JP7700403B2 - citrus flavored drinks - Google Patents

Description

The present invention relates to a citrus-flavored beverage, and more specifically to a citrus-flavored beverage with improved taste.

Citral, contained in citrus fruits such as lemons, is an aromatic component that gives a fresh citrus-like scent, but it is known to undergo a deterioration reaction when exposed to acid or heat, resulting in the production of undesirable almond-like or chemical-like odors (off-flavors). In the case of citrus-flavored beverages such as lemon-flavored beverages, the deterioration of citral in particular has a large impact on their commercial value, since the beverages are stored or served in a heated state in acidic conditions and off-flavors are likely to affect the flavor.

Various methods of improving the off-flavor caused by the deterioration of citral have been investigated. For example, Patent Document 1 describes an invention that suppresses the off-flavor of lemon juice drinks by adjusting the content of limonene and nonanal to a certain level. Patent Document 2 describes an invention that suppresses off-flavors using tea polyphenols, Patent Document 3 describes an invention that suppresses off-flavors using hinokitiol, and Patent Document 4 describes an invention that suppresses off-flavors using extracts of specific plants and their purified products.

The additive ingredients used in the above patent documents all have their own unique flavors, and depending on the amount added, they may adversely affect the flavor of the citrus-flavored beverage. In addition to suppressing off-flavors, there is a demand for citrus-flavored beverages that have the full flavor and citrus feel that is expected of citrus-flavored beverages.

Regarding the improvement of food flavor by branched glucans, Patent Document 5 describes the effect of panose, a branched oligosaccharide, in reducing unpleasant flavors, and Patent Document 6 describes the effect of a sugar composition containing panose in maintaining the flavor of heated packaged food and beverages. However, neither document describes the results of an investigation into the deterioration of flavor in citrus-flavored beverages.

JP 2019-97509 A JP 2003-96486 A JP 2020-99245 A JP 2020-94182 A JP 2005-137362 A JP 2013-198435 A

The present invention aims to provide a novel citrus-flavored beverage with improved taste. The present invention also aims to provide a novel taste enhancer for citrus-flavored beverages and a novel flavor deterioration inhibitor for citrus-flavored beverages.

According to the present invention, the following inventions are provided.
[1] A citrus-flavored beverage comprising a branched glucan or a reduced product thereof.
[2] The citrus-flavored beverage according to the above-mentioned [1], wherein the branched glucan is a glucan having a branched structure of α-1,6-glucoside bonds at the non-reducing end.
[3] The citrus-flavored beverage according to [1] or [2] above, wherein the branched glucan has a structure consisting of a linear glucan constituted by α-1,4-glucosidic bonds and a branched structure introduced at least to the non-reducing end of the linear glucan, and is a branched glucan having a degree of polymerization of 4 to 6.
[4] A citrus-flavored beverage according to any one of [1] to [3] above, comprising a branched glucan having a degree of polymerization of 4 to 6, the branched glucan having a structure consisting of a linear glucan formed by α-1,4-glucosidic bonds and at least a branched structure introduced into the non-reducing end of the linear glucan, or a reduced product thereof, in an amount of 20% by mass or more, and a sugar composition having an iodine coloring value (absorbance at a wavelength of 660 nm in an iodine coloring 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 container-packed beverage for heating.
[7] The citrus-flavored beverage described in [4] above, containing the sugar composition in an amount of 0.01 to 5.0% by mass based on the total beverage.
[8] A taste enhancer for citrus-flavored beverages, comprising a branched glucan or a reduced product thereof as an active ingredient.
[9] A flavor deterioration suppressant for citrus-flavored beverages, comprising a branched glucan or a reduced product thereof as an active ingredient.
[10] The flavor deterioration inhibitor described in [9] above, wherein the flavor deterioration is flavor deterioration of a beverage during warm storage.

According to the present invention, it is possible to provide a citrus-flavored beverage in which flavor deterioration is suppressed. The present invention also makes it possible to provide a citrus-flavored beverage in which the citrus flavor and richness of taste are improved.

Description of the Invention

<<Branched Glucan>>
In the present invention, "branched glucan" refers to a glucan having a branched structure in which at least the non-reducing terminal glucose residues of the glucan chain are bonded by a glucosidic bond other than an α-1,4-glucosidic bond. In the present invention, a branched glucan can be a glucan having a structure consisting of a linear glucan constituted by an α-1,4-glucosidic bond and at least a branched structure introduced into the non-reducing terminal of the linear glucan. In the present invention, "linear glucan" refers to a linear glucan constituted by glucose molecules bonded by a single glucosidic bond.

In the present invention, examples of glucosidic bonds other than α-1,4-glucosidic bonds include α-1,6-glucosidic bonds, α-1,3-glucosidic bonds, and α-1,2-glucosidic bonds. In the present invention, the branched glucan is preferably a glucan having a branched structure of α-1,6-glucosidic bonds at the non-reducing end, that is, a glucan having a branched structure in which the non-reducing end glucose residues of the glucan chain are bonded by α-1,6-glucosidic bonds.

In the branched glucan of the present invention, the number of glucose residues constituting the glucan residues of the branched structure is not particularly limited as long as it satisfies the degree of polymerization of the branched glucan of the present invention, but it can be preferably 1 to several, more preferably 1 to 3, 1 to 2, or 1.

In the present invention, the term "reducing end" refers to a sugar residue that exhibits reducing properties, and the term "non-reducing end" refers to a sugar residue that does not exhibit reducing properties, i.e., a terminal sugar residue other than the "reducing end."

In the present invention, the "degree of polymerization" (DP) refers to the number of glucose residues that make up a glucan, and includes not only the number of glucose residues that make up a linear glucan, but also the number of glucose residues that make up a branched structure. The degree of polymerization of branched sugars can be measured by high performance liquid chromatography (HPLC).

In the present invention, the term "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 reduced products of sugars are well known to those skilled in the art, and examples of reduction methods that can be used include a method using a hydride reducing agent, a method using a metal in a protic solvent, an electrolytic reduction method, and a catalytic hydrogenation reaction method. In the present invention, when preparing a small amount of reduced product, a method using a hydride reducing agent is simple and convenient because it does not require special equipment, while when carrying out the process on an industrial scale, a method using a catalytic hydrogenation reaction is preferred because it is economical and produces fewer by-products. In this specification, the terms "branched glucan" and "sugar composition" include reduced products of branched glucans.

The branched glucan used in the present invention includes, for example, isomaltooligosaccharides (isomaltose, isomaltotriose, panose, isomaltotetraose, etc.), which are oligosaccharides in which glucose is bound to the non-reducing end via an α-1,6-glucoside bond. Isomaltooligosaccharides can be obtained according to well-known methods, for example, by treating starch hydrolysate with a glycosyltransferase.

As shown in the examples, the branched glucan used in the present invention is preferably a "branched glucan having a degree of polymerization of 4 to 6, which has a structure consisting of a linear glucan composed of α-1,4-glucosidic bonds and at least a branched structure introduced 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 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, which has a structure consisting of a linear glucan composed of α-1,4-glucosidic bonds and at least a branched structure introduced at the non-reducing end of the linear glucan, or a reduced product thereof, and having an iodine coloring value (absorbance at a wavelength of 660 nm in an iodine coloring 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 glucan is a branched structure in which the branched structure introduced at the non-reducing end is bonded by α-1,6-glucosidic bonds.

In the present invention, "iodine color value" refers to the absorbance at a wavelength of 660 nm after an iodine color test, i.e., adding 100 μL of 0.05 M iodine aqueous solution to 1 mL of a 5.0% by mass (solid content concentration) sugar composition aqueous solution and stirring thoroughly. The iodine color value is a value that serves as an index of masking, and the higher this value, the higher the masking effect, and the lower this value, the lower the masking effect, and the more the taste improvement effect of the present invention is exerted.

The branched glucan of the present invention can be used in the form of a pure specific carbohydrate, or in the form of a sugar mixture (sugar composition). There are also no particular limitations on the form in which it is used, and it can be used in powder form or in syrup form.

The content of the branched glucan having a degree of polymerization of 4 to 6 in the sugar composition of the present invention (the branched glucan having a specific degree of polymerization of the present invention) can have a lower limit (not less than or exceeding) of 20 mass%, 22 mass%, 25 mass%, 27 mass%, or 34 mass%, and an upper limit (not more than or below) of 100 mass%, 99 mass%, 90 mass%, 80 mass%, 70 mass%, or 67 mass%. These lower and upper limits can be combined in any combination, and the range of the content can be, for example, 20 to 100 mass%, 25 to 80 mass%, or 34 to 67 mass%.

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

The sugar composition of the sugar composition of the present invention is not particularly limited as long as it produces the desired effect, but for example, the lower limit of the content of carbohydrates with degrees of polymerization 1 to 3 (not less than or exceeding) can be 0 mass%, 0.5 mass%, 1 mass%, 5 mass%, or 10 mass%, and the upper limit (not more than or below) can be 60 mass%, 58 mass%, 55 mass%, 50 mass%, or 45 mass%. These lower and upper limits can be combined in any combination, and the range of the content of carbohydrates with degrees of polymerization 1 to 3 can be, for example, 0 to 60 mass%, 0.5 to 58 mass%, 1 to 55 mass%, 5 to 50 mass%, or 10 to 45 mass%. The sugar composition of the sugar composition of the present invention can also have a content of sugars with 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), a content of sugars with 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 a content of sugars with 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 a lower limit (above or above) of the content of sugars with 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 an upper limit (below or below) of 50% by mass, 48% by mass, 45% by mass, 40% by mass, or 35% by mass. These lower and upper limits can be arbitrarily combined, and the range of the content of carbohydrates 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 a lower limit (greater than or equal to) of the content of carbohydrates having a degree of polymerization of 4 to 6 of 20% by mass, 25% by mass, 30% by mass, or 35% by mass, and an upper limit (less than or equal to) of 100% by mass, 90% by mass, 80% by mass, 70% by mass, or 60% by mass. These lower and upper limits can be arbitrarily combined, and the range of the content of carbohydrates 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 addition, when referring to the sugar components in the sugar composition, taste enhancer, and flavor deterioration inhibitor in this invention, all of them refer to the content per solid content (solid content equivalent).

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 exhibits color by being enclosed within the helical structure of the linear glucan chain. Although not bound by the following theory, it is believed that sugar compositions with an iodine color value of more than 0.05 have a high encapsulation ability of the glucan chain due to a high content of high molecular weight components, etc., and encapsulate and mask flavor components in foods and beverages, resulting in poor taste improvement effects. In other words, in the present invention, the iodine color value can be used as an index of the masking effect.

The method for producing the branched glucan with a specific degree of polymerization and the sugar composition of the present invention containing the same is not particularly limited, but it can be produced cheaply and efficiently by acting a glycosyltransferase on a starch hydrolysate. Specifically, the glycosyltransferase is added to a 5-50% solution of the starch hydrolysate, and the reaction is carried out at a suitable pH and temperature depending on the enzyme used. The reaction can usually be carried out at a pH range of 4-9, with a suitable reaction pH range of 5-7. The reaction can usually be carried out at a temperature range up to around 70°C, with a suitable reaction temperature range of 40-60°C. The amount of enzyme used and the reaction time are closely related, and the reaction time can be adjusted appropriately depending on the progress of the desired enzyme reaction, and the reaction is usually carried out for about 15-96 hours. After confirming the production of the target composition, purification such as filtration, desalting, and decolorization may be carried out as necessary, and the product may be concentrated or powdered depending on the product form.

The enzyme having a glycosyltransferase activity can be selected from, for example, α-glucosidase, 6-α-glucosyltransferase, dextrin dextranase, and cyclic maltosylmaltose-forming enzyme. The α-glucosidase that can be used can be, for example, that derived from Aspergillus niger or Acremonium sp.

When α-glucosidase is used as the enzyme having a glycosyltransferase activity, the amount of α-glucosidase added for the enzyme reaction can be 0.01 to 30 units per 1 g of substrate (solid) from the viewpoints of reaction efficiency and production costs. 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 method for measuring α-glucosidase activity described below.

The branched glucan of the present invention having a specific degree of polymerization and the sugar composition of the present invention containing the same can also be produced more efficiently by combining amylase with an enzyme having a sugar transfer activity and allowing it to act on starch hydrolysates. Examples of the amylase include cyclodextrin-forming enzymes and α-amylase.

Here, the cyclodextrin-forming enzyme can be selected from those derived from Paenibacillus sp. , Bacillus coagulans , Bacillus stearothermophilus , and Bacillus macerans , and the α-amylase can be selected from commercially available α-amylases, Kleistase L-1 and Kleistase T-5 (both manufactured by Amano Enzyme).

When a cyclodextrin-forming enzyme is used as the amylase, the amount of the cyclodextrin-forming enzyme used in the enzyme reaction can be 0.1 to 10 units per 1 g of substrate (solid) from the viewpoints of reaction efficiency and production costs. 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 method for measuring the activity of the cyclodextrin-forming enzyme described below.

When α-amylase is used as the amylase, the amount of α-amylase added for the enzyme reaction can be 0.0005 to 0.1% by mass per substrate (solid) from the standpoint of reactivity and production costs.

The branched glucan with a specific degree of polymerization of the present invention and the sugar composition of the present invention containing the same can be produced by further combining a debranching enzyme in addition to amylase and an enzyme having a sugar transfer activity and allowing them to act on a starch hydrolysate. It is preferable to allow the debranching enzyme to act on the starch hydrolysate together with amylase and an enzyme having a sugar transfer activity.

Here, the debranching enzyme can be selected from the group consisting of isoamylase, pullulanase, and a combination thereof. In a more preferred embodiment, the debranching enzyme can be selected from the group consisting of isoamylase derived from Myroides odoratus , isoamylase derived from Pseudomonas amyloderamosa , and pullulanase derived from Klebsiella pneumoniae , and a combination thereof.

When isoamylase is used as the debranching enzyme, the amount of isoamylase added in the enzyme reaction can be 10 to 1000 units per gram of substrate (solid) from the viewpoints of reaction efficiency and production cost. The amount of pullulanase added in the enzyme reaction of the production method can be 0.001 to 0.1 mass% per gram of 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 method for measuring isoamylase activity described below.

When the branched glucan of a specific degree of polymerization of the present invention is obtained in the form of a sugar composition, the content of branched glucan having 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 necessary. In addition, the iodine color value of the sugar composition can be made 0.05 or less by removing the fraction of the product with a high degree of polymerization. Examples of the removal method include fractionation or a method of decomposing with an enzyme. There is no particular restriction on the method of fractionation, and examples of the method include membrane fractionation, chromatographic fractionation, and precipitation fractionation. There is also no particular restriction on the enzyme used for decomposing with an enzyme, and examples of the enzyme include α-amylase.

<<Citrus-flavored drinks>>
In the present invention, the citrus flavored beverage means a beverage having a citrus flavor, specifically a beverage that gives the flavor of citrus when drunk. The flavor of citrus specifically means the flavor of citrus fruits. Examples of citrus fruits include lemon, orange, grapefruit, citron, Meyers lemon, sweetie, Unshu mandarin, summer mandarin, ponkan, daidai, navel orange, hassaku, kumquat, yuzu, lime, kabosu, sudachi, and shikuwasa. In the present invention, the citrus flavored beverage preferably contains a component that evokes the flavor of citrus fruits (e.g., citral). Preferred examples of the citrus flavored beverage in the present invention include lemon flavored beverage, orange flavored beverage, and yuzu flavored beverage.

The citrus-flavored beverage of the present invention may be any beverage having a citrus flavor, and representative examples include beverages containing citrus juice (e.g., lemon juice, orange juice, yuzu juice), but may also contain fruit peel (e.g., lemon peel, orange peel, yuzu peel), essential oil (e.g., lemon essential oil, orange essential oil, yuzu essential oil), and even citrus flavor flavor (e.g., lemon flavor flavor, orange flavor flavor, yuzu flavor flavor). In other words, the citrus-flavored beverage of the present invention also includes beverages that do not contain fruit juice or citrus-derived ingredients. In addition, the citrus-flavored beverage of the present invention is not particularly limited in type as long as it has a citrus flavor, and may be a soft drink such as a fruit juice beverage or a carbonated beverage, an alcoholic beverage such as a chuhai or a cocktail, or a non-alcoholic beverage such as a non-alcoholic chuhai or a non-alcoholic cocktail.

In one embodiment of the citrus-flavored beverage of the present invention, it can be a packaged beverage sold in a container such as a plastic bottle, a can, a bottle, or a paper carton. In other embodiments, the citrus-flavored beverage of the present invention can be a beverage sold heated in a hot vending machine or the like, or a beverage sold refrigerated in a refrigerated showcase or the like, but considering the effect of the present invention of suppressing off-flavors that arise when beverages are heated, it is preferable that the beverage be a beverage for heating, and more preferably a packaged beverage for heating.

There is no particular limit to the content of branched glucan in the citrus-flavored beverage of the present invention, and for example, the lower limit of the content of branched glucan (not less than or exceeding) can be 0.01% by mass, 0.05% by mass, 0.1% by mass, or 0.5% by mass, and the upper limit (not more than or below) can be 5.0% by mass, 3.0% by mass, or 2.0% by mass. These lower and upper limits can be combined in any combination, and the range of the content of branched glucan in the citrus-flavored beverage of the present invention can be, for example, 0.01 to 5.0% by mass, 0.05 to 3.0% by mass, 0.1 to 3.0% by mass, or 0.1 to 2.0% by mass. The lower limit of the content of the branched glucan of a specific degree of polymerization of the present invention in the citrus-flavored beverage of the present invention (not less than or exceeding) can be 0.001% by mass, 0.005% by mass, 0.01% by mass, or 0.02% by mass, and the upper limit of the content of the branched glucan of a specific degree of polymerization of the present invention (not more than or below) can be 1.0% by mass, 0.7% by mass, 0.5% by mass, or 0.3% by mass. These lower and upper limits can be arbitrarily combined, and the range of the content of the branched glucan of a specific degree of polymerization of the citrus-flavored beverage of the present invention can be, for example, 0.001 to 1.0% by mass, 0.005 to 0.7% by mass, 0.01 to 0.5% by mass, or 0.02 to 0.3% by mass. When the branched glucan of the present invention is contained in liquid sugar (aqueous solution), the above content means a value converted into solid content.

The lower limit of the content of the sugar composition of the present invention in the citrus-flavored beverage of the present invention (not less than or exceeding) can be 0.01 mass%, 0.05 mass%, 0.1 mass%, or 0.5 mass%, and the upper limit of the content of the sugar composition of the present invention (not more than or below) can be 5.0 mass%, 3.0 mass%, or 2.0 mass%. These lower and upper limits can be arbitrarily combined, and 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 to 5.0 mass%, 0.05 to 3.0 mass%, 0.1 to 3.0 mass%, or 0.1 to 2.0 mass%. When the branched glucan of the present invention or the sugar composition of the present invention is contained in a liquid sugar (aqueous solution), the above content means a value converted into solid content.

The citrus-flavored beverage of the present invention is not limited in its ingredients, except that it contains ingredients that impart a citrus flavor, such as citrus juice, citrus essential oil, and citrus flavoring, and branched glucan. For example, it may contain sweeteners such as sugar, glucose, starch syrup, isomerized sugar, honey, and high-intensity sweeteners, fruit juices other than citrus fruits, flavorings, acidulants, vitamin C, salt, colorings, etc., as appropriate.

In the present invention, as shown in the examples below, the taste of a citrus-flavored beverage can be improved by blending a branched glucan into the beverage. In the present invention, "improving taste" means suppressing the deterioration of flavor associated with the deterioration of citral, and enhancing the citrus feeling and depth of flavor. The deterioration of flavor associated with the deterioration of citral, i.e., the occurrence of off-flavors, is said to be caused by p-cresol and p-methylacetophenone, which are produced when citral changes due to the effects of acid or heat. In the present invention, "citrus feeling" refers to the sourness and flavor derived from the citrus, and "depth of flavor" refers to the complexity of the taste and the intensity of the taste, which is a combination of sweetness, sourness, umami, etc.

Regarding the effects of the present invention, Patent Document 5 describes that a branched glucan containing panose as a main component has the effect of reducing unpleasant taste and odor in carrot juice. Patent Document 6 describes that a branched glucan containing panose as a main component has the effect of maintaining the flavor of tomatoes after retort processing. When confirmed by the present inventors, the effects of the branched glucan containing panose as a main component in Patent Documents 5 and 6 were equal to or less than the effect of maltooligosaccharide 2 used as a comparative control in the Examples described below. Since the branched glucan of the present invention has a high taste-improving effect in citrus-flavored beverages compared to comparative controls such as maltooligosaccharide 2, the effects of the present invention can be said to be advantageous compared to Patent Documents 5 and 6.

According to another aspect of the present invention, there is provided a taste enhancer for citrus-flavored beverages, the active ingredient of which is a branched glucan or a reduced product thereof. According to the present invention, there is also provided a flavor deterioration inhibitor for citrus-flavored beverages, the active ingredient of which is a branched glucan or a reduced product thereof. The flavor deterioration inhibitor of the present invention can be used to inhibit flavor deterioration of beverages during warm storage. In other words, the flavor deterioration inhibitor of the present invention can be used to inhibit flavor deterioration of beverages for warm storage. The taste enhancer and flavor deterioration inhibitor of the present invention can be implemented according to the description relating to the citrus-flavored beverage of the present invention.

According to yet another aspect of the present invention, there is provided a method for improving the taste of a citrus-flavored beverage, comprising blending a branched glucan or a reduced product thereof. According to the present invention, there is also provided a method for suppressing flavor deterioration of a citrus-flavored beverage, comprising blending a branched glucan or a reduced product thereof. The method for suppressing flavor deterioration of the present invention can be used to suppress flavor deterioration of a beverage during warm storage. In other words, the method for suppressing flavor deterioration of the present invention can be used to suppress flavor deterioration of a beverage for warm storage. The method for improving taste and the method for suppressing flavor deterioration of the present invention can be carried out according to the description relating to the citrus-flavored beverage of the present invention.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

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

Quantitative determination of branched glucan content with polymerization degrees of 4 to 6 The branched glucan content was confirmed by the following method. 50 μL of 10 mg/mL β-amylase #1500 (Nagase Chemtex) dissolved in 1 M sodium acetate buffer (pH 5.5) was added to 1 mL of sugar solution adjusted to 5% by mass, and allowed to act at 55° C. for 1 hour, followed by boiling to inactivate. This was desalted with Amberlite MB4 (Organo), filtered through a 0.45 μm filter, and subjected to high performance liquid chromatography (HPLC). The saccharides with polymerization degrees of 4 to 6 remaining after the enzyme treatment were taken as branched glucans with polymerization degrees of 4 to 6.

The enzyme reaction for measuring the activity of β-cyclodextrin-forming enzyme was carried out by adding 0.1 mL of an enzyme solution appropriately diluted with water to 0.9 mL of 1% soluble starch (Nacalai Tesque) dissolved in 50 mM potassium phosphate buffer (pH 6.0) and keeping it at 40°C for 10 minutes. The reaction was stopped by adding 2.5 mL of 40 mM aqueous sodium hydroxide solution. The amount of β-cyclodextrin produced 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 solution, and the absorbance at 550 nm was measured after stirring. The amount of β-cyclodextrin produced was calculated based on a standard curve of β-cyclodextrin prepared in the range of 0 to 0.1 mg/mL.

The enzyme reaction for measuring the activity of α-glucosidase was carried out by adding 20 μL of an enzyme solution appropriately diluted with 10 mM sodium acetate buffer (pH 4.2) containing 0.05% Triton X-100 to 80 μL of 0.25% maltose dissolved in 50 mM sodium acetate buffer (pH 4.2) and holding at 37 ° C for 10 minutes. After 10 minutes of reaction, 50 μL of the reaction solution was extracted and 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 Industries, Ltd.), the mixture was kept at room temperature for 1 hour to develop color, and the absorbance at 490 nm was measured. The amount of glucose produced was calculated based on a standard curve of glucose created in the range of 0 to 0.01%.

The enzyme reaction for measuring the activity of isoamylase was carried out by adding 350 μL of 5 mg/mL waxy cornstarch (Nihon Shokuhin Kako) to 100 μL of 50 mM sodium acetate buffer (pH 6.0) containing 20 mM calcium chloride, and holding the mixture at 45 ° C for 5 minutes. 100 μL of an enzyme solution appropriately diluted with the same buffer was added and held at 45 ° C for 15 minutes. The reaction was stopped by adding 500 μL of reaction quenching iodine solution (a mixture of 2 mL of a solution consisting of 6.35 mg/mL iodine and 83 mg/mL potassium iodide and 8 mL of 0.1 N hydrochloric acid). The reaction stopping solution was held at room temperature for 15 minutes, and 10 mL of pure water was added to the mixture, and the absorbance at 610 nm was measured.

Iodine coloration test 100 μL of 0.05 M iodine aqueous solution was added to 1 mL of a sugar composition aqueous solution with a solid content concentration of 5.0%, and after thorough stirring, the solution was placed in a 1 cm quartz cell and the absorbance at 660 nm was measured using a spectrophotometer (U-2900, Hitachi High-Tech Science). The absorbance obtained by measuring ultrapure water as the test solution in the same manner was subtracted from the absorbance obtained, and the iodine coloration value of the sugar composition was determined.

Production Example 1: Production of Sugar Composition 1 A 30% (w/w) DE6.5 corn starch liquefaction liquid was adjusted to a temperature of 53°C and a pH of 6.0, and 0.3 units of cyclodextrin-forming enzyme from Paenibacillus sp., 200 units of isoamylase from Myloides odoratus, 0.2 mg of pullulanase "Amano" 3 (Amano Enzyme) per 1 g of solids, 3.75 units of transglucosidase L "Amano" (Amano Enzyme) per 1 g of solids, and 0.06 mg of clystase L-1 (Amano Enzyme) per 1 g of solids were added thereto and saccharified for 50 hours. The mixture was heated to 80°C, and 0.15 mg of clystase L-1 was added per 1 g of solids and allowed to act for 1 hour. The mixture was then purified and concentrated according to a conventional method. The content of branched glucan of DP4-6 in the obtained sugar composition (sugar composition 1) was measured and found to be 33.7%. The cyclodextrin-forming enzyme of Paenibacillus sp. was prepared according to the description in Agr. Biol. Chem., 40(9), 1785-1791(1976), and the isoamylase of Myloides odoratus was prepared according to the description in JP-A-5-227959.

Example 1: Study of the taste improving effect of branched glucan Each raw material was mixed in the amount (parts by mass) shown in Table 1, dispensed into cans, sterilized at 75° C. for 10 minutes, and rapidly cooled after sterilization to prepare a lemon-flavored beverage. The amounts of each syrup-like branched glucan and maltooligosaccharide mixed in terms of solid content are shown in Table 1.

The sugar composition of each branched glucan used, the branched glucan content of DP4-6, and the iodine color value are shown in Table 2. Note that branched glucan 1 is an isomaltooligosaccharide with a lower molecular weight than branched glucan 2, and because its sugar composition clearly indicates that the branched glucan content and iodine color value of DP4-6 are comparable to those of branched glucan 2, some data acquisition was omitted.

The resulting lemon-flavored beverage was heated to 60° C., and a sensory evaluation was carried out by five experienced panelists on the herbal odor, richness of flavor, and lemoniness. The evaluation items and evaluation methods are defined below.
Herbal odor: A medicinal flavor caused by the lemon-derived aroma components due to acid and heat deterioration. The comparison group was given a score of 0, and the evaluation was made on a 7-point scale from -3 to 3. The stronger the herbal odor, the higher the evaluation score.
Flavor intensity: The complexity of flavor and the intensity of flavor, combining sweetness, sourness, umami, etc. The comparison group was scored 0 points, and the evaluation was done on a 7-point scale from -3 points to 3 points. The stronger the flavor, the higher the evaluation score.
Lemon flavor: sourness and flavor derived from lemon. The comparison group was scored as 0, and the score was 7-point scale from -3 to 3. The stronger the lemon flavor, the higher the score.

Sensory evaluation was performed immediately after the beverages were produced and after storage at 60°C for 14 days.

The evaluation results (average evaluation scores) are shown in Table 3.

The lemon-flavored beverages containing branched glucan (Test Areas 1-1 to 1-5) had an enhanced flavor and lemon feel both immediately after production and after 14 days compared to the control area without the addition of branched glucan, and the flavor was improved. In addition, the lemon-flavored beverages containing branched glucan had a reduced herbal odor (off-flavor) after 14 days of storage at 60°C compared to the control area, and the flavor was improved. Both effects were particularly noticeable in Test Area 1-5, which contained branched glucan 5. On the other hand, the lemon-flavored beverages containing sugar other than branched glucan (Test Areas 1-6 to 1-9) did not have sufficient effects of enhancing the flavor and lemon feel, and the herbal odor after 14 days of storage was stronger than that of the control area.

Example 2: Investigation of the amount of branched glucan Lemon-flavored beverages were prepared in the same manner as in Example 1, except that the amount of branched glucan was set to the amount (parts by mass) shown in Table 4. In addition, sensory evaluation was performed immediately after production of the beverage and after storage at 60° C. for 14 days, using the same criteria as in Example 1. The results are shown in Table 5.

The lemon-flavored beverages containing branched glucan 5 (Test Areas 2-1 to 2-4) all had a stronger flavor and a stronger lemon feel than the lemon-flavored beverages in the control area, and the flavor was improved. The lemon-flavored beverages containing branched glucan 5 had a reduced herbal odor (off-flavor) after 14 days of storage at 60°C compared to the control area, and the flavor was improved.

Claims (9)

A citrus-flavored beverage comprising a sugar composition containing 20% by mass or more of a branched glucan or a reduced product thereof, the branched glucan having a degree of polymerization of 4 to 6 and a structure consisting of a linear glucan constituted by α-1,4-glucoside bonds and at least a branched structure introduced into a non-reducing end of the linear glucan, the branched structure being one to two glucose residues bonded to the non-reducing end of the linear glucan . The citrus-flavored beverage according to claim 1, wherein the branched glucan is a glucan having a branched structure of α-1,6-glucoside bonds at the non-reducing end. The citrus-flavored beverage according to claim 1 or 2 , wherein the sugar composition has an iodine color value (absorbance at a wavelength of 660 nm in an iodine color test) of 0.05 or less. The citrus flavored beverage according to any one of claims 1 to 3 , wherein the citrus flavor is a lemon flavor. The citrus flavored beverage according to any one of claims 1 to 4 , which is a container-packed beverage for heating. 2. The citrus flavored beverage according to claim 1 , comprising the sugar composition in an amount of 0.01 to 5.0% by mass based on the total mass of the beverage. A taste improver for citrus-flavored beverages , comprising a branched glucan or a reduced product thereof as an active ingredient, the branched glucan being a branched glucan having a degree of polymerization of 4 to 6, the branched glucan having a structure consisting of a linear glucan constituted by α-1,4-glucoside bonds and at least a branched structure introduced into a non-reducing end of the linear glucan, the branched structure being one to two glucose residues bonded to the non-reducing end of the linear glucan . A flavor deterioration inhibitor for citrus-flavored beverages, comprising a branched glucan or a reduced product thereof as an active ingredient , the branched glucan being a branched glucan having a degree of polymerization of 4 to 6, the branched glucan having a structure consisting of a linear glucan constituted by α-1,4-glucoside bonds and at least a branched structure introduced into the non-reducing end of the linear glucan, and the branched structure being one to two glucose residues bonded to the non-reducing end of the linear glucan . The flavor deterioration inhibitor according to claim 8 , wherein the flavor deterioration is flavor deterioration of a beverage during warm storage.