oxidation and hydrolysis.

19. The method according to claim 18, further characterized in that said treatment is homogenization.

20. A composition comprising: (a) a gellan gum with reduced molecular weight of the formula: having a weight average molecular weight less than or equal to about 1.7 x 106 measured according to Size Exclusion / Light-Spray Chromatography by Multiple Angle Laser; (b) water; (c) a gelling salt; and (d) a sequestrant, wherein said composition is a gel.

21. The composition according to claim 20, further characterized in that the weight average molecular weight of said gellan gum with reduced molecular weight is less than or equal to approximately 1.2 x 106 measured according to Size Exclusion / Light Spray Chromatography. by Multiple Angles Laser.

22. The composition according to claim 21, further characterized in that said gelling salt is selected from the group consisting of a calcium salt, a potassium salt and a sodium salt.

23. The composition according to claim 22, further characterized in that said gelling salt is a calcium salt.

24. The composition according to claim 23, further characterized in that said sequestrant is sodium citrate. 25.- The product obtained through the process comprises: (a) hydrating pure gellan gum in water; and (b) reducing the molecular weight of said pure gelano gum. 26. The process according to claim 25, further characterized in that the molecular weight of said pure gelano gum is reduced by a treatment selected from the group consisting of homogenization, treatment with sound, radiation, oxidation and hydrolysis. 27. The method according to claim 26, further characterized in that said treatment is homogenization. SUMMARY OF THE INVENTION This invention provides gellan gums with reduced molecular weight; the gellan gums with reduced molecular weight of this invention generally have a weight average molecular weight of less than about 1.7 x 10 6, and usually on a scale of about 1.2 x 10 6 to about 9.3 x 10 5; this invention also provides compositions, for example, solutions and gels, comprising gellan gums with reduced molecular weight; the gellan gums with reduced molecular weight of this invention can be prepared by «. any method that reduces the molecular weight of polymers; such methods * include homogenization, sound treatment, radiation, oxidation and hydrolysis. MC / osu * eos * lca * tpr * kra * jtc * P01 / 761 F LL [_ JO / ie? Pp (O), OR 101 10 10 'Cartridge force speed [S *]