DK152435B - PROCEDURE FOR THE PREPARATION OF POLYSACCHARIDES OR POLYSACCHARIDE DERIVATIVES BY POLYCONDENSATION OF GLUCOSE, MALTOSE OR A MIXTURE THEREOF WITH A FOOD ACCEPTABLE POLYCARBOXYLIC ACID CATALYST - Google Patents

Description

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The invention relates to a process for the preparation of polysaccharides or polysaccharide derivatives, thereby polycondensing glucose, maltose or a mixture thereof with up to 10 mol% of a food acceptable polycarboxylic acid catalyst and optionally 5-20%, based on the total weight of reactants, sorbitol, glycerol, erythritol, xylitol, mannitol or galactitol at reduced pressure and at a temperature of 150-300 ° C while evaporating the water formed. This process is characterized by first forming an aqueous solution of the starting materials and then dehydrating the aqueous solution at a temperature below 100 ° C and at reduced pressure to a substantially anhydrous syrup, after which this syrup is polycondensed, stopping the polycondensation before significant pyrolysis occurs.

A process for preparing such saccharide condensation polymers by a substantially anhydrous melt polymerization process and the use of these materials for incorporation into food products as non-nutritive substitutes for carbohydrate sweeteners, non-nutritious substitutes for flour and starch, and in many fat-saving agents. recipes for diet foods are described in U.S. Patent No. 3,766,165.

However, the method of the present invention provides several advantages and surprising features which make it clearly superior to the known method.

It is well known that precise mixing and transfer of solids as required by the known methods is more difficult and expensive in commercial practice than mixing and transferring liquids or solutions which have the advantage of being easily transferable by mechanical pumps and that could be accurately measured using ordinary volumetric measuring devices. Generally, however, addition of water is avoided prior to the commencement of a condensation polymerization because it would be expected to suppress the overall velocity and delay the reactor flow. Surprisingly, it has been found that the addition of water increases the overall reaction rate and facilitates the reactor passage in the process of the invention.

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In commercial practice, polysaccharides such as polyslucose and polymaltose products are most efficiently prepared by a continuous process. However, the known melt polymerization process requires continuous mixing of the correct amounts of solid reactants which must then be heated to a temperature in the range of from about 110 to about 150 ° C to melt the reaction mixture. The molten mixture is kept at this temperature until it is introduced into the polycondensation reactor.

During this storage period, harmful coloration occurs and there is a tendency for the formation of oxidative degradation products if the reactants are kept in contact with the atmosphere, especially if the storage period exceeds approx. 1 hour. If the molten mixture is kept under vacuum, the rapid release of condensation water in the form of steam tends to cause solid particles before the melting is complete, which particles tend to collect and clog the steam line.

According to the present invention, these problems, which are characteristic of industrial scale solids, are solved since the storage prior to introduction into the evaporator is carried out in solution at room temperature or slightly above, and no solid particles are introduced into the evaporator.

Furthermore, it has unexpectedly been found that the substantially anhydrous molten state required for polycondensation can actually be achieved in a much shorter time than required to simply melt the dry ingredients by starting with the aqueous mixture and removing the water. in vacuum using an efficient evaporator. This is especially the case if the melting is to be carried out at a temperature close to the melting range of the solid mixture. If temperatures are used significantly over the melt range of the solid mixture, the resulting molten mass may be discolored due to poor heat transfer.

The process according to the invention also has the clear economic advantage that commercially available solutions such as glucose and sorbitol syrups which are considerably cheaper than the corresponding substantially anhydrous can be used as starting materials.

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solid mixtures required by the method of U.S. Patent No. 3,766,165.

Surprisingly, the process according to the invention produces a product of higher quality than the known melt polymerization process, as evidenced by the better color and lower content of by-products such as 5-hydroxymethylfurfural. Furthermore, the need for subsequent bleaching or decolorization steps can be eliminated by this particular method due to the significant reduction in the color material content, with consequent savings in process time and cost. It also follows from the removal of the need for bleaching with reagents, such as hydrogen peroxide, which is known to produce low volatile acid content as by-products [h.S. Isbell et al., Carbohydrate Research 26, 287-295 (1973)] eliminated the introduction of impurities such as formic acid and acetic acid. As a result of the above, the product of the process according to the invention has improved aroma quality.

From an article by E. Pascu and P.T. Mora: "Polycondensation of D-glucose and other simple sugars in the presence of acids" in J. Am.

Chem. Soc., 72, 1045 (1950), a process for preparing polysaccharides is known, wherein a ca. 50% solution of a mono- or disaccharide or a mixture thereof in about 50%.

5% hydrochloric acid is concentrated by rapid evaporation under greatly reduced pressure at 0-45 ° C to a dry and brittle glassy product in which a portion of the hydrogen chloride remains contained.

The differences between this prior art and the method of the invention can be summarized as follows:

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Process according to Process according to the invention: JACS article: 1. Provides edible product No use indicated, using edible simple monosaccharide, in food accept or disaccharides and approx.

Table polycarboxylic acid and 5% hydrochloric acid as catalyst, optionally in food acceptable polyol.

2. Aqueous Solution of React- No concentration of reactants is dehydrated by aunts before polycondensation.

reduced pressure to form an anhydrous syrup before polycondensation.

3. Polycondensate at Reaction temperature 0 - 45 ° C

150 - 300 ° C

4. Edible acid is used, the Hydrogen Chloride catalyst which is combined with the product and must be removed, e.g. by slide-not excreted; the yield is bright and the product is then quantitatively extracted. precipitated with alcohol to obtain only 15 - 20% yield.

5. The product inert to the product is hydrolyzed by salivary enzymes. enzyme and hemicellulose.

6. 1- ^ 6 bonds considered- Methylation studies know in the product. sees that free 6-hydroxy group is predominantly in the product.

The process of the invention can be effectively used to prepare either a water-soluble polymer or a water-insoluble polymer or a mixture containing both types. The parameters that determine the polymer type obtained are initial acidity.

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concentration, reaction temperature and reaction time.

With a given saccharide starting material, e.g. glucose, two types of polysaccharide can be produced by the process of the invention, a water-soluble polysaccharide which can be used to replace sugars in diet foods when the sweetening effect of the sugar is obtained using artificial sweeteners, and a water-insoluble type incorporating the acidic polymerization activator into the polymer in the form of crosslinking moieties.

The insoluble type can be used as a substitute for flour or starch in the preparation of diet foods.

It will be appreciated that the terms polyglucose, polymaltose and polysaccharide in this specification shall include polymeric materials wherein the majority of the monomer units are glucose, maltose or other saccharide, as well as polymeric materials in which glucose, maltose or other saccharide units are esterified with units. derived from the polycarboxylic acids used as polymerization activators.

The starting materials used in the process of the invention are aqueous solutions of maltose, glucose or mixtures thereof. In many cases, such solutions are readily available in the trade. Alternatively, the solutions may be prepared by dissolving one or more of the solid forms of glucose, maltose or mixtures thereof in a suitable amount of water or a solution containing one or more of the other reactants such that the total solids concentration in the resulting starting mixture is in the range from about 30 to about 85 weight percent.

The acids used as catalysts, crosslinking agents or polymerization activators can be any of a variety of relatively non-volatile, edible, organic polycarboxylic acids.

In particular, it is preferred to use citric acid, fumaric acid, tartaric acid, malic acid, succinic or adipic acid, although others such as itaconic acid, terephthalic acid, citraconic acid, citramalic acid and β-ketoglutaric acid, and anhydrides of acids such as succinic acid, adipic acid,

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acid, itaconic acid and citraconic acid, may be used. The solution can be prepared by dissolving a solid form of the acid in an appropriate amount or solution containing one or more of the other reactants, so that a solids content of about 30 to about 85% by weight is reached in the starting solution.

The acid or anhydride must be acceptable in foods, ie. have an acceptable taste and be free from significant detrimental effect in the normally used quantity. Non-edible acids, although chemically suitable for the process, are not suitable for use in the preparation of edible polysaccharides.

Therefore, the selection of the acidic catalyst must be guided by the need for human non-toxicity. Inorganic acids are not suitable for use as acidic catalysts as they are too degradable for both the monomer and polymer units at the temperatures required for the process of the invention. The acid selected must be relatively non-volatile as more volatile acids can be evaporated during the dehydration of the liquid starting mixture or during the polycondensation phase of the process. The polycarboxylic acids used are esterified, for the most part, but incompletely, with the polysaccharide during the polymerization process to form acid polysaccharide esters. This is evidenced by the residual acidity of these polycondensation products after dialysis and the recovery of the acid by hydrolysis of the dialyzed products. The incorporation of the acid moieties into the polysaccharides does not affect their suitability for human consumption.

The acid units are believed to serve as crosslinking agents between different polysaccharide moieties in the insoluble polymers, while in the soluble polymers each acid moiety is believed to be esterified to only one polysaccharide moiety.

The polyols optionally included in the starting solution are solutions of sorbitol, glycerol, erythritol, xylitol, mannitol or galactitol. Alternatively, the solution may be prepared by dissolving the substantially anhydrous form of the polyol in an appropriate amount of water or solution containing one or more of the other reactants so that the total

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holdings in the resulting starting mixture are from about 30 to about 85% by weight.

The starting solution containing saccharide, edible organic polycarboxylic acids and optionally an edible polyol usually has a total solids concentration in the range of from about 30 to about 85% by weight, and preferably from about 65 to about 70% by weight. The exact concentration selected depends on such factors as the solubility of the reactants, the viscosity of the solution and the ease with which the solution is pumped into the evaporator.

In carrying out the process of the invention, the saccharide, the acidic catalyst and, if desired, the polyol are combined in an aqueous starting solution. This is metered into an effective thin film or spray-drying evaporator operating at reduced pressure to concentrate the starting mixture into a substantially anhydrous syrup. The syrup is quickly transferred to a polycondensation reactor, which also operates at reduced pressure and at a temperature of from about 150 to about 300 ° C. The residence time of the reactants is maintained so that substantial polycondensation occurs before substantial pyrolysis takes place. The water formed during the polycondensation reaction is continuously removed by evaporation. Soluble and insoluble polymer product types can then be separated if desired.

In the preparation of insoluble polysaccharides, such as insoluble polyglucoses or polymaltoses, the concentration of acid may also be within the limits set forth below for the preparation of the soluble polysaccharides, and especially from about 2.5 up to 10 mole percent acid. However, it is preferred to use acid concentrations in the range of about 4 to about 8 mole percent in the preparation of insoluble polyglucose or poly-maltose. These ratios are preferred despite the requirements of high reaction temperature and relatively long reaction time, because the total yield of soluble and insoluble polyglucose or polymaltose is between 90 and 99% at these sugar-acid ratios. Thus, using these higher proportions, it is possible to produce in a single reaction mixture a yield of between ca. 50 and approx. % insoluble polyglucose or polymaltose and between ca. 40 0 £ approx. 50% insoluble nolvelucose or nolvmaltose.

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The water-soluble polyglucose or polymaltose can be separated from the insoluble polyglucose or polymaltose contained in the reaction mixture by extraction with water and subsequent centrifugation. A further important advantage of carrying out the reaction at high molar ratios of glucose or maltose to acid is that the resulting products require very little or no neutralization, while neutralization of excess acid content introduces salt concentrations which are unacceptable in a product for use in foods.

The preparation of a high amount of soluble polysaccharides, such as soluble glucose or maltose polymers, usually requires a concentration of acidic catalyst of from 0.1 to 10 mole percent and it is preferred to use between 0.5 and 5 mole percent. As the amount of acid increases, the degree of acid cross-linking increases, and the resulting amount of water-insoluble polyglucose or polymaltose. Where the acid concentrations are unnecessarily high, there may be problems in neutralizing the excess acid present in the final product mixture. As will be appreciated by those skilled in the art, the amount of acid required for a particular polymerization, the duration of the polymerization, the polymerization temperature, and the nature of the desired products are all mutually dependent. The selection of the amount of acid to be used in the process of the invention must take these factors into account.

The inclusion of a food acceptable polyol, such as sorbitol, in the saccharide-carboxylic acid reaction mixtures prior to polycondensation results in better products. In most cases, 90% or more of the polyol cannot be isolated from the condensation product, demonstrating that it has been chemically incorporated into the polymer. These additives act as internal softeners to reduce the viscosity and also bring about improved color and taste. This is seen, for example, in the preparation of caramel from such condensation polymers, where the rheological properties of the melt are improved during processing, the foaming is reduced and a better tasting product of lighter color is obtained. In addition to sorbitol, other polyols acceptable in foods may be used such as glycerol, erythritol, xylitol, mannitol and galactitol. Polyol concentrations of 5 - 20% of it

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total weight reactants provide the aforementioned advantages and contents of from about 8 to about 12% of the total weight reactants are preferred.

Evaporation of the aqueous starting solution into a substantially anhydrous syrup as well as the polycondensation reaction is carried out at a pressure under atmospheric pressure. The preferred absolute pressures for both of these steps do not exceed approx. 40 kpa and is, for example, from about 0.00133 Pa to 13 - 40 kPa, and they can be obtained using a vacuum pump, a steam jet ejector, a water jet pump or by other conventional means.

The temperature used to evaporate the aqueous starting solution to a substantially anhydrous syrup is kept below 100 ° C, and preferably in the range of about 50 to 100 ° C. The evaporation step may be carried out in a separate evaporator of the above drying thin film type or a nebulizer evaporator. Alternatively, the evaporation may take place in the first section of a flow-through reactor adapted to treat highly viscous materials. The subsequent sections of the reactor, set within the specified temperature range, can be used to perform the polycondensation so that both operations are performed in one reactor.

For the polycondensation step of the process of the invention, the reaction time and temperature are mutually dependent.

The optimum temperature for the polycondensation depends on the initial ratio of saccharide, e.g. glucose, and organic polycarboxylic acid, the reaction time and the desired ratio of soluble polysaccharide to insoluble polysaccharide in the final product mixture. Exposure to heat (reaction time and temperature) should be the minimum required to obtain the desired polycondensation product as discoloration, caramelization and degradation increase with prolonged exposure to high temperature. Fortunately, however, the time required to obtain substantially complete polymerization decreases as the polymerization temperature increases. Therefore, the process of the invention can be carried out with a polymerization temperature of about 160 ° C and a reaction time of about 8 hours, as well as with a temperature of about 140 ° C and a reaction time of about 24 hours with approximately the same final polymerization time.

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degree. Comparable results are also obtained by continuous polymerization at temperatures in the range of about 190 to 300 ° V. over about 10 minutes or less.

Chemical purification is generally not necessary for the products of the process of the invention. Where insoluble and soluble polysaccharide is produced together, separation may be necessary.

Neutralization of the polysaccharides is desirable for certain applications, despite the very low acid catalyst content used. For example, where the polyglucose is to be used in diet foods containing whole milk, excess acid which may be present in the unneutralized polyglucose tends to coagulate the milk. In the case of the soluble polyglucose or polymaltose, their solutions are directly neutralized. This neutralization can be accomplished by adding carbonates of potassium, sodium, calcium or magnesium to the solutions of polyglucose or polymaltose. Where the sodium and potassium salts are used together, a physiologically balanced mixture can be used. The salt content of a typical polyglucose solution which has been adjusted to a pH of about 5-6 is only 0.5 - 1.0%. Other materials that can be used to adjust the pH of soluble polyglucose or polymaltose solutions include 1-lycin, d-glucosamine, N-methylglucamine and ammonium hydroxide. The first two of these compounds are natural materials and should not be undesirable as an ingredient in diet foods, and the latter compound, which is rapidly excreted by the body in the form of urea, will also not be undesirable as an ingredient in diet foods. N-methylglucamine is used as a solubilizer for drugs and should also not be undesirable as an ingredient in diet foods. Other methods for reducing the acidity of polysaccharide solutions are dialysis and ion exchange.

Where insoluble polyglucose is to be used as a substitute in dietary foods, it can be ground or mechanically ground so that it has a texture similar to wheat flour. Typically, a material having a fineness of 44 µm is used as wheat substitute.

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The solutions of soluble polyglucose or polymaltose are almost tasteless and the insoluble polyglucose is a mild tasting almost white powder.

Most of the polyglucose produced by the process of the invention has an average molecular weight of from about 1500 to about 36,000. The soluble polyglucoses have been found to have an average molecular weight of from about 1500 to about 18,000 and the insoluble polyglucoses have shown say to have an average molecular weight of from about 6,000 to about 36,000.

The experimentally determined average molecular weight figure of the polyglucoses produced by the process of the invention is usually found to be in the range of about 1,000 to about 24,000, with most of the molecular weights falling in the range of 4,000 to about 12,000. The method is based on the reduction of alkaline copper citrate reagent. The average molecular weight values are calculated on the basis of standardization with gentiobiosis, as determined by the modified reducing end group method according to Isbell (J. Res. Nautti. Bur. Standards 24.241 (1940). It is assumed that equimolar amounts of polyglucose and gentiobiosis have approximately the same reducing ability and assumes that there is one reducing end group of the molecule. The average molecular weight determined in this way turns out to be a deceptively low number which highlights the low end. of the molecular weight distribution of wide molecular weight lining polycondensation products divisions. When the modified reducing end group method was used to determine the average molecular weight number of a commercial clinical dextran grade with a known average molecular weight number of 40,000 + 3,000, the reducing end group method yielded an average molecular weight number of 25,600. For this reason, it is considered proper to multiply the average molecular weight numbers found by the modified reducing end group method by about 1.5. The average molecular weight numbers are therefore called the apparent average molecular weight number, where they have been determined by the modified end-group reducing method as outlined here. These apparent average molecular weight numbers are given as α H 2. Where sorbitol or one

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other polyol being incorporated into the polymerization mixture, this agent tends to be incorporated at the end of the polymer chain, in which case molecular weight determinations based on end-group methods prove inaccurate. As a result, one of the many other well-known methods of molecular weight determination must be used in conjunction with these polymers.

The bonds predominantly in the polyglucose are primarily 1-6, but other bonds also occur. In the soluble polyglucose, each of the acid moieties is esterified to polyglucose. Where the acid moiety is esterified to less than one polyglucose moiety, the result is a crosslinking.

Synthetic polyglucoses produced by the process of the invention are not affected by amylolytic enzymes such as amylo (1,4-glucosidases, amylo (1,4, 1,6) glucosidases, amylo (1,4) dextrinases and amylo (1,4) maltosidases as well such as α- and β-glucosidases, sucrase and phosphorylase. Animal feeding tests and radioactive tracer studies also show that these polyglucoses are essentially devoid of calories.

The soluble polyglucoses and polymaltoses are useful in providing dietary foods from which the natural sugars have been removed and replaced by artificial or other sweeteners, the physical properties of natural foods other than sweetness.

For example, in baked goods, the polysaccharides in question affect rheology and consistency in a manner analogous to sugar and may replace sugar as a filler. Typical applications for the soluble polyglucose are found in gels, jams, boiled fruit, jams and low calorie fruit mash; in frozen diet foods including ice cream, milkshake, sorbet and water ice; in baked goods, such as cakes, cookies, pastries and other foods containing wheat or other flour; in glaze, toppings and chewing gum; in beverages such as non-alcoholic low-carbon drinks and root extracts; in syrups; in desserts, sauces and puddings; in salad dressings and as fillers in low-calorie sweeteners containing cyclamate or saccharin.

The use of the polyglucose produced by the process of the invention allows the removal of 20-100% of the normal

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paint fat, oil or fat triglyceride components in the food.

The degree to which fat, oil or fat triglycerides are removed will naturally vary with the type of food; eg. in a French salad dressing it is possible to completely remove the normally contained oil component. In chocolate coatings, ice cream blends and whipped desserts, 20-50% of the fat, oil or triglycerides can be removed while preserving the necessary properties of the food product, such as texture, gloss, viscosity and taste.

As mentioned earlier, in addition to the removal of sugar in many recipes, there is a considerable flour and / or fat-saving effect, which is possible without reducing the quality of the food. Of course, this results in a further reduction of the total calorie content of the food.

The insoluble polyglucoses are useful as flour substitutes in cakes, cookies, breads, pastries and other dairy products based on flour from wheat, corn, rice or potatoes as well as bakery products which would normally contain graham flour, rye, soybean, oatmeal or bean flour. In addition, the insoluble polyglucoses are useful in non-swelling foods such as spaghetti and noodles, or as a substance in meat hashes and mashed potatoes as well as for other uses which may include flour as an ingredient.

When the polyglucoses and polymaltoses prepared by the process of the invention are incorporated into diet foods, the resulting foods retain the taste quality and appetizing properties of their natural counterparts. Furthermore, the caloric content of these diet foods is significantly lowered by the fact that the products in question have been used to replace sugars, starches and fats contained in the natural counterparts of the diet foods.

The aforementioned food uses of the disclosed soluble and insoluble polysaccharides are illustrated in U.S. Patent No. 3,766,165.

The method according to the invention is illustrated in more detail by the following embodiments.

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EXAMPLE 1

S2 ^ _Y2SÉiS_HÉS2SS§2El22SiSS

A 65% by weight aqueous starting mixture was prepared by dissolving 202 kg of dextrose, 32.4 kg of 70% sorbitol solution and 2.3 kg of anhydrous citric acid in 112.8 kg of deionized water. The resulting solution was applied to a 0.38 m Pfaudler super dry film evaporator maintained at a vacuum of 68 kPa, vapor sheath gauge pressure 690 kPa. The feed rate was adjusted such that the yield of dehydrated starting mixture was 59.4 kg / h. A representative sample of dehydrated starting mixture was found to have 97.5% total solids; Gardner Color (10% by weight aqueous solution) less than 1; % transmission at 490 nm (10% aqueous solution) 100; levoglucosan 0.00%.

The dehydrated starting mixture was continuously fed into a vacuum-powered 7.7 liter continuous double-arm mixer (Baker-Perkins Multipurpose Continuous Mixer). The pressure was maintained at 10.0 - 13.3 kPa; the temperature measured at different zones of the unit ranged from 115 to 245 ° C. The feed rate was set to obtain a residence time of about 5 minutes. The almost white product was completely soluble in water. The following data were determined for the polymer:

Reduction value * (Munson & Walker method) .............. 8.5

Gardner Color (10% by weight solution) .............. 1.2% transmission at 490 nm ..................... ........ 95.7 5-Hydroxymethylfurfural,% ............................ 0.055 pH (5% by weight solution ) .......................... 2.9

Acid equivalent (mg NaOH per g) ........................ 4.0 * See e.g. David Pearson: "The Chemical Analysis of Foods"

Chemical Publishing Company, Inc., New York 1971, pages 123-126.

EXAMPLE 2

Comparison_of_inventory_and_initial_initial mixture A. Initial mixture prepared by evaporation of aqueous solution 2

Conditions: 0.38 m Pfaudler super dry film evaporator driven

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at a vacuum of 68 kPa, vapor sheath pressure gauge 690 kPa. Supply temperature maximum 100 ° C. Composition of starting mixture as in Example 1.

Production speed Color, 10 wt. Res.

of Dehydrated ———— - Ingredient% Total Gardner% Transm. % Levo-

Test_kg / hr solid Color 490 nm glucosane in 31.8 99+ <1 97.2 0.02 ii 47.2 99.0 <1 100 trace iii 59.4 97.6 <1 100 0.00 iv 73.0 96 , 8 <1 100 0.00 v 88.0 96.1 <1 100 0.00 vi 104.4 94.8 <1 100 0.00

Aqueous mixture - 65.0 <1 100 0.00 B. Starting mixture prepared by the melting method

Conditions: The melting was carried out in a worm conveyor with steam jacket (Rietz Thermascrew Feed Melter) at atmospheric pressure, steam jacket pressure gauge 172 kPa. Melting temperature 125 - 5 ° C.

Initial composition: 403 kg glucose monohydrate, 45.4 kg sorbitol, 4.5 kg citric acid. The total solids content for both starting mixture and melt was 92% by weight. The components were mixed dry and then continuously fed into the melter. Representative samples of molten starting mixture were cooled and ground in a Waring mixer. The following tests were obtained on samples from six experiments.

Gardner Color% Levo-

Experiment_10% by weight solution_glucosan36 in 1-2 0.34 in 1-2 tracks iii 1-2 0.54 iv 1-2 0.62 v 1-2 0.62 vi 2 0.74

X

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Levoglucosan (1,6-anhydro-D-glucose) was determined by silyylation gas-liquid chromatography on a 1.5 mx 3.75 mm, 10% OV-1 of 0.177 - 0.250 mm "Supelcoporf column at 205 Under these conditions, the levoglucosan retention time was approx.

4.5 minutes.

EXAMPLE 5 A. Polyglucose prepared from the dehydrated starting samples of Example 2 A

Representative samples of each 2.0 g of the dehydrated starting mixtures i-v of Example 2 A were placed in each tube of a test tube. Each glass was connected to a vacuum manifold with a vacuum of .68 kPa. The jars were immersed in a 200 ° C hot oil bath for 5.0 minutes. The following data was obtained for the products.

Color of 10 weight nets. resolution

Reduction value, Gardner% transm. % 5-Hydroxy Test Munson & Walker Color 490 nm methylfurfural * 14.1 1-2 95.0 0.080 ii 7.4 1-2 96.5 0.051 iii 13.3 1-2 92.5 0.094 iv 8, 5 1-2 95.7 0.055 v 8.7 1-2 94.5 0.064

Average 10.4 1-2 94.8 0.069 x 10

Determined by comparing the sample E ^ '0 ^ at 283' nm with the value of pure 5-hydroxymethylfurfural:

El ^ cm (Sample)% HMF = c? -, - 15.55

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B. Polyglucose prepared from the molten starting mixture samples of Example 2B__

Representative samples of each 2.0 g of the molten starting mixtures i-v of Example 2B were converted to water-soluble polymer as described above under A in this example. The following data were obtained for the. resulting products:

Color of 10 wt. resolution

Reduction value, Gardner% transm. % 5-Hydroxy Test Munson & Walker Color 490 nm_methylfurfural * i 9.9 2-3 87.9 0.092 ii 8.1 2-3 85.9 0.085 iii 8.2 2-3 88.9 0.100 iv 13.0 2-3 88.0 0.079 v 7.5 2-3 90.0 0.071 section Sm ~ 9'3 2-3 88.1 0.085 EXAMPLE 4

Tartrated_polyglucose_with_sorbitol_yed_polycondensation_of dehydrated_and_and_initial mixture 500 g of solution (70% total solids) containing dextrose, sorbitol and tartaric acid in a ratio of 89: 10: 1 on a dry weight is slowly introduced into a rotary evaporator of glass (No. 5). using an insertion tube. The system is maintained at a pressure of 2-4 kPa. The rotary flask is immersed in a boiling water bath. In this way, the aqueous starting solution is flash evaporated over 30-45 minutes to give an almost colorless residue. While held under a nitrogen atmosphere, the flask containing the dehydrated starting mixture is placed in an oil bath at 170 ° C and heated to a bath temperature of 1β5 - 170 ° C at a pressure of 3.3-6.7 kPa for 4 hours. The resulting water-soluble polymer proves very advantageous when compared to the product obtained in Example 1. Compared to a tartrated soluble polyglucose sample, prepared in exactly the same way, but from a molten starting mixture with the same solid ratio, the above mentioned niches are found. of.

1 ft

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have a better color, a lower 5-hydroxymethylfurfural content (determined at 283 nm), and it is judged to have a milder taste.

EXAMPLE 5

Tartrated_golyglucose_with_20 _% _ ° rbitol by glycation condensation of_aqueous_ starting mixture

The process of Example 4, in which the sorbitol content is increased to 20% by weight with a corresponding reduction in the dextrose content, yields a polyglucose very similar to that obtained in Example 4.

EXAMPLE 6 Density of the same reaction 908 kg of an aqueous solution containing 568 kg of glucose, 63.5 kg of sorbitol and 6.4 kg of citric acid are placed in a suitable storage tank. The solution is pumped from the tank to the entrance by a vertical thin film reactor adapted to perform both solvent evaporation from viscous materials and polycondensation. The reactor operates at a pressure of 2.7-4 kPa. The upper part of the reactor is maintained at 85-100 ° C; the lower part is kept at maximum temperature of 245 ° C. Water vapor is removed by means of a condenser whose outlet is located above the inlet of the liquid outlet mixture. The molten viscous product is discharged at the bottom by means of a pump adapted to move highly viscous polymers.

The citrated polyglucose produced is substantially identical to the product of Example 1 and exhibits better properties than analogous citrated polyglucose samples prepared by the molten starting mixture method of U.S. Pat.

3 766 165.

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EXAMPLE 7

Polymerization_of_maltose_with_citrons2re_out_from_and_and_and_output mixture

A solution is prepared from 285 g of maltose monohydrate and 15 g of citric acid by dissolving them in 100 g of deionized water. This solution is evaporated in a rotary evaporator in the same way as in Example 4. The dehydrated mixture is then heated to 160 ° C at a pressure of 1.3-2 kPa, for 7 hours. The resulting polymer is substantially lighter in color, has a significantly lower content of 5-hydroxymethylfurfural, and has better taste quality than analogous products made by the known melt polymerization process. Otherwise, the products produced by these processes show no significant differences.

EXAMPLE 8

500 g of a solution (65% total solids) containing 315 g of dextrose and 10 g of citric acid in 175 g of water was prepared. The solution is flash evaporated as described in Example 4. The resulting dehydrated mixture is placed in a 170 ° C hot oil bath and maintained at 165-170 ° C and a pressure of 2.7 kPa for 4 hours, then cooled to room temperature. The resulting citrated polyglucose is completely soluble in water. Compared to an analog product made by melt polymerization, it exhibits significantly better color and flavor properties and has a reduced content of 5-hydroxymethylfurfural.

EXAMPLE 9

Fumarated_Osoluble_E2llgl '! I2222_Y2 ^ _ £ E25S2ES2must be an aqueous starting mixture

The process of Example 8 is repeated using an aqueous solution containing 10 g of food-grade fumaric acid instead of citric acid. The resulting nolvelucose is strongly similar to the product.

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Example 8 and show the same improvements in color, taste and 5-hydroxymethylfurfural content as compared to an analog fumarated polyglucose prepared by melt polymerization.

EXAMPLE 10 Malic Acid Catalyzed_Soluble_Polyglucose_ By the Method_ With Aqueous Exit

The process of Example 8 is repeated using an aqueous solution containing 10 g of malic acid instead of the citric acid.

The resulting polyglucose strongly resembles the product of Example 8 and shows the same improvement in color, taste and 5-hydroxymethylfurfural content as compared to an analog malic acid-catalyzed polyglucose prepared by melt polymerization.

EXAMPLE 11

Succinate-soluble polyglucose by the method_within

A solution is prepared from 190 g glucose monohydrate and 10 g succinic acid by dissolving in 135 ml water. The solution is evaporated as described in Example 4 and then heated to 150 ° C at a pressure of 670 Pa for 18 hours. The resulting water-soluble polyglucose is then compared with a similar product made by melt polymerization. The product from the aqueous starting mixture shows the same advantages as described for the product of Example 8.

EXAMPLE 12 starting mixture

The process of Example 11 is repeated using an aqueous solution containing 10 g of food grade adipic acid instead.

21 DK 152435 B

for the succinic acid with essentially the same results.

EXAMPLE 13

Fumarated polyglucose with sorbitol_by_continuous_process_with_and_and_initial mixture

A 65% aqueous solution of a starting mixture containing 50 kg of dextrose monohydrate, 5 kg of sorbitol monohydrate and 1.77 kg of fumaric acid is prepared. The solution is introduced continuously into a 0.1 m 2 super dry film evaporator held at 90-100 ° C. The viscous 2 pass is in turn introduced into a 0.1 m super dry film vacuum reactor heated to 220-295 ° C. The whole system is maintained at a pressure of 40 kPa. The supply speed of the evaporator is set such that the residence time throughout the system is 4-10 minutes. Comparative tests with the same product prepared by melt polymerization again show the aforementioned improvements in color, taste and 5-hydroxymethylfurfural content, while other properties are found to be substantially identical.

EXAMPLE 14

Fumarated_polyglucose_ with sorbitol_by_continuous_ method of aqueous starting mixture

The process of Example 13, in which the sorbitol content of the starting mixture is reduced to 5% by weight of the total solids content, gives a polyglucose which is very similar to that produced in Example 13 and which has the same advantages over a similar melt polymerization product.

EXAMPLE 15

Fumarated_polyglucose_with_erythritol_with_continuous_process- S§ ^ ®_H ^: _ ii! S_Y§ ^ iS_ ^ S§2-Ssb mixture

The process of Example 13, in which sorbitol is replaced by an equal amount of weight of erythritol, yields a polyglucose of the same

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EXAMPLE 16 Glycerol by Continuous Procedure_ From Aqueous Initial Mixture

The process of Example 13, in which sorbitol is replaced by an equal amount of weight of glycerol, provides a polyglucose with the same properties and benefits as the product of Example 13.

EXAMPLE 17

Tartrateret_2olyglucosejned_xylitol_yed_fremgangsmåden_med_yan--

The process of Example 4, in which sorbitol is replaced by an equal amount of weight xylitol, provides a polyglucose with the same properties and benefits as the product of Example 4.

EXAMPLE 18

Tartrated polyglucose_with_mannitol_with_the method_with van-ÉiiJ ^ ggSgg mixture

The process of Example 4, in which sorbitol is replaced by an equal amount of weight mannitol, provides a polyglucose with the same properties and benefits as the product of Example 4.

EXAMPLE 19 Y22

The process of Example 4, in which sorbitol is replaced by galactitol and the starting solution contains dextrose, galactitol and tartaric acid 94: 5: 1 by weight, gives a polyglucose with the same properties and benefits as the product of Example 4.

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EXAMPLE 20

Mixture_of_citrated_and insoluble_and_uo soluble_20lYglucose_by ^ the method of strapping_with_aqueous_ output

A solution of 320 g of D-glucose and 25 g of citric acid in 230 ml of water was prepared.

A two-liter, three-neck flask fitted with a stirrer, thermometer, drip funnel and condenser for distillation was immersed in an oil bath at 170 ° C and the system pumped out to a pressure of 2.7-3.3 kPa. Stirring was started and the aqueous solution was introduced into the flask over 30-45 minutes during which most of the water evaporated. Stirring was continued until the mixture became very sticky. The reactants were then maintained at 170 ° C for 18 hours. The crude polymer was ground and divided into a water-soluble (35%) and a water-insoluble (65%) fraction.

The products are very similar to the similar products made by melt polymerization, but the products in this example had a significantly lighter color.

EXAMPLE 21

Preparation of 70% neutralized solution of citrated poly (22É2_E2iZSi ^ 2222_252iiii2i_Y2É-_252ii2E2iZ®2i22ii22 200 g of the product of Example 1 is dissolved in an equal amount of deionized water and adjusted to pH 5.5. The resulting solution is then concentrated in vacuo to give a 70% by weight solution. The color of the resulting solution is "light straw yellow" and judged to be organoleptically perfectly acceptable.

Compared to a 70% solution prepared from an analog melt polymerization product which had been bleached with alkaline (CaO) peroxide and neutralized to pH 5.5, the color of the bleached solution is only slightly brighter. The solution of the product

Claims (1)

24 DK 152435 B prepared from aqueous starting mixture is judged to be less bitter and less "chalky" in taste and has substantially lower calcium, ash and volatile fatty acid content than the bleached product. Process for preparing polysaccharides or polysaccharide derivatives, polycondensing glucose, maltose or a mixture thereof with up to 10 mol% of a food acceptable polycarboxylic acid catalyst and optionally 5-20% by weight of the total weight of reactants, sorbitol, glycerol, erythritol, xylitol, mannitol or galactitol at reduced pressure and at a temperature of 150 - 300 ° C during evaporation of the formed water, characterized in that an aqueous solution of the starting materials is first formed and then the aqueous solution is dehydrated at a temperature below 100 ° C and at reduced pressure. to a substantially anhydrous syrup, after which this syrup is polycondensed, stopping the polycondensation before substantial pyrolysis occurs.