Claims
- 1. A method of producing an oligosaccharide syrup comprising the steps of:
enzymatic reaction of a substrate at a temperature in the range of 50° C. to 100° C. obtaining a saccharide solution comprising monosaccharides and disaccharides, trisaccharides and higher saccharides, nanofiltration of the saccharide solution at a temperature in the range of 60° C. to 100° C. obtaining a syrup essentially comprising disaccharides, trisaccharides and higher saccharides, recovering said syrup, optionally recycling the permeate resulting from the nanofiltration step to the enzymatic reaction.
- 2. A method according to claim 1, wherein the substrate comprises at least one monosaccharide type.
- 3. A method according to claim 1, wherein the substrate is a mixture of at least two different monosaccharide types.
- 4. A method according to any of claims 1-3, wherein the monosaccharide type is selected from glucose, fructose, galactose, UDP-galactose, mannose, xylose, and arabinose.
- 5. A method according to claim 3, wherein the mixture comprises glucose and fructose.
- 6. A method according to claim 5, wherein fructose is from 40% to 50% and glucose is from 46% to 56%, preferably fructose is from 42% to 46% and glucose is from 50% to 54%.
- 7. A method according to claim 1, wherein the substrate is liquefied starch or maltodextrins.
- 8. A method according to claim 1, wherein the substrate is a disaccharide, such as sucrose or lactose.
- 9. A method according to any of the preceding claims, wherein the enzymatic reaction is conducted with immobilised enzymes.
- 10. A method according to claim 9, wherein the enzymes are entrapped in a particle with a semipermeable membrane.
- 11. A method according to any of claims 1-8, wherein the enzymes are soluble enzymes and the enzymatic reaction is conducted in a membrane reactor separating the saccharide solution from the enzymes.
- 12. A method according to any of the preceding claims, wherein the enzymatic reaction is conducted at a temperature from 60° C. to 100° C., preferably 63° C. to 80° C., more preferably from 65° C. to 75° C.
- 13. A method according to any of the preceding claims, wherein the enzymes are heatstable enzymes.
- 14. A method according to any of the preceding claims, wherein the enzymatic reaction is a reverse hydrolysis reaction.
- 15. A method according to claim 14, wherein the enzyme is selected from the group consisting of glucoamylase, α-glucosidase, β-glucosidase (cellobiase), β-galactosidase, α-galactosidase, xylobiase, β-mannosidase, α-mannosidase.
- 16. A method according to any of the preceding claims, wherein the enzymatic reaction is a transferase reaction.
- 17. A method according to claim 16, wherein the enzyme is selected from the group consisting of fructosyltransferase, dextransucrase, transglucosidase, sialyltranferase, and fucosyltransferase.
- 18. A method according to any of the preceding claims, wherein the oligosaccharide syrup is a disaccharide syrup.
- 19. A method according to claim 18, wherein the disaccharide syrup is selected from the group consisting of isomaltose syrup and gentobiose syrup.
- 20. A method according to claim 19, wherein the isomaltose concentration in the saccharide solution is from 5% to 30%, preferably from 10% to 20%.
- 21. A method according to any of claims 18-20, wherein the ratio of disaccharide to total dry substance in the syrup recovered is from at least 40%, preferably at least 50%, most preferably at least 70%.
- 22. A method according to any of the claims 1-17, wherein the oligosaccharide syrup comprises a mixture of oligosaccharides having a degree of polymerization from 2 to at least 10, preferably 2 to 6.
- 23. A method according to any of the preceding claims, wherein the nanofiltration step comprises diafiltration.
- 24. A method according to any of the preceding claims, wherein nanofiltration is operated at a pressure of 10-30 atm.
- 25. A method according to any of the preceding claims, wherein nanofiltration is operated at a temperature in the range of 63° C. to 90° C., preferably 65° C. to 80° C.
- 26. A method according to any of the preceding claims, which is a continuous method.
- 27. A method according to any of the claims 1 to 25, which is conducted as a batch method.
- 28. A method according to any of the preceding claims, wherein the recycled permeate is subjected to reverse osmosis to remove water before the permeate enters the enzymatic reaction.
- 29. A method according to any of the preceding claims, wherein the ratio by weight of monosaccharides to total dry substance in the permeate is at least 80%, preferably at least 90%.
- 30. A method according to claim 5 or 6, wherein the permeate comprises at least 55% fructose on basis of total dry substance in the permeate.
- 31. A system for producing a oligosaccharide syrup comprising
an enzyme reactor (1) having at least one inlet and at least one outlet and means for controlling the temperature in the tank, means (4) for passing saccharide solution from the reactor outlet(s) to at least one nanofiltration unit (2), at least one nanofiltration unit (2) having a nanofiltration membrane dividing the nanofiltration unit (2) into an entrance side having at least one inlet and at least one outlet (3), and an exit side having at least one outlet (5), and having means for controlling the pressure applied to the membrane, optionally means for recycling material from an outlet (5) of the exit side of the nanofiltration unit (2) to the enzyme reactor (1).
- 32. A system according to claim 31, wherein the enzyme reactor (1) is a membrane reactor.
- 33. A system according to claim 31, wherein the enzyme reactor (1) is a column reactor.
- 34. A system according to any of the claims 31-33, wherein the nanofiltration unit (2) is operated as a diafiltration unit.
- 35. A system according to any of the claims 31-34, wherein means for reverse osmosis (7) is provided downstream of the nanofiltration unit (2) in the means for recycling material to the enzyme reactor (1).
- 36. A disaccharide syrup obtainable by the method according to any of the claims 1-29, wherein the ratio by weight of disaccharide to total dry substance is from at least 40%, preferably at least 50%, most preferably at least 70%, and the ratio by weight of monosaccharide to total dry substance is from 0.5% to 30%, preferably 0.5% to 20%, most preferably 0.5% to 10% the balance being trisaccharides and higher saccharides.
- 37. A disaccharide syrup according to claim 36, wherein the composition is as follows:
- 38. A disaccharide syrup according to claims 36 or 37, wherein the disaccharide is isomaltose.
- 39. A disaccharide syrup according to claim 38, wherein the syrup comprises at least 40% isomaltose, preferably at least 50% isomaltose, more preferably at least 70% isomaltose.
- 40. An oligosaccharide syrup obtainable by the method according to any of the claims 1-29, wherein the ratio by weight of monosaccharide to total dry substance is at most 10%, preferably at most 5% and the ratio by weight of saccharides having a polymerization degree from 2 to 6 to total dry substance is at least 90%.
- 41. A method of producing at least 55% pure fructose, comprising the steps of:
enzymatic reaction of glucose and fructose at a temperature in the range of 50° C. to 80° C. obtaining a saccharide solution comprising glucose and fructose, and disaccharides, trisaccharides and higher saccharides, nanofiltration of the saccharide solution at a temperature in the range of 60° C. to 80° C. obtaining a syrup essentially comprising disaccharides, trisaccharides and higher saccharides, recovering said syrup, and recovering the permeate resulting from the nanofiltration step.
Priority Claims (1)
Number |
Date |
Country |
Kind |
1997 01356 |
Nov 1997 |
DK |
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a division of U.S. patent application Ser. No. 09/200,109, filed on Nov. 25, 1998, now allowed, and claims priority from Danish application no. 1356/97, filed on Nov. 27, 1997, the contents of which are fully incorporated herein by reference.
Divisions (1)
|
Number |
Date |
Country |
Parent |
09200109 |
Nov 1998 |
US |
Child |
09976224 |
Oct 2001 |
US |