US3883365A
Expired / Lapsed
US
⏱️ 0.0 years remaining
PH adjustment in fructose crystallization for increased yield
Assignee: Suomen Sokeri Oy
•
Filing: 1974-01-28
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Granted: 1975-05-13
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Expires: 1994-01-28
Abstract
Abstract Method for crystallization of fructose from water solution to obtain crystals whose average crystal size is between 200 and 600 Mu m, by (1) providing a solution which is saturated with respect to fructose, (2) by adjusting the pH of the solution to within the range of 4.5 to 5.5, and by (3) lowering the temperature of the solution and optionally evaporating to cause crystals to form. The large crystals thus obtained are easily separated from the solution by means of centrifugation. The crystals are free-flowing and easy to handle. The fructose obtained by this process is of a highly homogeneous crystal size and very pure.
Inventors
- 👤 K Holger Forsberg
- 👤 Lauri Hamalainen
- 👤 Asko J Melaja
- 👤 Jouko Johannes Virtanen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:07
CPC Classifications
C; C13; C13K; C13K11/00
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
162 words
A METHOD FOR CRYSTALLIZING FRUCTOSE FROM A WATER SOLUTION THEREOF CONTAINING GLUCOSE AS AN IMPURITY WHICH COMPRISES THE STEPS OF A. PROVIDING AN AQUEOUS FRUCTOSE SOLUTION CONTAINING GLUCOSE AS AN IMPURITY AND AT LEAST ABOUT 90 PERCENT DRY SUBSTANCE, THE FRUCTOSE CONTENT OF THE DRY SUBSTANCE BEING AT LEAST ABOUT 90 PERCENT BY WEIGHT, B. ADJUSTING THE PH OF THE SOLUTION TO WITHIN THE RANGE OF 4.5 TO 5.5, C. BRINGING THE AQEOUS FRUCTOSE SOLUTION TO A TEMPERATURE AT WHICH IT IS SATURATED WITH RESPECT TO THE FRUCTOSE, D. ADDING FRUCTOSE SEED CRYSTALS TO THE SOLUTION, E. LOWERING THE TEMPERATURE OF THE RESULTING MASS AT A CONTROLLED RATE TO CAUSE THE MASS TO BE SUPERSATURATED WITH RESPECT TO FRUCTOSE AND TO BRING ABOUT AN INCREASE IN CRYSTAL SIZE OF THE SEED CRYSTALS WITHOUT SUBSTANTIAL FORMATION OF NEW FRUCTOSE CRYSTALS, AND F. SEPARATING THE FRUCTOSE CRYSTALS FROM THE MASS WHEN THE CRYSTAL SIZE IS IN THE RANGE OF ABOUT 200 TO 500 UM.
Claim 2
Independent Claim
162 words
A METHOD FOR CRYSTALLIZING FRUCTOSE FROM A WATER SOLUTION THEREOF CONTAINING GLUCOSE AS AN IMPURITY WHICH COMPRISES THE STEPS OF A. PROVIDING AN AQUEOUS FRUCTOSE SOLUTION CONTAINING GLUCOSE AS AN IMPURITY AND AT LEAST ABOUT 90 PERCENT DRY SUBSTANCE, THE FRUCTOSE CONTENT OF THE DRY SUBSTANCE BEING AT LEAST ABOUT 90 PERCENT BY WEIGHT, B. ADJUSTING THE PH OF THE SOLUTION TO WITHIN THE RANGE OF 4.5 TO 5.5, C. BRINGING THE AQEOUS FRUCTOSE SOLUTION TO A TEMPERATURE AT WHICH IT IS SATURATED WITH RESPECT TO THE FRUCTOSE, D. ADDING FRUCTOSE SEED CRYSTALS TO THE SOLUTION, E. LOWERING THE TEMPERATURE OF THE RESULTING MASS AT A CONTROLLED RATE TO CAUSE THE MASS TO BE SUPERSATURATED WITH RESPECT TO FRUCTOSE AND TO BRING ABOUT AN INCREASE IN CRYSTAL SIZE OF THE SEED CRYSTALS WITHOUT SUBSTANTIAL FORMATION OF NEW FRUCTOSE CRYSTALS, AND F. SEPARATING THE FRUCTOSE CRYSTALS FROM THE MASS WHEN THE CRYSTAL SIZE IS IN THE RANGE OF ABOUT 200 TO 500 UM.
Claim 3
Dependent Claim
27 words
The method of claim 1, wherein the mass in step (e) is maintained at a supersaturation in the range of 1.1 to 1.2 wIth respect to fructose.
Claim 4
Dependent Claim
112 words
The method of claim 1, wherein, after the formation of a substantial quantity of crystals in the crystallization step (e), an additional quantity of the aqueous fructose solution of step (b) is added, the temperature and quantity of added solution being controlled to provide a solution which is at the saturation point for fructose, a second crystallization step is conducted by again lowering the temperature of the mass at a controlled rate to increase the size of the fructose crystals therein without substantial formation of new fructose crystals, and the fructose crystals are separated from the mass when the crystal size is in the range of about 200 to 500 Mu m.
Claim 5
Dependent Claim
29 words
The method of claim 3, wherein the step (e), and the subsequent second crystallization, the mass is maintained at a supersaturation of 1.1 to 1.2 with respect to fructose.
Claim 6
Dependent Claim
43 words
A method according to claim 3, characterized in that the crystallization is carried out as not less than two steps, where for each step a separate crystallization device is used, and where the volume of the mass is increased from step to step.
Claim 7
Dependent Claim
64 words
A method according to claim 3, wherein a crystal quantity of 45 to 55 percent by weight of the dry-substance quantity of the solution is reached in step (e) before a quantity of fresh solution is added whose temperature is such that it together with the mass forms a mixture in which the mass is approximately at the saturation point in respect of fructose.
Claim 8
Dependent Claim
97 words
A method according to claim 1, characterized in that the temperature of the mass is controlled in step (e) in a crystallizer to provide optimum conditions for growth of the original seed crystals without substantial formation of new crystals, and, while maintaining this temperature constant, fresh solution at the same temperature as or above the temperature of the mass is added to the mass at a controlled accelerating rate corresponding to the crystallization rate until the crystallizer is filled, the supersaturation of the mass with respect to fructose being maintained within the range of 1.1 to 1.2.
Claim 9
Dependent Claim
38 words
The method of claim 7, wherein, after the step of adding fructose solution, the temperature of the mass is lowered at a rate controlled to maintain supersaturation with respect to fructose within the range of 1.1 to 1.2.
Claim 10
Dependent Claim
28 words
A method according to claim 1, characterized in that a crystal mass that has been taken from a step of a previous crystallization is used as seed crystals.
Claim 11
Dependent Claim
26 words
A method according to claim 1, characterized in that during crystallization dry warm air is blown onto the surface of the mass to evaporate water therefrom.
Claim 12
Dependent Claim
14 words
The method of claim 1, wherein the method is conducted in a continuous manner.
Claim 13
Dependent Claim
59 words
The method of claim 1, wherein the aqueous fructose solution contains a low molecular weight organic solvent selected from the group consisting of methanol, ethanol and isopropanol at a level from about 2 to about 4% by weight of the sugar solids present therein, the presence of the solvent providing an increase in the rate of crystallization of fructose.
Claim 14
Independent Claim
174 words
A method for crystallizing fructose from a water solution thereof containing glucose as an impurity which comprises the steps of a. providing an aqueous fructose solution containing glucose as an impurity and at least about 90 percent dry substance, the fructose content of the dry substance being at least about 90 percent by weight, b. adjusting the pH of the solution to within the range of 4.5 to 5.5, c. bringing the aqueous fructose solution to a temperature of about 58* to 65*C at which it is saturated with respect to fructose, d. adding fructose seed crystals to the solution, e. lowering the temperature of the resulting mass at a controlled rate to cause the mass to be supersaturated in the range of 1.1 to 1.2 with respect to fructose and to bring aboUt an increase in crystal size of the seed crystals without substantial formation of new fructose crystals, and f. separating the fructose crystals from the mass when the crystal size is in the range of about 200 to 500 Mu m.
Claim 15
Independent Claim
174 words
A method for crystallizing fructose from a water solution thereof containing glucose as an impurity which comprises the steps of a. providing an aqueous fructose solution containing glucose as an impurity and at least about 90 percent dry substance, the fructose content of the dry substance being at least about 90 percent by weight, b. adjusting the pH of the solution to within the range of 4.5 to 5.5, c. bringing the aqueous fructose solution to a temperature of about 58* to 65*C at which it is saturated with respect to fructose, d. adding fructose seed crystals to the solution, e. lowering the temperature of the resulting mass at a controlled rate to cause the mass to be supersaturated in the range of 1.1 to 1.2 with respect to fructose and to bring aboUt an increase in crystal size of the seed crystals without substantial formation of new fructose crystals, and f. separating the fructose crystals from the mass when the crystal size is in the range of about 200 to 500 Mu m.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-12 | 1978-11-11 | 1979-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-12 | 1982-11-11 | 1983-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-12 | 1986-11-11 | 1987-05-13 | $7700.00 | Window Closed / Lapsed |