Sweetener and process for producing the same
The present invention provides a sweetener which has mild sweetness like sugar while maintaining a high sweetness intensity of a Stevia sweetener and also has a sharp head-taste of sweetness, a sharp after-taste of sweetness, as well as reduction of the bitterness and astringency of after-taste peculiar to the Stevia sweetener, and a process for producing the same. The sweetener contains steviol glucosides comprising β-1,4-galactosyl rebaudioside A having one to three β-1,4-bonded galactosyl groups in a molecule and rebaudioside A, wherein the following expressions (1) and (2) are satisfied: [( GRA+RA )/( X )]≧0.4 (1) [( GRA )/( RA )]≧1.0 (2) wherein GRA represents the weight percentage of the β-1,4-galactosyl rebaudioside A having one to three β-1,4-bonded galactosyl groups in a molecule, RA represents the weight percentage of the rebaudioside A, and X represents the weight percentage of the steviol glucosides.
1. A sweetener which contains steviol glucosides comprising
β-1,4-galactosyl rebaudioside A having one to three β-1,4-bonded galactosyl groups in a molecule and
rebaudioside A,
wherein the following expressions (1) and (2) are satisfied:
[( GRA+RA )/( X )]≧0.4 (1)
[( GRA )/( RA )]≧1.0 (2)
wherein GRA represents the weight percentage of the β-1,4-galactosyl rebaudioside A having one to three β-1,4-bonded galactosyl groups in a molecule, RA represents the weight percentage of the rebaudioside A, and X represents the weight percentage of the steviol glucosides; and
at least one of the β-1,4-bonded galactosyl groups is bonded to the 13-G1 glucose residue of rebaudioside A, or is bonded to at least one of the 13-G2 and 13-G3 glucose residues, of rebaudioside A.
2. A sweetener according to claim 1 , wherein the following expressions (3) and (4) are satisfied:
0.95≧[( GRA+RA )/( X )]≧0.5 (3)
10.0≧[( GRA )/( RA )]≧1.1 (4).
3. The sweetener according to claim 1 or 2 , wherein the steviol glucosides further comprise
β-1,4-galactosyl stevioside having one to two β-1,4-bonded galactosyl groups in a molecule and
stevioside,
and the following expression (5) is satisfied:
[( GRA+RA )/( GST+ST )]≧1.0 (5)
wherein GST represents the weight percentage of the β-1,4-galactosyl stevioside having one to two β-1,4-bonded galactosyl groups in a molecule, and ST represents the weight percentage of the stevioside.
4. A sweetener according to claim 1 , wherein the steviol glucosides further comprise
β-1,4-galactosyl stevioside having one to two β-1,4-bonded galactosyl groups in a molecule and
stevioside,
and the following expressions (3), (6) and (7) are satisfied:
0.95≧[( GRA+RA )/( X )]≧0.5 (3)
5.0≧[( GRA )/( RA )]≧1.1 (6)
[( GRA+RA )/( GST+ST )]≧1.5 (7)
wherein GST represents the weight percentage of the β-1,4-galactosyl stevioside having one to two β-1,4-bonded galactosyl groups in a molecule, and ST represents the weight percentage of the stevioside.
5. A sweetener according to claim 1 , wherein the β-1,4-galactosyl rebaudioside A includes two or three β-1,4-bonded galactosyl groups.
6. A sweetener according to claim 1 , wherein the β-1,4-bonded galactosyl groups are a 13-1,4-bonded galactosyl group bonded to a glucose residue bonded at the 13-position of a steviol skeleton of rebaudioside A and a β-1,4-bonded galactosyl group bonded to a glucose residue bonded at the 19-position of a steviol skeleton of rebaudioside A.
7. A process for preparing a sweetener, the process comprising
allowing a β-1,4-galactosyl transferase to react on an aqueous solution containing a Stevia extract containing 40% by weight or more of rebaudioside A and a β-1,4-galactosyl sugar compound in a 5- to 20-fold amount based on the solid content of the Stevia extract, wherein the β-1,4-galactosyl transferase is reacted to provide at least one f3-1,4-bonded galactosyl group which is bonded to the 13-G1 glucose residue of rebaudioside A, or is reacted to provide at least one β-1,4-bonded galactosyl group which is bonded to at least one of the 13-G2 and 13-G3 glucose residues of rebaudioside A.
8. A process for preparing a sweetener according to claim 7 , wherein the solid content of the Stevia extract containing 40% by weight or more of rebaudioside A in the aqueous solution is from 1 to 5% by weight and the β-1,4-galactosyl transferase is used in an amount of 1 to 1000 units based on 1 g of the solid content of the Stevia extract.
9. A process for preparing a sweetener according to claim 7 or 6 , wherein the Stevia extract containing 40% by weight or more of rebaudioside A is a Stevia extract containing rebaudioside A in a 1.5-fold amount or more based on the weight of stevioside.
10. A process for preparing a sweetener according to claim 9 , wherein the β-1,4-galactosyl sugar compound is lactose.
11. A process for preparing a sweetener according to claim 9 , wherein the β-1,4-galactosyl transferase is an enzyme derived from microorganisms of the genus Bacillus.
12. A process for preparing a sweetener according to claim 7 , wherein the sweetener prepared is a sweetener which contains steviol glucosides comprising β-1,4-galactosyl rebaudioside A having one to three β-1,4-bonded galactosyl groups per molecule and rebaudioside A, and the sweetener satisfies the following expressions (1) and (2):
[( GRA+RA )/( X )]≧0.4 (1)
[( GRA )/( RA )]≧1.0 (2)
wherein GRA represents the weight percentage of the β-1,4-galactosyl rebaudioside A having one to three β-1,4-bonded galactosyl groups per molecule, RA represents the weight percentage of the rebaudioside A, and X represents the weight percentage of the steviol glucosides.
13. A process for preparing a sweetener according to claim 7 , wherein the Stevia extract contains 50% by weight or more of rebaudioside A.
14. A process for preparing a sweetener according to claim 7 , wherein the β-1,4-galactosyl transferase is reacted to provide a β-1,4-bonded galactosyl rebaudio side A wherein two or more β-1,4-bonded galactosyl groups are included.
15. A process for preparing a sweetener according to claim 5 , wherein the β-1,4-galactosyl transferase is reacted to provide both groups of: a β-1,4-bonded galactosyl group bonded to a glucose residue bonded at the 13-position of a steviol skeleton of rebaudioside A; and a 13-1,4-bonded galactosyl group bonded to a glucose residue bonded at the 19-position of a steviol skeleton of rebaudioside A.
16. A sweetener which contains steviol glucosides comprising:
at least one of β-1,4-galactosyl rebaudioside A having two to three β-1,4-bonded galactosyl groups in a molecule and
rebaudioside A, wherein the following expressions (1) and (2) are satisfied:
[( GRA+RA )/( X )]≧0.4 (1)
[ GRA )/( RA )]≧1.0 (2)
wherein GRA represents the weight percentage of the β-1,4-galactosyl rebaudioside A having two to three β-1,4-bonded galactosyl groups in a molecule, RA represents the weight percentage of the rebaudioside A, and X represents the weight percentage of the steviol glucosides.
17. A sweetener according to claim 16 , wherein the following expressions (3) and (4) are satisfied:
0.95≧[( GRA+RA )/( X )]≧0.5 (3)
10.0≧[( GRA )/( RA )]≧1.1 (4).
18. The sweetener according to claim 16 , wherein the steviol glucosides further comprise:
β-1,4-galactosyl stevio side having one to two β-1,4-bonded galactosyl groups in a molecule and
stevioside,
and the following expression (5) is satisfied:
[( GRA+RA )/( GST+ST )]≧1.0 (5)
wherein GST represents the weight percentage of the β-1,4-galactosyl stevioside having one to two β-1,4-bonded galactosyl groups in a molecule, and ST represents the weight percentage of the stevioside.
19. A sweetener according to claim 16 , wherein the steviol glucosides further comprise:
β-1,4-galactosyl stevioside having one to two β-1,4-bonded galactosyl groups in a molecule and
stevioside,
and the following expressions (3), (6) and (7) are satisfied:
0.95≧[( GRA+RA )/( X )]≧0.5 (3)
5.0≧[( GRA )/( RA )]≧1.1 (6)
[( GRA+RA )/( GST+ST )]≧1.5 (7)
wherein GST represents the weight percentage of the β-1,4-galactosyl stevioside having one to two β-1,4-bonded galactosyl groups in a molecule, and ST represents the weight percentage of the stevioside.