Citrus beverage and method for producing the same

Abstract

To provide a citrus beverage containing citral that reduces the formation of degradation by-products of citral, while offering excellent sensory properties without stickiness or astringency.SOLUTION: A citrus beverage contains 0.45 mass%-5.4 mass% glucose, 0.1 ppm-10 ppm citral, and glucose oxidase. The glucose oxidase activity per 1 g of glucose is 0.1 U-100 U.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a citrus beverage and a method for producing the same.

Background Art

[0002] Lemon contains a component called citral, which is an aroma component having characteristics that make people perceive it as characteristic of lemon. Citral imparts a lemon-like feel. However, citral is also known as a component that degrades under the influence of temperature, pH and oxygen during the storage period, and generates degraded odors such as chemical odor. In contrast, Japanese Patent Laid-Open No. 2005-171116 discloses that adding theaflavins contained in fermented tea and the like as active ingredients to foods and beverages or the like suppresses the production of p-cresol and p-methylacetophenone, which are degraded odor components derived from citral.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a citrus beverage containing citral that suppresses the production of degraded components of citral and is excellent in sensory evaluation with reduced stickiness and harshness.

Means for Solving the Problems

[0005] The present inventors have found that the above problems can be solved by using glucose oxidase in a citral-containing citrus beverage, and have completed the present invention. That is, the present invention is as follows. [1] A citrus beverage containing 0.45% to 5.4% by mass of glucose, 0.1 ppm to 10 ppm of citral, and glucose oxidase, A citrus beverage with a glucose oxidase activity of 0.1U to 100U per gram of glucose. A citrus beverage in which at least a portion of the glucose oxidase of the citrus beverage described in [2][1] has been inactivated. [3] A citrus beverage containing 0.45% to 5.4% by mass of glucose and 10 ppm or less of citral, A citrus beverage containing inactivated glucose oxidase and gluconic acid derived from glucose in the citrus beverage. [4] A citrus beverage containing 0.45% to 5.4% by mass of glucose and 10 ppm or less of citral, In the aforementioned citrus beverage, inactivated glucose oxidase is present. A citrus beverage containing 0.1 ppb to 100 ppb of p-methylacetophenone and 0.1 ppb to 25 ppb of p-cresol. [5] The citrus beverage according to any one of items [2] to [4], wherein the citrus beverage contains alcohol. [6] The citrus beverage according to any one of items [2] to [5], wherein the citrus beverage is a carbonated beverage. [7] The citrus beverage according to any one of items [2] to [6], wherein the citrus beverage is a bottled beverage. [8] A method for producing a citrus beverage, comprising adding glucose oxidase to a citrus beverage containing glucose and citral. [9] The manufacturing method according to [8], wherein the citral concentration in the citrus beverage is 0.1 ppm to 10 ppm.

[10] The method of production according to [8] or [9], wherein glucose oxidase is added so that the glucose oxidase activity per gram of glucose is 0.1 U to 100 U.

[11] The method for producing the citrus beverage according to any one of items [8] to

[10] , wherein the citrus beverage contains alcohol.

[12] The manufacturing method according to any one of items [8] to

[11] , wherein the citrus beverage is a carbonated beverage.

[13] The manufacturing method according to any one of items [8] to

[12] , wherein the citrus beverage is a packaged beverage. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a citrus beverage containing citral that suppresses the generation of citral degradation components and exhibits excellent sensory evaluation, such as stickiness and bitterness. [Modes for carrying out the invention]

[0007] The citrus beverage of the present invention can be produced by adding glucose oxidase to a citrus beverage containing glucose and citral (hereinafter sometimes referred to as the "citrus beverage before addition"). The glucose oxidase used in the production of the citrus beverage of the present invention is not particularly limited as long as it has glucose oxidase activity. Commercially available glucose oxidase may be used. Alternatively, a microorganism that produces glucose oxidase may be cultured, and the glucose oxidase may be purified from the culture and used. Examples of commercially available glucose oxidases include Gluzyme 10000BG (manufactured by Novozymes Japan Co., Ltd.), Sumizyme GOP (manufactured by Shin Nippon Chemical Industries, Ltd.), Hyderase, Hyderase 15 (manufactured by Amano Enzyme Co., Ltd.), Bakezyme GO1500, Maxapal GO4 (all manufactured by DSM Japan Co., Ltd.). In the production of the citrus beverage of the present invention, the glucose oxidase used is preferably a glucose oxidase that contains catalase activity as a secondary activity. Examples of glucose oxidases that contain catalase activity as a secondary activity include Hyderase and Hyderase 15 (manufactured by Amano Enzyme Co., Ltd.). It is preferable to add glucose oxidase to the citrus beverage such that the glucose oxidase activity per gram of glucose contained in the citrus beverage before addition is 0.1 U to 100 U. More preferably, the glucose oxidase activity is 1 U to 50 U, even more preferably 5 U to 50 U, even more preferably 5 U to 25 U, and particularly preferably 10 U to 25 U. In a citrus beverage to which glucose oxidase has been added (hereinafter sometimes referred to as "citrus beverage before enzymatic reaction"), an enzymatic reaction with glucose oxidase is then carried out. The enzymatic reaction may be carried out by standing the mixture at a predetermined temperature (for example, 10°C to 40°C, preferably 15°C to 35°C) for a predetermined time (for example, 15 minutes to 4 hours, preferably 30 minutes to 2 hours). The liquid temperature of the citrus beverage during the enzymatic reaction is, for example, 5°C to 25°C, preferably 10°C to 20°C. Since glucose oxidase carries out an enzymatic reaction that consumes oxygen using glucose as a substrate, it is thought that the dissolved oxygen in the citrus beverage can be reduced by carrying out an enzymatic reaction with glucose oxidase. It is also known that gluconic acid derived from glucose is produced by the enzymatic reaction of glucose oxidase using glucose as a substrate. Furthermore, glucose oxidase may be inactivated in the citrus beverage after the enzymatic reaction (hereinafter sometimes referred to as "pre-inactivation citrus beverage"). Inactivation of glucose oxidase may be carried out at a predetermined temperature (for example, 50°C to 85°C, preferably 55°C to 75°C) for a predetermined time (for example, 10 minutes to 60 minutes, preferably 20 minutes to 40 minutes) (hereinafter sometimes referred to as "post-inactivation citrus beverage").

[0008] The citrus beverage before addition preferably has a citral concentration of 0.1 ppm to 10 ppm. More preferably, the citral concentration is 1 ppm to 10 ppm, and even more preferably 3 ppm to 10 ppm. The citral content in citrus beverages decreases at each stage of their production, distribution, and storage. Specifically, the citral concentration in citrus beverages before enzymatic reaction, before deactivation, and after deactivation is less than or equal to the citral concentration in the beverage before addition, and is 10 ppm or less. It typically takes about one to three months from the time a citrus beverage is manufactured until it is put on the market for sale. Although it depends on the storage conditions of the citrus beverage, if the period is about one month, the citral concentration decreases to about one-third to one-fourth of the citral concentration at the time of manufacture, and if the period is about three months, the citral concentration decreases to about one-tenth of the citral concentration at the time of manufacture. In other words, the citral concentration in a citrus beverage during distribution and storage after manufacture is, for example, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, or 1 ppm or less. On the other hand, in terms of perceiving the citrus flavor, a citral concentration of 0.01 ppm or higher is preferable, 0.05 ppm or higher is more preferable, and 0.1 ppm or higher is even more preferable. Under acidic conditions in particular, citral undergoes structural changes through reactions such as cyclization, hydration, and isomerization. Oxidation of citral-derived products generates p-cresol and p-methylacetophenone, which are off-flavor components. In the citrus beverage of the present invention, dissolved oxygen in the beverage is reduced by enzymatic reactions using glucose oxidase, which is thought to suppress the generation of p-cresol and p-methylacetophenone, which are off-flavor components (hereinafter, this may be referred to as "the citrus beverage of the present invention in which the generation of citral off-flavor components is suppressed").

[0009] In the citrus beverage of the present invention, in which the generation of citral degradation components is suppressed, the citral concentration is, for example, 2 ppm or less or 1 ppm or less, preferably 0.01 ppm or more, more preferably 0.05 ppm or more, even more preferably 0.1 ppm or more, and may be, for example, 0.01 ppm to 2 ppm, 0.05 ppm to 2 ppm, or 0.1 ppm to 2 ppm. Furthermore, in the citrus beverage of the present invention in which the generation of citral degradation components is suppressed, the p-methylacetophenone concentration is preferably 100 ppb or less, for example 0.1 ppb to 100 ppb, more preferably 50 ppb or less, for example 0.1 ppb to 50 ppb, and even more preferably 25 ppb or less, for example 0.1 ppb to 25 ppb or less. Furthermore, in the citrus beverage of the present invention in which the generation of citral degradation components is suppressed, the p-cresol concentration is preferably 25 ppb or less, for example 0.1 ppb to 25 ppb, more preferably 10 ppb or less, for example 0.1 ppb to 10 ppb, even more preferably 5 ppb or less, for example 0.1 ppb to 5 ppb, and even more preferably 2 ppb or less, for example 0.1 ppb to 2 ppb.

[0010] Citral is an aromatic compound found in citrus fruits such as lemons. The citral may be synthetic or derived from natural sources, and a citral-containing flavoring composition may be added to beverages. Examples of citral-containing flavoring compositions include lemon flavoring. Furthermore, since citral accounts for more than half of the oxygen-containing compounds in lemon oil (essential oil derived from lemons), lemon oil may also be used as a raw material. Furthermore, the citral, p-methylacetophenone, and p-cresol concentrations in citrus beverages can be quantified, for example, by GC-MS (gas chromatography-mass spectrometry).

[0011] The citrus beverage before addition preferably has a glucose concentration of 0.45% to 5.4% by mass. More preferably, the glucose concentration is 0.9% to 4.5% by mass, and even more preferably 0.9% to 2.25% by mass. These preferred ranges of glucose concentration are also true for the citrus beverage before enzymatic reaction, the citrus beverage before inactivation, the citrus beverage after inactivation, and the citrus beverage of the present invention in which the generation of citral degradation components is suppressed. Incidentally, the glucose concentration in the citrus beverage can be quantified by, for example, LC-MS (liquid chromatography-mass spectrometry).

[0012] In the present invention, the term "citrus beverage" refers to a beverage imparted with a citrus flavor. The citrus beverage of the present invention is imparted with a citrus flavor by containing citral, which is a typical component contained in citrus fruits. Preferably, the citrus beverage is a lemon-flavored beverage. In the present invention and the specification of the present application, the term "lemon-flavored beverage" means a beverage having the flavor that lemon possesses. The lemon-flavored beverage in the present invention is not particularly limited as long as it is a beverage having a flavor that reminds drinkers of lemon fruits, and examples thereof include beverages containing lemon fruit juice or extract, and beverages containing characteristic aroma components of lemon.

[0013] The citrus beverage of the present invention may contain other sweeteners in addition to glucose. Examples of the sweetener include high-fructose corn syrup, sugar (including sucrose and granulated sugar), fructose, high-fructose liquid sugar, oligosaccharides, lactose, honey, starch syrup (maltose), sugar alcohols, dextrin, starch, sweet-tasting amino acids, and high-intensity sweeteners. Examples of the sugar alcohol include reduced starch syrup (reduced starch hydrolyzate), erythritol, trehalose, sorbitol, xylitol, maltitol, isomalt, mannitol, lactitol, reduced palatinose, and glycerin. Examples of the high-intensity sweetener include aspartame, acesulfame potassium, disodium glycyrrhizinate, saccharin, calcium saccharin, sodium saccharin, sucralose, neotame, arabinose, licorice extract, xylose, stevia, thaumatin, luo han guo extract, rhamnose, and ribose. One type of the aforementioned sweetener may be used alone, or two or more types may be used in combination.

[0014] The citrus beverage of the present invention may contain an acidulant. Examples of the acidulant include citric acid, adipic acid, gluconic acid, succinic acid, tartaric acid, lactic acid, fumaric acid, malic acid, acetic acid, phosphoric acid, and salts thereof, and the like. Preferably, citric acid is used as the acidulant. The acidity of the beverage in terms of citric acid is, for example, 0.05 to 0.5 (g / 100ml), preferably 0.10 to 0.4 (g / 100ml).

[0015] The pH of the citrus beverage of the present invention is not particularly limited, but may be adjusted according to purposes such as microbial control and suppression of deterioration of aroma components. Since citral is more likely to deteriorate as the pH is lower, the pH is preferably 2.8 or higher, more preferably 3.0 or higher. In particular, the pH is preferably 3.0 to 4.0, more preferably 3.0 to 3.7, because the growth of microorganisms can be sufficiently suppressed and a sour taste favorable as a citrus flavor can be easily achieved. The pH can be adjusted, for example, by changing the amount of the acidulant, using a pH adjuster, or the like.

[0016] The citrus beverage of the present invention may contain fruit juice. Examples of the fruit juice include citrus fruit juice. Examples of the citrus fruit juice include lemon juice, orange juice, mandarin orange juice, Unshu mandarin orange juice, navel orange juice, ponkan juice, summer orange juice, grapefruit juice, lime juice, hassaku juice, iyokan juice, yuzu juice, sudachi juice, calamansi juice, shekwasha juice, kabosu juice, mandarin juice, tangerine juice, temple orange juice, tangelo juice, and calamansi juice, and the like. When the beverage is a fruit juice beverage, the fruit juice content is preferably 10% or less, more preferably 5% or less in terms of fruit juice percentage.

[0017] The citrus beverage of the present invention may be an alcohol-containing beverage containing alcohol. When the citrus beverage of the present invention contains alcohol, the stickiness and harshness of the aftertaste can be more significantly improved. In the present invention and this specification, "alcohol-containing beverage" means any beverage containing ethanol, and may be a sparkling beverage or a non-sparkling beverage. It may also be a beverage produced through a fermentation process or a beverage produced without a fermentation process. Specifically, alcohol-containing beverages include non-sparkling alcoholic beverages such as distilled spirits and liqueurs like vodka, whiskey, brandy, shochu, rum, spirits, and gin; sparkling alcoholic beverages such as beer, beer-flavored alcoholic beverages (alcoholic beverages having the same or similar flavor, taste, and texture as beer), sparkling wine, and cider; and cocktails such as chuhai, which are made by mixing non-sparkling alcoholic beverages such as distilled spirits and liqueurs with non-alcoholic beverages such as juice, soft drinks, cider, ramune, and carbonated water. When the citrus beverage of the present invention contains alcohol, the alcohol concentration is not particularly limited. For example, the alcohol concentration of the citrus beverage can be in the range of 1.0 to 9.0 v / v%, or in the range of 3.0 to 8.0 v / v%. Furthermore, the alcohol concentration of the citrus beverage may be less than 1.0 v / v%. If the citrus beverage in question is an alcoholic beverage, it can be manufactured using various types of alcohol as a base. The alcohol used as the base may be raw material alcohol or alcoholic beverages manufactured by conventional methods. The alcoholic beverage may be a distilled spirit or a brewed alcoholic beverage. Examples of distilled spirits include vodka, whiskey, brandy, spirits, shochu, rum, gin, etc., and may also be liqueurs. Examples of brewed alcoholic beverages include beer, wine, cider, etc. Preferably, the alcohol used as a raw material is one that has been fermented from molasses and refined to a high degree (for example, an alcohol concentration of 95 v / v% or higher). Since raw material alcohol is inexpensive, it can reduce manufacturing costs. In addition, because raw material alcohol has a low content of aromatic components compared to other base alcohols, it is easier to obtain a beverage with a clean taste.

[0018] The citrus beverage according to the present invention may be a non-carbonated beverage that does not contain carbon dioxide, or it may be a carbonated beverage that contains carbon dioxide. If the citrus beverage is a carbonated beverage, the carbon dioxide pressure is preferably 0.5 to 5.0 gas volume (GV), more preferably 1.0 to 4.0 GV, and even more preferably 1.5 to 3.5 GV. Gas volume refers to a unit that represents the amount of carbon dioxide in a carbonated beverage, and means the ratio of the volume of carbon dioxide dissolved in the carbonated beverage to the volume of the carbonated beverage at standard conditions (1 atmosphere, 20°C).

[0019] The citrus beverage according to the present invention may further contain other ingredients, provided that they do not impair the effects of the present invention. Examples of such other ingredients include water-soluble dietary fiber, colorants, foaming agents, proteins or their hydrolysates, yeast extract, raw water, antioxidants, emulsifiers, and the like. Water-soluble dietary fiber refers to carbohydrates that dissolve in water and are not digested or are difficult to digest by human digestive enzymes. Examples of water-soluble dietary fiber include soy fiber, polydextrose, indigestible dextrin, galactomannan, inulin, guar gum hydrolysate, pectin, and gum arabic. These water-soluble dietary fibers may be used individually or in combination of two or more types. Examples of colorants include caramel coloring and other colorants commonly used in food and beverages. These colorants may be used individually or in combination of two or more types. Examples of foaming agents include soy peptides, soy saponins, alginate esters, and quillaja saponins. These foaming agents may be used individually or in combination of two or more types. Examples of protein hydrolysates include soy protein hydrolysates. These protein hydrolysates may be used individually or in combination of two or more types. Examples of antioxidants include sulfurous acid and vitamin C. These antioxidants may be used individually or in combination of two or more types. Examples of emulsifiers include lecithin, saponin, sucrose fatty acid esters, and glycerin fatty acid esters. These emulsifiers may be used individually or in combination of two or more types.

[0020] The citrus beverage according to the present invention can be manufactured by, for example, a method (formulation) of mixing various raw materials, including glucose and citral. The order in which the raw materials are mixed is not particularly limited. All raw materials may be added to the raw water at the same time, or the raw materials may be added sequentially, such as by dissolving the raw materials added first and then adding the remaining raw materials. Alternatively, solid raw materials (e.g., in powder or granular form) and alcohol as needed may be mixed with the raw water, or the solid raw materials may be prepared as aqueous solutions beforehand, and these aqueous solutions, along with alcohol and raw water as needed, may be mixed. Furthermore, heated raw materials may be added to the raw water, or the prepared formulation may be heated. If insoluble matter is present in the prepared solution, it is preferable to remove the insoluble matter by filtration or other methods. The insoluble matter removal process is not particularly limited and can be carried out by methods commonly used in the art, such as filtration or centrifugation. It is preferable to remove the insoluble matter by filtration, and more preferably by diatomaceous earth filtration. If the citrus beverage according to the present invention is a carbonated beverage, it can be manufactured, for example, by using carbonated water or carbonated soft drinks such as cider or ramune as raw materials. Alternatively, it can be manufactured by preparing a mixture of all raw materials except carbon dioxide, and then introducing carbon dioxide into this mixture. The introduction of carbon dioxide can be carried out by conventional methods.

[0021] Bottled citrus beverages can be manufactured by filling the produced citrus beverage into containers and sealing them. Filling and sealing the containers can be done by conventional methods. In addition, the empty space in the bottled citrus beverage may be filled with an inert gas such as nitrogen or carbon dioxide. These inert gases can reduce the amount of oxygen present in the container. The containers used to fill the manufactured citrus beverages are not particularly limited and may include two-piece beverage cans, three-piece beverage cans, bottle cans, flexible containers, glass bottles, etc. Flexible containers include those made by molding flexible resins such as PE (polyethylene), PP (polypropylene), EVOH (ethylene-vinyl alcohol copolymer), and PET (polyethylene terephthalate) into a bottle shape. Flexible containers may be made of a single layer of resin or a multi-layer resin. When citrus beverages are carbonated, containers with high pressure resistance should be used. Currently, the manufacturer-guaranteed pressure resistance of aluminum (alloy) two-piece beverage cans and aluminum (alloy) bottle cans on the market is around 686 kPa at the highest. Considering the actual pressure resistance, it should be approximately 3.2 GV or less if heat sterilization is required, and approximately 3.8 GV or less if heat sterilization is not required. Furthermore, the citrus beverage according to the present invention undergoes heat sterilization treatment as necessary during its manufacturing process. Heat sterilization treatment may be performed before or after filling the containers. Sterilization can be carried out by conventional methods such as UHT (ultra-high temperature) sterilization, pasteurization, or retort sterilization. [Examples]

[0022] <Preparation of the base solution> A base solution was prepared by injecting carbon dioxide gas under pressure into the prepared liquid according to the formulation shown in Table 1 below, to achieve a carbon dioxide pressure of 2.3 GV. The raw material alcohol used had an alcohol content of 95 v / v%. The alcohol content of the base solution was set to 5 v / v%. [Table 1]

[0023] [Example 1] The effect of glucose oxidase on citral-containing citrus beverages was investigated. Hyderase (Hyderase 15, manufactured by Amano Enzyme Co., Ltd.) was used as the glucose oxidase.

[0024] (Control sample) Control samples were prepared by adding citral to the base solution to achieve citral concentrations of 0.1 ppm, 1 ppm, and 10 ppm, respectively. 350 ml of each control sample was poured into 350 ml high-gas aluminum cans (Toyo Seikan Co., Ltd. C350L14GH), and the containers were sealed by crimping high-gas aluminum can lids (Toyo Seikan Co., Ltd. 204Q11) using a seamer (Toyo Seikan Co., Ltd.). Each sealed container was left to stand at 25°C for 1 hour (the liquid temperature inside the container was approximately 15°C). Subsequently, each sealed container was sterilized in a constant-temperature water bath (Thomas Scientific Instruments Co., Ltd. T-104NC) at 65°C for 20 minutes. After sterilization, the containers were stored in a constant-temperature room at 37°C for 2 weeks (equivalent to approximately 3 months of storage at room temperature of 25°C), and the control samples in the containers were evaluated after storage.

[0025] (Example: Hyderase-added sample) Samples were prepared by adding hydrase (Hyderase 15, manufactured by Amano Enzyme Co., Ltd., with a glucose oxidase activity of approximately 1500 U per gram of hydrase) to control samples at concentrations of 50 ppm, 100 ppm, 200 ppm, and 300 ppm, respectively. 350 ml of each sample was poured into 350 ml high-gas aluminum cans (C350L14GH, manufactured by Toyo Seikan Co., Ltd.), and the containers were sealed by crimping high-gas aluminum can lids (204Q11, manufactured by Toyo Seikan Co., Ltd.) using a seamer (manufactured by Toyo Seikan Co., Ltd.). Each sealed container was left to stand at 25°C for 1 hour to allow the enzymatic reaction by hydrase to occur inside the container (the liquid temperature inside the container was approximately 15°C). Subsequently, each sealed container was heated in a constant temperature water bath (T-104NC, manufactured by Thomas Scientific Instruments Co., Ltd.) at 65°C for 20 minutes to inactivate the hydrase. Each sealed container was then stored in a constant temperature room at 37°C for 2 weeks (equivalent to approximately 3 months of storage at room temperature of 25°C), and the samples in the containers were evaluated after storage.

[0026] (Comparative example: Sample with added ascorbic acid) As a control, the effects of ascorbic acid and ascorbic acid oxidase on citrus beverages were investigated. Two samples were prepared: one in which ascorbic acid (manufactured by Marugo Corporation) was added to the control sample to achieve an ascorbic acid concentration of 200 ppm, and another in which ascorbic acid oxidase (manufactured by Nagase & Co., Ltd.) was added to the control sample to achieve an ascorbic acid oxidase concentration of 100 ppm. 350 ml of each sample was poured into 350 ml high-gas aluminum cans (C350L14GH, manufactured by Toyo Seikan Co., Ltd.), and the containers were sealed by crimping high-gas aluminum can lids (204Q11, manufactured by Toyo Seikan Co., Ltd.) using a seamer (manufactured by Toyo Seikan Co., Ltd.). Each sealed container was left to stand at 25°C for 1 hour. For samples to which ascorbate oxidase was added, the enzymatic reaction with ascorbate oxidase was carried out in the container (the liquid temperature in the container was approximately 15°C). Subsequently, the containers were heated to 65°C for 20 minutes using a constant temperature water bath (T-104NC, manufactured by Thomas Scientific Instruments Co., Ltd.), and the ascorbate oxidase in the samples to which it was added was inactivated. Each sealed container was stored in a constant temperature room at 37°C for 2 weeks (equivalent to storage at room temperature of 25°C for approximately 3 months), and the samples in the containers after storage were evaluated.

[0027] (Comparative example: Theaflavin-added sample) As a comparative control, the effect of theaflavins on citrus beverages was investigated. A sample was prepared by adding theaflavin (theaflavin TF25 manufactured by Yaizu Suisankagaku Industry Co., Ltd.) to a control sample such that the theaflavin concentration was 5 ppm. 350 ml of the sample was poured into a 350 ml high-gas aluminum can container (C350L14GH manufactured by Toyo Seikan Co., Ltd.), and the container was sealed by double-seaming a high-gas aluminum can lid (204Q11 manufactured by Toyo Seikan Co., Ltd.) using a seamer (manufactured by Toyo Seikan Co., Ltd.). The sealed container was allowed to stand at 25°C for 1 hour (the liquid temperature in the container was approximately 15°C). Thereafter, the sealed container was sterilized at 65°C for 20 minutes using a constant-temperature water bath (T-104NC manufactured by Thomas Kagaku Co., Ltd.). The sterilized container was stored in a thermostatic chamber at 37°C for 2 weeks (equivalent to storage at room temperature of 25°C for about 3 months), and the sample in the container after storage was evaluated.

[0028] For each sample, quantitative analysis of p-methylacetophenone and p-cresol, which are degradation components of citral, and sensory evaluation for stickiness of aftertaste and harshness were performed. The sample evaluation results are shown in Table 2.

[0029] <Quantitative Analysis of p-Methylacetophenone and p-Cresol> An internal standard substance was added to each sample, and a standard solution for a calibration curve was further added to the calibration curve samples. After diluting these samples with pure water, the mixture was stirred for a certain period of time with a stirrer, and the entire amount was passed through a conditioned solid phase (OASIS HLB (Waters Corporation) 200 mg) to adsorb the components. Pure water was passed through the solid phase with the adsorbed components to remove excess components, air was passed through for dehydration, and the components were eluted with dichloromethane for residual pesticides (10158-3B for residual pesticide reagent and PCB test, manufactured by Kanto Chemical Co., Ltd.) and then concentrated, followed by analysis and quantification by GC-MS. The conditions of the GC-MS and column used, etc., are as follows. GC-MS used: Agilent 5975 Conditions JPEG0007933649000002.jpg49110

[0030] <Sensory Evaluation> Sensory evaluations regarding stickiness and astringency were conducted as follows. In this invention, "stickiness" refers to a sticky aftertaste that lingers in the mouth. "Astringency" refers to a rough, gritty texture that is close to bitterness that lingers in the aftertaste. Sensory evaluations of stickiness and bitterness were conducted by a panel of five experts using a 7-point scale. Unless otherwise specified, evaluations were performed using a control sample as a reference, according to the following criteria. (stickiness) 7: I don't feel any stickiness at all. 6: Not as sticky as "7," but less sticky than the other one. 5: Less sticky than the control. 4: Similar to the control group 3: Feels slightly stickier than the control. 2: It's not as sticky as "1," but it feels stickier than the other one. 1: I feel a sticky, clinging sensation in my mouth. (bitter taste) 7: I don't taste any bitterness at all. 6: Not as harsh as "7," but less so than the contrasting "7." 5: Slightly less bitter than the comparison. 4: Similar to the control group 3: It has a slightly more bitter taste than the comparison. 2: Not as much as "1", but it has a more bitter taste than the contrast. 1: I strongly feel a bitter, almost acrid, rough texture in my mouth. For each sample, the average of the scores given by a panel of five experts was used as the evaluation result for that sample. When the control sample was scored at 4.0, a statistically significant difference (p-value < 0.05 in the t-test) was defined as a score of 2.8 or less or a score of 4.8 or more.

[0031] [Table 2]

[0032] As shown in Table 2, in citrus beverages containing citral, samples to which hydrase concentrations of 50 ppm, 100 ppm, 200 ppm, and 300 ppm were added suppressed the production of p-methylacetophenone and p-cresol, which are citral degradation components, compared to the control sample. Furthermore, the evaluation of aftertaste stickiness and astringency was also better than that of the control. The reason why the aftertaste was rated better in terms of stickiness and bitterness than the control group is unclear, but since p-methylacetophenone and p-cresol, which are degradation components of citral, affect the aftertaste, it is presumed that the deterioration of the aftertaste was suppressed by inhibiting the production of these degradation components. In addition, when hydrase uses glucose as a substrate and performs an enzymatic reaction that consumes oxygen, an acid called gluconic acid is produced as a byproduct, and it is presumed that this acid contributes to the improvement of the aftertaste by moderately masking the above-mentioned degradation components.

[0033] Samples with added ascorbic acid, and samples with added ascorbic acid and ascorbic acid oxidase, suppressed the production of citral degradation components compared to the control. However, sensory evaluation results showed that the aftertaste was worse in terms of stickiness and astringency than the control. The reason for this is unclear, but it is known that ascorbic acid decomposes to produce furfural, and it is presumed that the furfural produced by this decomposition affected and worsened the aftertaste of stickiness and astringency. Furthermore, while the samples with theaflavin added also suppressed the production of citral degradation components compared to the control, the control samples and the samples with hydrase added were transparent, whereas the samples with theaflavin added had a slightly pale yellow to brownish color. At a citral concentration of 1 ppm, the chromaticity measurements were 0.006 for the control sample, 0.024 for the sample with 100 ppm of hydrase added, and 0.224 for the sample with theaflavin added. The chromaticity was measured as follows: The sample was placed in a 10 mm disposable cell for the spectrophotometer, and the absorbance was measured using a spectrophotometer (Shimadzu UV2700) with monochromatic light at 430 nm. The chromaticity (°EBC) was then obtained by multiplying this value by a coefficient.

[0034] As described above, it was confirmed that adding hydrase to citrus beverages with a citral concentration of 0.1 to 10 ppm can suppress the production of citral degradation components and improve the sticky and bitter aftertaste.

[0035] Furthermore, tests were also conducted without alcohol in the base liquid, except that no alcohol was used as a raw material. In the tests without alcohol, a tendency to suppress the formation of degradation components such as p-methylacetophenone and p-cresol was observed, but the suppression effect of degradation flavor was more pronounced with alcohol. The reason for this is not clear, but it is presumed that in alcohol-containing beverages, the aftertaste such as the aroma and bitterness of alcohol enhances the adverse effects on the odor and aftertaste caused by the degradation components of citral, and that the improvement effect due to the suppression of the formation of degradation components and the masking of degradation components by gluconic acid is more pronounced in alcohol-containing beverages.

Claims

1. A citrus beverage containing 0.45% to 5.4% by mass of glucose, 0.1 ppm to 10 ppm of citral, and glucose oxidase, A citrus beverage before enzymatic reaction, with a glucose oxidase activity of 1 U to 100 U per gram of glucose.

2. A citrus beverage containing 0.45% to 5.4% by mass of glucose and 0.1 ppm to 10 ppm of citral, A citrus beverage containing inactivated glucose oxidase and gluconic acid derived from glucose in the citrus beverage.

3. A citrus beverage containing 0.45% to 5.4% by mass of glucose and 0.1 ppm to 10 ppm of citral, In the aforementioned citrus beverage, inactivated glucose oxidase is present. A citrus beverage containing 0.1 ppb to 100 ppb of p-methylacetophenone and 0.1 ppb to 25 ppb of p-cresol.

4. The citrus beverage according to claim 2 or 3, wherein the citrus beverage contains alcohol.

5. The citrus beverage according to claim 2 or 3, wherein the citrus beverage is a carbonated beverage.

6. The citrus beverage according to claim 2 or 3, wherein the citrus beverage is a bottled beverage.

7. The citrus beverage according to claim 2 or 3, wherein the fruit juice content is 10% or less.

8. A method for producing a citrus beverage, comprising adding glucose oxidase to a citrus beverage containing 0.45% to 5.4% by mass of glucose and 0.1 ppm to 10 ppm of citral, such that the glucose oxidase activity per gram of glucose is 1 U to 100 U.

9. The manufacturing method according to claim 8, further comprising carrying out an enzymatic reaction with glucose oxidase to inactivate at least a portion of the glucose oxidase.

10. The manufacturing method according to claim 8, wherein the citrus beverage contains alcohol.

11. The manufacturing method according to claim 8, wherein the citrus beverage is a carbonated beverage.

12. The manufacturing method according to claim 8, wherein the citrus beverage is a packaged beverage.

13. The manufacturing method according to claim 8, wherein the fruit juice content of the citrus beverage is 10% or less.

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