HU193380B - Process for preparing crystalline d-fructose in high purity, with min. 95% fructose content - Google Patents

Abstract

The present invention relates to a process for the preparation of crystalline D-fructose. The process according to the invention is carried out by diluting the total sugar content of the so-called isospir or chickpeas obtained as a starting material from corn meal or Helianthus Tuberosus by dilution to 9-14 m% by adding silica gel of 4-6 m% based on the total sugar content, followed by dilution. the diluted syrup is treated with 2 to 3 moles of calcium hydroxide containing 10 to 20 m% excess of total sugar content at a temperature of 5 to 25 ° C, and the precipitate formed is separated by centrifugation, the precipitate is washed with cold water and then suspended in cold water , then carbon dioxide is introduced into the suspension at about 0 ° C, the precipitated calcium carbonate is isolated by filtration and centrifugation, and then sulfur dioxide is optionally added to the fructose-containing solution, and the precipitated inorganic salts are removed by filtration and the solution is active. the fructose-containing solution is then concentrated by distillation under reduced pressure, alcohol is added to the thick syrup obtained, and 6 to 8% by weight of the crystalline chlorine at 350 ° C is added to the alcoholic solution for 3 hours at room temperature leave, the clinosor is filtered, washed with absolute ethanol, and the washing liquid is combined with the filtrate, then the pure filtrate is distilled until cloudy, the tgv is obtained! absolute ethanol and then crystal are added to the cloudy solution, and the resulting crystals are then separated by filtration and washed with 1:

Description

Process for the preparation of high purity crystalline D-fructose having a fructose content of at least 95% by weight.

D-fructose is an important source of energy for the living organism; cells can utilize it without insulin, so it can be used by patients with diabetic breast meat.

D-fructose has a significant sweetening power, fructose at 5 ° C is 1437 times sweeter than sugar, at 40 ° C is the same sweetness, and at room temperature in 10% solution D-fructose is 1.2 times sweeter than sucrose .

D-fructose is found in fruits, honey, and sucrose along with D-glucose. In aqueous solution at 25 ° C, it is predominantly in the structure of β-D-fructopyranose, with about 22% β-D-fructofuranos. D-fructopyranosine is present in the a and β isomeric forms, both isomers turning to the left.

It crystallizes from alcohol in the form of colorless prisms, m.p. 102-104 ° C. The colorless, crystalline D-fructose is slightly hygroscopic and slowly yellow when standing in the air. Its stability in aqueous solution is a function of temperature, pH and redox potential. It decomposes rapidly in alkaline and acidic media, especially at elevated temperatures.

Due to its favorable properties, the production of D-fructose is of industrial importance. Bates et al., F.J. Bates and Associates, National Bureau of Standards Circular C440, p. 399, Washington (1942)] investigated the conditions for crystallization of D-fructose from aqueous syrup by ethanol precipitation and found that it can only be achieved with poor production and very slowly over a long period of time.

The enzymatic preparation of D-fructose from sucrose is described by Koepsell and Rohrman in F.A. Rohrman, Sugar, 13, 10-11, 18 (1950). U.S. Pat. 2,729,857]

The first large-scale, almost continuous, sucrose-based process was developed by Rohrman et al. [F. A. Rohrman, Sugar, 13, 10-11, 18 (1950). U.S. Pat. 2,729,857 (1956; Koepsell et al. To U.S.A.) and Sugar Research Foundation, The Pilot Plant Production of Levulose (D-Fructose) (Member Rept. No. 29, December 1951)].

The industrial preparation of D-fructose by oxidation of dextrose is described in Cantor and Docal, U.S. Pat. Pat. 2,354,664 (Aug. 03, 1944). S. M Cantor (to U.S.A.) and U.S.A. Pat. 2,567,060 (Sep. 04, 1951). G. C. Docal (to Sugár Research Foundation)].

D-fructose can also be prepared from an aqueous sucrose solution using a dextrin-forming enzyme; after removal of the resulting dextrin, D-fructose can be isolated [U.S. Pat. 2,729,587 (Dec. 26, 1952). I. Harold (to U.S.A.)].

Smaller amounts of D-fructose can also be obtained by isolating D-glucose from invert sugar in the form of an insoluble benzidine derivative or sodium chloride addition compound, and subsequently recovering the fructose.

The disadvantages of the known solutions are that the yield of the final product is unsatisfactory, the preparation is time consuming and the purity and stability of the obtained product are not satisfactory. However, in the preparation of a product of sufficient purity, the known processes are very expensive.

In contrast, the process according to the invention has the advantage that inexpensive starting materials can be produced by a simple process to produce high quality stable D-fructose in good yields on an industrial scale.

Surprisingly, it has now been found that high purity crystalline D-fructose can be obtained from the concentrated hydrolyzate from maize, mainly containing D-glucose and D-fructose (the so-called isos syrup), through calcium fructose. Similarly, the process of the present invention provides high quality D-fructose from a syrup obtained from the tuber of Helianthus Tuberosus (hereinafter referred to as Jerusalem artichoke syrup),

The measures of the present invention make it possible to isolate the otherwise heat-sensitive and unstable calcium fructose complex without decomposition and to isolate pure D-iructose from the complex in good yield. Due to the high purity of the product thus obtained, it is non-hygroscopic and can be stored for a long period of time.

The purification steps used in the process of the present invention are less expensive and simpler than those of the prior art (e.g., column chromatography purification). Under these circumstances, the process of the invention can be successfully applied on a large scale.

The process according to the invention is carried out by adjusting the total sugar content of the so-called isos syrup or Jerusalem artichoke syrup obtained from corn flour or tubers of Helianthus Tuberosus by dilution to between 4% and 6% by weight, based on the total sugar content. Treatment of a portion of calcined sorbitol with a piece of calcined sorbitol, followed by dilution of the diluted syrup with lime milk containing from 10 to 20% by weight of calcium hydroxide containing 2 to 3 moles of total sugars at 5 to 25 ° C and separating the precipitate by centrifugation. wash, then slurry in cold water, add carbon dioxide to the slurry at about 0 ° C, separate the precipitated calcium carbonate by filtration and centrifugation, optionally add sulfur dioxide to the fructose-containing solution, and the solution is subjected to activated charcoal clarification, then the fructose-containing solution is concentrated by distillation under reduced pressure, alcohol is added to the thick syrup obtained, 6-8% by weight of the fructose-treated clinic sorbent at 350 ° C is added. After 2193380 hours of standing for 3 hours at room temperature, the clinic sorbent is filtered off, washed with absolute ethanol, and the washings are combined with the filtrate, then distilled to a cloudy solution, the resulting cloudy solution is filtered off with suction and crystallized.

Characteristics of the isos syrup used as starting material:

Species weight (23-25 ° C) = 1.32

Dry content = 71.60%; from this

D-fructose = 42.99 mZ (2.39 mol / kg leachate)

D-glucose = 47.98 mZ (2.66 Moles / kg isos syrup) oligosaccharides = 2.89 mZ trisaccharides = 2.14 mZ disaccharides = 4.00 mZ.

Jerusalem artichoke syrup features:

57.00 mZ; of which 70.97 mZ (2.24 Moles / kg syrup) 25.77 mZ (0.81 Moles / kg syrup) 3.30 mZ

Dry matter content used for the experiments

D-fructose =

D-glucose = other sugar =

Details of lime milk filtered through a 24 Mesh filter as reagent:

Ca (0H) ₂ content = 2.49 M

CaCO ₃ = 0.59M

Test methods used in the experiments:

Quantitative analytical tests by HPLC (High Performance Liquid Chromatography); qualitative controls were performed by thin layer chromatography (TLC).

TLC: adsorbent = DC - Alufolien Kieselgel (Merck Art. 5553)

Solvent = n-butanol: pyridine: benzene: water = 5: 3: 3: 1

Chamber saturation time = 1 hour

Chromatography mode = Ascending TLC Development = Alpha-naphthol reagent spray (freshly prepared)

10.5 ml of a 15% solution of alpha-naphthol in ethanol

6.5 ml cc. H ₂ SO ₄

40.5 ml of ethanol

4.0 ml of distilled water

After spraying with the reagent, develop the chromatogram under an infrared lamp (at about 100 ° C) until the maximum color difference of the spots is achieved. As the color difference between the spots disappears after 15-20 minutes (all spots will be dark violet), it is advisable to make a color photocopy of the chromatogram developed.

R _f (D-fructose) = 0.35 purple spot R, (D-glucose) = 0.28 pink spot Other sugars found in the "isos syrup":

Rfixi) = 0.03 pink spot

R f (x 2) = 0.11

R ( _HX3) = 0.15

R 4 x 4, = 0.17

R / IX5, = 0.23

Calcium fructtoate separation and aqueous washing with samples from the reaction mixture, the filtrate or the washing liquid by TLC; the quality of the final product is checked by HPLC, TLC, melting point and [a].

Similarly, D-glucose and other sugar derivatives remaining in the syrup and washings are assayed. After removal of the calcium carbonate, the sugars which are a by-product of the process can be fermented into ethyl alcohol under appropriate conditions. Calcium fructtoate precipitation is carried out at 5 to 25 ° C. The total sugar content of the reaction mixture is adjusted to 0.50-0.80M.

The precipitation of calcium carbonate from an aqueous suspension of calcium umfructtoate _{45 is} monitored with phenolphthalein and a universal indicator (pH 6.5-7.0). Crystalline D-fructose production = 80-90% (based on D-fructose content in syrups).

The crystalline D-fructose has a melting point = 102-140 ° C. D-fructose content of the final crystalline product m = 97.50 to 99.80% '.alpha ° = -89.5 ° (c = 2, H ₂ O, after 2 days position).

The following examples illustrate the process of the invention.

Example 1

Production of crystalline D-fructose from Jerusalem artichoke syrup

To a mixture of 261 g of Jerusalem artichoke syrup and 766 ml of water was added 6-8% by weight of fructose-coated clinic sorbent, allowed to stand at room temperature for 3 hours, filtered, washed with absolute ethanol and combined with the filtrate. then melting ice3

During stirring, 358 ml of lime cc was added under stirring in such a way that the internal temperature did not rise above 15 ° C. After the addition was complete, the mixture was stirred for another 30 minutes at 15 ° C and then centrifuged in a refrigerated centrifuge (3800 rpm) for 15 minutes. The white, wet calcium fructate is suspended in 360 ml of cold water and centrifuged again under the same conditions.

The product thus washed free of calcium gluconate is suspended in 680 ml of cold water and carbon dioxide is bubbled through a melting ice bath to pH 6.5-7.0 at 15 ° C.

The precipitated calcium carbonate was filtered off, washed with water (120 ml) and the washings were combined with the filtrate.

The combined filtrate was distilled under reduced pressure until a thick syrup was obtained; 800 ml of ethyl alcohol are added to the syrup, homogenized with stirring, and 6-8% by weight of fructose on clinic sorbent at 350 [deg.] C. is added, the mixture is allowed to stand for 3 hours at room temperature, the clinic sorb is filtered, washed with absolute ethanol and the filtrate and distill under reduced pressure (to about 500 ml volume) (azeotropic distillation to remove water).

The ethyl alcohol syrup is seeded with D-fructose seed crystal and allowed to stand under protected conditions at a temperature of 5 C, ^Q, air and moisture.

The precipitated crystals were filtered, abs. washed with ethyl alcohol and dried to constant weight.

Yield = 78.95 g (74.66%)

Mp = 96-100 ° C.

D-fructose content of the material obtained: 97.80 wt% [alpha] ® -88.6 ° = (c - 2, H ₂ O, after 2 days position).

Example 2

Preparation of crystalline D-fructose from isos syrup

To a mixture of 52.98 g of isos syrup and 200 ml of water is added 4-6 wt% of glutinous clinic sorbitol based on the total sugar content, and 100 ml of lime milk is added in small portions while stirring in an ice bath until the internal temperature rises above 15 ° C. in about 20 minutes). The thick white slurry was stirred for an additional 30 minutes in a melting ice bath and centrifuged in a cooled centrifuge (7000 rpm for 10 minutes). The resulting wet product was suspended in 90 ml of cold water and centrifuged again for 5 minutes under the same conditions.

The resulting calcium fructtoate complex is suspended in 170 ml of cold water and carbon dioxide (pH 7.5-8.0) is added with stirring in a melting ice bath for one hour. The precipitated calcium carbonate was filtered through a G-4 sintered glass filter and the filtrate was distilled off under reduced pressure (20 mm Hg, 60 ° C). The precipitate on the filter was washed by slurrying it with 3 x 30 ml of water and dissolving the distillation residue in this wash. The resulting solution was filtered again, washed with a small amount of insoluble white crystalline material, suspended in water (20 mL) and combined with the filtrate (weight of filtered calcium carbonate after drying = 16.40 g).

The water was distilled off under reduced pressure and the crude fructose concentrate, a light yellow color which was cloudy with a few white crystals, weighed 10.19 g. To the crude product thus obtained, 150 ml of abs. Ethyl alcohol is added and heated (vigorously digested if necessary) under vigorous stirring under a reflux condenser with calcium chloride until the inorganic insoluble inorganic alcohol is dissolved into a white powdery product (about 10-15 minutes).

The resulting reaction mixture was filtered hot on a G-4 sintered glass filter, 3 x 15 mL hot abs. The slurry was washed with slurry of ethanol and the washings were combined with the filtrate (weight of filtered inorganic material after drying = 1.27 g). To the alcoholic solution was added 6-8% by weight of fructose-treated clinic sorbent at 350 ° C, allowed to stand for 3 hours at room temperature, filtered the clinic-sorb, washed with absolute ethanol and combined the washings with the filtrate.

The resulting solution was distilled under reduced pressure (20 mm Hg, 40 ° C) to a high yield (80-100 mL volume), inoculated with D-fructose seed crystal 1 and left to stand in a refrigerator. The precipitated crystals are filtered off with little cold abs. washed with ethanol and dried in a vacuum desiccator at room temperature over P ₂ O ₅ and CaCl ₂ to constant weight.

Yield = 8.63 g (52.81%)

Mp: 96-98 ° C

D-fructose. content = 97.90% w / w ₌ 88.9 '(c = 2, H, O after 2 days).

Example 3

Preparation of crystalline D-fructose from isos syrup

To a mixture of 132.45 g of isos syrup and 300 ml of water is added 4-6 wt% of glutinous clinic sorbitol based on the total sugar content, and 325 ml of lime milk is added in small portions while stirring in a melting ice bath so that the internal temperature does not rise above 15 ° C. 20-30 minutes). Stir for a further 30 minutes in an ice bath, centrifuge cold (3200 rpm, 30 minutes), slurry in 225 mL of cold water, re-centrifuge (3200 rpm, 30 minutes), and combine the filtrate with washings (this fraction contains, among others) calcium gluconate).

-4193380

The separated and washed calcium fructtoate is suspended in 375 ml of cold water and carbon dioxide is added with stirring in a melting ice bath until the red color of phenolphthalein disappears (about 80 minutes).

The precipitated calcium carbonate was filtered off and washed with 3 x 75 ml of cold water (calcium carbonate weight after drying = 39.59 g), and the washings were combined with the filtrate.

Sulfur dioxide (15-20 minutes) was then added to the solution under stirring until a pH of 3.5 was reached in a melting ice bath, refluxed and cooled to room temperature under reduced pressure (20 mmHg, 60 ° C) to give a thick syrup. The weight of the crude fructose concentrate thus obtained = 36.95 g.

To the crude product was added 375 ml of ethyl alcohol and refluxed under vigorous stirring to obtain a white powdery suspension (10-15 minutes). The suspension was filtered hot, and the filtered inorganic material was 3x30 mL of hot abs. wash with slurry in ethyl alcohol and combine the washings with the filtrate (1.84 g weight of the filtered inorganic material after drying). Add 3.0 g of activated carbon, reflux for 5 minutes, decolorize the filtrate to 6-8% fructose Clinical sorb sorbent (m% at 350 ° C) was added, the mixture allowed to stand for 3 hours at room temperature, the clinic sorbent was filtered, washed with absolute ethanol, and the washings were combined with the filtrate and the clear filtrate under reduced pressure (20 mm Hg, 40 Distil (230-300 ml), inoculate with a D-fructose seed crystal and allow to stand in the refrigerator under anhydrous conditions. The precipitated off-white crystalline product is filtered off with suction and dried in a vacuum desiccator over P ₂ O ₅ and CaCl ₂ to constant weight.

Yield: 33.62 g (82.32%)

Mp: 96-102 ° C

D-fructose content of the material obtained: 97.50 wt% [α] ρ = -88.4 ° (c - 2, H ₂ O, 2 days after resolution)

Example 4

Preparation of crystalline D-fructose from isos syrup

150 ml (197.35 g) of isos syrup containing 800 mM D-glucose and D-fructose (of which D-glucose = 422 mM and D-fructose 378 mM) were charged into the cooled reactor equipped with stirrer and thermometer. To do this, 800 ml of distilled water and the total sugar content calculated from 4-6 wt% lumpy fired klinoszorbot, then in addition to the external cooling with ice added 385 ml milk of lime (960 mM Ca (OH) ₂ per 227 mM CaCO ₃ in small portions under vigorous stirring - at a rate such that the internal temperature does not rise above 15 ° C (about 10 minutes). The molten ice cream product is then stirred for another 20 minutes in a melting ice bath and cooled in a centrifuge (no temperature rise above 15 ° C during centrifugation) at 3400 to 3600 rpm. Centrifuge for 20 minutes. The supernatant was discarded, resuspended in 360 ml of cold distilled water and centrifuged again under the same conditions.

The resulting snow-white calcium fructtoate was suspended in 680 ml of cold distilled water and carbon dioxide (about 40 minutes) was added to the suspension under vigorous stirring in a melting ice bath, until the phenolphthalein indicator was flushed, then more slowly, ca. carbon dioxide is added over a further 5 minutes until pH 6.5-7.0 is reached.

The precipitated calcium carbonate is filtered through a G-4 sintered glass filter and the filtrate is distilled off under reduced pressure until a thick syrup is obtained. The calcium carbonate on the filter was washed with 3 x 120 ml of cold distilled water, and the syrup was dissolved in the dense syrup as the previous distillation residue. If necessary, filter again on a G-4 sintered glass filter, wash the product remaining in the filter by slurrying in 80 ml of distilled water, and combine the washings with the filtrate.

Distil off the water under reduced pressure, 600 ml abs. Ethyl alcohol was added under stirring under reflux for ca. Bring to the boil for 10 minutes with stirring until complete dissolution of the insoluble matter (digestion hot if necessary) and filter the hot reaction mixture through a G-4 sintered glass frit, 6-8% by weight of the clinic sorbent at 350 ° C. The mixture was allowed to stand for 3 hours at room temperature, the clinic sorbent was filtered off, washed with absolute ethanol and the washings were combined with the filtrate.

The alcoholic solution is distilled under reduced pressure to a volume of 320-400 ml (residual weight about 270 g). After cooling, inoculate with D-fructose seed crystal and allow to stand in a refrigerator (5-8 ° C).

The precipitated crystals are filtered off with little abs. washed with alcohol and dried (Lgen = 57.89 g). The washings are combined with the filtrate and 50 ml of abs. ethyl alcohol and distilled under reduced pressure to a strong milk. Inoculate with D-fructose seed crystals and allow to stand at 5-8 ° C until complete crystallization, and the precipitated crystals are filtered off with a few cold abs. washed with ethyl alcohol and dried to constant weight (Gene II = 3.14 g).

Yield (1- (- gen 11)) = 61.03 g (89.60%)

Mp = 102-104 ° C

D-fructose content in the resulting material: 99.80% w / w (HPLC) RK = 0.35 homogeneous purple spot.

-5193380 ί ^α ] ο ° = -89.5 ° (c = 2, Η ₂ Ο) after standing for 2 days.

Example 5

Processing of mother liquor containing D-glucose

In the method described in Example 3, carbon dioxide was added to the yellow solution obtained after the recovery of the calcium fructtoate in a melting ice bath with a phenolphthalein indicator, after stirring the indicator, for approx. 15 minutes.

The precipitated calcium carbonate was filtered off, washed with 3 x 75 ml of cold water, and the washings were combined with the filtrate (the weight of the filtered calcium carbonate after drying was 14.41 g).

The dark colored solution was stirred in an ice-water bath while stirring with sulfur dioxide until pH = 5.5. The pale greenish yellow solution was boiled and after cooling to room temperature the precipitate was filtered off, washed with a little cold water and the washings were combined with the filtrate (filtered product weighing 2.55 g).

The water is distilled off under reduced pressure, and the residual distillation is ca. Dissolve 60.91 g of a yellow resin crude product in 100 ml of water at 50-60 ° C, add 4.00 g of activated carbon, ca. After stirring at 50 ° C for 30 minutes, the clarifying carbon is filtered off and the water from the filtrate is distilled under reduced pressure to a volume which is suitable (e.g., fermentation to ethanol).

According to analytical results, this solution contains D-glucose and other sugar derivatives in the isos syrup, with a concentration of about 5% by weight of D-fructose. 3-5% by weight with inorganic material.

Claims (2)

PATENT CLAIMS A process for the preparation of high purity crystalline D-fructose having a fructose content of at least 95% by lime treatment, wherein the total sugar content of the so-called isos syrup or Jerusalem artichoke syrup used as starting material from corn flour or tuberosus tuberosus is diluted to 9%. Add 4 to 6% by weight of glutinous clinic sorbitol to the total sugar content, followed by the addition of 2 to 3 moles of calcium hydroxide in the diluted syrup, with 5 to 25 ° C in excess of 10 to 20% by weight of the total sugar content. The precipitate formed is separated by centrifugation, the precipitate is washed with cold water, then suspended in cold water and then carbon dioxide is added to the suspension at about 0 ° C, and the precipitated calcium carbonate is then filtered off and then separated by centrifugation. p Atbara gaseous sulfur dioxide, and then the precipitated inorganic salts were removed by filtration and the solution was subjected to nude ^r v charcoal decolorization to then af uktóz containing solution is concentrated by distillation under reduced pressure, alcohol was added to the resulting thick syrup and the alcoholic solution based on the fructose content 6 - 8% by weight of clinic sorbent at 350 ° C is added, the mixture is allowed to stand for 3 hours at room temperature, the clinic sorbent is filtered off, washed with absolute ethanol, and the washings are combined with the filtrate, distilled to remove the turbid filtrate. ethanol and then seed crystals are added, and the crystals formed are then filtered off and washed. Process according to claim 1, characterized in that the lime treatment is carried out at a temperature of 8-12 ° C.