U.S. patent application number 11/249629 was filed with the patent office on 2006-04-20 for sweetener composition.
This patent application is currently assigned to AJINOMOTO CO. INC. Invention is credited to Kenichi Mori.
Application Number | 20060083695 11/249629 |
Document ID | / |
Family ID | 36148499 |
Filed Date | 2006-04-20 |
United States Patent
Application |
20060083695 |
Kind Code |
A1 |
Mori; Kenichi |
April 20, 2006 |
Sweetener composition
Abstract
Storing monatin or a salt thereof in the presence of a radical
scavenger and/or in a UV light-shielding container is effective for
preventing the decomposition of monatin or a salt thereof by
exposure to ultraviolet light, particularly under acidic
conditions. Sweetener compositions which contain monatin or a salt
thereof and a radical scavenger and the like are resistant to
decomposition by UV light.
Inventors: |
Mori; Kenichi;
(Kawasaki-shi, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
AJINOMOTO CO. INC
Tokyo
JP
104-8315
|
Family ID: |
36148499 |
Appl. No.: |
11/249629 |
Filed: |
October 14, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60618979 |
Oct 18, 2004 |
|
|
|
Current U.S.
Class: |
424/49 ; 424/400;
426/660; 548/495 |
Current CPC
Class: |
C07D 209/20 20130101;
A23L 27/32 20160801; A23L 27/70 20160801; C07D 403/06 20130101;
A61K 8/4926 20130101; A61Q 11/00 20130101; A61K 47/12 20130101;
A61K 8/347 20130101; A61K 8/60 20130101; A61K 9/0056 20130101; A61K
8/676 20130101; A61K 8/498 20130101; C07D 405/06 20130101; A61K
8/492 20130101; A23L 2/60 20130101; A23L 27/31 20160801 |
Class at
Publication: |
424/049 ;
426/660; 424/400; 548/495 |
International
Class: |
A61K 9/00 20060101
A61K009/00; A23G 3/00 20060101 A23G003/00; A61K 8/49 20060101
A61K008/49; C07D 209/18 20060101 C07D209/18 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 15, 2004 |
JP |
2004-302120 |
Claims
1. A sweetener composition, comprising monatin or a salt thereof
and a radical scavenger.
2. The composition of claim 1, wherein said radical scavenger is at
least one member selected from the group consisting of ascorbate
acid, ascorbate, an ascorbic acid ester, erythorbic acid,
erythorbic acid salt, an erythorbic ester, uric acid, bilirubin,
albumin, vitamin A, vitamin E, ubiquinol, carotenoid, histidine,
tryptophan, 2,6-d-tert-butyl-4-methylphenol,
2-tert-butyl-4-hydroxyanisole, 3-tert-butyl-4-hydroxyanisole,
propyl gallate, catechin, and mixtures thereof.
3. The composition of claim 1, wherein said radical scavenger is at
least one member selected from the group consisting of ascorbic
acid, ascorbate, an ascorbic acid ester, erythorbic acid,
erythorbic acid salt, an erythorbic acid ester, and mixtures
thereof.
4. The composition of claim 1, wherein said radical scavenger is
ascorbic acid.
5. The composition of claim 1, which is a liquid composition having
a pH of not less than 2 and less than 7.
6. The composition of claim 1, wherein said radical scavenger is
present in an amount of 1 to 10000 mass parts relative to 100 mass
parts of said monatin or a salt thereof.
7. A beverage, a food, a mouth cavity composition, or a
pharmaceutical product, which comprises a composition according to
claim 1.
8. A beverage comprising a composition according to claim 1.
9. A preservation stabilizer for monatin or a salt thereof, which
comprises a radical scavenger.
10. A method of preserving monatin or a salt thereof, said method
comprising maintaining monatin or a salt thereof in the presence of
a radical scavenger.
11. A method of preserving a sweetener composition, a beverage, a
food, a mouth cavity composition, or a pharmaceutical product,
which comprises monatin or a salt thereof, said method comprising
maintaining said monatin or a salt thereof in the presence of a
radical scavenger.
12. A method of preserving a beverage, which comprises monatin or a
salt thereof, said method comprising maintaining said monatin or a
salt thereof in the presence of a radical scavenger.
13. A method of preserving monatin or a salt thereof, said method
comprising placing monatin or a salt thereof under a condition free
of exposure to ultraviolet light.
14. A method of preserving a sweetener composition, a beverage, a
food, a mouth cavity composition, or a pharmaceutical product,
which comprises monatin or a salt thereof, said method comprising
placing monatin or a salt thereof under a condition free of
exposure to ultraviolet light.
15. A method of preserving a beverage, which comprises monatin or a
salt thereof, said method comprising placing monatin or a salt
thereof under a condition free of exposure to ultraviolet
light.
16. The method of claim 13, which further comprises preserving said
monatin or salt thereof in the presence of a radical scavenger.
17. Monatin or a salt thereof, which is enclosed in a container
shielding ultraviolet light.
18. A sweetener composition, a beverage, a food, a mouth cavity
composition, or a pharmaceutical product, which comprises monatin
or a salt thereof, wherein said sweetener composition, beverage,
food, mouth cavity composition, or pharmaceutical product is
enclosed in a container shielding ultraviolet light.
19. A beverage, which comprises monatin or a salt thereof, wherein
said beverage is enclosed in a container shielding ultraviolet
light.
20. A sweetener composition, a beverage, a food, a mouth cavity
composition, or a pharmaceutical product, which comprises monatin
or a salt thereof and a radical scavenger, wherein said sweetener
composition, beverage, food, mouth cavity composition, or
pharmaceutical product is enclosed in a container shielding
ultraviolet light.
21. A beverage, which comprises monatin or a salt thereof and a
radical scavenger, wherein said beverage is enclosed in a container
shielding ultraviolet light.
Description
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent
Application No. 60/618,979, filed on Oct. 18, 2004, and Japanese
Patent Application No. 302120/2004, filed on Oct. 15, 2004, both of
which are incorporated herein by reference in their entireties.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to sweetener compositions
comprising monatin or a salt thereof. More particularly, the
present invention relates to a method for preserving monatin or a
salt thereof.
[0004] 2. Discussion of the Background
[0005] Monatin is a natural amino acid derivative isolated from the
root bark of a native plant (Schierochiton ilicifolius) of northern
Transvaal of South Africa, and its structure has been reported by
R. Vleggaar et al to be
(2S,4S)-2-amino-4-carboxy-4-hydroxy-5-(3-indolyl)-pentanoic acid
((2S,4S)-4-hydroxy-4-(3-indolylmethyl)-glutamic acid) (R. Vleggaar
et al., J. Chem. Soc. Perkin Trans., pp. 3095-3098, (1992)). The
synthesis of monatin is described in, for example, ZA 87/4288, ZA
88/4220, U.S. Pat. No. 5,994,559, WO03/045914, WO03/059865,
WO03/056026, WO04/067494, WO04/053125, C. W. Holzapfel et al.,
Synthetic Communication, vol. 24(22), pp. 3197-3211 (1994), K.
Nakamura et al., Organic Letters, vol. 2, pp. 2967-2970 (2000), and
the like. Monatin is a superior sweetener which is 1400 times
sweeter than sugar and contains no calories. It is stable to heat
and expected to be applicable to various kinds of food.
SUMMARY OF THE INVENTION
[0006] The present inventor has first clarified at this time that
monatin in the solution state tends to decompose when exposed to
ultraviolet light, and that the tendency becomes particularly
remarkable under acidic conditions (particularly at a pH of less
than 5). As mentioned above, therefore, a means to use a superior
sweetener, monatin, in a stable state irrespective of the condition
it is placed in, becomes necessary.
[0007] Thus, the problem to be solved by the present invention
solves the above-mentioned novel problem. Specifically, the problem
of the present invention is to provide a method for preserving
monatin or a salt thereof in a stable state even under ultraviolet
light, and further, a sweetener composition, a beverage, a food, a
pharmaceutical product and the like, which contain stable monatin
or a salt thereof. In addition, provision of a preservation
stabilizer for monatin or a salt thereof is also a problem of the
present invention.
[0008] Accordingly, it is one object of the present invention to
provide novel compositions which contain monatin or a salt
thereof.
[0009] It is another object of the present invention to provide
novel compositions which contain monatin or a salt thereof and
which exhibit increased stability.
[0010] It is another object of the present invention to provide
novel compositions which contain monatin or a salt thereof and
which exhibit increased stability, even when exposed to ultraviolet
light.
[0011] It is another object of the present invention to provide
novel beverages, foods, pharmaceutical products, and the like,
which contain stable monatin or a salt thereof.
[0012] These and other objects, which will become apparent during
the following detailed description, have been achieved by the
inventor's discovery that monatin and a salt thereof can be
maintained in a stable state by maintaining monatin or a salt
thereof in the co-presence of a radical scavenger.
[0013] Accordingly, the present invention provides the
following:
[0014] (1) A sweetener composition, comprising monatin or a salt
thereof and a radical scavenger.
[0015] (2) The composition of (1), wherein the radical scavenger is
at least one member selected from the group consisting of ascorbic
acid, ascorbate, ascorbic acid ester, erythorbic acid, erythorbic
acid salt, erythorbic acid ester, uric acid, bilirubin, albumin,
vitamin A, vitamin E, ubiquinol, carotenoid, histidine, tryptophan,
2,6-di-tert-butyl-4-methylphenol, 2-tert-butyl-4-hydroxyanisole,
3-tert-butyl-4-hydroxyanisole, propyl gallate, catechin, and
mixtures thereof.
[0016] (3) The composition of (1), wherein the radical scavenger is
at least one member selected from the group consisting of ascorbic
acid, ascorbate, ascorbic acid ester, erythorbic acid, erythorbic
acid salt, erythorbic acid ester, and mixtures thereof.
[0017] (4) The composition of (1), wherein the radical scavenger is
ascorbic acid.
[0018] (5) The composition of any of (1)-(4), which is a liquid
composition having a pH of not less than 2 and less than 7.
[0019] (6) The composition of any of (1)-(5), wherein the radical
scavenger content is 1 to 10000 mass parts relative to 100 mass
parts of monatin or a salt thereof.
[0020] (7) A beverage, a food, a mouth cavity composition, or a
pharmaceutical product comprising a composition of any of
(1)-(6).
[0021] (8) A beverage comprising a composition of any of
(1)-(6).
[0022] (9) A preservation stabilizer for monatin or a salt thereof,
which comprises a radical scavenger.
[0023] (10) A method of preserving monatin or a salt thereof, which
comprises maintaining monatin or a salt thereof in the presence of
a radical scavenger.
[0024] (11) A method of preserving a sweetener composition, a
beverage, a food, a mouth cavity composition, or a pharmaceutical
product, comprising monatin or a salt thereof, which method
comprises maintaining monatin or a salt thereof in the presence of
a radical scavenger.
[0025] (12) A method of preserving a beverage comprising monatin or
a salt thereof, which method comprises maintaining monatin or a
salt thereof in the presence of a radical scavenger.
[0026] (13) A method of preserving monatin or a salt thereof, which
method comprises placing monatin or a salt thereof under a
condition free of exposure to ultraviolet light.
[0027] (14) A method of preserving a sweetener composition, a
beverage, a food, a mouth cavity composition, or a pharmaceutical
product comprising monatin or a salt thereof, which method
comprises placing monatin or a salt thereof under a condition free
of exposure to ultraviolet light.
[0028] (15) A method of preserving a beverage comprising monatin or
a salt thereof, which method comprises placing monatin or a salt
thereof under a condition free of exposure to ultraviolet
light.
[0029] (16) The method of (13)-(15), which comprises preservation
in the presence of a radical scavenger.
[0030] (17) Monatin or a salt thereof, which is enclosed in a
container shielding ultraviolet light.
[0031] (18) A sweetener composition, a beverage, a food, a mouth
cavity composition, or a pharmaceutical product comprising monatin
or a salt thereof, which is enclosed in a container shielding
ultraviolet light.
[0032] (19) A beverage comprising monatin or a salt thereof, which
is enclosed in a container shielding ultraviolet light.
[0033] (20) A sweetener composition, a beverage, a food, a mouth
cavity composition, or a pharmaceutical product comprising monatin
or a salt thereof and a radical scavenger, which is enclosed in a
container shielding ultraviolet light.
[0034] (21) A beverage comprising monatin or a salt thereof and a
radical scavenger, which is enclosed in a container shielding
ultraviolet light.
[0035] According to the present invention, a sweetener composition,
a food, a beverage, a mouth cavity composition, and a
pharmaceutical product are provided, which contain monatin or a
salt thereof, and which suppress decomposition of the monatin or
salt thereof due to ultraviolet light, and provide a stable
sweetness. According to the present invention, moreover, a
preservation stabilizer for and a method of preserving monatin or a
salt thereof are also provided.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] The sweetener composition of the present invention contains
monatin and a radical scavenger. Monatin is a compound represented
by the formula (I): ##STR1## Monatin has an asymmetric moieties at
the 2-position and the 4-position and includes the following 4
kinds of optical isomers. ##STR2## In the present invention, the
stereoisomer is not particularly limited. Where necessary,
(2R,4R)monatin, (2R,4S)monatin, (2S,4R)monatin, and (2S,4S)monatin,
and any mixture of these can be used. Unless otherwise specified,
in the present specification, simple monatin means one without
limitation on stereoisomerism. Moreover, the monatin used in the
present invention may be used as a salt with an alkali metal, such
as sodium, potassium, and the like; an alkaline earth metal such as
magnesium and the like; and the like. In this case, the potassium
salt is preferable, and monopotassium salt is more preferable.
[0037] According to the finding of the present inventor, of the 4
kinds of optical isomers, (2S,4R)monatin and (2R,4S)monatin tend to
be more easily decomposed by ultraviolet light than the other
isomers. Monatin is a known substance, and its production method is
also known. For example, it can be produced by a method described
in ZA 87/4288, ZA 88/4220, U.S. Pat. No. 5,994,559, WO03/045914,
WO03/059865, WO03/056026, WO04/067494, WO04/053125, C. W. Holzapfel
et al., Synthetic Communications, vol. 24(22), pp. 3197-3211(1994),
K. Nakamura et al., Organic Letters, vol. 2, pp. 2967-2970(2000),
and the like.
[0038] The term radical scavenger as used in the present invention
refers to a compound used to efficiently catch a radical (free
group) produced during reaction and, for example, ascorbic acid,
ascorbate, ascorbic acid ester, erythorbic acid (isoascorbic acid),
erythorbic acid salt, erythorbic acid ester, uric acid, bilirubin,
albumin, vitamin A, vitamin E, ubiquinol, carotenoid, histidine,
tryptophan, 2,6-di-tert-butyl-4-methylphenol (BHT),
2-tert-butyl-4-hydroxyanisole, 3-tert-butyl-4-hydroxyanisole,
propyl gallate, catechin, and the like can be mentioned. As the
radical scavenger in the present invention, ascorbic acid,
ascorbate, ascorbic acid ester, erythorbic acid, erythorbic acid
salt, and erythorbic acid ester are preferable. As the salt of
ascorbate or erythorbic acid salt, alkali metal salts (e.g., sodium
salt, potassium salt, etc.) and the like can be mentioned.
Particularly, a sodium salt is preferable. As the ascorbic acid
ester or erythorbic acid ester, fatty acid esters (e.g., palmitic
acid ester, stearic acid ester, and the like) are preferable. In
the present invention, particularly preferable radical scavenger is
ascorbic acid. As the ascorbic acid, L-ascorbic acid (vitamin C) is
more preferable.
[0039] The content of the radical scavenger in the sweetener
composition of the present invention is not particularly limited as
long as the effect of the present invention is afforded, and the
content is generally not less than 1 mass part, preferably not less
than 5 mass parts, more preferably not less than 10 mass parts,
relative to 100 mass parts of monatin or a salt thereof. The upper
limit of the content is not particularly set and it is
appropriately determined depending on the kind of radical scavenger
to be used, and the kind of food on which a sweetener composition
is used. A radical scavenger is generally used in an amount of not
more than 10000 mass parts, preferably not more than 5000 mass
parts, relative to 100 mass parts of monatin or a salt thereof.
[0040] The sweetener composition of the present invention is
preferably used as a sweetener, and may further contain other
optional components such as a carrier, an extender, an excipient,
an additive, a flavor, and the like as necessary. The sweetener
composition of the present invention may contain other sweeteners
such as saccharides (e.g., sucrose, invert sugar, isomerized sugar,
glucose, fructose, lactose, maltose, trehalose, xylose. etc.);
sugar alcohols (e.g., multitol, sorbitol, mannitol, erythritol,
xylitol, lactitol, etc.); oligosaccharides; dietary fiber;
aspartame; saccharin; acesulfame K; sucralose; and the like.
[0041] The form of the sweetener composition of the present
invention is not particularly limited, and it is provided in
various forms such as a freeze-dried product, a mixed and ground
product, a liquid, an emulsion, and the like. The sweetener
composition as a freeze-dried product or a mixed and ground product
may be granulated, where necessary, by a method known to those of
ordinary skill in the art such as dry granulation, wet granulation
and the like, to give granules. For a liquid sweetener, water,
alcohol, glycerol, propylene glycol, and the like can be used as a
solvent to dissolve solute and, more preferably, water and alcohol
can be used. For control of the specific gravity of each component,
the amounts of the aforementioned composition and solvent to be
added are adjusted according to methods known to those of ordinary
skill in the art.
[0042] The sweetener composition of the present invention can be
used for a wide variety of products including beverages, foods,
pharmaceutical products, and the like. To be specific, various
foods include powder juices, powder cocoas, instant coffee,
chocolate, chewing gum, health foods, bread, cake, and the like,
and various beverages such as coffee beverages, vegetable juice
beverages, Japanese tea, Chinese tea, tea, milk beverages, soup
beverages, carbonated beverages, sweet beverages, juice beverages,
alcohol beverages, and the like. In addition, it can be used for
various products that require a sweet taste such as toothpaste
powders, pharmaceutical products and the like, and the like.
[0043] The present invention moreover provides a preservation
stabilizer of monatin or a salt thereof. The preservation
stabilizer is characterized in that it contains a radical
scavenger. The radical scavenger is the same as those mentioned
above. Using this preservation stabilizer, decomposition of monatin
and a salt thereof can be suppressed even under ultraviolet light,
and they can be used for a stable sweetener composition and the
like. Where desired, any other components such as the
above-mentioned extenders, excipients, additives, flavors,
sweeteners other than monatin, and the like can be added as long as
the object of the present invention can be achieved.
[0044] Generally, the preservation stabilizer of the present
invention is so used as to make the mass ratio of monatin or a salt
thereof and radical scavenger the same as the mass ratio of the
composition explained above.
[0045] According to the findings of the present inventor, when
monatin is present in a liquid state such as aqueous solution and
the like, it tends to be decomposed by ultraviolet light, and a
pronounced tendency is found in an acidic pH range (pH of 2 to 7).
Decomposition is particularly remarkable when pH is not more than
6. In general, the pH of food is not less than 2, and the
decomposition suppressive effect and preservation stabilization
effect of monatin of the present invention become remarkable in
sweetener compositions and food having a pH of not less than 2 and
not more than 7, further not less than pH 2 and not more than 6,
still further not less than pH 2 and not more than 5, and even
further not less than pH 2 and not more than 4. Since decomposition
of monatin due to ultraviolet light is observed when monatin is
present in a liquid state such as aqueous solution and the like,
the decomposition suppressive effect and preservation stabilization
effect of the present invention is particularly remarkably
exhibited in beverages containing monatin. In addition, the
decomposition suppressive effect and preservation stabilization
effect can be exhibited in food and pharmaceutical products
containing monatin in a liquid state, food and pharmaceutical
products containing monatin together with a solvent in which
monatin is dissolved, and food and pharmaceutical products in which
monatin is used or preserved in a liquid state. Furthermore, the
decomposition suppressive effect and preservation stabilization
effect can be exhibited in food and pharmaceutical products
produced via a step comprising monatin in a liquid state during
production thereof.
[0046] The term ultraviolet light refers to an electromagnetic wave
having a shorter wavelength than visible light and a longer
wavelength than X-ray, and the wavelength range thereof can be made
to fall within the range of approximately 400 nm to 1 nm.
Ultraviolet light is divided according to wavelength range into
near ultraviolet light 400 to 300 nm, deep ultraviolet light 300 to
200 nm, and vacuum ultraviolet light 200 to 1 nm. Since absorption
due to oxygen is seen in a wavelength range of not more than 195
nm, a spectroscope for this wavelength range requires a special
design such as vacuum optical path and the like. Ozone in the upper
atmosphere absorbs not more than about 290 nm of the sunlight.
(Tokyo Kagaku Dozin Co., Ltd., Encyclopedia of Chemistry, 1st ed.
4th printing, 1998). As is clear from the Examples to be mentioned
later, light irradiation from a lamp with a UV absorption film
hardly decomposes monatin, but irradiation of sunlight, D65 lamp
and near ultraviolet lamp (all having a wavelength in the
ultraviolet light region) decomposes monatin. It is clear therefrom
that the decomposition of monatin is attributable to an
electromagnetic wave having a wavelength in the ultraviolet light
region (assumed to be mainly 290 to 400 nm wavelength).
[0047] According to the findings of the present inventor, when
monatin is present in a liquid state, it is decomposed by
ultraviolet light, namely, by the electromagnetic wave having a
wavelength in the ultraviolet light region, and also decomposed by,
for example, irradiation with sunlight. For example, when preserved
in an ultraviolet shield, decomposition is hardly observed. Based
on such finding, the present invention further provides a method of
preserving monatin or a salt thereof, a method of preserving a
sweetener composition containing monatin or a salt thereof, and a
method of preserving a beverage, a food, a mouth cavity
composition, or a pharmaceutical product containing monatin or a
salt thereof.
[0048] A first preservation method includes maintaining monatin or
a salt thereof in the presence of a radical scavenger. Generally,
decomposition of monatin is observed when monatin or a salt thereof
is present in a liquid state. However, since monatin may also
become partially liquid and may be decomposed when it is present in
a solid state (e.g., a powder, etc.) due to moisture absorption and
the like, the preservation method of the present invention is
useful for the retention of quality. Moreover, any other component
such as the above-mentioned extenders, excipients, additives,
flavors, sweeteners other than monatin, and the like may be
co-existent. Generally, the preservation method of the present
invention is so performed as to make the mass ratio of monatin or a
salt thereof and radical scavenger similar to the mass ratio
thereof in the composition explained earlier.
[0049] A second preservation method includes placing monatin or a
salt thereof under a condition free of exposure to ultraviolet
light. To be specific, any state may be employed as long as monatin
and a salt thereof are not exposed to ultraviolet light and, for
example, placing them in a container made from an ultraviolet light
shielding material, such as aluminum and the like, wrapping them
with a film and the like, which shield ultraviolet light, and the
like can be mentioned. Therefore, the present invention also
encompasses a means to prevent exposure of monatin or a salt
thereof to ultraviolet light, for example, monatin or a salt
thereof in a container, wherein monatin or a salt thereof is
enclosed in a container that shields ultraviolet light, a sweetener
composition, a beverage, a food, a mouth cavity composition, or a
pharmaceutical product in a container, wherein monatin or a salt
thereof is enclosed in a container that shields ultraviolet light,
and the like.
[0050] Even when monatin and the like are preserved under an
ultraviolet light shield or monatin is enclosed in a container that
shields ultraviolet light, it is still preferable to keep monatin
in the presence of a radical scavenger, because consumer and the
like may use or re-preserve monatin and the like under an
ultraviolet light condition.
[0051] Other features of the invention will become apparent in the
course of the following descriptions of exemplary embodiments which
are given for illustration of the invention and are not intended to
be limiting thereof.
EXAMPLES
[0052] Various conditions, light irradiation conditions, and HPLC
analysis conditions employed for the following Examples,
Comparative Examples and Reference Example are as described
below.
Various Conditions:
[0053] Monatin used: (2R,4R)monatin potassium salt, (2S,4S)monatin
potassium salt, and (2S,4R)monatin potassium salt.
[0054] Preservation PET container: Toyo Seikan Kaisha, Ltd. PET
bottle (type: STHH350SA, maximum content: 376 ml, height: 157 mm,
maximum diameter: 60 mm, liquid filled: 370 ml).
Light Irradiation Conditions:
[0055] Illuminance: [0056] 2900-3100 LUX. [0057] UV-A: 0.06
mW/cm.sup.2.
[0058] UV-B: 0.006 mW/cm.sup.2. TABLE-US-00001 TABLE 1 UV-A(360 nm)
UV-B(305 nm) illuminance place mW/cm.sup.2 lux outside 9:10 1.102
0.376 44,000 outside 13:40 1.790 0.696 72,300 outside 15:40 1.007
0.399 48,000 near ultraviolet 0.597 0.053 23 light lamp D65 lamp
0.06 0.006 2,900 lamp with UV 0.001 0.001 2,700 absorption film
(ref.: illuminance about 700-1000 lux on indoor desk)
[0059] Temperature: 25.degree. C. constant temperature room (forced
circulation).
[0060] Apparatus: [0061] Luminance meter: Tokyp Koden Ltd. [0062]
Digital luminance meter ANA-F11. [0063] UV Radiometer: Topcon
Corporation UV Radiometer UVR-3036/S. [0064] (light receiver: UV-A
(365 nm), UV-B (305 nm)). [0065] Lamp: manufactured by Toshiba
Corporation, tube diameter 32.5 mm, [0066] tube length 580 mm, 20 W
(common). [0067] D65 fluorescence lamp type: FL20S.D-EDL-D65.
[0068] Near ultraviolet light lamp type: FL20S.BLB. [0069]
Fluorescence lamp with UV absorption film type: FL20S.N-SDL-NU.
[0070] (the light emmitted by D65 fluorescence lamp has similar
spectrum as sunlight). HPLC Analysis Used:
[0071] Instruments used: [0072] Pump: LC-9A manufactured by
Shimadzu Corporation. [0073] Column oven: CTO-10A manufactured by
Shimadzu Corporation. [0074] Detector: SPD-10A manufactured by
Shimadzu Corporation. [0075] Autosampler: SIL-9A manufactured by
Shimadzu Corporation. [0076] Gradient: LPG-1000 manufactured by
Tokyo Rikakikai Co., Ltd.
[0077] Column: CAPCELL PAK C18 TYPE MG 5 .mu.m [0078] 4.6
mm.times.250 mm manufactured by Shiseido Company, Limited.
[0079] Column temperature: 40.degree. C.
[0080] Detection wavelength: 210 nm.
[0081] Mobile liquid composition: [0082] Solution A 20 mm
KH.sub.2PO.sub.4/acetonitrile=100/5. [0083] Solution B acetonitrile
alone.
[0084] Gradient pattern: (shown in Table 2). TABLE-US-00002 TABLE 2
Time (min) Solution A (%) Solution B (%) 0 100 0 15 100 0 40 63 37
45 63 37
[0085] Injection volume: 10 .mu.L.
[0086] Analysis cycle: 70 min/1 sample.
pH Measurement Conditions:
[0087] pH meter: type HM-30G, manufactured by DKK Toa
Corporation.
[0088] PH standard solution: phosphate pH standard equimolal
solution (JIS Z 8802) pH=7, manufactured by Junsei Chemical Co.,
Ltd.
[0089] Phthalate pH standard solution (JIS Z 8802) pH=4
manufactured by Junsei Chemical Co., Ltd.
[0090] Measurement method: two-point calibration by automatic
temperature calibration was performed and pH of the model drink was
measured.
Preservation of Monatin by Addition of Radical Scavenger.
EXAMPLES 1-9, COMPARATIVE EXAMPLES 1-5, REFERENCE EXAMPLE 1
[0091] The pH of a beverage model solution, a (citric acid 2 g,
sodium benzoate 0.045 g)/L solution, was adjusted with 8N sodium
hydroxide. (2R,4R)monatin potassium salt (25 mg) and various
additives were dissolved in the adjusted beverage model solution
(500 mL) and filled in PET containers. In Reference Example 1,
L-Trp (25 mg) was added instead of monatin. The containers were
left standing for about 165 hours in a constant temperature room
controlled to room temperature 25.degree. C. under a D65
fluorescence lamp adjusted to illuminance of about 3000 Lux. The
solution was simultaneously filled in a 20 ml screw cap vial and
left standing for the same time in the same constant temperature
room under a light shield. These light exposure solutions and light
shield solutions were subjected to HPLC analysis, and
photodecomposition rates were calculated by the following formula:
The photodecomposition rate (%)=(1-(mass % concentration of monatin
in light exposure solution/mass % concentration of monatin in light
shield solution)).times.100
[0092] The pH, monatin used, and additives used for each solution
were as shown in Table 3. The results are shown in Table 3. From
Table 3, it is clear that the decomposition of monatin was
remarkably suppressed by the presence of a radical scavenger under
light irradiation including ultraviolet light by D65 lamp.
[0093] As described in ZA 87/4288 and ZA 88/4220, monatin is known
to be present as an equilibrium of a lactone form of the formula
(II) and a lactam form of the formula (III) in an aqueous solution,
and the content ratio of the lactone form and lactam form tends to
increase with lower pHs of the solution. ##STR3##
[0094] In the following Tables, the monatin residual ratio (%) is
shown in the upper line, the lactone present ratio (%) is shown in
the lower left line, and the lactam present ratio (%) is shown in
the lower right line, all under light exposure and light
shield.
[0095] The monatin residual ratio was calculated by the following
formula: The monatin residual ratio (%)=((monatin mass %
concentration after light exposure or light shield
preservation)/(monatin mass % concentration before light exposure
or light shield preservation)).times.100
[0096] The presence rates of lactone and lactam were calculated by
the following formula: The lactone and lactam presence rates
(%)=((HPLC peak area of lactam or lactone after light exposure or
light shield preservation)/(HPLC peak area of monatin immediately
after sample preparation)).times.100
[0097] The HPLC peak areas of lactone and lactam are not observed
immediately after sample preparation.
Difference in photodecomposition rate of monatin due to pH
difference.
COMPARATIVE EXAMPLES 6-11
[0098] In the same manner as in Example 1, except that additives
were not added, the photodecomposition rate of monatin was
determined. The pH and monatin used for each solution are shown in
Table 4. The results are shown in Table 4.From Table 4, it is clear
that decomposition of monatin due to ultraviolet light tends to
increase with lower pHs.
Decomposition rate of monatin with ultraviolet light shield.
EXAMPLES 10-12
[0099] In the same manner as in Example 1, except that a
fluorescence lamp with a UV absorption film (exposure time 73
hours) was used instead of a D65 lamp, the photodecomposition rate
of monatin was determined. The pH, monatin, and additives used for
each solution are shown in Table 5. The results are shown in Table
5. From Table 5, it is clear that decomposition of monatin was
markedly suppressed when ultraviolet light was shielded.
EXAMPLE 13 AND COMPARATIVE EXAMPLES 12-13
[0100] In the same manner as in Example 1, except that sunlight
(exposure time 14 hours) was used instead of a D65 lamp, the
photodecomposition rate of monatin was determined. The pH, monatin,
and additives used for each solution are shown in Table 6. The
results are shown in Table 6. From Table 6, it is clear that the
decomposition of monatin due to sunlight including ultraviolet
light was markedly suppressed when a radical scavenger was
present.
EXAMPLE 14 AND COMPARATIVE EXAMPLES 14-15
[0101] In the same manner as in Example 1, except that a near
ultraviolet light lamp (exposure time 73 hour) was used instead of
a D65 lamp, the photodecomposition rate of monatin was determined.
The pH, monatin, and additives used for each solution are shown in
Table 7. The results are shown in Table 7. From Table 7, it is
clear that the decomposition of monatin due to ultraviolet light
was markedly suppressed when a radical scavenger was present.
pH dependency of photodecomposition behavior of Trp and
monatin.
EXPERIMENTAL EXAMPLE
[0102] The pH dependency of the photodecomposition behavior of
tryptophan (Trp) and monatin was examined.
[0103] For Trp, a solution having a concentration of 50 ppm was
prepared (25.degree. C.). The test solution was adjusted to a given
pH with citrate buffer, and in the same manner as in Example 1, the
photodecomposition rates of Trp and monatin were determined. The
test conditions and results are shown in Table 8. From Table 8, it
is clear that Trp tends to show photodecomposition in a neutral
region rather than in an acidic region, and the photodecomposition
behavior of monatin having an indole structure as does Trp is
strikingly different from that of Trp, as evidenced by the tendency
toward photodecomposition in an acidic region rather than in a
neutral region, and the like. Therefore, the photodecomposition
property of monatin cannot be predicted at all from the finding in
the photodecomposition property of Trp.
[0104] Furthermore, it was surprisingly found that addition of
ascorbic acid to monatin afforded an effect comparable to shading
over a wide pH range. TABLE-US-00003 TABLE 3 Light source D65 lamp
illuminance 3000 lux exposure time 165 hr photo- decom- light light
position pH monatin additive exposure shielding rate Ex. 1 3.1
(2R,4R) ascorbic acid 25 71.3% 64.0% -11.5% mg (50 ppm) (25.7%,
1.2%) (23.2%, 1.7%) Ex. 2 3.1 (2R,4R) ascorbic acid 54.6% 76.9%
29.1% 0.25 mg (16.6%, 0.1%) (20.8%, 1.0%) (0.5 ppm) Ex. 3 3.1
(2R,4R) ascorbic acid 75.0% 74.4% -0.9% 2.5 mg (5 ppm) (21.2%,
0.9%) (25.1%, 1.8%) Ex. 4 3.1 (2R,4R) ascorbic acid 72.8% 68.8%
-5.7% 250 mg (26.2%, 1.7%) (25.1%, 1.8%) (500 ppm) Ex. 5 3.1
(2R,4R) BHT 25 mg 67.4% 76.6% 12.0% (50 ppm) (19.4%, 0.9%) (21.3%,
1.0%) Ex. 6 3.1 (2R,4R) catechin 74.9% 77.3% 3.1% 25 mg (50 ppm)
(21.2%, 0.5%) (21.6%, 1.0%) Ex. 7 3.1 (2S,4S) ascorbic acid 75.5%
73.1% -3.3% 25 mg (50 ppm) (12.2%, 0.7%) (19.9%, 0.9%) Ex. 8 3.1
(2S,4R) ascorbic acid 63.3% 62.6% -1.1% 25 mg (50 ppm) (13.2%,
1.4%) (36.3%, 1.6%) Ex. 9 3.1 (2S,4S) ascorbic acid 75.3% 72.3%
-4.1% (2R,4R) 25 mg (50 ppm) (13.2%, 1.4%) (20.9%, 0.9%) Com. Ex. 1
3.1 (2R,4R) none 42.4% 77.3% 45.1% (12.5%, 0.6%) (21.6%, 0.9%) Com.
Ex. 2 3.1 (2S,4S) none 41.0% 77.9% 47.4% (12.2%, 0.7%) (21.1%,
1.1%) Com. Ex. 3 3.1 (2S,4R) none 7.9% 63.6% 87.6% (5.5%, 0.0%)
(39.5%, 1.7%) Com. Ex. 4 3.1 (2S,4S) none 46.6% 80.8% 42.3% (2R,4R)
(14.1%, 0.8%) (22.2%, 0.1%) Com. Ex. 5 3.1 (2R,4R) trehalose 42.1%
77.0% 45.3% 25 mg (12.3%, 0.8%) (21.3%, 1.0%) Ref. Ex. 1 3.1 L-Trp
none 94.0% 100.0% 6.0%
[0105] TABLE-US-00004 TABLE 4 Light source D65 lamp illuminance
3000 lux exposure time 165 hr photo- light light decomposition pH
monatin additive exposure shielding rate Com. Ex. 6 2.8 (2R,4R)
none 36.8% 77.4% 52.5% (13.0%, 0.9%) (25.5%, 13%) Com. Ex. 7 3.5
(2R,4R) none 63.4% 87.6% 27.6% (11.5%, 0.5%) (14.7%, 0.5%) Com. Ex.
8 4.0 (2R,4R) none 79.8% 94.8% 15.9% (6.5%, 0.0%) (7.1%, 0.0%) Com.
Ex. 9 4.5 (2R,4R) none 89.8% 100.0% 10.2% (2.6%, 0.0%) (2.7%, 0.0%)
Com. Ex. 10 5.5 (2R,4R) none 96.9% 101.8% 4.8% (0.0%, 0.0%) (0.0%,
0.0%) Com. Ex. 11 6.5 (2R,4R) none 97.3% 101.7% 4.3% (0.0%, 0.0%)
(0.0%, 0.0%)
[0106] TABLE-US-00005 TABLE 5 Light source fluorescence lamp with
UV absorption film 73 hr photo- light decomposition pH monatin
additive exposure light shielding rate Ex. 10 3.1 (2R,4R) ascorbic
acid 76.7% 74.2% -3.4% 25 mg (21.1%, 0.6%) (20.0%, 0.5%) (50 ppm)
Ex. 11 3.1 (2R,4R) K.sub.2SO.sub.3 74.4% 76.0% 2.1% 25 mg (20.0%,
0.5%) (20.0%, 0.5%) (50 ppm) Ex. 12 3.1 (2R,4R) none 75.2% 76.8%
2.1% (20.9%, 1.4%) (20.9%, 0.5%)
[0107] TABLE-US-00006 TABLE 6 Light source: sunlight, 14 hr photo-
light light decomposition pH monatin additive exposure shielding
rate Ex. 13 3.1 (2R,4R) ascorbic acid 77.3% 74.2% -4.2% 25 mg
(22.2%, 0.6%) (20.1%, 0.5%) (50 ppm) Com. Ex. 12 3.1 (2R,4R)
K.sub.2SO.sub.3 2.2% 76.0% 97.2% 25 mg (0.7%, 0.0%) (20.0%, 0.5%)
(50 ppm) Com. Ex. 13 3.1 (2R,4R) none 41.9% 76.8% 45.4% (13.3%,
0.9%) (20.9%, 0.5%)
[0108] TABLE-US-00007 TABLE 7 Light source: near ultraviolet light
lamp; 73 hr photo- light light decomposition pH monatin additive
exposure shielding rate Ex. 14 3.1 (2R,4R) ascorbic 76.2% 74.2%
-2.7% acid (21.0%, 0.6%) (20.1%, 0.5%) 25 mg (50 ppm) Com. Ex. 14
3.1 (2R,4R) K.sub.2SO.sub.3 3.9% 76.0% 94.8% 25 mg (0.8%, 0.0%)
(20.0%, 0.5%) (50 ppm) Com. Ex. 15 3.1 (2R,4R) none 16.3% 76.8%
78.8% (6.3%, 1.4%) (20.9%, 0.5%)
[0109] TABLE-US-00008 TABLE 8 Light source: D65 lamp illuminance
3000 lux, exposure time 165 hr photodecomposition rate Trp monatin
monatin (50 ppm) + pH (50 ppm) (50 ppm) ascorbic acid (50 ppm) 2.8
7.3% 52.5% not measured 3.1 6.0% 45.1% -2% 3.5 6.2% 27.6% not
measured 4 5.5% 15.9% not measured 4.5 5.4% 10.2% -1% 5.5 12.5%
4.8% not measured 6.5 55.1% 4.3% 0%
[0110] Obviously, numerous modifications and variations of the
present invention are possible in light of the above teachings. It
is therefore to be understood that, within the scope of the
appended claims, the invention may be practiced otherwise than as
specifically described herein.
[0111] All patents and other references mentioned above are
incorporated in full herein by this reference, the same as if set
forth at length.
* * * * *