Beverage, method for producing beverage, and method for reducing bitterness irritation of caffeine-containing beverage

Abstract

A beverage comprising killed cells of beneficial bacteria and caffeine, wherein the concentration of the killed cells of beneficial bacteria is 500 million cells / L or more, the concentration of the caffeine is 10 mg / 100 mL or more, and the pH is 1.90-4.60.

Description

Beverage, method for producing a beverage, and method for reducing bitter taste stimulation of a caffeine-containing beverage 【0001】 The present invention relates to a beverage, a method for producing a beverage, and a method for reducing bitter taste stimulation of a caffeine-containing beverage. 【0002】 Caffeine-containing beverages have effects such as a wake-up effect and an improvement in concentration, and are favored for the stimulation when consumed, so various types are in circulation. On the other hand, since caffeine has a bitter taste, various methods for suppressing the bitter taste of caffeine-containing beverages have been conventionally studied. 【0003】 For example, Patent Document 1 discloses an invention of a beverage containing 1 to 150 ppm of caffeine, 0.4 ppb or more of phenethyl alcohol, and having a pH of 5.0 to 8.0. And according to this invention, it is described that in a beverage having a pH of 5.0 or more containing caffeine, the bitter taste derived from caffeine felt at the time of drinking can be reduced. 【0004】 Japanese Unexamined Patent Application Publication No. 2020-130100 【0005】 However, the present inventors have found a new problem that in acidic caffeine-containing beverages, unlike the bitter taste of conventionally known caffeine-containing beverages, the expression timing at the time of drinking is late and the sharp bitter taste (bitter taste stimulation) lingers for a long time after drinking. Therefore, there was room for improvement in the bitter taste stimulation peculiar to the above acidic caffeine-containing beverages in conventional caffeine-containing beverages. Thus, an object of the present invention is to provide a beverage with reduced bitter taste stimulation, a method for producing the beverage, and a method for reducing bitter taste stimulation of a caffeine-containing beverage. 【0006】 The present inventors conducted intensive studies for the purpose of solving the above problems. And the present inventors newly found that in a beverage containing dead bacteria of useful bacteria and caffeine and having a pH of 1.90 or more and 4.60 or less, by setting the dead bacteria concentration of useful bacteria to 500 million cells / L or more and the concentration of caffeine to 10 mg / 100 mL or more, the bitter taste stimulation of the beverage can be reduced, and completed the present invention. 【0007】In other words, the present invention aims to advantageously solve the above problems, and the present invention is a beverage containing [1] dead beneficial bacteria and caffeine, wherein the concentration of dead beneficial bacteria is 500 million cells / L or more, the concentration of caffeine is 10 mg / 100 mL or more, and the pH is 1.90 or more and 4.60 or less. The above beverage has reduced bitterness due to the inclusion of dead beneficial bacteria. In this specification, bitterness refers to a sharp bitterness that lingers long after consumption, which is characteristic of acidic caffeine-containing beverages and is different from the bitterness of caffeine-containing beverages that have been known in the past. 【0008】 [2] Here, it is preferable that the beverage in [1] has an acidulant concentration of 0.005% by mass or more and 5.000% by mass or less. When the acidulant concentration is within the above range, the bitter taste of the beverage is more pronounced, and therefore the bitter taste reduction effect of dead beneficial bacteria is even more useful. 【0009】 [3] The beverage described in [1] or [2] above preferably further contains one or more selected from the group consisting of citric acid, phosphoric acid, malic acid, tartaric acid, and salts thereof as an acidulant. 【0010】 [4] It is preferable that any of the beverages described in [1] to [3] above have a sodium concentration of 15 mg / 100 mL or more. If the sodium concentration is within the above range, the effect of reducing the bitter taste of the beverage can be further improved. The sodium concentration of the beverage can be measured by the method described later in this specification. 【0011】 [5] It is preferable that any of the beverages in [1] to [4] above be non-carbonated beverages. 【0012】 [6] In any of the beverages described in [1] to [5] above, it is preferable that the concentration of dead beneficial bacteria is 4,000 billion cells / L or less. If the concentration of dead beneficial bacteria is below the above upper limit, the beverage can be made to have even less off-odor derived from dead beneficial bacteria. In this specification, "off-odor derived from dead beneficial bacteria" refers to a characteristic odor that arises from the addition of beneficial bacteria. 【0013】[7] In any of the beverages described in [1] to [6] above, it is preferable that the beneficial bacteria consist of one or more species selected from the group comprising Lactobacillus and Lactococcus species. 【0014】 [8] In any of the beverages described in [1] to [7] above, it is preferable that the beneficial bacteria consist of one or more species selected from the group consisting of Lactobacillus rhamnosus CRL1505 and Lactococcus lactis subspecies lactis JCM5805. 【0015】 [9] It is preferable that any of the beverages in [1] to [8] above have a caffeine concentration of 200 mg / 100 mL or less. If the caffeine concentration is below the above upper limit, the bitter taste of the beverage can be further reduced. 【0016】

[10] Any of the beverages in [1] to [9] above is preferably a packaged beverage. 【0017】

[11] The present invention also relates to a method for producing a beverage containing dead beneficial bacteria and caffeine, comprising the steps of: when blending the dead beneficial bacteria and caffeine in the beverage, ensuring that the concentration of dead beneficial bacteria in the beverage is 500 million cells / L or more and the concentration of caffeine is 10 mg / 100 mL or more; and adjusting the pH of the beverage to be between 1.90 and 4.60. According to the above production method, a beverage with reduced bitterness can be obtained. 【0018】

[12] Furthermore, the present invention relates to a method for reducing the bitter taste of a beverage containing dead beneficial bacteria and caffeine, comprising the step of, when blending the dead beneficial bacteria and caffeine, ensuring that the concentration of dead beneficial bacteria in the beverage is 500 million cells / L or more and the concentration of caffeine is 10 mg / 100 mL or more. 【0019】 According to the present invention, it is possible to provide a beverage with reduced bitterness, a method for producing the beverage, and a method for reducing bitterness in a caffeine-containing beverage. 【0020】 Embodiments of the present invention will be described in detail below. 【0021】(Beverage) The beverage of the present invention contains dead beneficial bacteria and caffeine, characterized in that the concentration of dead beneficial bacteria is 500 million cells / L or more, the concentration of caffeine is 10 mg / 100 mL or more, and the pH is 1.90 or more and 4.60 or less. The inventors have newly discovered that acidic caffeine-containing beverages have a sharp bitterness (bitter stimulus) that differs from the bitterness of conventionally known caffeine-containing beverages, with a delayed onset at the time of consumption and a long-lasting after-effect. In contrast, the beverage of the present invention is a beverage in which the above-mentioned bitter stimulus is reduced by containing dead beneficial bacteria. Furthermore, the inventors have newly discovered that acidic caffeine-containing beverages, compared to neutral caffeine solutions, cause difficulty in swallowing and an unpleasant grittiness. The beverage of the present invention also reduces these difficulties in swallowing and grittiness. 【0022】 The beverage of the present invention is not particularly limited and may be, for example, a tea-based beverage, a fruit juice beverage, cocoa, a dairy beverage, a coffee beverage, a functional beverage, or flavored water. Examples of tea-based beverages include black tea beverages and unsweetened tea beverages. Examples of unsweetened tea beverages include green tea beverages, oolong tea beverages, barley tea beverages, brown rice tea beverages, Job's tears tea beverages, and unsweetened black tea beverages. Examples of dairy beverages include fermented milk beverages (lactic acid bacteria beverages), milk drinks, and drinking yogurt. Examples of functional beverages include sports drinks and energy drinks. It is preferable that the beverage of the present invention is a beverage other than a tea-based beverage or a coffee beverage. The beverage of the present invention is even more useful as a functional beverage, a fruit juice beverage, and flavored water, even more useful as a functional beverage, and particularly useful as an energy drink. The beverage of the present invention may be a carbonated beverage or a non-carbonated beverage, but it is preferable that it be a non-carbonated beverage from the viewpoint of not easily detecting an off-odor derived from dead beneficial bacteria when consumed. 【0023】<Beneficial Bacteria> In this invention, dead beneficial bacteria are used. The beneficial bacteria are not particularly limited, but examples include bacteria of the genera Oenococcus, Bifidobacterium, Weissella, Tetragenococcus, Lactococcus, Leuconostoc, Pediococcus, Streptococcus, Enterococcus, Lactobacillus, Acetic acid bacteria, and Bacillus bacteria. 【0024】Furthermore, the Lactobacillus species used in this invention includes bacteria that were classified under the Lactobacillus genus before the reclassification of the Lactobacillus genus. For example, with the reclassification of the Lactobacillus genus, new genera have been added: Acetilactobacillus, Agrilactobacillus, Amylolactobacillus, Apilactobacillus, Bombilactobacillus, Companilactobacillus, Dellaglioa, Fructilactobacillus, Furfurilactobacillus, Holzapfelia, Lacticaseibacillus, Lactiplantibacillus, and Lapidilactobacillus. This includes bacteria classified under genera such as Lapidilactobacillus, Latilactobacillus, Lentilactobacillus, Levilactobacillus, Ligilactobacillus, Limosilactobacillus, Liquorilactobacillus, Loigolactobacillus, Paralactobacillus, Paucilactobacillus, Schleiferilactobacillus, and Secundilactobacillus. 【0025】Among the above, the following are preferred as useful bacteria: Oenococcus, Bifidobacterium, Lentilactobacillus, Weissella, Tetragenococcus, Lactococcus, Leuconostoc, Pediococcus, Enterococcus, Lactobacillus, and Lactiplantibacillus. In particular, it is more preferable that the useful bacteria include one or more species selected from the group consisting of Lactobacillus and Lactococcus species. 【0026】 Examples of the Oenococcus genus mentioned above include Oenococcus oeni. A specific example of an Oenococcus genus is Oenococcus oeni JCM6125. 【0027】 Examples of Bifidobacterium species mentioned above include Bifidobacterium animalis subsp. lactis, Bifidobacterium longum subsp. longum, and Bifidobacterium longum subsp. infantis. Specific examples of Bifidobacterium species include Bifidobacterium animalis subsp. lactis JCM10602, Bifidobacterium longum BB536, and Bifidobacterium longum subsp. infantis JCM1222. 【0028】Examples of the Weissella genus mentioned above include Weissella paramesenteroides and Weissella viridescens. Specific examples of Weissella genus include Weissella paramesenteroides JCM9890 and Weissella viridescens JCM1174. 【0029】 Examples of the Tetragenococcus genus mentioned above include Tetragenococcus halophilus. A specific example of Tetragenococcus halophilus is Tetragenococcus halophilus NRIC0098. 【0030】 Examples of Lactococcus species mentioned above include Lactococcus lactis, Lactococcus lactis subsp. lactis, Lactococcus garvieae, Lactococcus lactis subsp. cremoris, Lactococcus lactis subsp. hordniae, and Lactococcus plantarum. 【0031】Specific examples of the above Lactococcus species include Lactococcus lactis subspecies lactis JCM5805, Lactococcus lactis subspecies lactis NBRC12007, Lactococcus lactis subspecies lactis NRIC1150, Lactococcus lactis subspecies lactis JCM20101, Lactococcus lactis subspecies lactis JCM7638, Lactococcus lactis subspecies Examples include Lactosus lactis ATCC11454, Lactococcus garbieae NBRC100934, Lactococcus lactis subspecies cremoris JCM16167, Lactococcus lactis subspecies cremoris NBRC100676, Lactococcus lactis subspecies heldniae JCM1180, Lactococcus lactis subspecies heldniae JCM11040, and Lactococcus plantarum JCM11056. 【0032】 Examples of Leuconostoc species mentioned above include Leuconostoc carnosum and Leuconostoc lactis. Specific examples of Leuconostoc species include Leuconostoc carnosum JCM9695 and Leuconostoc lactis NBRC12455. 【0033】Examples of the Pediococcus species mentioned above include Pediococcus acidilactici, Pediococcus pentosaceus, Pediococcus cellicola, Pediococcus claussenii, Pediococcus damnosus, Pediococcus ethanolidurans, Pediococcus inopinatus, Pediococcus parvulus, and Pediococcus stilesii. Specific examples of Pediococcus species include Pediococcus acidilactici JCM8797, Pediococcus acidilactici K15, and Pediococcus damnosus JCM5886. 【0034】 Examples of the Streptococcus genus mentioned above include Streptococcus thermophilus. Specific examples of Pediococcus genus include Streptococcus thermophilus SBC8781. 【0035】 Examples of Enterococcus species mentioned above include Enterococcus alcedinis. 【0036】Examples of Lactobacillus species include Lactobacillus paracasei, Lactobacillus delbrueckii, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus fructivorans, Lactobacillus hilgardii, Lactobacillus rhamnosus, Lactobacillus gasseri, Lactobacillus acidophilus, Lactobacillus bulgaricus, and Lactobacillus parakefilii. Examples include Lactobacillus parakefiri, Lactobacillus plantarum, and Lactobacillus pentosus. 【0037】 Specific examples of Lactobacillus species include Lactobacillus paracasei KW3110, Lactobacillus paracasei MCC1849, Lactobacillus paracasei K71, Lactobacillus rhamnosus species including one or more Lactobacillus rhamnosus species, Lactobacillus rhamnosus GG, Lactobacillus rhamnosus CRL1505, Lactobacillus gasseri SBT2055, and Lactobacillus... Examples include L-92 of Lactobacillus acidophilus, OLL1073R-1, Lactobacillus parakephyli (Lentilactobacillus parakephyli in the new classification) JCM8573, Lactobacillus plantarum (Lactiplantibacillus plantarum in the new classification) L-137, and Lactobacillus pentosa (Lactiplantibacillus pentosa in the new classification) ONRICb0240. 【0038】The above-mentioned acetic acid bacteria are not particularly limited, but examples include bacteria of the genus Gluconacetobacter, Acetobacter, and Gluconobacter, preferably Gluconacetobacter, more preferably Gluconacetobacter hanzenii, and even more preferably Gluconacetobacter hanzenii GK-1. 【0039】 The above-mentioned Bacillus species are not limited to Bacillus coagulans, but examples include Bacillus coagulans. A specific example of a Bacillus species is Bacillus coagulans strain SANK70258. 【0040】 Among the above, it is particularly preferable that the useful bacteria include one or more species selected from the group consisting of Lactobacillus rhamnosus CRL1505 and Lactococcus lactis subspecies lactis JCM5805. 【0041】 In the present invention, the dead beneficial bacteria are not particularly limited and may be either dried or not; however, from the viewpoint of storage stability of the dead beneficial bacteria, they are preferably dried. Among these, dried powder of dead beneficial bacteria is preferred. 【0042】 The method for preparing dead beneficial bacteria is not particularly limited. For example, methods include sterilizing the culture medium on which the beneficial bacteria were cultured, then collecting the bacteria by filtration and centrifugation, or collecting the bacteria from the culture medium on which the beneficial bacteria were cultured by filtration and centrifugation, and then sterilizing the medium. Among beneficial bacteria, lactic acid bacteria, for example, can be cultured using a lactic acid bacteria culture medium known to those skilled in the art, such as MRS (de Man-Rogosa-Sharp) medium, which contains glucose, protein hydrolysate, and yeast extract. Generally, the culture temperature is 30°C to 37°C, the culture period is 2 to 3 days, and the culture can be carried out under anaerobic conditions. 【0043】Further, the collected cells after culturing can be further subjected to drying treatment and crushing treatment as necessary. Note that the means of sterilization is not particularly limited, and conventional means for killing bacteria such as not only heating but also ultraviolet irradiation and γ-ray irradiation can be used. 【0044】 The dead cell concentration of the useful bacteria contained in the beverage of the present invention needs to be 500 million cells / L or more, preferably 1 billion cells / L or more, more preferably 10 billion cells / L or more, still more preferably 400 billion cells / L or more, preferably 40,000 billion cells / L or less, more preferably 35,000 billion cells / L or less, and still more preferably 30,000 billion cells / L or less. Among them, when the useful bacteria are Lactobacillus rhamnosus, the dead cell concentration contained in the beverage needs to be 500 million cells / L or more, preferably 1 billion cells / L or more, more preferably 1.5 billion cells / L or more, preferably 2,000 billion cells / L or less, more preferably 1,000 billion cells / L or less, and still more preferably 500 billion cells / L or less. If the dead cell concentration of the useful bacteria is at least the above lower limit value, the bitter taste stimulation of the beverage can be reduced by adding the useful component, the dead cells of the useful bacteria, without depending on the addition of saccharides and sweeteners. Also, if the dead cell concentration of the useful bacteria is at most the above upper limit value, the beverage can be made to have even less odor derived from the dead cells of the useful bacteria. 【0045】 The dead cell concentration of the useful bacteria contained in the beverage can be controlled by adjusting the addition amount of the dead cells of the useful bacteria formulated in the beverage. Also, the dead cell concentration of the useful bacteria contained in the beverage can be measured by known methods for measuring the number of bacteria, and for example, the flow cytometry method is preferably mentioned. 【0046】<Caffeine> The beverage of the present invention must have a caffeine concentration of 10 mg / 100 mL or more, preferably 15 mg / 100 mL or more, more preferably 20 mg / 100 mL or more, preferably 200 mg / 100 mL or less, more preferably 180 mg / 100 mL or less, and even more preferably 150 mg / 100 mL or less. When the caffeine concentration in the beverage is above the lower limit, the bitter taste of the beverage is more pronounced, and the bitter taste reduction effect of the dead beneficial bacteria can work more effectively. Also, if the caffeine concentration in the beverage is below the upper limit, the bitter taste of the beverage can be further reduced. The caffeine concentration in the beverage can be measured by high-performance liquid chromatography (HPLC). 【0047】 <Acidulants> The beverage of the present invention may contain acidulants. The type of acidulant is not particularly limited, but examples include citric acid, phosphoric acid, malic acid, tartaric acid, lactic acid, acetic acid, gluconic acid, phytic acid, and succinic acid, as well as their salts. In particular, when one or more are selected from the group consisting of citric acid, phosphoric acid, malic acid, tartaric acid, lactic acid, and acetic acid, the bitter taste of the beverage becomes more pronounced, and the effect of reducing bitter taste by adding dead beneficial bacteria is even more useful. Therefore, it is preferable that one or more are selected from the group consisting of citric acid, phosphoric acid, malic acid, and tartaric acid, as well as their salts, and even more preferably that citric acid and phosphoric acid are used from the viewpoint of flavor. The acidulant may be one type or multiple types may be used in combination. 【0048】The concentration of the acidulant contained in the beverage of the present invention is preferably 0.005% by mass or more, more preferably 0.010% by mass or more, still more preferably 0.020% by mass or more, preferably 5.000% by mass or less, more preferably 2.000% by mass or less, still more preferably 1.500% by mass or less, and even more preferably 1.000% by mass or less. When the concentration of the acidulant in the beverage is within the above range, the bitter taste stimulation of the beverage is more prominent, so the effect of reducing the bitter taste stimulation by the dead useful bacteria is more useful. Further, when the concentration of the acidulant is below the above upper limit value, the acidity of the beverage can be suppressed within a preferable range for drinking. In addition, the acidulant concentration in the beverage can be measured by a high performance liquid chromatography (HPLC) method. 【0049】 <Sodium> The beverage of the present invention preferably has a sodium concentration of 15 mg / 100 mL or more, more preferably 20 mg / 100 mL or more, still more preferably 30 mg / 100 mL or more, even more preferably 50 mg / 100 mL or more, preferably 250 mg / 100 mL or less, more preferably 200 mg / 100 mL or less, and still more preferably 180 mg / 100 mL or less. If the sodium concentration in the beverage is at least the above lower limit value, the effect of reducing the bitter taste stimulation of the beverage can be further improved. Further, if the sodium concentration in the beverage is below the above upper limit value, a beverage with less saltiness can be obtained. Note that the "sodium concentration" in this specification refers to the total concentration of sodium present in the beverage, for example, the total concentration of sodium derived from useful bacteria and sodium derived from other additives. In addition, examples of the method for measuring the sodium concentration in the beverage include atomic absorption spectrometry. 【0050】The sodium concentration in a beverage can be adjusted by adjusting the amount of one or more substances selected from the group consisting of sodium, sodium compounds, and sodium-containing compositions that are added to the beverage. Water-soluble sodium compounds are preferred as the sodium compounds, with sodium chloride, trisodium citrate, sodium bicarbonate, and sodium gluconate being particularly preferred, and sodium chloride being even more preferred among these. The sodium-containing compositions include compositions containing the aforementioned sodium compounds. Commercially available sodium compounds and sodium compositions can be used. 【0051】 <Other Ingredients> The beverage of the present invention may contain one or more additives selected from the group consisting of flavorings, colorings, sweeteners, preservatives, thickeners, stabilizers, emulsifiers, dietary fiber, bittering agents, antioxidants, pH adjusters, vitamins, nutritional fortifiers, umami components, dietary fiber, extracts, solvents, minerals, water-soluble functional components, and fat-soluble functional components, to the extent that they do not interfere with the effects of the present invention. 【0052】 The beverage of the present invention preferably contains a carbohydrate-based sweetener of 22 g / 100 mL or less, more preferably 15 g / 100 mL or less, even more preferably 10 g / 100 mL or less, and most preferably 8 g / 100 mL or less. If the carbohydrate-based sweetener content is below the above upper limit, the bitter taste of the beverage can be reduced by adding beneficial bacteria, which are beneficial components, without relying on the sweetness derived from the sweetener, and a beverage with high health benefits can be made. Examples of carbohydrate-based sweeteners include sugar, starch-derived sugars (glucose, maltose, and fructose, etc.), other sugars (fructooligosaccharides, galactooligosaccharides, and lactose, etc.), and sugar alcohols (sorbitol, reduced starch syrup, etc.). 【0053】The beverage of the present invention preferably contains a non-carbohydrate sweetener of 220 mg / 100 mL or less, more preferably 150 mg / 100 mL or less, even more preferably 120 mg / 100 mL or less, and most preferably 100 mg / 100 mL or less. If the content of the non-carbohydrate sweetener is below the above upper limit, the bitter taste of the beverage can be reduced by adding beneficial bacteria, which are beneficial components, without relying on sweetness derived from the sweetener, and a beverage with high health benefits can be made. Examples of non-carbohydrate sweeteners include stevia, licorice, aspartame, acesulfame potassium, and sucralose. 【0054】 <pH of the beverage> The beverage of the present invention must have a pH of 1.90 or higher, preferably 2.00 or higher, more preferably 2.10 or higher, and must have a pH of 4.60 or lower, preferably 4.00 or lower, and more preferably 3.50 or lower. When the pH of the beverage is within the above range, the bitter taste of the beverage is more pronounced, making the bitter taste reduction effect of dead beneficial bacteria even more useful. Furthermore, if the pH of the beverage is above the lower limit, the acidity of the beverage can be suppressed to a range that is preferable for drinking. The pH of the beverage can be adjusted by adding acidulants, pH adjusters, etc. to the beverage. 【0055】 Furthermore, the beverage of the present invention may also be an immunostimulatory composition. An immunostimulatory composition is a composition having immunostimulatory ability (immune activation ability). Immunostimulatory ability (immune activation ability) is the stimulating effect (activation effect) of the innate immune system on cells or living organisms. An immunostimulatory composition according to one embodiment may be a dendritic cell activation composition, or a plasmacytoid dendritic cell activation (pDC activation) composition. 【0056】The beverage of the present invention as an immunostimulatory composition may be a pharmaceutical composition or a quasi-drug. The beverage of the present invention as an immunostimulatory composition contains an effective amount of dead beneficial bacteria as described above. Here, "effective amount" refers to the amount of dead beneficial bacteria that, when consumed in a normal amount of the beverage of the present invention, are ingested to the extent that immune-boosting effects are exerted. When the beverage of the present invention is an immunostimulatory composition, it may be a health food, a functional food, a nutritional supplement, a health functional food (e.g., a food for specified health uses, a nutritional functional food, a food with functional claims), a food for special dietary uses (e.g., a food for infants, a food for pregnant and lactating women, a food for the sick), and a supplement. 【0057】 When the beverage of the present invention is provided as an immune-boosting composition, the beverage of the present invention may particularly be a health food, functional food, nutritional composition, nutritional supplement, health food, food for specified health uses, food with nutritional function, or food with functional claims, etc., that has immune-boosting ability. When the beverage of the present invention is an immune-boosting composition, the beverage of the present invention may be labeled with, for example, support for maintaining the immune function of healthy people (immune care), for those concerned about a decline in immune function, to suppress a decline in immune function, for those concerned about sunburn, for those concerned about skin damage in daily life, for those concerned about dry skin, for those concerned about skin flushing, for those concerned about skin erythema, for those concerned about redness of the skin, for those concerned about facial redness, for those concerned about rough hands, etc. 【0058】 Furthermore, if the beverage of the present invention is an immunostimulatory composition, the beverage of the present invention can be ingested by individuals who require immunostimulation. While there are no particular limitations on the individuals who require immunostimulation, examples include individuals infected with a virus, individuals with a cold, and individuals aged 65 or older. 【0059】(Method for Manufacturing a Beverage) The method for manufacturing a beverage of the present invention is a method for manufacturing a beverage containing dead beneficial bacteria and caffeine. The method for manufacturing the present invention is not particularly limited, as long as it includes a step (hereinafter also referred to as the blending step) to ensure that the concentration of dead beneficial bacteria in the beverage is 500 million cells / L or more and the concentration of caffeine is 10 mg / 100 mL or more when blending the dead beneficial bacteria and caffeine, and a step (hereinafter also referred to as the pH adjustment step) to adjust the pH of the beverage to be between 1.90 and 4.60 (hereinafter also referred to as the pH adjustment step). In other words, as long as it includes the above steps, it can be manufactured according to conventionally known methods for manufacturing beverages. 【0060】 <Formulation Process> When formulating the dead beneficial bacteria and caffeine, the process to ensure that the concentration of dead beneficial bacteria in the beverage is 500 million cells / L or more and the concentration of caffeine is 10 mg / 100 mL or more can be, for example, by adding caffeine in a proportion of 10 mg / 100 mL or more, optionally water, and other optional components to a mixing tank, and then adding dead beneficial bacteria in a proportion of 500 million cells / L or more. Alternatively, the dead beneficial bacteria and caffeine, water, and optional components can be added to the mixing tank simultaneously. Of course, the manner of addition and the order of formulation are not limited to the above-mentioned methods. 【0061】 <pH Adjustment Process> As a process for adjusting the pH of the beverage to be between 1.90 and 4.60, for example, an acidulant or pH adjuster may be added simultaneously with the above blending process, or after mixing the components added in the above blending process, to bring the pH of the beverage within the above range. Here, as the acidulant, the one described above in the "Acidulant" section of the "Beverage" section can be used. It is preferable to add the acidulant to a concentration within the range described above in the same section. 【0062】The beverage of the present invention does not have to be a packaged beverage, but it is preferable that it be a packaged beverage. Examples of such containers include containers made of plastic materials such as PET bottles, polypropylene bottles, and polyvinyl chloride bottles (resin bottle containers), glass bottles, paper cartons, and cans. The capacity of the container is not particularly limited, but is, for example, 50 mL or more, preferably 100 mL or more, for example 1000 mL or less, and preferably 500 mL or less. 【0063】 A packaged beverage can be manufactured by filling a beverage obtained according to the manufacturing method of the present invention described above into a container as listed above and sealing it according to a known method. 【0064】 Furthermore, the beverage of the present invention may or may not undergo heat sterilization. The heat sterilization method and conditions can be those commonly used for beverages such as bottled beverages, but preferably, retort sterilization, UHT (Ultra High Temperature) sterilization, HTST (High Temperature Short Time) sterilization, or pasteurization. 【0065】 (Method for reducing bitterness in caffeine-containing beverages) The method for reducing bitterness in caffeine-containing beverages according to the present invention is a method for reducing bitterness in a beverage containing dead beneficial bacteria and caffeine, and is not particularly limited in that it includes a step of ensuring that the concentration of dead beneficial bacteria in the beverage is 500 million cells / L or more and the concentration of caffeine is 10 mg / 100 mL or more when blending the dead beneficial bacteria and caffeine. 【0066】 When incorporating dead beneficial bacteria and caffeine, the method used to ensure that the concentration of dead beneficial bacteria in the beverage is 500 million cells / L or more and the concentration of caffeine is 10 mg / 100 mL or more can be the same as the formulation process described in the method for producing the beverage of the present invention. 【0067】The present invention will be described in detail below based on examples, but the present invention is not limited to these examples. In the following description, "%" representing quantity refers to mass unless otherwise specified. Various evaluations were performed in each test group using the following methods. 【0068】 (Test Example 1) pH of a beverage and bitterness stimulation To investigate the relationship between the pH of a beverage and bitterness stimulation, the following test was conducted. <Sample Preparation> Deionized water was mixed with caffeine at a final concentration of 50 mg / 100 mL and citric acid (anhydrous) at the final concentrations shown in Table 1 to prepare test groups 1-8. <Sensory Evaluation> [Bitterness Stimulation] The beverages obtained from each test group, prepared at approximately 20°C, were evaluated for bitterness stimulation by five trained panelists with sensory discrimination abilities based on the evaluation criteria below. The average value and standard deviation of the scores from the five panelists were calculated. The results are shown in Table 1. Test group 4 (pH 2.73, citric acid concentration 0.10 mass%) was fixed at 4 points, and test group 8 (pH 5.78, no citric acid added) was fixed at 1 point. The interval from 1 to 4 points was divided equally and evaluated in 0.5-point increments (higher scores indicate stronger bitterness stimulation). 【0069】 (Test Example 2) Relationship between the type of acidulant and the bitterness stimulus of the beverage To investigate the relationship between the type of acidulant and the bitterness stimulus of the beverage, the following test was conducted. <Sample Preparation> Caffeine and various acidulants listed in Table 2 were added to deionized water to a final concentration of 50 mg / 100 mL of caffeine and 0.1% by mass of the acidulants to prepare test groups 9-13. <Sensory Evaluation> The bitterness stimulus of each test group sample prepared above was evaluated according to the same criteria as in Test Example 1. The results are shown in Table 2. 【0070】(Test Example 3) To investigate the relationship between the concentration of beneficial bacteria and the effect of reducing bitterness in beverages and off-odors derived from beneficial bacteria, the following tests were conducted. <Sample Preparation> To deionized water, caffeine was added at a final concentration of 50 mg / 100 mL, citric acid (anhydrous) at a final concentration of 0.1% by mass, and beneficial bacteria (Lactococcus lactis subspecies lactis JCM5805, or Rhamnosus live bacterial powder (containing one or more types of Lactobacillus rhamnosus)) were added to the final concentrations shown in Table 3. The resulting beverages were pasteurized under conditions equivalent to 60°C for 10 minutes to prepare test groups 14-25. <Sensory Evaluation> [Bitterness] For bitterness, the samples from each test group prepared above were evaluated according to the same criteria as in Test Example 1. The results are shown in Table 3. [Off-odor derived from dead beneficial bacteria] Five trained panelists with sensory discrimination abilities evaluated the off-odor derived from dead beneficial bacteria in the beverages obtained in each of the above test groups, which were prepared at approximately 20°C, based on the evaluation criteria below. The average and standard deviation of the scores from the five panelists were calculated. The results are shown in Table 3. Test group 4 (no added dead beneficial bacteria) was fixed at 1 point, and test group 20 (added 100,000 billion JCM5805 dead bacteria / L) was fixed at 5 points. The interval from 1 to 5 points was divided equally and evaluated in 0.5-point increments (the lower the score, the less off-odor derived from dead beneficial bacteria). Here, off-odor derived from dead beneficial bacteria refers to off-odor such as a characteristic culture medium odor that arises from the addition of dead beneficial bacteria. 【0071】(Test Example 4) Caffeine concentration and the effect of beneficial bacteria on reducing bitterness in beverages To investigate the relationship between caffeine concentration and the effect of beneficial bacteria on reducing bitterness in beverages, the following test was conducted. <Sample Preparation> Citric acid (anhydrous) was added to deionized water at a final concentration of 0.1% by mass, and beneficial bacteria (Lactococcus lactis subspecies lactis JCM5805 raw powder) and caffeine were added to the final concentrations shown in Table 4. The resulting beverages were pasteurized under conditions equivalent to 60°C for 10 minutes to prepare test groups 26-33. <Sensory Evaluation> [Bitterness] The bitterness was evaluated for each test group sample prepared above according to the following criteria. Test group 4 (citric acid concentration 0.1% by mass, caffeine 50 mg / 100 mL) was fixed at 4 points, and test group 32 (citric acid concentration 0.1% by mass, caffeine concentration 200 mg / 100 mL) was fixed at 15 points. The interval from 4 to 15 points was divided equally and evaluated in 0.5-point increments (higher scores indicate stronger bitterness). The results are shown in Table 4. 【0072】 (Test Example 5) Effect of beneficial bacteria on reducing bitterness in carbonated and non-carbonated beverages To investigate the effect of beneficial bacteria on reducing bitterness in carbonated and non-carbonated beverages, the following test was conducted. <Sample Preparation> To ion-exchanged water, caffeine was added to a final concentration of 50 mg / 100 mL, citric acid (anhydrous) to a final concentration of 0.01% by mass, and beneficial bacteria (Lactococcus lactis subspecies lactis JCM5805 raw powder) were added to a final concentration of 2,000 billion cells / L. Carbonated water was then added to the prepared beverage so that the final gas pressure was 0.1 MPa. The obtained beverages were pasteurized under conditions equivalent to 60°C for 10 minutes to prepare test group 34. <Sensory Evaluation> The bitterness of each test group sample prepared above was evaluated according to the same criteria as in Test Example 1. The results are shown in Table 5. 【0073】(Test Example 6) Sodium Concentration and the Effect of Beneficial Bacteria on Reducing Bitterness Intensity in Beverages To investigate the relationship between sodium concentration and the effect of beneficial bacteria on reducing bitterness in beverages, the following tests were conducted. <Sample Preparation> Beneficial bacteria (Lactococcus lactis subspecies lactis JCM5805 raw powder), caffeine, and sodium chloride were added to deionized water to achieve the final concentrations shown in Tables 6 and 7, respectively. The resulting beverages were pasteurized under conditions equivalent to 60°C for 10 minutes to prepare test groups 35-48. <Sensory Evaluation> The bitterness intensity of the samples from each test group prepared above was evaluated according to the same criteria as in Test Examples 1 and 4. The results are shown in Tables 6 and 7. 【0074】 【0075】 【0076】 【0077】 【0078】 【0079】 【0080】 【0081】Table 1 shows that a characteristic bitter taste occurs in caffeine-containing beverages with a pH between 1.90 and 4.60. Table 2 shows that bitter taste occurs in the above-mentioned acidic caffeine-containing beverages when various acidulants are used. Table 3 shows that when an acidic caffeine-containing beverage contains dead beneficial bacteria at a concentration of 500 million cells / L or more, the bitter taste is reduced compared to a beverage without added beneficial bacteria. Table 4 shows that when the caffeine concentration in an acidic caffeine-containing beverage is 10 mg / 100 mL or higher, the bitter taste of the beverage is even more pronounced, and the bitter taste reduction effect of adding dead beneficial bacteria is even more effective. Table 5 shows that when an acidic caffeine-containing beverage with added dead beneficial bacteria is a carbonated beverage, the bitter taste of the beverage is further reduced. Furthermore, Tables 6 and 7 show that when the sodium concentration of an acidic caffeine-containing beverage is 15 mg / 100 mL or higher, the bitter taste reduction effect of dead beneficial bacteria is further improved. 【0082】 According to the present invention, it is possible to provide a beverage with reduced bitterness, a method for producing the beverage, and a method for reducing bitterness in a caffeine-containing beverage.

Claims

1. A beverage containing dead beneficial bacteria and caffeine, wherein the concentration of dead beneficial bacteria is 500 million cells / L or more, the concentration of caffeine is 10 mg / 100 mL or more, and the pH is 1.90 or higher and 4.60 or lower.

2. The beverage according to claim 1, wherein the concentration of the acidulant is 0.005% by mass or more and 5.000% by mass or less.

3. The beverage according to claim 1, further comprising one or more selected from the group consisting of citric acid, phosphoric acid, malic acid, and tartaric acid and their salts as an acidulant.

4. The beverage according to claim 1, wherein the sodium concentration is 15 mg / 100 mL or more.

5. The beverage according to claim 1, wherein the beverage is a non-carbonated beverage.

6. The beverage according to claim 1, wherein the concentration of dead beneficial bacteria is 4,000 billion cells / L or less.

7. The beverage according to claim 1, wherein the beneficial bacteria are one or more species selected from the group consisting of Lactobacillus and Lactococcus species.

8. The beverage according to claim 1, wherein the beneficial bacteria is one or more selected from the group consisting of Lactobacillus rhamnosus CRL1505 and Lactococcus lactis subspecies lactis JCM5805.

9. The beverage according to claim 1, wherein the concentration of caffeine is 200 mg / 100 mL or less.

10. The beverage according to claim 1, which is a packaged beverage.

11. A method for producing a beverage containing dead beneficial bacteria and caffeine, comprising the steps of: when blending the dead beneficial bacteria and caffeine in the beverage, ensuring that the concentration of dead beneficial bacteria in the beverage is 500 million cells / L or more and the concentration of caffeine is 10 mg / 100 mL or more; and adjusting the pH of the beverage to be between 1.90 and 4.

60.

12. A method for reducing the bitter taste of a beverage containing dead beneficial bacteria and caffeine, comprising the step of, when blending the dead beneficial bacteria and caffeine, ensuring that the concentration of dead beneficial bacteria in the beverage is 500 million cells / L or more and the concentration of caffeine is 10 mg / 100 mL or more.

Images