FI58335C - FOERFARANDE FOER FRAMSTAELLNING AV POLYSACKARIDER OCH POLYSACKARIDDERIVAT - Google Patents

Description

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Patent · och reflrtentyrelMn v 'AmMcm uttagd och uti ^ krtfun pubttcund 3' y '(32) (33) (31) Pyri «tty atuelkau * —- Bugtrd prtortt · * 05.0¾. 7¾ USA (US) ¾58079 (71) Pfizer Inc., 235 East ¾2nd Street, New York, NY, USA (US) (72) Peter Joseph Senator, Baldwin, New York, USA (US) (7¾) Oy Kolster Ab ( 5¾) Process for the preparation of polysaccharides and polysaccharide derivatives - For the preparation of polysaccharides and polysaccharides

The present invention relates to an improved, easy, economical process for the preparation of edible condensation polymers of sacharides and their derivatives. In particular, it relates to a process for the preparation of edible polysaccharides and polysaccharide derivatives by polycondensation of glucose, maltose or a mixture thereof, using as catalyst 10 to 10 molar citric, fumaric, tartaric, malic, succinic or adipic acid and optionally 5 to 20 based on the total weight of the reactants, sorbitol, glycerol, erythritol, xylitol, mannitol or galactitol at a pressure of less than 300 mmHg and a temperature of 150-300 ° C while evaporating the water formed in the reaction.

The process according to the invention is characterized in that an aqueous polycondensation solution with 65-70 wt.% Solids is used, which is dehydrated at 300 mmHg to a substantially anhydrous syrup before polycondensation and then polycondensed. The preparation of saccharide condensation polymers mainly by the anhydrous melt-feed polymerization process 2,58335 and the new use of these substances in foods as nutritional substitutes and fat-saving agents for carbohydrate sweeteners in flour and starch are described in U.S. Pat.

It is well known that the precise mixing and transport of solids used in prior art methods is more difficult and expensive than similar treatments of liquids or solutions. Liquids can be easily transported with mechanical pumps and dispensed accurately with standard volume measuring devices. Usually, however, the addition of water is avoided before starting the condensation polymerization because water slows down the condensation reaction.

Polysaccharides such as polyglucose and polymaltose products are most commercially produced by a continuous process. However, the prior art melt polymerization process requires continuous agitation of the exact amounts of solid reactants, after which the reaction mixture must be melted at about 110-150 ° C and fed to the polycondensation reactor at this temperature.

During the treatment period, atmospheric oxygen causes undesirable discoloration and decomposition products are formed, especially if the treatment time exceeds one hour. If the molten feed is kept under vacuum, due to the rapid evaporation of the water generated in the condensation reaction, solid particles are removed with the steam before complete melting, with these particles tending to accumulate in the steam line and clog it.

The present invention solves these problems, which are characteristic of the melting of solids on an industrial scale, since the reaction mixture is in solution at or slightly above room temperature before being fed to the evaporator, and thus no solids enter the evaporator.

It has also been found that the substantially anhydrous molten state required in polycondensation can in fact be achieved in a significantly shorter time by using an aqueous feed material and removing water in a vacuum by means of an efficient evaporator than by using a molten feed material. This is especially the case if the melting has to be carried out at a temperature close to the melting range of the solid mixture. If temperatures well above the melting range of the solid mixture are used, the molten mass may discolor due to poor heat transfer.

The process of the invention also has a clear economic advantage in that it can use commercially available solutions as starting materials, such as 3,583,35 glucose and sorbitol syrups, which become considerably cheaper than their substantially anhydrous counterparts found in the process of U.S. Patent No. 3,766,165. used.

The process according to the invention surprisingly gives a higher quality product than the previous melt-feeding process, as evidenced by the excellent color and the small amount of by-products such as 5-hydroxymethylfurfural.

In addition, in the new method, post-bleaching or decolorization steps are unnecessary due to the substantial reduction in dye amounts, resulting in reduced processing times and costs. When bleaching is unnecessary • bleaching with reagents such as hydrogen peroxide, which is known to cause the formation of volatile acids as by-products / H.S. Isbell et al., Carbohydrate Research 26, 287-295 (19733 * eliminates the presence of impurities such as formic acid and acetic acid, resulting in improved odor properties of the product of the invention.

This improved method can be effectively used to produce either a water-soluble polymer, a water-insoluble polymer, or a mixture containing both types. The parameters that determine the type of polymer obtained are the initial acid concentration, the reaction temperature and the reaction time.

According to the process of the invention, two types of polysaccharides can be prepared from a certain saccharide starting material, for example glucose, a water-soluble polysaccharide which can be used to replace sugars in dietary foods, the sweetening effect of sugar is achieved by using artificial sweeteners, and a water-insoluble type with acidic polymerization. in the form of crosslinking moieties to the polymer. The insoluble type can be used as a substitute for flour and starch in diet foods.

It is to be understood that the terms polyglucose, polymaltose and polysaccharide, as used herein, refer to polymers in which the monomer units are predominantly glucose, maltose or other saccharide, as well as polymers in which the glucose, maltose or other saccharide units are polycarboxylated groups.

The starting materials used in the process of this invention are aqueous solutions of maltose, glucose or mixtures thereof, although solutions of other saccharides such as xylose, ribose, arabinose, fructose, mannose, galactose, lactose, cellobiose and the like may also be used. In many cases, such solutions are already commercially available. Alternatively, solutions may be prepared by dissolving one or more

It 58335 solid forms of glucose, maltose, mixtures thereof or other saccharides in a suitable amount of either water or a solution containing one or more other reactants so that the total concentration of solids in the resulting feedstock is between about 65-TO by weight.

The acids used as catalysts, crosslinking agents or polymerization catalysts can be any relatively non-volatile, edible organic polycarboxylic acids. In particular, citric, fumaric, tartaric, malic, succinic or adipic acids are recommended, although other acids such as itaconic, terephthalic, citraconic, citric, malic and ketoglutaric acids and acids such as succinic, adipic -, itacone and citric acid anhydrides may be used. The solution can be prepared by dissolving the solid form of the acid in a suitable amount of water or a solution containing one or more other reactants to achieve a solids content of about 65 "TO by weight - $ in the feed solution.

The acid or anhydride must be acceptable for human consumption, i.e., tasty and free from significant adverse effects in normal amounts of use. Inedible acids, although chemically suitable for the process, are not suitable for use in the preparation of edible polysaccharides. Therefore, the choice of the acid catalyst to be used must be determined by the fact that it is not toxic to humans. Inorganic acids are not suitable for use as acid catalysts because they have the effect of decomposing both monomers and polymers at the temperatures at which the process of the invention is carried out. The acid selected should be relatively non-volatile, as more volatile acids may evaporate during the removal of water from the liquid feed or during the polycondensation step of the process. The polycarboxylic acids used are extensively but incompletely esterified with the polysaccharide in the polymerization process to form acidic polysaccharide esters. This is demonstrated by the residual acidity of these polycondensate products after dialysis and by acid recovery in the hydrolysis of the dialyzed products. The combination of acid moieties with polysaccharides has no effect on their suitability for human consumption.

In insoluble polymers, the acid moieties are crosslinkers between different polysaccharide moieties, whereas in soluble polymers, each acid moiety is esterified to only one polysaccharide moiety.

The polyols which are optionally added to the feed solution are preferably solutions of sorbitol, glycerol, erythritol, xylitol, mannitol or galactitol, although threitol, ribitol, arabitol, maltitol, lactitol or other edible polyol may also be used. Alternatively, the solution may be prepared by dissolving the substantially anhydrous form of the polyol in a suitable amount of either water or a solution containing one or more other reactants such that the total solids content of the resulting feed solution is between about β5 and Τ0% by weight.

In a feed solution containing a saccharide, an edible organic polycarboxylic acid and optionally an edible polyol, the total solids content is generally about 65-70% by weight. The exact concentration chosen depends on the solubility of the reactants, the viscosity and the pumpability of the solution.

In carrying out the process of the invention, the saccharide, acid catalyst and, if desired, polyol are combined into an aqueous feed solution. This is metered into an efficient evaporator operating under reduced pressure to concentrate the feed into a substantially anhydrous syrup. The syrup is suddenly transferred to a polycondensation reactor, which also operates under reduced pressure and at a temperature between about 150-30 ° C. The residence time of the reactants is considered to be such that the major polycondensation occurs. Soluble and insoluble types of polymer products can then be separated if desired.

In the preparation of insoluble polysaccharides, such as insoluble polyglucoses or polymaltoses, the acid concentration may be in the range used in the preparation of soluble polysaccharides as defined below, about 2.5 to 10 molar acids. However, it is preferred to use either concentrations in the range of about U-8 moles in the practice of this invention to prepare insoluble polyglucose or polymaltose. These ratios are advantageous despite high reaction temperature requirements and relatively long reaction times because the total yield of soluble and insoluble polyglucoses or polymaltoses at these sugar / acid ratios is 90-99 # · Thus, using these higher ratios it is possible to produce 50-60 # yields in one reaction mixture. polyglucose or polymaltose and a yield of 1 + 0-50 # of soluble polyglucose or polymaltose. Water-soluble polyglucose or polymaltose can be separated from insoluble polyglucose or polymaltose by extracting the reaction mixture with water and then centrifuging. An important additional advantage of carrying out the reaction with a high molar ratio of glucose or maltose to acid is that the resulting products require little or no neutralization, whereas neutralization of excess acid produces salt levels that are not acceptable in the product used in food.

In the preparation of products in which the proportion of soluble polysaccharides, such as soluble glucose or maltose polymers, is high, an acid catalyst concentration of between about 0.1 and 10 mol% is usually required and preferably 0.5 to 5 mol% is used. As the amount of acid increases, the degree of cross-linking of the acid increases and the proportion of water-insoluble polyglucose or polymaltose increases. When the acid concentrations are unnecessarily high, there may be problems in neutralizing the excess acid in the final product mixture. As will be readily apparent to 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 products desired are all interdependent. These factors should be considered when selecting the amount of acid to be used in this invention.

The incorporation of an edible polyol such as sorbitol into the saccharide-carboxylic acid reaction mixtures prior to polycondensation gives better products. In most cases, a maximum of 10 # of polyol can be isolated from the condensate product, indicating that it is chemically linked to the polymer. These additives act as internal plasticizers to reduce viscosity and also improve color and flavor. This is evident, for example, in the preparation of hard caramels from such condensation polymers, whereby the Theological properties of the melt are improved during processing, foaming is reduced and a lighter colored product tastes better. In addition to sorbitol, other edible polyols include glycerol, erythritol, xylitol, mannitol, and galactitol. Polyol concentrations of about 5 to 20% by weight of the total reactants provide such advantages, and amounts of about 8 to 12% by weight of the total reactants are preferred.

Evaporation of the aqueous feed solution to a substantially anhydrous syrup and a polycondensation reaction are preferably carried out at atmospheric pressure. Preferred absolute pressures in either of these steps do not exceed about 300 mmHg, for example from about 10 mmHg to 100-300 mmHg. It can be achieved with a vacuum pump, steam jet ejector, vacuum cleaner or other conventional method.

The temperature used to evaporate the aqueous feed solution into a substantially anhydrous syrup is suitably maintained below 100 ° C and preferably between about 50-100 ° C. The evaporation step can be performed in a separate evaporator of the sweep bed evaporator type or in an expansion evaporator. Alternatively, evaporation can be performed at the beginning of a flow-through reactor designed for handling highly viscous materials. Subsequent reactor compartments brought to a specific temperature range can be used to perform polycondensation, thus performing both operations in the same reactor.

58335 The reaction time and temperature of the polycondensation step of this invention are interdependent variables. The optimum temperature for polycondensation depends on the initial ratio of the saccharide, e.g. glucose, to the organic polycarboxylic acid used, the reaction time and the desired ratio of soluble polysaccharide to insoluble polysaccharide in the final product mixture. Heat treatment (reaction time and temperature) should be the minimum required to obtain the desired polycondensation product, as discoloration, caramelization, and chain shortening increase with prolonged exposure to high temperature. Fortunately, however, as the polymerization temperature rises, the time required for complete polymerization decreases. Therefore, the process of the present invention can be carried out at a reaction time of about 160 ° C for about 8 hours or just as well at a reaction time of about 10 hours for about 2 hours, whereby approximately the same degree of polymerization is achieved. Comparable results are also obtained in continuous polymerization at temperatures between about 190-300 ° C in about 10 minutes or less.

Dry cleaning is generally not required for the products of this invention.

When insoluble and soluble polysaccharides are prepared together, their separation may be necessary.

Neutralization of polysaccharides may be desirable for certain applications, despite very low amounts of acid catalyst. For example, when polyglucoses are used in diet foods that contain whole milk, the excess acid that may be present in unneutralized polyglucoses tends to flow the milk. In the case of soluble polyglucoses or polymaltoses, their solutions are immediately neutralized. This neutralization can be carried out by adding potassium, sodium, calcium or magnesium carbonates to solutions of polyglucose or polymaltose. When sodium and potassium are used together, a physiologically balanced mixture can be used. A typical polyglucose solution adjusted to a pH of about 5-6 has a salt content of only 0.5-1.0%. Other substances that can be used to adjust the pH of solutions of soluble polyglucose or polymaltose include 1-glycine, d-glucosamine, N-methylglucamine, and ammonium hydroxide. The first two of these compounds are natural substances and should not be repulsive as an ingredient in diet foods, and the last compound that is rapidly excreted by the body in the form of urine should not be repulsive as an ingredient in diet foods. N-methylglucamine is used as a drug solubilizer and should not be repulsive as an ingredient in diet foods. Other procedures for reducing the acidity of polysaccharide solutions include dialysis and ion exchange.

When insoluble polyglucose is used as a meal replacement in dietary foods, it can be ground or mechanically comminuted so that its structure is similar to that of wheat flour. As a substitute for wheat flour, it is typically ground to a particle size of 0.0 mm (325 mesh).

Solutions of soluble polyglucoses or polymaltoses are almost tasteless and insoluble polyglucose is a mild off-white powder.

. Most of the polyglucoses prepared in accordance with this invention have an average molecular weight of about 1,500 to 36,000. The average molecular weight of the soluble polyglucoses prepared has been found to be about 1,500 to 18,000 and the average molecular weight of the insoluble polyglucoses prepared in accordance with the invention has been found to be about 6,000 to 36,000. .

The polyglucoses prepared in accordance with this invention have been found experimentally to have a number average molecular weight of about 1,000 to 2,000,000, with most molecular weights being about 1,000 to 12,000. These number average molecular weights are determined by a modified reducing end group method according to Isbell. (J. Res. Natl. Bur. Standards 2k32k \ (19 ^ * 0). This method is based on the reduction of an alkaline copper citrate reagent. The number average molecular weights are calculated by standardization with gentiobiosis, assuming that equimolar amounts of polyglucose and gentiobiosis have approximately the same reduction capacity. The number average molecular weight determined in this manner appears to be a misleadingly low number highlighting the lower end of the molecular weight distribution for polycondensation products with broad molecular weight distributions. was obtained by the end-group reduction method to a number average molecular weight of 25,600. It is therefore considered appropriate to multiply the results obtained by the modified end-group reduction method number average molecular weights at about 1.5. Number average molecular weights are therefore referred to as apparent number average molecular weights when determined by the modified end group reduction method described herein. These apparent number average molecular weights are denoted by αM ^. When sorbitol or another polyol is added to the polymerization mixture, such a substance tends to combine at the end of the polymer chain, in which case molecular weight determinations based on end-group methods prove inaccurate. Thus, one of many other well known methods should be used to determine the molecular weight of these polymers.

Polyglucoses are dominated by bonds 1 -) 6 but other bonds are also present. In soluble polyglucoses, each of the 9,58335 acid moieties is esterified to polyglucose. When the acid moiety is esterified to more than one polyglucose moiety, cross-linking results.

Synthetic polyglucoses, such as those prepared by the method of this invention, are not subjected to anylolytic enzymes such as amyl (1, U) glucosidases, amyl (1,1 + 1,6) glucosidases, any (1, U) dextrinases and amylo (1, 1) maltosidases. nor of β- and β-glucosidases, invertase and phosphorylase. Nutritional and radioactive tracer studies in animals also show that these polyglucoses are predominantly calorie-free.

In addition to sweetness, other physical properties of natural foods can be obtained from dietary foods with soluble polyglucoses and polymaltoses. In pastries, for example, new polysaccharides affect Theology and structure in the same way as sugar, and can replace sugar as a filler. Typical uses for soluble polyglucoses include low-calorie jellies, jams, preserves, marmalades, and fruit butter, frozen dietary food combinations such as ice cream, frozen milk, sorbet and frozen fruit juices, other bread juices, bakery products, bakery products such as cakes, - or other flour, glazes, caramels and chewing gum, beverages such as non-alcoholic soft drinks and root extracts, syrups, sprinkles, sauces and puddings, salad dressings and low-calorie cyclamate or saccharin-containing sweeteners.

By using the polyglucoses prepared according to the invention, 20-100% of the normal fat, oil or fat triglycerin ingredients in the food can be removed. The degree of removal of fat, oil or fat triglycerides naturally varies according to the type of food, for example in a French salad dressing it is possible to completely remove the oil component it normally contains. In chocolate coatings, ice cream mixes and whipped icings, 2-50% of fat, oil or triglycerides can be removed without compromising the desired properties of the food, such as texture shine, viscosity and taste.

Insoluble polyglucoses can be used as a flour substitute in cakes, biscuits, breads, sugar cakes and other bakery products using wheat, corn, rice or potato flour, as well as in bakery products that normally contain graham flour, rye flour or oats, oats, oats. In addition, insoluble polyglucoses can be used in non-raised foods such as spaghetti and macaroni, or as an aid in minced meat and mashed potatoes, and for other uses to which flour is added as a food.

10 5 83 35

When the polyglucoses and polymaltoses of this invention are added to dietary foods, the resulting foods retain the tasty and appetizing properties of their natural requirements. In addition, the caloric value of these diet foods is significantly reduced due to the fact that the products of this invention have been used to replace the sugars, starches and fats contained in the natural counterparts of diet foods.

Descriptions of the use of the soluble and insoluble polysaccharides of this invention for the above-mentioned food purposes are described in U.S. Patent No. 3,766,165, but should not be construed as being limited to the examples therein.

The invention will be better understood in the light of the following specific examples.

Example 1 Citric acid catalyzed by a process for the preparation of sorbitol-modified polyglucose using an aqueous feed.

An aqueous feed solution of 65% by weight was prepared by dissolving 202 kg of dextrose, 32, U kg of a 70- $ sorbitol solution and 2.3 kg of anhydrous citric acid in 112.7 kg of deionized water. The resulting solution was fed at 0. U m

For a Pfaudler Wipeed Film Evapropator evaporator maintained at 0.5 m vacuum, 2 vapor jacket pressures of 690 kN / m. The feed rate was adjusted so that the output of the dehydrated feed was 59 kg / h. A dehydrated feed of a representative sample was found to contain a total of 97-5% solids; Gardner color (10% w / w aqueous solution) less than 1; at +90 + (10% w / w aqueous solution) 100; levoglucosane 0.00%.

... .... . . . 3

The dehydrated feed was continuously passed to a 0.007 m continuous double-blade mixer (Baker Perkins Multipurpose Continuous Mixer). The pressure was maintained between 75 ~ 100 mmHg; the temperature measured in the zones of the different unit was at least 115-2U5 ° C. The feed rate was adjusted to give a residence time of about 5 minutes. The grayish white product was completely water soluble. The following characteristics were determined for the polymer: 58335

Reduction value (Munson & Walker) 8.5

Gardner color (10 # w / w solution) 1.2

Transmission # ^ * 490 mp 95.7 5-hydroxymethylfurfural, # 0.055 pH (5 # w / w solution) 2.9

Acid equivalent (mg NaOH / g) 4.0

Example 2

Evaporated aqueous feed compared to feed by melting method.

A. Feed prepared by evaporation of an aqueous solution.

2

Conditions: 0.4 m Praulder Wiped-Film Evaporator operating at 2 o 0.5 m vacuum, vapor jacket pressure 690 kN / m. Supply temperature 100 ° C, maximum. The composition of the feed as in Example 1.

Experiment with Dehydrated Total Color, 10 # weight / feed to produce solid weight solution. rv Lr HS Ö.fiTn fl ton speed kg / h substances # Gardner- Trans. # color 490 mp i 31.6 99+ <1 97.2 0.02 ii 47.2 99.0 <1 100 traces 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 104.3 94.8 <1,100 0.00 aqueous feed - 65.0 <t1 100 0.00 B. Feed prepared by the melting method.

Conditions: melting was performed in a steam-jacketed screw conveyor (Rietz Thermascrew Feed Melter) at atmospheric pressure, steam jacket vapor pressure 172 kN / m 2. Melt temperature 125-5 ° C.

Feed composition: 4–4 kg glucose monohydrate, 45 kg sorbitol, 4.5 kg citric acid. The total solids content for both feed and melt was 92 wt. The feed component was mixed dry, then continuously fed to the melter. Representative samples of the molten feed were cooled and ground in a Waring Blender. The following assay values were obtained from samples from six experiments.

Experiment with Gardner color # levogluco- 100 # w / w solution mania x) i 1-2 0.34 ii 1-2 traces iii 1-2 0.54 iv 1-2 0.62 v 1-2 0.62 vi 2 0.74 feed solids before melting <1 0.00 58335 *) Levoglucosane (1,6-anhydro-D-glucose) was determined by gas chromatography with a column length of 1.5 m and an external beginning and 0, 32 cm and filled with 60-80 mesh silylated Supelcoport with 10% OV-1 at 205 ° C. Under these conditions, the retention time of levoglucosane was 1.5 ± 5 minutes. Example 3

Effect of feed preparation method on the quality of water-soluble sorbitol-modified polyglucose as a function.

A. Polyglucose prepared from the dehydrated feed samples of Example 2A.

Representative samples, 2.0 g of each of the dehydrated feeds i-v from Example 2A, were placed in separate test tubes. Each tube was connected to a vacuum suction set at 0.5 m vacuum. The tubes were immersed in a 200 ° C oil bath for 5> 0 minutes. The following values were obtained for the product:

Experiment Reduction value 10% w / w.

Color of Munson & Walker solution_% 5-hydroxymethyl- '

Gardner- Trans .-% furfural color 1 + 90 mu i 11 +, 1 1-2 95.0 0.080 ii 7.1+ 1-2 96.5 0.051

iii 13.3 1-2 92.5 0.09U

iv 8.5 1-2 95.7 0.055

v 8.7 1-2 91 + .5 0.06 H

average 10.1+ 1-2 91 +, 8 0.069 value 1% X) Determined by comparing the E ^ cm ~ value of the sample in 283 spi with the corresponding value of pure 5-hydroxymethylfurfural: 1 1% HMF = E. *. (sample) i cm 13.35 B. Polyglucose prepared from the melt feed samples of Example 2B. Representative samples, 2.0 g each, of the molten feeds i-v in Example 2B were converted to a water-soluble polymer as described above in Section A of this example. The following values were obtained for the resulting products:

Experience Reduction value 1Q% press / weight

Color of Munson & Walker solution% 5-hydroxymethyl

Gardner- Trans .-% furfural color 1 + 90 nju 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 average 9.3 2-3 88.1 0.085 13 58335

Example U

Tartaric acid catalyzed preparation of sorbitol-modified polyglucose by polycondensation of dehydrated aqueous feed.

500 g of a solution (total TO% solids) containing dextrose, sorbitol and tartaric acid in a ratio of 89: 10: 1 on a dry weight basis were slowly fed to a full glass rotary evaporator. (Rotovapor, Fisher Gatalog No. 9-5I8-15O) by means of a feed pipe. The system is maintained at a pressure of 15-30 mmHg. The rotating bottle is immersed in a boiling water bath. The aqueous feed solution is swelled or evaporated in this way for 30 - * + 5 minutes to obtain an almost colorless residue. Under a nitrogen atmosphere, the flask containing the dehydrated feed is placed in an oil bath at 1 ° C and heated at a bath temperature of 165 ° C. .

170 C and 25-50 mmHg at b hours. The water-soluble polymer obtained is very comparable to the product obtained in Example 1 above. Compared to a tartaric acid-catalyzed soluble polyglucose sample prepared in exactly the same manner, but starting from a melt feed with the same solids ratio, the product of this example has been found to have a better lower 1% 5-hydroxymethylfurfural content (as determined by E, 283 nui). 1 cm t and a finer taste.

Example 5

Tartaric acid catalyzed preparation of polyglucose with 20% sorbitol by polycondensation of the aqueous feed.

The method of Example k, in which the sorbitol content is increased to 20 weights by reducing dextrose, respectively, gives a polyglucose closely resembling that obtained in Example h.

Example 6

Continuous preparation of citric acid catalyzed sorbitol-modified polyglucose from an aqueous feed solution by dehydration and polycondensation in the same reactor.

907 kg of an aqueous solution containing 567 kg of glucose, 63.5 kg of sorbitol and 6. h kg of citric acid is placed in a suitable storage tank. The solution is pumped from the tank to a vertical thin-layer processor suitable for both solvent removal from viscous materials and polycondensation. The processor is operated at a pressure of 20-30 mmHg. The temperature of the top of the processor is maintained between 85-100 ° C. The lower part is kept at a temperature of not more than 2ä5 ° C. The water vapor is removed by means of a condenser for which the outlet is located above the liquid supply opening. The molten viscous product is removed from the bottom by a pump designed to convey highly viscous polymers.

^ 58335

The finished citrated polyglucose is substantially similar to the product of Example 1 and has better properties compared to similar sintered polyglucose samples prepared according to the melt feed process of U3 Patent No. 3,766,165.

Example 7

Polymerization of maltose with citric acid using aqueous feed.

A solution of 285 g of maltose monohydrate and 15 g of citric acid is prepared by dissolving them in 100 g of deionized water. This solution is evaporated on a rotary evaporator as shown in Example h. The dehydrated mixture is then heated at 160 ° C and 10-15 mmHg for 7 hours. The resulting polymer is significantly lighter in color, has a significantly lower content of 5-hydroxymethylfurfural and has better taste properties compared to similar products made by the previous melt polymerization process. Otherwise, there are no significant differences between products made by these two processes.

Example 8

Citric acid catalyzed production of soluble polyglucose by an aqueous feed process.

Prepare 500 g of a solution (total solids content 65%) containing 315 g of dextrose and 10 g of citric acid in 175 g of water. The solution is then expanded or evaporated as described in Example U. The resulting dehydrated mixture is placed in an oil bath at 170 ° C and the temperature is maintained at 165-170 ° C and the pressure at 20 mmHg for k hours is then cooled to room temperature. The resulting citric acid-catalyzed polyglucose is completely water-soluble. Compared to a similar product made by melt polymerization, it has significantly better color and taste properties and a lower 5-hydroxymethylfurfural content.

Example 9

Fumaric acid catalyzed production of soluble polyglucose by an aqueous feed process.

The process of Example 8 is repeated using an aqueous solution containing 10 g of edible fumaric acid instead of citric acid. The polyglucose formed closely resembles the product of Example 8 and has the same improvement in color, taste and 5-hydroxymethylfurfural content compared to a similar fumaric acid catalyzed polyglucose prepared:; u 1 up oi y me r o i n n i 11 a.

15 58335

Example 10

Malic acid catalyzed production of soluble polyglucose by an aqueous feed process.

The procedure of Example 8 is repeated using an aqueous solution containing 10 g of malic acid instead of citric acid. The polyglucose formed closely resembles the product of Example 8 and has the same improvement in color, taste and 5-hydroxymethylfurfural content compared to a similar malic acid-catalyzed polyglucose prepared by melt polymerization.

Example 11

Succinic acid catalyzed production of soluble polyglucose by an aqueous feed process.

A solution of 190 g of glucose monohydrate and 10 g of succinic acid is prepared by dissolving them in 135 ml of water. The solution is evaporated as described in Example h, then heated at 150 ° C under 5 mmHg for 18 hours. The water-soluble polyglucose formed is then compared with a comparable product prepared by melt polymerization. The product prepared using the aqueous feed has the same advantages as described for the product of Example 8.

Example 12

Adipic acid catalyzed production of soluble polyglucose by an aqueous feed process.

The procedure of Example 11 is repeated using an aqueous solution containing 10 g of edible adipic acid instead of succinic acid, with essentially the same results.

Example 13

Fumaric acid catalyzed preparation of sorbitol-modified polyglucose by a continuous process using an aqueous feed.

A 63% aqueous feed solution containing 50 kg of dextrose monohydrate, 5.0 kg of sorbitol monohydrate and 1.8 kg of fumaric acid is prepared.

.... 2

The solution is continuously fed to a 0.09 m sweep bed evaporator maintained at 90-100 ° C. The viscous effluent is fed in half to a 0.1 m scrubber bed vacuum reactor heated to 220-295 ° C. The entire system is maintained at a pressure of 300 mmHg. The feed rate to the evaporator is adjusted so that the residence time in the entire system is U-10 minutes. Comparative tests with the same product prepared by melt polymerization again show the above-mentioned improvements in color, taste and 5 "hydroxy-58335 ι6 methylfurfural content, while the other properties have been found to be essentially the same.

Example lU

Fumaric acid catalyzed preparation of sorbitol-modified polyglucose by a continuous process using an aqueous feed.

The process of Example 13, in which the amount of sorbitol in the feed is reduced to 5% by weight of the total solids, gives a polyglucose closely resembling that obtained in Example 13 and having the same advantages over a comparable product prepared by melt polymerization.

Example 15

Fumaric acid catalyzed preparation of erythritol-modified polyglucose by a continuous process using an aqueous feed.

The process of Example 13, in which sorbitol is replaced by an equal amount of erythritol by weight, gives polyglucose having properties and other advantages similar to the product of Example 13.

Example 16

Fumaric acid catalyzed production of glycerol-modified polyglucose by a continuous process using an aqueous feed.

The method of Example 13, in which sorbitol is replaced by an equal amount of glycerol by weight, gives polyglucose having properties and advantages similar to the product of Example 13.

Example 17

Tartaric acid catalyzed production of xylitol-modified polyglucose by an aqueous feed process.

The method of Example 1+, in which sorbitol is replaced by an equal weight of xylitol, gives polyglucose having properties and advantages similar to the product of Example U.

Example 18

Tartaric acid catalyzed production of mannitol-modified polyglucose by an aqueous feed process.

The method of Example U, in which sorbitol is replaced by an equal weight of mannitol, yields polyglucose having properties and advantages similar to the product of Example U.

Example 19

Tartaric acid catalyzed production of galactitol-modified polyglucose by an aqueous feed process.

The method of Example U, in which sorbitol is replaced by galactitol and the initial solution contains dextrose, galactitol and tartaric acid in a ratio of 17,583 35% by dry weight to 9,583: 5, gives polyglucose having the same properties and advantages as the product of Example U.

Example 20

Citric acid catalyzed preparation of a mixture of soluble and insoluble polyglucose by a process using an aqueous feed.

Prepare a solution of 320 g of D-glucose and 25 g of citric acid in 23Ο ml of water.

The 2-liter three-necked flask is equipped with a stirrer, thermometer, dropping funnel and condenser for distillation. The flask is immersed in an oil bath (1T0 ° C) and the system is evacuated to a pressure of 20-25 mmHg. Stirring is started and the aqueous solution is fed into the flask for 30-1 + 5 minutes, during which time most of the water evaporates. Stirring is continued until the mixture becomes very sticky. The reactants are then kept at 170 ° C for 18 hours. The crude polymer is ground and separated into a water-soluble (35%) and insoluble (65%) fraction.

The products closely resemble their counterparts made by melt polymerization, but the products in this example were significantly lighter in color.

Example 21

Preparation of a citrated sorbitol-modified citrate polyglucose 70 Rist neutralized solution by an aqueous feed method and comparison with its bleached and neutralized melt polymerized counterpart.

200 g of the product of Example 1 are dissolved in an equal volume of deionized water and the pH is adjusted to 5> 5 with potassium carbonate. The resulting solution is then concentrated in vacuo to give a solution of 70% by weight. The resulting solution is "pale oil yellow" in color and has been judged to be completely organoleptically acceptable.

Compared to a 70 - # solution prepared from a similar molten polymerized product bleached with alkaline (CaO) peroxide and neutralized to pH 5> 5, the color of the bleached solution is only slightly lighter. The 70 - # solution of the aqueous feed product is judged to be less bitter and less (chalky) malate and has significantly lower levels of calcium, ash and volatile fatty acids than the bleached product.