Citrus-flavored beverage

Abstract

To provide a novel citrus-flavored beverage that has improved taste.SOLUTION: According to the present invention, there is provided a citrus-flavored beverage comprising branched glucan or a reduced product thereof. The branched glucan preferably is a branched glucan with a degree of polymerization of 4 to 6 having a structure consisting of a linear glucan composed by α-1,4-glucoside bond and a branch structure introduced at least at the non-reduction terminal of the linear glucan. The citrus-flavor preferably is a lemon flavor, and the beverage preferably is a packaged beverage for warming.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a citrus - flavored beverage, and more particularly to a citrus - flavored beverage with improved taste.

Background Art

[0002] Citral contained in citrus fruits such as lemon is an aromatic component that gives a citrus - like fresh aroma. However, it undergoes a degradation reaction due to acids or heat, and it is known to generate unpleasant almond - like or chemical - like odors (off - flavors). In citrus - flavored beverages such as lemon - flavored beverages, due to the acidic conditions, the fact that off - flavors easily affect the flavor, and the fact that they may be stored or provided in a heated state, the degradation of citral particularly has a great impact on their commercial value.

[0003] Regarding the off - flavors caused by the degradation of citral, various improvement methods have been studied. For example, Patent Document 1 describes an invention for suppressing the off - flavor of lemon juice beverages by adjusting the contents of limonene and nonanal to certain levels. Patent Document 2 describes an invention for suppressing off - flavors with tea polyphenols, Patent Document 3 describes an invention for suppressing off - flavors with hinokitiol, and Patent Document 4 describes an invention for suppressing off - flavors with extracts and purified products of specific plants.

[0004] Since the additive components used in the above - mentioned patent documents all have unique flavors, they may have an adverse effect on the flavor of citrus - flavored beverages depending on the blending amount. In citrus - flavored beverages, in addition to suppressing off - flavors, a beverage in which the richness of taste and the citrus feeling as a citrus - flavored beverage can be sufficiently felt has been desired.

[0005] Regarding the improvement of the flavor of food by branched glucan, Patent Document 5 describes the effect of reducing unpleasant taste by panose, which is a branched oligosaccharide, and Patent Document 6 describes the effect of maintaining the flavor of container-packed heat-treated foods and beverages by a sugar composition containing panose. However, in neither document is there any description of the results of examining the flavor deterioration of citrus-flavored beverages.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Summary of the Invention

Problems to be Solved by the Invention

[0007] An object of the present invention is to provide a novel citrus-flavored beverage with improved taste. Another object of the present invention is to provide a novel taste enhancer for citrus-flavored beverages and a novel flavor deterioration inhibitor for citrus-flavored beverages.

Means for Solving the Problems

[0008] According to the present invention, the following inventions are provided. [1] A citrus-flavored beverage comprising branched glucan or a reduced product thereof. [2] The citrus-flavored beverage according to [1] above, wherein the branched glucan is a glucan having a branched structure of an α-1,6-glucoside bond at the non-reducing end. [3] The citrus - flavored beverage according to [1] or [2] above, wherein the branched glucan has a structure composed of a linear glucan formed by α - 1,4 - glucoside bonds and a branched structure introduced at least at the non - reducing end of the linear glucan, and is a branched glucan with a degree of polymerization of 4 to 6. [4] The citrus - flavored beverage according to any one of [1] to [3] above, which contains 20% by mass or more of a branched glucan with a degree of polymerization of 4 to 6 or its reduced product having a structure composed of a linear glucan formed by α - 1,4 - glucoside bonds and a branched structure introduced at least at the non - reducing end of the linear glucan, and has an iodine color value (absorbance at a wavelength of 660 nm in the iodine color test) of 0.05 or less. [5] The citrus - flavored beverage according to any one of [1] to [4] above, wherein the citrus flavor is a lemon flavor. [6] The citrus - flavored beverage according to any one of [1] to [5] above, which is a heat - resistant container - filled beverage. [7] The citrus - flavored beverage according to [4] above, which contains the sugar composition in an amount of 0.01 to 5.0% by mass based on the whole beverage. [8] A flavor - enhancing agent for citrus - flavored beverages, which contains a branched glucan or its reduced product as an active ingredient. [9] A flavor - deterioration inhibitor for citrus - flavored beverages, which contains a branched glucan or its reduced product as an active ingredient.

[10] The flavor - deterioration inhibitor according to [9] above, wherein the flavor deterioration is the flavor deterioration of the beverage during heat preservation.

[0009] According to the present invention, a citrus - flavored beverage with suppressed flavor deterioration can be provided. According to the present invention, a citrus - flavored beverage with improved citrus feeling and taste thickness can also be provided. Detailed description of the invention

[0010] <<Branched glucan>> In the present invention, the "branched glucan" means a glucan having a branched structure in which at least the non-reducing terminal glucose residue of the glucan chain is bonded by a glucoside bond other than the α-1,4-glucoside bond. In the present invention, the branched glucan can be a glucan having a structure composed of a linear glucan formed by α-1,4-glucoside bonds and a branched structure introduced at least at the non-reducing terminal of the linear glucan. In the present invention, the "linear glucan" means a linear glucan formed by bonding glucose molecules by a single glucoside bond.

[0011] In the present invention, examples of the glucoside bond other than the α-1,4-glucoside bond include α-1,6-glucoside bond, α-1,3-glucoside bond, and α-1,2-glucoside bond. In the present invention, the branched glucan is preferably a glucan having a branched structure of an α-1,6-glucoside bond at the non-reducing terminal, that is, a glucan having a branched structure in which the non-reducing terminal glucose residue of the glucan chain is bonded by an α-1,6-glucoside bond.

[0012] In the branched glucan of the present invention, the number of glucose residues constituting the glucan residue of the branched structure is not particularly limited as long as the degree of polymerization of the branched glucan of the present invention is satisfied, but is preferably 1 to several, more preferably 1 to 3, 1 to 2, or 1.

[0013] In the present invention, the "reducing terminal" means a sugar residue showing reducibility, and the "non-reducing terminal" means a sugar residue not showing reducibility, that is, a terminal sugar residue other than the "reducing terminal".

[0014] In the present invention, the "degree of polymerization" (DP) refers to the number of glucose residues constituting the glucan, and includes not only the number of glucose residues constituting the linear glucan but also the number of glucose residues constituting the branched structure. The degree of polymerization of branched saccharides can be measured by high performance liquid chromatography (HPLC).

[0015] In the present invention, the "reduced product" refers to a product in which the aldehyde group of the glucosyl group at the reducing end of a sugar has been reduced to a hydroxyl group. Methods for obtaining the reduced product of a sugar are well known to those skilled in the art. Examples of reducible methods that can be used include methods using hydride reducing agents, methods using metals in protic solvents, electrolytic reduction methods, catalytic hydrogenation reaction methods, and the like. In the present invention, when preparing a small amount of the reduced product, the method using a hydride reducing agent is convenient and does not require a special device, while when carried out industrially on a large scale, the method using a catalytic hydrogenation reaction is preferred in terms of excellent economy and few by-products. In addition, in this specification, when referring to "branched glucan" or "sugar composition", it shall include the reduced product of the branched glucan.

[0016] Examples of the branched glucan used in the present invention include isomaltooligosaccharides (isomaltose, isomaltotriose, panose, isomaltotetraose, etc.) which are oligosaccharides in which glucose is bonded to the non-reducing end by an α-1,6-glucoside bond. Isomaltooligosaccharides can be obtained according to well-known techniques, and can be produced, for example, by allowing a glycosyltransferase to act on a starch hydrolyzate.

[0017] The branched glucan used in the present invention is also, from the viewpoint of its effects as shown in the examples, "a branched glucan having a degree of polymerization of 4 to 6, which consists of a linear glucan composed of α-1,4-glucoside bonds and a branched structure introduced at least at the non-reducing end of the linear glucan" (hereinafter sometimes referred to as "the branched glucan with a specific degree of polymerization of the present invention"). The branched glucan used in the present invention is also preferably used in "a sugar composition containing 20% by mass or more of a branched glucan having a degree of polymerization of 4 to 6 or its reduced product, which consists of a linear glucan composed of α-1,4-glucoside bonds and a branched structure introduced at least at the non-reducing end of the linear glucan, and having an iodine color value (absorbance at a wavelength of 660 nm in the iodine color test) of 0.05 or less" (hereinafter sometimes referred to as "the sugar composition of the present invention"). It is particularly preferable that the branched structure introduced at the non-reducing end of the above-mentioned branched glucan is a branched structure bonded by an α-1,6-glucoside bond.

[0018] In the present invention, the "iodine color value" refers to the absorbance at a wavelength of 660 nm after adding 100 μL of 0.05 M iodine aqueous solution to 1 mL of an aqueous solution of a sugar composition with a solid content concentration of 5.0% by mass in an iodine color test, that is, an iodine color test, and stirring well. The iodine color value is an index of masking. The larger this value, the higher the masking effect, and the smaller this value, the lower the masking effect and the more the taste improvement effect according to the present invention is exerted.

[0019] The branched glucan of the present invention can be used in the form of a pure product of a specific saccharide, or can also be used in the form of a sugar mixture (sugar composition). Also, there are no particular restrictions on the properties during use, and it can be used in powder form or in syrup form.

[0020] The content of the branched glucan with a degree of polymerization of 4 to 6 (the specific degree of polymerization branched glucan of the present invention) in the sugar composition of the present invention can have a lower limit value (greater than or equal to) of 20% by mass, 22% by mass, 25% by mass, 27% by mass, or 34% by mass, and an upper limit value (less than or equal to) of 100% by mass, 99% by mass, 90% by mass, 80% by mass, 70% by mass, or 67% by mass. These lower limit values and upper limit values can be arbitrarily combined respectively, and the range of the above content can be, for example, 20 to 100% by mass, 25 to 80% by mass, or 34 to 67% by mass.

[0021] The content of the branched glucan with a degree of polymerization of 4 to 6 (the specific degree of polymerization branched glucan of the present invention) in the sugar composition of the present invention can be measured by HPLC analysis as the content of the 4-saccharide to 6-saccharide remaining after treating the sugar composition with β-amylase. Specific examples of the branched glucan in the sugar composition include branched oligosaccharides with a degree of polymerization of 4 to 6, which have a structure composed of a linear glucan formed by α-1,4-glucoside bonds and a branched structure introduced only at the non-reducing end of the linear glucan.

[0022] The sugar composition of the sugar composition of the present invention is not particularly limited as long as it exhibits a predetermined effect. For example, the lower limit value (greater than or equal to) of the content of saccharides having a degree of polymerization of 1 to 3 can be 0% by mass, 0.5% by mass, 1% by mass, 5% by mass or 10% by mass, and the upper limit value (less than or equal to) can be 60% by mass, 58% by mass, 55% by mass, 50% by mass or 45% by mass. These lower limit values and upper limit values can be arbitrarily combined respectively, and the range of the content of saccharides having a degree of polymerization of 1 to 3 can be, for example, 0 to 60% by mass, 0.5 to 58% by mass, 1 to 55% by mass, 5 to 50% by mass or 10 to 45% by mass. The sugar composition of the sugar composition of the present invention can also have the content of saccharides having a degree of polymerization of 1 of 20% by mass or less (preferably 18% by mass or less, more preferably 15% by mass or less), the content of saccharides having a degree of polymerization of 2 of 25% by mass or less (preferably 20% by mass or less, more preferably 18% by mass or less), and the content of saccharides having a degree of polymerization of 3 of 25% by mass or less (preferably 20% by mass or less, more preferably 19% by mass or less). The sugar composition of the sugar composition of the present invention can also have the lower limit value (greater than or equal to) of the content of saccharides having a degree of polymerization of 7 or more of 0% by mass, 0.5% by mass, 1% by mass, 5% by mass or 7% by mass, and the upper limit value (less than or equal to) can be 50% by mass, 48% by mass, 45% by mass, 40% by mass or 35% by mass. These lower limit values and upper limit values can be arbitrarily combined respectively, and the range of the content of saccharides having a degree of polymerization of 7 or more can be, for example, 0 to 50% by mass, 0.5 to 48% by mass, 1 to 45% by mass, 5 to 40% by mass, 5 to 35% by mass or 7 to 35% by mass. The sugar composition of the sugar composition of the present invention can also have the lower limit value (greater than or equal to) of the content of saccharides having a degree of polymerization of 4 to 6 of 20% by mass, 25% by mass, 30% by mass or 35% by mass, and the upper limit value (less than or equal to) can be 100% by mass, 90% by mass, 80% by mass, 70% by mass or 60% by mass. These lower limit values and upper limit values can be arbitrarily combined respectively, and the range of the content of saccharides having a degree of polymerization of 4 to 6 can be, for example, 20 to 100% by mass, 25 to 90% by mass or 30 to 80% by mass.In the present invention, when referring to the sugar components in the sugar composition, the flavor enhancer, and the flavor deterioration inhibitor, it always means the content per solid content (in terms of solid content conversion).

[0023] The iodine color value of the sugar composition of the present invention is preferably 0.04 or less, more preferably 0.03 or less, and particularly preferably 0.02 or less. Iodine shows color when included in the helical structure of the linear glucan chain. Although not bound by the following theory, a sugar composition with an iodine color value exceeding 0.05 has a high inclusion ability for glucan chains due to reasons such as a large amount of polymer components, and includes and masks flavor components in food and beverages, so it is considered inferior in the flavor improvement effect. That is, in the present invention, the iodine color value can be used as an index of the masking effect.

[0024] There is no particular limitation on the production method of the specific degree of polymerization branched glucan of the present invention and the sugar composition of the present invention containing the same, but it can be produced inexpensively and efficiently by allowing a glycosyltransferase to act on a starch hydrolyzate. Specifically, a glycosyltransferase is added to a 5 to 50% solution of the starch hydrolyzate and reacted at a suitable pH and temperature according to the enzyme used. The reaction can usually be carried out in the range of pH 4 to 9, and the suitable reaction pH is in the range of pH 5 to 7. The reaction can usually be carried out in the temperature range up to around 70°C, and the suitable reaction temperature is in the range of 40 to 60°C. The amount of enzyme used and the reaction time are closely related, and the reaction time can be appropriately adjusted according to the progress of the target enzyme reaction, and usually the reaction is carried out for about 15 to 96 hours. After confirming the generation of the target composition, purification such as filtration, desalting, and decolorization may be carried out as necessary, and it may be concentrated or powdered according to the product form.

[0025] Here, the enzyme having a glycosyltransferase action can be selected, for example, from α-glucosidase, 6-α-glucosyltransferase, dextrin dextranase, and cyclic maltosyl maltose-forming enzyme. α-Glucosidase is, for example, Aspergillus niger ( Aspergillus niger ) or Acremonium species ( Acremoniumsp. ) Those derived therefrom can be used.

[0026] When using α-glucosidase as an enzyme having a glycosyltransferase action, the addition amount of α-glucosidase used in the enzyme reaction can be 0.01 to 30 units per 1 g of the substrate (solid) from the viewpoints of reaction efficiency and production cost. Here, 1 unit of α-glucosidase refers to the amount of enzyme required to hydrolyze 1 μmol of maltose per minute under the conditions of the α-glucosidase activity measurement method described later.

[0027] The specific degree of polymerization branched glucan of the present invention and the sugar composition of the present invention containing the same can also be produced more efficiently by allowing an amylase and an enzyme having a glycosyltransferase action to act on a starch degradation product in combination. Examples of the amylase include cyclodextrin-forming enzyme and α-amylase.

[0028] Here, the cyclodextrin-forming enzyme is from Paenibacillus species ( Paenibacillus sp. ), Bacillus coagulans( Bacillus coagulans ), Bacillus stearothermophilus( Bacillus stearothermophilus ), and Bacillus megaterium( Bacillus macerans ) and can be selected from those derived therefrom. Further, the α-amylase can be selected from commercially available α-amylases, Clistase L-1 and Clistase T-5 (both from Amano Enzyme).

[0029] When using a cyclodextrin-forming enzyme as the amylase, the addition amount of the cyclodextrin-forming enzyme used in the enzyme reaction can be 0.1 to 10 units per 1 g of the substrate (solid) from the viewpoints of reaction efficiency and production cost. Here, 1 unit of cyclodextrin-forming enzyme refers to the amount of enzyme required to produce 1 mg of β-cyclodextrin per minute under the conditions of the cyclodextrin-forming enzyme activity measurement method described later.

[0030] When using α-amylase as the amylase, the addition amount of the α-amylase used in the enzyme reaction can be 0.0005 to 0.1% by mass per substrate (solid) from the viewpoints of reactivity and production cost.

[0031] The specific degree of polymerization branched glucan of the present invention and the sugar composition of the present invention containing the same can be further produced by further combining a debranching enzyme in addition to the amylase and the enzyme having a transglycosylation action to act on the starch degradation product. The debranching enzyme is preferably allowed to act on the starch degradation product together with the amylase and the enzyme having a transglycosylation action.

[0032] Here, the debranching enzyme can be selected and used from the group consisting of isoamylase, pullulanase, and combinations thereof. In a more preferred embodiment, isoamylase derived from Myroides odoratus ( Myroides odoratus ), isoamylase derived from Pseudomonas amyloderamosa ( Pseudomonas amyloderamosa ), pullulanase derived from Klebsiella pneumoniae ( Klebsiella pneumoniae ), and combinations thereof can be selected.

[0033] When using isoamylase as the debranching enzyme, the addition amount of the isoamylase used in the enzyme reaction can be 10 to 1000 units per 1 g of substrate (solid) from the viewpoints of reaction efficiency and production cost. The addition amount of pullulanase among the debranching enzymes used in the enzyme reaction of the production method can be 0.001 to 0.1% by mass per substrate (solid) from the viewpoints of reactivity and production cost. Here, 1 unit of isoamylase is the enzyme titer that increases the absorbance at 610 nm by 0.01 under the conditions of the isoamylase activity measurement method described below.

[0034] When obtaining the branched glucan with a specific degree of polymerization of the present invention in the form of a sugar composition, the content of the branched glucan with a degree of polymerization of 4 to 6 in the sugar composition can be made 20% by mass or more by fractionating the necessary fraction of the product as needed. Further, by removing the high-degree-of-polymerization fraction of the product, the iodine color value of the sugar composition can be made 0.05 or less. Examples of the removal method include fractionation or decomposition with an enzyme. There is no particular limitation on the method for performing the above fractionation, and examples thereof include membrane fractionation, chromatographic fractionation, precipitation fractionation, etc. There is also no particular limitation on the enzyme used when decomposing with an enzyme, and examples thereof include α-amylase, etc.

[0035] <<Citrus-flavored beverage>> In the present invention, the citrus-flavored beverage means a beverage having the flavor of citrus fruits, specifically, a beverage that gives the feeling of the flavor of citrus fruits when consumed. Further, the flavor of citrus fruits specifically means the flavor of the fruits of citrus fruits. Examples of citrus fruits include lemon, orange, grapefruit, citron, Meyer lemon, Sweety, Satsuma mandarin, summer mandarin, ponkan, daidai, navel orange, hassaku, kinkan, yuzu, lime, kabosu, sudachi, shikwasa, etc. In the present invention, it is preferable that the citrus-flavored beverage contains a component (for example, citral) that evokes the flavor of citrus fruits. Preferable examples of the citrus-flavored beverage in the present invention include lemon-flavored beverage, orange-flavored beverage, and yuzu-flavored beverage.

[0036] The citrus-flavored beverage of the present invention may be any beverage having the flavor of citrus fruits. Typical examples include beverages containing citrus fruit juices (e.g., lemon juice, orange juice, yuzu juice). In addition to fruit juices, those containing fruit peels (e.g., lemon peel, orange peel, yuzu peel), essential oils (e.g., lemon essential oil, orange essential oil, yuzu essential oil), and furthermore, those having citrus flavoring agents (e.g., lemon flavoring agent, orange flavoring agent, yuzu flavoring agent) are also acceptable. That is, the citrus-flavored beverage of the present invention includes non-fruit juice beverages and beverages that do not contain citrus-derived raw materials. Also, the type of the citrus-flavored beverage of the present invention is not particularly limited as long as it is a beverage having the flavor of citrus fruits. It may be a soft drink such as a fruit juice drink or a carbonated drink, an alcoholic beverage such as a chu-hi or a cocktail, or a non-alcoholic beverage such as a non-alcoholic chu-hi or a non-alcoholic cocktail.

[0037] As one aspect of the citrus-flavored beverage of the present invention, for example, it can be a container-packed beverage sold in containers such as PET bottles, cans, bottles, and paper packs. As another aspect, the citrus-flavored beverage of the present invention may be a beverage sold heated by a hot vendor or the like, or a beverage sold refrigerated in a refrigerated showcase or the like. However, considering the effect of the present invention of suppressing off-flavors caused by heating the beverage, it is preferably a heated beverage, and more preferably a container-packed heated beverage.

[0038] There is no particular limitation on the content of the branched glucan in the citrus - flavored beverage of the present invention. For example, the lower limit value (greater than or equal to) of the content of the branched glucan can be 0.01% by mass, 0.05% by mass, 0.1% by mass or 0.5% by mass, and the upper limit value (less than or equal to) can be 5.0% by mass, 3.0% by mass or 2.0% by mass. These lower limit values and upper limit values can be arbitrarily combined respectively. The range of the content of the branched glucan in the citrus - flavored beverage of the present invention can be, for example, 0.01 - 5.0% by mass, 0.05 - 3.0% by mass, 0.1 - 3.0% by mass or 0.1 - 2.0% by mass. Also, the lower limit value (greater than or equal to) of the content of the branched glucan with a specific degree of polymerization in the citrus - flavored beverage of the present invention can be 0.001% by mass, 0.005% by mass, 0.01% by mass or 0.02% by mass, and the upper limit value (less than or equal to) can be 1.0% by mass, 0.7% by mass, 0.5% by mass or 0.3% by mass. These lower limit values and upper limit values can be arbitrarily combined respectively. The range of the content of the branched glucan with a specific degree of polymerization in the citrus - flavored beverage of the present invention can be, for example, 0.001 - 1.0% by mass, 0.005 - 0.7% by mass, 0.01 - 0.5% by mass, 0.02 - 0.3% by mass. When the branched glucan of the present invention is contained in liquid sugar (aqueous solution), the above - mentioned content means the value in terms of solid content.

[0039] The lower limit value (greater than or equal to) of the content of the sugar composition of the present invention in the citrus - flavored beverage of the present invention can be 0.01% by mass, 0.05% by mass, 0.1% by mass or 0.5% by mass, and the upper limit value (less than or equal to) can be 5.0% by mass, 3.0% by mass or 2.0% by mass. These lower limit values and upper limit values can be arbitrarily combined respectively. The range of the content of the sugar composition of the present invention in the citrus - flavored beverage of the present invention can be, for example, 0.01 - 5.0% by mass, 0.05 - 3.0% by mass, 0.1 - 3.0% by mass or 0.1 - 2.0% by mass. When the branched glucan or the sugar composition of the present invention is contained in liquid sugar (aqueous solution), the above - mentioned content means the value in terms of solid content.

[0040] The citrus-flavored beverage of the present invention has no restrictions on its raw materials except that it contains raw materials that impart a citrus flavor such as citrus fruit juice, citrus essential oil, and citrus flavoring, and branched glucan. For example, sweeteners such as sugar, glucose, maltose, isomerized sugar, honey, and high-intensity sweeteners, fruit juices other than citrus fruits, flavorings, acidulants, vitamin C, salt, colorants, etc. can be appropriately blended.

[0041] In the present invention, as in the examples described later, by blending branched glucan into the citrus-flavored beverage, its taste can be improved. In the present invention, "taste improvement" means suppressing flavor deterioration associated with the deterioration of citral, and enhancing the citrus flavor and the richness of the taste. The flavor deterioration associated with the deterioration of citral, that is, the generation of off-flavors, is said to be caused by p-cresol and p-methylacetophenone generated by the change of citral under the influence of acid and heat. Further, in the present invention, "citrus flavor" means the sour taste and flavor derived from citrus fruits, and "richness of taste" means the complexity of the taste and the intensity of the richness of the taste, which is a combination of sweetness, sourness, umami, etc.

[0042] Regarding the effects of the present invention, Patent Document 5 describes that branched glucan mainly composed of panose has an effect of reducing unpleasant taste and odor in carrot juice. Further, Patent Document 6 describes that branched glucan mainly composed of panose has an effect of maintaining flavor in tomatoes after retort processing. As confirmed by the present inventors, the effects shown by the branched glucan mainly composed of panose in Patent Documents 5 and 6 were equivalent to or lower than the effects of maltooligosaccharide 2 used as a comparative control in the examples described later. Since the branched glucan of the present invention has a high taste improvement effect on the comparative controls including maltooligosaccharide 2 in the citrus-flavored beverage, it can be said that the effects of the present invention are advantageous effects compared with Patent Documents 5 and 6.

[0043] According to another aspect of the present invention, there is provided a flavor enhancer for citrus - flavored beverages, which contains a branched glucan or a reduced product thereof as an active ingredient. According to the present invention, there is also provided a flavor deterioration inhibitor for citrus - flavored beverages, which contains a branched glucan or a reduced product thereof as an active ingredient. The flavor deterioration inhibitor of the present invention can be used to inhibit the flavor deterioration of beverages during heat preservation. That is, the flavor deterioration inhibitor of the present invention can be used to inhibit the flavor deterioration of beverages for heat preservation. The flavor enhancer and the flavor deterioration inhibitor of the present invention can be implemented according to the description of the citrus - flavored beverage of the present invention.

[0044] According to still another aspect of the present invention, there is provided a method for improving the flavor of citrus - flavored beverages, which comprises blending a branched glucan or a reduced product thereof. According to the present invention, there is also provided a method for inhibiting the flavor deterioration of citrus - flavored beverages, which comprises blending a branched glucan or a reduced product thereof. The method for inhibiting flavor deterioration of the present invention can be used to inhibit the flavor deterioration of beverages during heat preservation. That is, the method for inhibiting flavor deterioration of the present invention can be used to inhibit the flavor deterioration of beverages for heat preservation. The method for improving flavor and the method for inhibiting flavor deterioration of the present invention can be implemented according to the description of the citrus - flavored beverage of the present invention.

Examples

[0045] The present invention will be described more specifically based on the following examples, but the present invention is not limited to these examples.

[0046] Saccharide composition analysis Sugar composition analysis was performed using high - performance liquid chromatography (HPLC). The analysis column used was MCI GEL CK04S (Mitsubishi Chemical), and ultrapure water was used as the eluent. The analysis was carried out at a flow rate of 0.4 mL / min and a column temperature of 70 °C. A differential refractive index detector (RID - 10A, Shimadzu Corporation) was used for detection, and the analysis time was 35 minutes. The content of each degree - of - polymerization component was determined from the peak area of the obtained chromatogram.

[0047] Quantification of the content of branched glucan with a polymerization degree of 4 to 6 The content of branched glucan was confirmed by the following method. 50 μL of 10 mg / mL β-amylase #1500 (Nacalai Tesque) dissolved in 1 M sodium acetate buffer (pH 5.5) was added to 1 mL of a sugar solution adjusted to 5 mass%, and the mixture was allowed to react at 55°C for 1 hour and then inactivated by boiling. After desalting this with Amberlite MB4 (Organo), the filtrate through a 0.45 μm filter was subjected to high performance liquid chromatography (HPLC). The saccharides with a degree of polymerization of 4 to 6 remaining after the enzyme treatment were regarded as branched glucans with a degree of polymerization of 4 to 6.

[0048] Measurement of the activity of β-cyclodextrin-forming enzyme For the enzyme reaction, 0.1 mL of an enzyme solution appropriately diluted with water was added to 0.9 mL of 1% soluble starch (Nacalai Tesque) dissolved in 50 mM potassium phosphate buffer (pH 6.0), and the mixture was held at 40°C for 10 minutes. To this, 2.5 mL of a 40 mM aqueous sodium hydroxide solution was added to stop the reaction. The generated β-cyclodextrin was measured by the phenolphthalein method. Specifically, 0.3 mL of a solution consisting of 0.1 mg / mL phenolphthalein and 2.5 mM sodium carbonate was added to the above solution, and after stirring, the absorbance at 550 nm was measured. The amount of β-cyclodextrin generated was determined based on the standard curve of β-cyclodextrin prepared in the range of 0 to 0.1 mg / mL.

[0049] Measurement of the activity of α-glucosidase For the enzyme reaction, 20 μL of an enzyme solution appropriately diluted with 10 mM sodium acetate buffer (pH 4.2) containing 0.05% Triton X-100 was added to 80 μL of 0.25% maltose dissolved in 50 mM sodium acetate buffer (pH 4.2), and the mixture was held at 37°C for 10 minutes. At 10 minutes of the reaction, 50 μL of the reaction solution was withdrawn, mixed with 100 μL of 2 M Tris-HCl buffer (pH 7.0) to stop the reaction. After adding 40 μL of Glucose CII-Test Wako (FUJIFILM Wako Pure Chemical Corporation) thereto, the mixture was held at room temperature for 1 hour to develop color, and the absorbance at 490 nm was measured. The amount of glucose generated was calculated based on the standard curve of glucose prepared in the range of 0 to 0.01%.

[0050] Measurement of the activity of isoamylase For the enzymatic reaction, 350 μL of 5 mg / mL waxy corn starch (Nihon Shokuhin Kako) was added to 100 μL of 50 mM sodium acetate buffer (pH 6.0) containing 20 mM calcium chloride, and the mixture was kept at 45°C for 5 minutes. Then, 100 μL of an enzyme solution appropriately diluted with the same buffer was added, and the mixture was kept at 45°C for 15 minutes. To this, 500 μL of a reaction-terminating iodine solution (a solution prepared by mixing 2 mL of a solution consisting of 6.35 mg / mL iodine and 83 mg / mL potassium iodide with 8 mL of 0.1 N hydrochloric acid) was added to stop the reaction. The reaction-terminated solution was kept at room temperature for 15 minutes, and 10 mL of pure water was added thereto, and the absorbance at 610 nm was measured.

[0051] Iodine color development test 100 μL of 0.05 M aqueous iodine solution was added to 1 mL of an aqueous solution of a sugar composition with a solid content concentration of 5.0%, and after thorough stirring, the mixture was placed in a 1-cm quartz cell, and the absorbance at 660 nm was measured with a spectrophotometer (U-2900, Hitachi High-Technologies). From the obtained absorbance, the value obtained by subtracting the absorbance measured in the same manner using ultrapure water as the test solution was defined as the iodine color value of the sugar composition.

[0052] Production Example 1: Production of saccharide composition 1 The 30% (w / w) DE6.5 corn starch liquefied liquid was adjusted to a temperature of 53 °C and a pH of 6.0, and to this was added cyclodextrin-forming enzyme of Paenibacillus species at 0.3 units per 1 g of solid content, isoamylase of Myroides odoratus at 200 units per 1 g of solid content, pullulanase “Amano” 3 (Amano Enzyme) at 0.2 mg per 1 g of solid content, transglucosidase L “Amano” (Amano Enzyme) at 3.75 units per 1 g of solid content, and Crisylase L-1 (Amano Enzyme) at 0.06 mg per 1 g of solid content, followed by saccharification for 50 hours. This was heated to 80 °C, and Crisylase L-1 was added at 0.15 mg per 1 g of solid content and allowed to act for 1 hour. Subsequently, purification and concentration were carried out according to a conventional method. When the content of branched glucan with DP4 - 6 in the obtained sugar composition (sugar composition 1) was measured, it was 33.7%. The cyclodextrin-forming enzyme of Paenibacillus species was prepared according to the description in Agr. Biol. Chem., 40(9), 1785 - 1791 (1976), and the isoamylase of Myroides odoratus was prepared according to JP-A-5-227959.

[0053] Example 1: Examination of the taste improvement effect of branched glucan Each raw material was blended in the amounts (parts by mass) shown in Table 1, dispensed into cans, sterilized at 75 °C for 10 minutes, and then rapidly cooled to prepare a lemon-flavored beverage. The blending amounts of each branched glucan and maltooligosaccharide in syrup form are shown in Table 1 in terms of solid content conversion.

[0054] The sugar composition, the content of branched glucan with DP4 - 6, and the iodine color value of each branched glucan used are shown in Table 2. Since branched glucan 1 is a lower molecular weight isomaltooligosaccharide than branched glucan 2, and it is obvious that the content of branched glucan with DP4 - 6 and the iodine color value are comparable to those of branched glucan 2 from its sugar composition, partial data acquisition was omitted.

[0055]

Table 1

[0056]

Table 2

[0057] The obtained lemon - flavored beverage was heated to 60°C, and a sensory evaluation by 5 trained panelists was conducted regarding the herbal smell, taste richness, and lemon flavor. Each evaluation item and evaluation method are defined as follows. Herbal smell: The chemical - like flavor generated by the aroma components derived from lemon due to acid and heat degradation. Using the comparative group as 0 points, it was evaluated on a 7 - point scale from - 3 to 3 points. The stronger the herbal smell, the higher the evaluation score. Taste richness: The complexity of the taste and the intensity of the taste concentration, which is a combination of sweetness, sourness, umami, etc. Using the comparative group as 0 points, it was evaluated on a 7 - point scale from - 3 to 3 points. The stronger the taste richness, the higher the evaluation score. Lemon flavor: The sourness and flavor derived from lemon. Using the comparative group as 0 points, it was evaluated on a 7 - point scale from - 3 to 3 points. The stronger the lemon flavor, the higher the evaluation score.

[0058] The sensory evaluation was conducted immediately after the production of the beverage and after storing it at 60°C for 14 days, respectively.

[0059] The evaluation results (average value of the evaluation scores) are shown in Table 3.

Table 3

[0060] The lemon - flavored beverages formulated with branched glucan (Test groups 1 - 1 to 1 - 5) had enhanced taste richness and lemon flavor compared to the non - added comparative group both immediately after production and after 14 days, and the taste was improved. Also, the lemon - flavored beverages formulated with branched glucan had a reduced herbal smell (off - flavor) after storage at 60°C for 14 days compared to the comparative group, and the taste was improved. All these effects were particularly prominent in Test group 1 - 5 formulated with 5% branched glucan. On the other hand, the lemon - flavored beverages formulated with sugars other than branched glucan (Test groups 1 - 6 to 1 - 9) had insufficient enhancing effects on taste richness and lemon flavor, and the herbal smell after 14 - day storage was stronger than that of the comparative group.

[0061] Example 2: Examination of the blending amount of branched glucan A lemon - flavored beverage was prepared in the same manner as in Example 1, except that the blending amount of branched glucan was set to the amount (parts by mass) shown in Table 4. Also, in the same criteria as in Example 1, sensory evaluations were conducted immediately after the production of the beverage and after storage at 60°C for 14 days, respectively. The results are shown in Table 5.

[0062]

Table 4

[0063]

Table 5

[0064] For the lemon - flavored beverages (Test groups 2 - 1 to 2 - 4) containing branched glucan 5, the thickness of the taste and the lemon flavor were enhanced compared to the lemon - flavored beverages in the control group, and the taste was improved. For the lemon - flavored beverages containing branched glucan 5, the herbal smell (off - flavor) after storage at 60°C for 14 days was reduced compared to the control group, and the taste was improved.

Claims

1. A citrus - flavored beverage comprising a sugar composition containing 20% by mass or more of a branched glucan or a reduced product thereof, wherein the branched glucan has a structure composed of a linear glucan formed by α - 1,4 - glucoside bonds and at least a branched structure introduced at the non - reducing end of the linear glucan, and the branched structure is 1 to 2 glucose residues bonded to the non - reducing end of the linear glucan, and is a branched glucan having a degree of polymerization of 4 to 6.

2. The citrus - flavored beverage according to claim 1, wherein the branched glucan is a glucan having a branched structure of α - 1,6 - glucoside bond at the non - reducing end.

3. The citrus - flavored beverage according to claim 1 or 2, wherein the iodine color - developing value (absorbance at a wavelength of 660 nm in the iodine color - developing test) of the sugar composition is 0.05 or less.

4. The citrus - flavored beverage according to any one of claims 1 to 3, wherein the citrus flavor is a lemon flavor.

5. The citrus - flavored beverage according to any one of claims 1 to 4, which is a beverage in a heat - resistant container.

6. The citrus - flavored beverage according to claim 1, which contains the sugar composition in an amount of 0.01 to 5.0% by mass based on the whole beverage.

7. A flavor - enhancing agent for citrus - flavored beverages, comprising a branched glucan or a reduced product thereof as an active ingredient, wherein the branched glucan has a structure composed of a linear glucan formed by α - 1,4 - glucoside bonds and at least a branched structure introduced at the non - reducing end of the linear glucan, and the branched structure is 1 to 2 glucose residues bonded to the non - reducing end of the linear glucan, and is a branched glucan having a degree of polymerization of 4 to 6.

8. A flavor - deterioration inhibitor for citrus - flavored beverages, comprising a branched glucan or a reduced product thereof as an active ingredient, wherein the branched glucan has a structure composed of a linear glucan formed by α - 1,4 - glucoside bonds and at least a branched structure introduced at the non - reducing end of the linear glucan, and the branched structure is 1 to 2 glucose residues bonded to the non - reducing end of the linear glucan, and is a branched glucan having a degree of polymerization of 4 to 6.

9. The flavor - deterioration inhibitor according to claim 8, wherein the flavor deterioration is the flavor deterioration of the beverage during heat preservation.

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