WO2000032064A1

WO2000032064A1 - Controlled release carbohydrate embedded in a crosslinked polysaccharide

Info

Publication number: WO2000032064A1
Application number: PCT/US1999/026024
Authority: WO
Inventors: David Craig Zecher
Original assignee: Hercules Incorporated
Priority date: 1998-11-30
Filing date: 1999-11-29
Publication date: 2000-06-08
Also published as: AU1908500A

Abstract

Composition comprising a mixture of carbohydrate, e.g. starch, and covalently crosslinked polysaccharide, e.g. carboxymethylecellulose, suitable for use as controlled release carbohydrates.

Description

CONTROLLED RELEASE CARBOHYDRATE EMBEDDED IN A CROSSLINKED POLYSACCHARIDE

Background of the Invention

Field of the Invention

This invention relates to controlled release carbohydrate and more particularly it relates to digestible carbohydrate material coated, encapsulated, entrapped, or embedded in crosslinked polysaccharide matrix. Description of the Prior Art

In the human diet, carbohydrates carry energy and supply carbon atoms to biosynthetic pathways. In western countries, starch constitutes about 60% of the carbohydrates consumed. Starch is hydrolyzed in the intestinal tract into oligo-, di-, and mono-saccharides, such as glucose. Three types of starch can be identified according to how readily they undergo enzymatic digestion. Firstly, rapidly digestible starch (RDS> consists mainly of amorphous and dispersed starch and is measured in vitro chemically as that which is converted into glucose within 20 minutes of enzyme digestion. Secondly, slowly digestible starch (SDS) is measured chemically as the starch converted to glucose between 20 minutes to 120 minutes of enzyme digestion. Finally, resistant starch (RS) is physically inaccessible, granular, or retrograded starch that chemically requires more than 120 minutes to be converted enzymatically to glucose. Most prepared foods contain high levels of RDS. It is desirable for glycemic control of diabetics and for sustainment of physical activity, that the digestibility of carbohydrates be slowed to provide a controlled or steady release of glucose to the body over a period of several hours.

US Patents 5,360,614 and 5,536,156 issued to Estee Corporation are directed to a food composition comprised of a carbohydrate core with an edible time release coating, and a method of preparing the same, respectively. Metabolizable carbohydrates disclosed include sucrose, glucose, lactose, dextrins, and pregelatinized starches, but no mention is made of raw or modified starches. The coatings disclosed include stearic acid, hydrogenated oils, calcium stearate, stearyl alcohol, and the like, but no mention is made of hydrocolloids like carboxymethylcellulose. The coating is said to be evenly distributed on the core. US Patent 5,545,410, also issued to Estee Corporation, relates to a composition and a process very similar to the previous two patents, but includes raw starches and modified starches as examples of metabolizable carbohydrates, and states that hydrocolloids such as carboxymethylceliulose, gum arabic, carrageenan, 5 alginates, xanthan, pectins, and methyl cellulose can be used as the coating. This patent also discloses that it is not necessary that the coating film be equally distributed on the particle.

There are a number of disadvantages to the coatings proposed in the Estee patents. Firstly, many of the proposed coating agents are fatty substances which 0 many people wish to avoid in their diet. Secondly, some of these coating agents are applied using a non-aqueous organic solvent, which is expensive and undesirable. Thirdly, the coating method results in relatively large amounts of the coating material relative to the carbohydrate core. For instance, in Example 6 of US 5,545,410, 100g of comstarch is coated with a blend of 40g of stearic acid, 20g of ethyl cellulose, and 5 140g of hydrogenated tallow. Accordingly, the final coating weight is about 66.7%. Finally, coatings with hydrocolloids such as carboxymethylceliulose would not, by themselves, be expected to be particularly effective because they are water-soluble polymers and would readily dissolve in the gastrointestinal tract.

European Patent Application 0749697 A1 (Hercules Incorporated) provides for o the use of a cationically crosslinked polysaccharide coating for reducing the giycemic response of a carbohydrate-containing food. The polysaccharide is preferably alginate, pectinate, carrageenan, a crosslinkable cellulosic, xanthan, agar, or guar. A cation, preferably calcium or magnesium, is used to crosslink the polysaccharide. The carbohydrate-containing food is typically a whole food such as rice grains or 5 pasta shapes, but can include food ingredients such as starch granules. The coated food comprises 0.01-5% by weight, preferably 1-3 wt%, of the cationically crosslinked polysaccharide. Example 11 describes the use of Ca-stearate or Ca-pectate to coat cornstarch to provide delayed glucose release.

There are several disadvantages in the above European patent application o regarding its use in food ingredients such as starch rather than whole foods. The coating is limited to 5% by weight. This may be sufficient for relatively large food pieces, such as whole rice, but is usually insufficient for small starch granules. For example, rice kernels are often a few millimeters in length, while cornstarch granules have ~15μ diameters. Since the surface area of a sphere is proportional to the square of the diameter, the difference in surface area of spheres 1.5mm and 15 in diameter is 10, 000-fold. Hence, higher percent coating by weight is required simply to provide the same coating thickness for the smaller particles. Furthermore, although calcium is an effective cationic precipitant or crosslinker for alginate and pectinates, it is not particularly effective for most cellulosics like carboxymethylceliulose because CaCMC is too water soluble. Summary of the Invention According to the present invention there is provided a composition comprising a mixture of carbohydrate and physically and/or covalently crosslinked polysaccharide.

Further provided is a process to prepare a mixture of carbohydrate and covalently crosslinked polysaccharide comprising (1) contacting carbohydrate with crosslinkable polysaccharide and (2) crosslinking the crosslinkable polysaccharide. Still further provided is a diabetic food comprising a mixture of digestible carbohydrate and covalently crosslinked polysaccharide. Detailed Description of the Invention

It was found that a controlled release carbohydrate could be prepared by embedding, coating, or encapsulating a carbohydrate with a physically and/or covalently crosslinked polysaccharide. The carbohydrate can include mono-, di-, oligo-, and polysaccharides, such as glucose, lactose, maltose, fructose, dextrins, maltodextrins, raw starches, modified starches, and pregelatinized starches. Raw and modified starches are preferred. Raw and modified cornstarches are most preferred. The amount of carbohydrate in the final controlled release carbohydrate

(CRC) product is generally at least about 40 weight percent, preferably at least about 60 wt%, and most preferably at least about 70 wt%. The amount of carbohydrate in the final product is generally up to about 95 weight % and preferably up to about 90 weight %. The crosslinked polysaccharide includes food hydrocolloids such as carrageenan, pectins, xanthan, alginates, gum arabic, galactomannans like locust bean gum, guar and tara gum, and cellulosics like carboxymethylceliulose, methylcellulose, hydroxypropylcellulose and methylhydroxypropylcellulose. Preferably, the crosslinkable polysaccharide contains carboxyl or carboxymethyl groups and hydroxyl groups, such as alginates, pectins with low degrees of esterification (methylation), gum arabic, xanthan, gellan and carboxymethylceliulose. Of these, carboxymethylceliulose with a carboxymethyl degree of substitution of at least about 0.3 is preferred and carboxymethylceliulose with a degree of substitution of at least about 0.6 is most preferred. Carboxymethylceliulose with a carboxymethyl degree of substitution of up to about 1.5 is preferred and carboxymethylceliulose with a degree of substitution of up to about 1.2 is most preferred. For food applications, the degree of substitution of the carboxymethylceliulose employed is preferably up to about 0.95. The amount of crosslinked polysaccharide in the final product is typically at least about 5% by weight, preferably at least about 10 weight %. The amount of crosslinked polysaccharide in the final product is typically up to about 60 wt%, preferably up to about 40 wt% and most preferably up to about 30 wt%.

In the context of the present invention, physically crosslinked polysaccharides mean polysaccharides wherein there is strong physical interaction between polymer molecules or regions of polymer molecules through strong hydrogen bonding, crystalline or semi-crystalline regions. Such association may often restrict or reduce the solubility of the polysaccharide in water. Physical crosslinking might arise by the association of unsubstituted regions of a non-uniformly substituted polysaccharide during thermal treatment at high temperature at low water contents.

Although heat treatment alone or with crosslinking agents such as various organic polyamines, polyols, polyalkylhalides (e.g., Cl, Br, I, F), polyacylhalides, diepoxides, dialdehydes, divinylsulfone urea, dimethylolurea diacids, diisocyanates, and dianhydrides and combinations thereof can be used to covalently crosslink polysaccharides containing hydroxyl and carboxyl groups, the preferred crosslinking method is to acid heat-treat the carboxyl-containing polysaccharide.

Acids can be strong mineral acids such as hydrochloric, sulfuric, phosphoric, and nitric acid, and organic acids such as formic, acetic, propionic, citric, tartaric, malic, malonic, succinic and adipic acid. Generally, suitable organic acids are aliphatic mono-di- and polycarboxylic acids having from 1 to 10, preferably from 2 to

6 and most preferably 2 carbon atoms. Hydrochloric acid and acetic acid are most preferred. Typical use levels of the acids are at least about 2 weight percent, as concentrated solutions (that is, concentrated HCI is 36 wt% and concentrated acetic is 100 wt% glacial acetic), based on the weight of the crosslinkable polysaccharide. Most preferably at least about 5 wt% concentrated acid, based on the weight of the polysaccharide is employed. Typically the acid is present in an amount of up to about 10 t% and preferably up to about 8 wt%. Too little acid is ineffective and too much acid can cause undesirable acid hydrolysis of the carbohydrate.

Generally, after contacting the digestible carbohydrate with crosslinkable polysaccharide, the mixture is dried, then subjected to a heat-treatment step to acid crosslink the polysaccharide. In some cases, the drying and heat-treatment steps can be combined into one step. The temperature and time for heat-treatment can be varied to provide the desired crosslinking. Preferably, the temperature of the heat- treatment step is at least about 80°C, and most preferably at least about 100°C. Preferably the temperature of the heat treatment is up to about 200°C and most preferably up to about 150°C. Generally, the higher the temperature, the less time required for effective crosslinking. At 100°C, up to 24 hours may be required for beneficial results by heat-treatment. At 150°C, up to 2 hours may be required. When heat treatment is used alone, without acid or other polyamine, polyol, etc. crosslinking agent being present, the time required for crosslinking will be longer and/or the temperature employed will be higher. Generally, as the pH of the polysaccharide is decreased with acid, the temperature and time required to crosslink decreases.

Slowly digestible starch is shown to provide controlled release of glucose and is suitable for those who have certain metabolic disorders such as diabetes and as an energy source for those who are performing sustained physical activity. The slowly digestible carbohydrates i.e. controlled release carbohydrates (CRCs) of this invention would be useful in various food products like cereals, granola bars, high energy bars, diabetic foods, and nutritional beverages for giycemic control of diabetics, and for sustainment of physical activity for athletes and the general population. Other uses for the composition of the present invention are in foodstuffs, spreadable gels, particle stabilization and pharmaceuticals.

Any process that effectively coats, encapsulates, entraps, or embeds the carbohydrate with the crosslinked polysaccharide can be used to prepare the composition of the present invention. Possible processes include spray drying, air suspension or fluidized bed coating, extrusion coating, centrifugal extrusion, coextrusion, rotational suspension separation, coacervation, and precipitation techniques. Some of these processes will obviously be better suited than others, 5 depending on the nature of the carbohydrate and polysaccharide.

Three processes that have been found to provide particularly effective CRCs based on starch and carboxymethylceliulose are described below, but the processes of the present invention are not limited to these three methods.

In Method A (sheet casting process), starch is suspended in a 0 carboxymethylceliulose solution, acid is added, then the slurry is poured into a large flat pan and oven dried at low temperature, ~50°C, to form a thin sheet. The sheet is ground to a coarse powder, then heat treated to crosslink the carboxymethylceliulose to form an effective CRC.

In Method B (dough process), carboxymethylceliulose, water, acid, and starch 5 are added and mixed in a high solids mixer, extruder, or continuous processor and the like, or combinations thereof for a sufficient length of time to form a homogeneous, high solids dough. The dough is chopped into small pieces, dried, ground to a coarse powder, and heat-treated to provide a CRC.

In Method C (precipitation process), starch is added to an acidified o carboxymethylceliulose solution, then the entire slurry is added to a water miscible nonsolvent for the carboxymethylceliulose, such as methanol, ethanol, isopropanol, or acetone, with stirring, to precipitate the carboxymethylceliulose as a coating on agglomerated starch particles. The solids are filtered, washed, dried, and heat- treated to give a powdered CRC. More specific and detailed examples of these 5 general process methods are given below.

The present invention is illustrated by the following examples, which are for illustration only and not intended to be limiting. All parts and percentages are by weight unless otherwise indicated.

EXAMPLES o Procedure of Method A - 40g of unmodified cornstarch and 0.5g of cone. HCI were added to 200g of a 5% CMC7MF solution in water (CMC7MF is a product of Hercules Incorporated with about 0.7 carboxymethyl degree of substitution and a weight average MW of about 250,000). The resulting slurry was poured into a flat glass pan to provide a thickness of about 0.5 inch. This was placed in a forced air oven and dried at 50°C to provide a white opaque sheet. The sheet was ground into granules or powder, then heat-treated at 100°C overnight to provide a crosslinked 5 CRC comprising about 20 wt% of carboxymethylceliulose.

Procedure of Method B - 40g of CMC7MF and 160g of raw cornstarch were added to the mixing chamber of a Brabender mixer. With the mixer turned on, 160g of water containing 2g of cone. HCI was added to form a dough. The dough was mixed at 50rpm for 30-60 minutes. The dough was removed from the mixer, broken 0 into small pieces, then dried and simultaneously heat-treated at 100°C overnight. The dried dough was then ground into a granular or powdered CRC comprising about 20 wt% of carboxymethylceliulose.

Procedure of Method C - 40g of cornstarch and 0.5g of cone. HCI were added to 250g of a 4% CMC7MF solution to form a slurry. The slurry was added slowly, 5 with stirring, to 1 -liter of isopropanol, causing the carboxymethylceliulose to precipitate from solution as a coating on agglomerated starch particles. Alternatively, isopropanol could be added slowly to the starch suspension to cause the same effect. The solids were filtered, washed with isopropanol, then dried and simultaneously heat treated in a 100°C oven overnight to provide a granular CRC, o comprising about 20 wt% of carboxymethylceliulose.

Samples were evaluated for their effectiveness as controlled release carbohydrates by an adaptation of the Englyst in-vitro digestion assay method (Eur. J. Clin. Nutr. 1992. 46: pg 33-50). Controlled enzymatic hydrolysis with pancreatin and amyloglucosidase are used. The released glucose is measured colorimetrically 5 using a glucose oxidase kit. A brief description of the Englyst method follows.

About 0.850g of sample is weighed accurately into a Falcon tube containing five glass marbles and 20ml of 0.1 M sodium acetate buffer solution (pH 5.2). After preincubation in a 37°C shaker bath for 15minutes with the tube held horizontally, 5 ml of enzyme solution is added containing pancreatin, amyloglucosidase, and o invertase, and placed back in the 37°C bath and shaken. 500μL samples are removed via pipette as a function of time, typically at 5, 10, 20, 30, 60, 90, 120, and 180 minutes. The samples are pipetted into vials containing 1000μL of ethyl alcohol, centrifuged for 2 minutes, then 50μL is withdrawn from the aqueous solution and injected into 1000μL of distilled water. Finally, 50μL is withdrawn from the aqueous solution and injected into 1000ml of Boehringer Mannheim GOD-PAP glucose oxidase colorimetric reagent solution. The glucose concentration is determined spectrophotometrically after 35-60minut.es at 510nm, based on a calibration curve for glucose standards.

The total glucose in the sample is determined by subjecting the solution remaining after 180minutes digestion to the following steps. Place the Falcon tube in a boiling water bath for 30min, then cool down to ice bath temperatures. Add 10μL of cold 7M potassium hydroxide and incubate for 30 minutes in a shaking water bath at 0°C. Withdraw 10OOμL of the cold caustic solution and inject into a Falcon tube containing 50ml of 0.1M acetic acid solution. Add amyloglucosidase and place in a 60°C water bath for 30 minutes. Place the Falcon tube in a boiling water bath for 10 minutes, cool, centrifuge, then withdraw 50μL and inject into 1000μL of colorimetric reagent and measure glucose as before. Results are typically reported as the percent of glucose measured at a specific time relative to the total glucose for the sample.

Example 1 Samples were prepared by variations of the starch/carboxymethylcellulose dough process containing about 20 wt% of carboxymethylceliulose as described above in Method B. In Control 1 , no hydrochloric acid was added, the product was dried at 50°C, and no heat treatment step was employed. In Control 2, HCI was added, and the product was dried at 50°C without heat treatment, in Sample 1 , acid was added, and the product was dried at 50°C, then heat treated at 150°C for 30minutes. In Sample 2, acid was added and the product was simultaneously dried and heat treated at 100°C overnight. All samples were ground and sieved to provide a 40-100mesh fraction (that is, through 40 mesh onto 100 mesh). Glucose release rates for the cornstarch control and the four samples were as follows:

Glucose, as % of Total Glucose Cornstarch Control 1 Control 2 Sample 1 Sample 2

5 min 9.4 19.8 15.5^' 9.6 3.3

10 min 15.3 25.5 21.1 11.6 6.2

20 min 21.4 35.3 31.1 16.4 12.8

30 min 30.9 45.0 41.5 19.7 18.6 Glucose, as % of Total Glucose Cornstarch Control 1 Control 2 Sample 1 Sample 2

60 min 60.7 65.7 69.7 27.1 25.5

90 min 75.3 75.7 — 34.9 42.9

120 min 79.0 87.2 89.3 40.1 45.0

180 min 96.5 93.2 93.7 47.3 52.9

Control 1 is not an example of the current invention. No acid and no crosslinking heat treatment step were employed. The glucose release rate shows no benefit (that is, no delay) relative to the cornstarch control. Likewise, Control 2 is not an example of the current invention. Although an acid was employed, the 50°C drying temperature was too low to effectively crosslink the carboxymethylceliulose overnight. The glucose release rate shows no benefit relative to starch. On the other hand, Samples 1 and 2 are examples of this invention. Sample 1 employed acid, a low drying temperature, and a heat treatment step at high temperature. Sample 2 employed acid, and a combined drying/heat treatment step at a temperature and time sufficiently high to crosslink the product to effectively slow the rate of glucose released during digestion by the enzymes.

Example 2 Samples were prepared by Method B, but employing different levels of acid. All samples contained 20 wt% of CMC7MF and were simultaneously dried/crossiinked at 100°C. Control 3 contained no hydrochloric acid, Sample 3 contained 2 wt% of cone. HCI, based on carboxymethylceliulose, Sample 4 contained 5 wt% of cone. HCI, and Sample 5 contained 10 wt% of cone. HCI, all based on carboxymethylceliulose. Again, all samples were ground and sieved to provide a 40- 100 mesh fraction for glucose release.

Glucose, as % of Total Glucose Cornstarch Control 3 Sample 3 Sample 4 Sample 5

5 min 9.4 9.4 13.5 7.2 28.4

10 min 15.3 19.6 17.9 11.4 36.9

20 min 21.4 25.3 27.5 17.4 48.8

30 min 30.9 36.0 32.6 24.6 60.4

60 min 60.7 63.7 53.7 35.4 82.2

90 min 75.3 70.9 69.7 48.2 99.9

120 min 79.0 77.2 — 46.2 103.3

180 min 96.5 91.2 — 62.7 — Control 3, containing no acid, is not covalently crosslinked and is not an example of this invention. It shows no benefit in its glucose release rate relative to the starch control. The other three samples are examples of this patent, but illustrate the importance of having the proper amount of acid. Sample 3 with 2 wt% of HCI, based on carboxymethylceliulose, shows little benefit over the starch control. Heat treatment at temperatures higher than 100°C should crosslink this sample and provide a beneficial delayed glucose release rate. Sample 4 with 5 wt% of HCI, shows a significant reduction in the rate of glucose release relative to starch, illustrating the benefits of this invention. Sample 5 with 10 wt% of HCI, is interesting because it shows an accelerated rate of glucose release, opposite of that desired, indicating that too much acid can be detrimental, apparently due to acid hydrolysis or gelatinization of the starch. These samples illustrate that best results are obtained with the proper amount of acid and temperature/time of heat treatment.

Example 3 Samples were prepared by variations of the starch dough process (Method B), but using various starch arboxymethylcellulose ratios. All samples contained 5 wt% of cone. HCI, based on carboxymethylceliulose, and were simultaneously dried and crosslinked at 100°C overnight. In sample 6, a 9:1 starch arboxymethylcellulose ratio was employed (I0wt% of carboxymethylceliulose coating, based on total solids), in sample 7, an 8:2 starch arboxymethylcellulose ratio was used (20 wt% of carboxymethylceliulose), and in sample 8, a 7:3 starchxarboxymethylcellulose ratio was used (30 wt% of carboxymethylceliulose). The glucose release rates for the 40- 10Omesh fractions were as follows:

Glucose, as % of Total Glucose Cornstarch Sample 6 Sample 7 Sample 8

5 min 9.4 11.9 12.2 9.0

10 min 15.3 15.6 13.6 12.7

20 min 21.4 21.9 20.3 17.2

30 min 30.9 29.1 26.3 20.1

60 min 60.7 47.3 42.4 22.3

90 min 75.3 69.6 49.9 35.0

120 min 79.0 76.2 62.0 37.0

180 min 96.5 86.8 74.1 44.1 All three samples are examples of this invention, however, the data serves to illustrate that the glucose release rate is dependent on the starchxarboxymethylcellulose weight ratio, that is, on the amount of the covalently crosslinked polysaccharide coating or encapsulation material. Example 4

Samples were prepared in accordance with the isopropanol (IPA) precipitation process, Method C. Control 4 was prepared by addition of a starchxarboxymethylcellulose slurry to excess IPA, filtered, then dried at 50°C overnight. Sample 9 was prepared in a similar fashion, but simultaneously dried and crosslinked at 100°C overnight. Sample 10 was prepared by addition of IPA to a starchxarboxymethylcellulose (4:1 ) slurry, then filtered and simultaneously dried and crosslinked at 100°C overnight. The glucose release rates of a 40-100 mesh fraction were as follows:

Glucose, as % of Total Glucose Cornstarch Control 4 Sample 9 Sample 10

5 min 9.4 5.8 1.8 7.3

10 min 15.3 10.5 4.8 9.3

20 min 21.4 19.6 9.7 13.0

30 min 30.9 27.6 16.1 18.0

60 min 60.7 57.3 36.7 30.2

90 min 75.3 72.4 52.5 45.9

120 min 79.0 81.3 53.3 58.9

180 min 96.5 85.0 73.6 69.4

Control 4 is not an example of this invention because it was dried at low temperature without thermal crosslinking. As a consequence, the glucose release rate of Control 4 is very similar to the cornstarch control, perhaps showing only a modest reduction in glucose as a function of time. Samples 9-10 are examples of this invention and show that delayed glucose release can be obtained by coating starch with carboxymethylceliulose by the IPA precipitation methods followed by thermal crosslinking.

Example 5 Samples were prepared by variations of Method B described above in the absence of acid. In Control 5, a 4:4:1 water:starch:CMC (Aquasorb® A500, a product of Hercules Incorporated) ratio was used. The product was dried at 50°C without heat treatment. Sample 11 was similarly produced but was additionally heat treated at 150°C for 80 minutes. Glucose release rates were as follows:

Glucose, as % of Total Glucose Cornstarch Control 5 Sample 11

15 min 20.9 19.3 10.0

30 min 37.5 39.2 24.1

60 min 57.6 52.9 33.3

90 min 73.0 81.4 42.9

120 min 79.8 81.8 56.2

180 min 86.3 89.4 68.8

240 min 91.1 93.6 69.6

Control 5 is not an example of this invention. No heat treatment step was employed. It shows no benefit relative to the cornstarch control. Sample II is an example of this invention. It shows that heat treatment, even in the absence of acid, provided a material with delayed glucose release. This may be due to the presence of physical rather than covalent crosslinks.

Claims

Claims:

1. A composition comprising a mixture of carbohydrate and physically 5 and/or covalently crosslinked polysaccharide.

2. The composition of claim 1 wherein the polysaccharide is physically crosslinked.

3. The composition of claim 1 wherein the polysaccharide is covalently crosslinked. 0

4. The composition of claim 3 wherein the carbohydrate is digestible carbohydrate.

5. The composition of claim 4 wherein the digestible carbohydrate is selected from the group consisting of mono-, di-, oligo- and polysaccharides.

6. The composition of claim 4 wherein the digestible carbohydrate is 5 selected from the group consisting of glucose, lactose, maltose, fructose, dextrins, maltodextrins, raw starches, modified starches, and pregelatinized starches.

7. The composition of claim 4 wherein the crosslinked polysaccharide is selected from the group consisting of food hydrocolloids.

8. The composition of claim 1 wherein the crosslinked polysaccharide is o selected from the group consisting of carrageenan, pectins, xanthan, alginates, gum arabic, galactomannans selected from the group consisting of locust bean gum, tara gum and guar, and cellulosics selected from the group consisting of carboxymethylceliulose, methylcellulose, hydroxypropylcellulose, and methylhydroxypropylcellulose. 5

9. The composition of claim 4 wherein the crosslinked polysaccharide is selected from the group consisting of carrageenan, pectins, xanthan, alginates, gum arabic, galactomannans selected from the group consisting of locust bean gum, tara gum and guar, and cellulosics selected from the group consisting of carboxymethylceliulose, methylcellulose, hydroxypropylcellulose, and 0 methylhydroxypropylcellulose.

10. the composition of claim 4 wherein the amount of digestible carbohydrate is at least about 40% by weight.

11. The composition of claim 4 wherein the amount of digestible carbohydrate is up to about 95% by weight.

12. The composition of claim 4 wherein the amount of crosslinked polysaccharide is at least about 5% by weight.

5 13. The composition of claim 4 wherein the amount of crosslinked polysaccharide is up to about 60% by weight.

14. The composition of claim 5 wherein the crosslinked polysaccharide is selected from the group consisting of food hydrocolloids, the amount of digestible carbohydrate is from about 40 to about 95% by weight, and the amount of 0 crosslinked polysaccharide is from about 5 to about 60% by weight.

15. The composition of claim 6 wherein the crosslinked polysaccharide is selected from the group consisting of carrageenan, pectins, xanthan, alginates, gum arabic, galactomannans selected from the group consisting of locust bean gum, tara gum, and cellulosics selected from the group consisting of carboxymethylceliulose, 5 methylcellulose, hydroxypropylcellulose, and methylhydroxypropylcellulose, and the amount of crosslinked polysaccharide is from about 5 to about 60% by weight.

16. The composition of claim 15 wherein the digestible carbohydrate is selected from the group consisting of raw and modified starches.

17. The composition of claim 15 wherein the crosslinked polysaccharide 0 contains carboxyl or carboxymethyl groups.

18. The composition of claim 15 wherein the crosslinked polysaccharide is selected from the group consisting of alginates, pectins having low degree of esterification, gum arabic, xanthan, gellan and carboxymethylceliulose.

19 The composition of claim 15 wherein the amount of digestible 5 carbohydrate is at least about 60% by weight.

20. The composition of claim 15 wherein the amount of digestible carbohydrate is up to about 90% by weight.

21. The composition of claim 15 wherein the amount of crosslinked polysaccharide is at least about 10% by weight. o

22. The composition of claim 15 wherein the amount of crosslinked polysaccharide is up to about 40% by weight.

23. The composition of claim 16 wherein the crosslinked polysaccharide contains carboxymethyl groups, the amount of digestible carbohydrate is from about 60 to about 90% by weight, and the amount of crosslinked polysaccharide is from about 10 to about 40% by weight. 5

24. The composition of claim 15 wherein the crosslinked polysaccharide is carboxymethylceliulose having a degree of substitution of at least about 0.3.

25. The composition of claim 15 wherein the crosslinked polysaccharide is carboxymethylceliulose having a degree of substitution of up to about 1.5.

26. The composition of claim 15 wherein the crosslinked polysaccharide is 0 carboxymethylceliulose having a degree of substitution of up to about 0.95.

27. The composition of claim 16 wherein the crosslinked polysaccharide is selected from the group consisting of alginates, pectins having low degree of esterification, gum arabic, xanthan, gellan and carboxymethylceliulose having a carboxymethyl degree of substitution of from about 0.3 to about 1.5, the amount of 5 digestible carbohydrate is from about 60 to about 90% by weight, and the amount of crosslinked polysaccharide is from about 10 to about 40% by weight.

28. The composition of claim 27 wherein the carboxymethylceliulose has a degree of substitution of up to about 0.95.

29. The composition of claim 27 wherein the digestible carbohydrate is 0 selected from the group consisting of raw and modified comstarches.

30. The composition of claim 27 wherein the crosslinked polysaccharide is carboxymethylceliulose having a degree of substitution of at least about 0.6.

31. The composition of claim 27 wherein the crosslinked polysaccharide is carboxymethylceliulose having a degree of substitution of up to about 1.2. 5

32. The composition of claim 27 wherein the crosslinked polysaccharide is carboxymethylceliulose having a degree of substitution of up to about 0.95.

33. The composition of claim 27 wherein the amount of digestible carbohydrate is at least about 70% by weight.

34. The composition of claim 27 wherein the amount of digestible o carbohydrate is up to about 90% by weight.

35. The composition of claim 27 wherein the amount of crosslinked polysaccharide is at least about 10% by weight.

36. The composition of claim 27 wherein the amount of crosslinked polysaccharide is up to about 30% by weight.

37. The composition of claim 29 wherein the crosslinked polysaccharide is carboxymethylceliulose having a degree of substitution of from about 0.6 to about

5 1.2, the amount of digestible carbohydrate is from about 70 to about 90% by weight and the amount of crosslinked polysaccharide of from about 10 to about 30% by weight.

38. The composition of claim 37 wherein the carboxymethylceliulose has a degree of substitution of up to about 0.95. 0

39. A process to prepare a mixture of carbohydrate and physically and/or covalently crosslinked polysaccharide comprising (1) contacting carbohydrate with crosslinkable polysaccharide and (2) crosslinking the crosslinkable polysaccharide.

40. The process of claim 39 wherein the carbohydrate is digestible carbohydrate. 5

41. The process of claim 39 wherein the polysaccharide is physically crosslinked.

42. The process of claim 40 wherein the crosslinking is effected by heat treatment.

43. The process of claim 40 wherein the crosslinking is effected by treat o treatment in the presence of crosslinking agent selected from the group consisting of organic polyamines, polyols, polyalkylhalides, polyacylhalides, diepoxides, dialdehydes, divinylsulfone urea, dimethylolurea diacids, diisocyanates, and dianhydrides and combinations thereof.

44. The process of claim 40 wherein the crosslinking is effected by heat 5 treatment in the presence of acid.

45. The process of claim 44 wherein the acid is strong mineral acid.

46. The process of claim 45 wherein the mineral acid is selected from the group consisting of hydrochloric acid, sulfuric acid, phosphoric acid, and nitric acid.

47. The process of claim 44 wherein the acid is organic acid. o

48. The process of claim 47 wherein the acid is selected from the group consisting of aliphatic mono-, di- and polycarboxylic acids having from 1 to 10 carbon atoms.

49. The process of claim 47 wherein the organic acid is selected from the group consisting of formic acid, acetic acid, propionic acid, citric acid, tartaric acid, malic acid, malonic acid, succinic acid, and adipic acid.

50. The process of claim 44 wherein the amount of acid is at least about 5 2% based on the weight of the crosslinkable polysaccharide.

51. The process of claim 44 wherein the amount of acid is up to about 10% based on the weight of the crosslinkable polysaccharide.

52. The process of claim 44 wherein the temperature is at least about 80°C.

53. The process of claim 44 wherein the temperature is up to about 200°C. 0

54. The process of claim 44 wherein the acid is selected from the group consisting of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, and aliphatic mono-, di- and polycarboxylic acids having from 1 to 10 carbon atoms, the amount of acid is from about 2 to about 10% by weight and the temperature is from about 80 to about 200°C. 5

55. The process of claim 44 wherein the acid is selected from the group consisting of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, formic acid, acetic acid, propionic acid, citric acid, tartaric acid, malic acid, malonic acid, succinic acid and adipic acid, the amount of acid is from about 2 to about 10% by weight and the temperature is from about 80 to about 200°C. 0

56. The process of claim 55 wherein the aliphatic acid has from 2 to 6 carbon atoms.

57. The process of claim 55 wherein the acid is selected from the group 5 consisting of hydrochloric acid and acetic acid.

58. The process of claim 55 wherein the amount of acid is up to about 8% by weight.

59. The process of claim 55 wherein the temperature is at least about 100°C. o

60. The process of claim 55 wherein the temperature is up to about 150°C.

61. The process of claim 56 wherein the amount of acid is from about 2 to about 8% by weight and the temperature is from about 100 to about 150°C.

62. The process of claim 61 wherein the amount of acid is at least about 5% by weight.

63. The process of claim 44 comprising:

5 a) preparing a slurry of starch in carboxymethylceliulose solution containing acid b) adding the slurry to water miscible nonsolvent for the carboxymethylceliulose to precipitate the carboxymethylceliulose c) recovering the precipitate and o d) heating the recovered precipitate to a temperature sufficient to crosslink the precipitate.

64. The process of claim 63 wherein the nonsolvent is selected from the group consisting of methanol, ethanol, isopropanol and acetone.

65. The process of claim 44 comprising: 5 a) mixing starch, carboxymethylceliulose, acid and water in a high solids mixer to form a dough b) reducing the size of the dough into small pieces and c) heating the small pieces of dough to a sufficient temperature to crosslink same. o

66. The process of claim 44 comprising: a) preparing a slurry of starch in carboxymethylceliulose solution containing acid, b) drying the slurry at low temperature to form a thin sheet, c) grinding the thin sheet to powder, and 5 d) heating the powder to sufficient temperature to crosslink same.

67. A diabetic food comprising the composition of claim 1.

68. A diabetic food comprising the composition of claim 4.

69. A diabetic food comprising the composition of claim 14.

70. A diabetic food comprising the composition of claim 27.