[Technical Field]
[0001] The present disclosure relates to a sweetener composition including glucosylated rebaudioside A, glucosylated stevioside, and glucosylated rebaudioside C, a composition for preparing a sweetener, a method of preparing a sweetener using a steviol glycoside by-product, and a method of improving sweetness quality.
[Background Art]
[0002] In response to concerns about diseases caused by excessive sugar intake of modern people and recommendations by the World Health Organization (WHO) on lowering sugar consumption, policies to reduce sugar intake are actively being discussed in developed countries, and sugar substitutes have been continuously developed in the market. In this regard, stevia, which has recently received considerable attention as a sugar substitute, is a natural high-intensity sweetener having 200 to 300 times the sweetness of sugar, and has been reported to have zero calories and cause no side effects in the human body, and thus the potential thereof as a sugar substitute has been approved.
[0003] Among commercially available stevia sweeteners, high-purity rebaudioside A with a purity of 95% to 97% is known to have the highest commercial value. However, a crystallization process is required in order to prepare high-purity stevia, a high-intensity sweetener, and components having low sweetness quality are contained in large quantities in a liquid-phase by-product generated while a solid is separated. Components of the by-product are typically stevioside, rebaudioside C, and the like. Since the commercial value of the by-product is low due to strong bitter taste, the by-product is dried to be used as inexpensive fertilizer or animal feed, or it is sold at a low value.
[0004] In order to solve such problems, attempts have been made to artificially increase the content of rebaudioside A and to produce rebaudioside A in a large quantity by breeding a plant including a high rebaudioside A content (U.S. Patent Application Publication No. 2009-0214753). However, since these methods cannot provide sufficient efficiency and have limitations in terms of costs and quality, there is a need for a method of reducing production of the by-product by increasing the production efficiency of stevia sweeteners, or a method of increasing the commercial value of the by-product.
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[Disclosure]
[Technical Problem]
[0005] The present inventors have found that a glucosylated stevia composition having a certain composition ratio may be prepared by applying a culture broth of Lactobacillus mali, as a crude enzyme liquid, to a by-product generated in a steviol production process and have confirmed that the glucosylated stevia composition having the certain composition ratio may be used as a high-value-added product with improved sweetness quality.
[Technical Solution]
[0006] An object of the present disclosure is to provide a sweetener composition including glucosylated rebaudioside A, glucosylated stevioside, and glucosylated rebaudioside C.
[0007] Another object of the present disclosure is to provide a composition for preparing a sweetener including a steviol glycoside by-product.
[0008] Another object of the present disclosure is to provide a method of preparing a sweetener composition including glucosylated rebaudioside A, glucosylated stevioside, and glucosylated rebaudioside C.
[0009] Another object of the present disclosure is to provide a method of improving sweetness quality.
[0010] Another object of the present disclosure is to provide a use for preparing a sweetener composition.
[0011] Another object of the present disclosure is to provide a use for improving sweetness quality.
[Advantageous Effects]
[0012] In the case of using the method of improving sweetness quality and the method of preparing a sweetener, a sweetener composition having a certain composition ratio may be prepared using a by-product generated in a steviol production process. In addition, since the sweetener composition having the certain composition ratio and the composition for preparing the sweetener have excellent sweetness quality, they may be used for manufacturing high-value-added products such as foods and feeds in various industrial fields.
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[0013] [Brief Description of Drawings]
[0014] FIGS. 1 to 3 show HPLC results of compositions including glucosylated steviol glycosides prepared from steviol glycoside by-products.
[Best Mode]
[0015] Hereinafter, the present disclosure will be described in detail. Meanwhile, in the present disclosure, each of the explanations and exemplary embodiments disclosed herein can be applied to other explanations and exemplary embodiments. Also, in the present disclosure, all combinations of various factors disclosed herein belong to the scope of the present disclosure. Furthermore, the scope of the present disclosure should not be limited by the specific disclosure provided hereinbelow.
[0016] An aspect of the present disclosure provides a sweetener composition including glucosylated rebaudioside A, glucosylated stevioside, and glucosylated rebaudioside C. Specifically, the sweetener composition includes 5 to 30 parts by weight of glucosylated rebaudioside A, 5 to 30 parts by weight of glucosylated stevioside, and 5 to 20 parts by weight of glucosylated rebaudioside C based on 100 parts by weight of the sweetener composition.
[0017] The sweetener composition may have improved sweetness quality compared to commercially available high-purity rebaudioside A, specifically, the sweetener composition may have improved sweetness quality compared to rebaudioside A having a purity of 95% or more, and more specifically, improvement of the sweetness quality may include improved sweetness, reduced off-flavor, and/or reduced off-odor, without being limited thereto.
[0018] The sweetener composition may have a certain composition ratio via a one-pot reaction by treating a typical steviol glycoside by-product with transglucosylase including an amino acid sequence of SEQ ID NO: 1, a microorganism expressing the same, or a culture of the microorganism or Lactobacillus mali, without being limited thereto.
[0019] The sweetener composition may further include a cofactor capable of improving stability of the sweetener composition, without being limited thereto. Examples of the cofactor may include a metal ion, a metal salt, an excipient, and a preservative, without being limited thereto.
[0020] The glucosylated rebaudioside A, glucosylated stevioside, and glucosylated rebaudioside C are glucosylated steviol glycosides in which glucose is bound to rebaudioside
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A, stevioside, and rebaudioside C, which are steviol glycosides, respectively.
[0021] In the present disclosure, “steviol glycoside” is a natural sweetener and may be represented by Formula 1 below.
[0022] [Formula 1]
[0023]
[0024] In Formula 1, at R1, hydrogen (H) may be bound or 1 to 3 glucose molecules may be bound via a β bond, and at R2, one molecule of glucose, xylose, and rhamnose may be bound via a β bond and 0 to 2 glucose molecules may be bound thereto via a β bound, without being limited thereto.
[0025] The steviol glycoside may include at least one selected from the group consisting of stevioside, rubusoside, dulcoside A, rebaudioside A, rebaudioside C, rebaudioside D, rebaudioside E, rebaudioside F, and rebaudioside M, without being limited thereto.
[0026] These steviol glycosides may be modified into glucosylated steviol glycosides in the presence of a crude enzyme liquid having a transglucosylating activity, the transglucosylase, transglucosylase including an amino acid sequence of SEQ ID NO: 1, a microorganism expressing the same, or a culture of the microorganism or Lactobacillus mali, and a glucose donor, without being limited thereto.
[0027] In the present disclosure, the “glucose donor” refers to any of oligomers or polymers of glucose and cyclic forms thereof participating in reactions to transfer one or more glucose molecules to a steviol glycoside in the presence of transglucosylase, and specifically may be sugar, but is not limited thereto.
[0028] In the present disclosure, since “rebaudioside A”, “stevioside”, and “rebaudioside C”
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are steviol glycosides, they may have structural characteristics of Formula 1 above. Specifically, the rebaudioside A may be represented by Formula 2 below, the stevioside may be represented by Formula 3 below, and the rebaudioside C may be represented by Formula 4 or 5 below.
[0029] [Formula 2]
[0030]
[0031] [Formula 3]
[0032]
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[0033] [Formula 4]
[0034]
[0035] [Formula 5]
[0036]
[0037] In the present disclosure, the “glucosylated steviol glycoside” may be a product in which glucose is added to a steviol glycoside.
[0038] The glucosylated steviol glycoside may be in a form in which 1 to 4 glucose molecules are added to a 19-OH site (-OH of C19 in the case where R1 of Formula 1 is H) via an α-bond,
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more specifically, in a form in which 1 to 4 glucose molecules are added to glucose conjugated to the 19-OH site of the steviol glycoside via an α-(1,6) bond, without being limited thereto.
[0039] The glucosylated rebaudioside A may be, for example, in a form in which glucose is added to a C6 position of glucose conjugated to the C19 site via an α-(1,6) bond and may be 13-[(2-O-β-D-glucopyranosyl-3-O-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy]ent-kaur-16-en-19-oic acid 6-O-α-D-glucopyranose-β-D-glucopyranosyl ester as shown in Formula 6, but is not limited thereto.
[0040] The glucosylated stevioside may be, for example, in a form in which glucose is added to a C6 position of glucose conjugated to the C19 site via an α-(1,6) bond, more specifically, 13-[(2-O-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy]ent-kaur-16-en-19-oic acid 6-O-α-D-glucopyranosyl-β-D-glucopyranosyl ester as shown in Formula 7, but is not limited thereto.
[0041] [Formula 6]
[0042]
[0043] [Formula 7]
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[0044]
[0045] The glucosylated steviol glycoside may be prepared using sugar and the steviol glycoside as substrates by adding glucose to a steviol glycoside by transglucosylase, transglucosylase including an amino acid sequence of SEQ ID NO: 1, a microorganism expressing the same, or a culture of the microorganism or Lactobacillus mali, without being limited thereto.
[0046] The “glucosylated rebaudioside A” may be a product in which glucose is added to rebaudioside A, the “glucosylated stevioside” may be a product in which glucose is added to stevioside, and the “glucosylated rebaudioside C” may be a product in which glucose is added to rebaudioside C.
[0047] The glucosylated rebaudioside A, glucosylated stevioside, and glucosylated rebaudioside C may be products in which glucose is added through glucose conjugated to the 19-OH site via an α-(1,6) bond, without being limited thereto.
[0048] The glucosylated rebaudioside A, glucosylated stevioside, and glucosylated rebaudioside C may include 1 to 4 glucose molecules, without being limited thereto.

We Claim
1. A sweetener composition comprising glucosylated rebaudioside A, glucosylated stevioside, and glucosylated rebaudioside C,
wherein the sweetener composition comprises 5 to 30 parts by weight of glucosylated rebaudioside A, 5 to 30 parts by weight of glucosylated stevioside, and 5 to 20 parts by weight of glucosylated rebaudioside C based on 100 parts by weight of the sweetener composition.
2. The sweetener composition of claim 1, wherein the glucosylated rebaudioside A, glucosylated stevioside, and glucosylated rebaudioside C are in a form in which glucose is bound and added thereto through glucose conjugated to a 19-OH site via an α-(1,6) bond.
3. The sweetener composition of claim 2, wherein the glucosylated rebaudioside A, glucosylated stevioside, and glucosylated rebaudioside C comprise 1 to 4 glucose molecules.
4. The sweetener composition of claim 1, wherein the sweetener composition has improved sweetness quality compared to rebaudioside A having a purity of 95% or more.
5. The sweetener composition of claim 3, further comprising at least one selected from the group consisting of glucosylated rebaudioside F in an amount of 0.5 to 3 parts by weight, glucosylated dulcoside A in an amount of 0.5 to 3 parts by weight, and glucosylated rubusoside in an amount of 0.5 to 5 parts by weight based on 100 parts by weight of the sweetener composition.
6. A composition for preparing a sweetener, the composition comprising a steviol glycoside by-product and transglucosylase including an amino acid sequence of SEQ ID NO: 1, a microorganism expressing the same, or a culture of the microorganism or Lactobacillus mali,
wherein the sweetener comprises 5 to 30 parts by weight of glucosylated rebaudioside A, 5 to 30 parts by weight of glucosylated stevioside, and 5 to 20 parts by weight of glucosylated rebaudioside C based on 100 parts by weight of the sweetener.
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7. A method of preparing a sweetener composition, the method comprising:
reacting a steviol glycoside by-product with transglucosylase including an amino acid sequence of SEQ ID NO: 1, a microorganism expressing the same, or a culture of the microorganism or Lactobacillus mali, in the presence of a glucose donor,
wherein the sweetener composition comprises 5 to 30 parts by weight of glucosylated rebaudioside A, 5 to 30 parts by weight of glucosylated stevioside, and 5 to 20 parts by weight of glucosylated rebaudioside C based on 100 parts by weight of the sweetener composition.
8. The method of claim 7, wherein the steviol glycoside by-product is a liquid-phase by-product in which crystalized rebaudioside A is isolated.
9. The method of claim 7, wherein the steviol glycoside by-product comprises rebaudioside A in amount greater than 0 parts by weight and equal to or less than 30 parts by weight based on 100 parts by weight of the by-product.
10. The method of claim 7, wherein the steviol glycoside by-product is a by-product generated in a stevia production process and comprises rebaudioside A, stevioside, and rebaudioside C in a weight ratio of 1.5 to 2.5 : 1.5 to 6 : 1.
11. The method of claim 7, wherein the glucose donor is sugar.
12. A method of improving sweetness quality, the method comprising:
reacting a steviol glycoside by-product with transglucosylase including an amino acid sequence of SEQ ID NO: 1, a microorganism expressing the same, or a culture of the microorganism or Lactobacillus mali, in the presence of a glucose donor,
wherein a sweetener having improved sweetness quality comprises glucosylated rebaudioside A, glucosylated stevioside, and glucosylated rebaudioside C,
wherein the sweetener comprises 5 to 30 parts by weight of glucosylated rebaudioside A, 5 to 30 parts by weight of glucosylated stevioside, and 5 to 20 parts by weight of glucosylated rebaudioside C based on 100 parts by weight of the sweetener.
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13. A use of steviol glycoside by-product and transglucosylase including an amino acid sequence of SEQ ID NO: 1, a microorganism expressing the same, or a culture of the microorganism or Lactobacillus mali for preparing a sweetener composition.
wherein the sweetener composition comprises 5 to 30 parts by weight of glucosylated rebaudioside A, 5 to 30 parts by weight of glucosylated stevioside, and 5 to 20 parts by weight of glucosylated rebaudioside C based on 100 parts by weight of the sweetener composition.
14. A use of steviol glycoside by-product and transglucosylase including an amino acid sequence of SEQ ID NO: 1, a microorganism expressing the same, or a culture of the microorganism or Lactobacillus mali for improving sweetness quality.
wherein the sweetener comprises 5 to 30 parts by weight of glucosylated rebaudioside A, 5 to 30 parts by weight of glucosylated stevioside, and 5 to 20 parts by weight of glucosylated rebaudioside C based on 100 parts by weight of the sweetener.