Milk drink containing black tea extract and its manufacturing method

Abstract

To provide a black tea extract-containing milk beverage that has high titers in both of black tea feeling and milk feeling and offers a good balance between them, and a method for producing the same.SOLUTION: In the whole of a black tea extract-containing milk beverage, the milk solid content is 8.4-12.3 wt.%, the polyphenol total content is 0.09-0.19 wt.%, the catechin content is 0.0045-0.012 wt.%, and the caffeine content is 0.01-0.024 wt.%, with {(polyphenol total content)-(catechin content)} / (catechin content) of 10-20, and (polyphenol total content) / (milk solid content) of 0.01-0.02.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a milk drink containing black tea extract and a method for producing the same. [Background technology]

[0002] Milk beverages containing black tea extract, prepared by mixing black tea extract with milk, are beverages that combine the rich flavor of black tea extract with the inherent sweetness and richness of milk, and have long been popular around the world. For such milk beverages containing black tea extract, the strength and balance of the black tea and milk flavors are important, and excellent balance between these is considered to be highly palatable. A well-known milk beverage containing black tea extract is royal milk tea, which typically uses Assam tea leaves and contains approximately 50 to 60% milk by weight. Milk also comes in a variety of flavors, and the flavor varies depending on the pasteurization method used.

[0003] Patent Document 1 discloses a black tea beverage with milk that contains specific amounts of vanillin and β-damascenone in a specific ratio with the aim of increasing the palatability of the black tea beverage with milk, and describes that the amount of milk solids in the black tea beverage with milk is 1 to 5% by weight. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-38336 Summary of the Invention [Problem to be solved by the invention]

[0005] The milk-added black tea beverage disclosed in Patent Document 1 has a low milk solid content, is insufficient in milk flavor, and has an undesirable balance between the milk flavor and the black tea flavor.

[0006] In view of the above circumstances, the object of the present invention is to provide a milk beverage containing black tea extract that has high titers of both black tea flavor and milk flavor and that has an excellent balance between the two, and a method for producing the same. [Means for solving the problem]

[0007] As a result of extensive research to solve the above problems, the inventors have discovered that by setting the content of milk solids and the components of black tea extract, polyphenols, catechins, and caffeine, in specific amounts in a black tea extract-containing milk beverage, and by controlling the ratio of the amount of polyphenols other than catechins to the amount of catechins and the ratio of the amount of polyphenols to the amount of milk solids to specific values, a black tea extract-containing milk beverage can be obtained that has a high level of both black tea flavor and milk flavor and an excellent balance between the two, and have completed the present invention. That is, in the first aspect of the present invention, the black tea extract-containing milk beverage as a whole has a milk solid content of 8.4 to 12.3% by weight, a total polyphenol content of 0.09 to 0.19% by weight, a catechin content of 0.0045 to 0.012% by weight, and a caffeine content of 0.01 to 0.024% by weight, {(the total content of the polyphenols)-(the content of the catechins)} / (the content of the catechins) is 10 to 20, The present invention relates to a black tea extract-containing milk beverage, in which the ratio of (the total content of the polyphenols) / (the content of the milk solids) is 0.01 to 0.02. Preferably, in the entire milk beverage containing black tea extract, the (total amount of C+GC+EC+EGC) is 0.0011 to 0.0024 wt%, the (total amount of CG+GCG+ECG+EGCG) is 0.004 to 0.01 wt%, and the (total amount of C+GC+EC+EGC) / (total amount of CG+GCG+ECG+EGCG) is 0.2 to 0.34. C: Catechin GC: Gallocatechin EC: Epicatechin EGC: epigallocatechin CG: Catechin gallate GCG: Gallocatechin gallate ECG: epicatechin gallate EGCG: epigallocatechin gallate Preferably, 70% by weight or more of the total content of the polyphenols and the caffeine is derived from Darjeeling tea leaves. Preferably, the milk beverage containing black tea extract is prepared by first heating a mixture containing black tea extract and milk ingredients from a temperature below 10°C at a rate of 0.1 to 5°C / second to 50 to 95°C, holding the mixture at that temperature for 15 to 300 seconds, and then secondly heating the mixture at a rate of 0.1 to 5°C / second to 110 to 135°C, and then heat-treating the mixture at that temperature for 2 to 10 seconds. Preferably, the milk beverage containing black tea extract contains, as a milk ingredient, raw milk that has been heated in a first heating step from a temperature below 10°C to 50 to 95°C at a rate of 0.1 to 5°C / second, held at that temperature for 15 to 300 seconds, and then heated in a second heating step at a rate of 0.1 to 5°C / second to 110 to 135°C, and then heat-treated at that temperature for 2 to 10 seconds. In a second aspect of the present invention, there is provided a mixture of black tea extract and milk raw materials blended together so that the total mixture has a milk solid content of 8.4 to 12.3% by weight, a total polyphenol content of 0.09 to 0.19% by weight, a catechin content of 0.0045 to 0.012% by weight, and a caffeine content of 0.01 to 0.024% by weight, and the ratio {(the total polyphenol content)-(the catechin content)} / (the catechin content) is 10 to 20, and the ratio (the total polyphenol content) / (the milk solid content) is 0.01 to 0.02, The present invention relates to a method for producing a milk beverage containing black tea extract, which includes a primary heating step of raising the temperature from a temperature below 10°C to 50 to 95°C at a rate of 0.1 to 5°C / second and maintaining that temperature for 15 to 300 seconds, followed by a secondary heating step of raising the temperature to 110 to 135°C at a rate of 0.1 to 5°C / second and maintaining that temperature for 2 to 10 seconds. Preferably, in the entire mixture, the (total amount of C+GC+EC+EGC) is 0.0011 to 0.0024 wt %, the (total amount of CG+GCG+ECG+EGCG) is 0.004 to 0.01 wt %, and the (total amount of C+GC+EC+EGC) / (total amount of CG+GCG+ECG+EGCG) is 0.2 to 0.34. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a black tea extract-containing milk beverage that has high titers of both black tea flavor and milk flavor and that has an excellent balance between the two, and a method for producing the same. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail. The milk beverage containing black tea extract according to this embodiment refers to a beverage containing milk solids derived from milk ingredients and black tea extract, and is characterized by the contents of milk solids, polyphenols, catechins, and caffeine each being within a specific range, and the ratio of the amount of polyphenols other than catechins to the amount of catechins and the ratio of the amount of polyphenols to the amount of milk solids each being specific values.

[0010] The milk solids content refers to the solid content remaining after removing water from the milk ingredients. The content of the milk solids content is preferably 8.4 to 12.3 wt % of the total black tea extract-containing milk beverage, more preferably 8.4 to 11.7 wt %, and even more preferably 8.4 to 10.4 wt %. If the milk solids content is less than 8.4 wt %, the milk flavor may be perceived as weak, or the balance between the black tea flavor and the milk flavor may be poor. On the other hand, if the milk solids content is more than 12.3 wt %, the milk flavor may be too strong, and the balance between the black tea flavor and the milk flavor may be poor. When preparing a black tea extract-containing milk beverage, it is preferable to use a milk ingredient containing milk solids.

[0011] The milk solids content can be measured by a method conforming to the method set forth in the Ministerial Ordinance on the Compositional Standards of Milk and Dairy Products. Specifically, it can be measured by the atmospheric drying method, microwave method, FT-IR milk component measurement method, etc. The milk solids content can be calculated by measuring the solids content in the milk ingredients used to prepare the black tea extract-containing milk beverage and multiplying this by the blending ratio of the milk ingredients in the black tea extract-containing milk beverage. Alternatively, the milk solids content can be calculated by subtracting the solids derived from ingredients other than milk, such as the solids in the black tea extract and the solids in the sweetener, from the total solids in the black tea extract-containing milk beverage.

[0012] The milk ingredient used in preparing the black tea extract-containing milk beverage is preferably raw milk. The amount of raw milk used may be set so that the black tea extract-containing milk beverage satisfies the milk solids content.

[0013] Dairy ingredients other than raw milk can also be used. Examples of such dairy ingredients include cow's milk, skim milk, partially skim milk, concentrated milk, concentrated skim milk, condensed milk, whole milk powder, skim milk powder, whey, whey protein concentrate (WPC), whey protein isolate (WPI), whole milk protein concentrate (TMP), cream, cream powder, whey powder, etc. These dairy ingredients can also be used in amounts that satisfy the milk solids content of the black tea extract-containing milk beverage. Furthermore, raw milk and dairy ingredients other than raw milk can be used in combination.

[0014] The black tea extract is obtained by subjecting black tea leaves to an extraction treatment. Any black tea extract conventionally used in the production of black tea beverages can be used as the black tea extract, without any particular limitation. Specific examples include extracts from black tea leaves and processed products thereof (e.g., concentrated liquid extracts, powdered extracts, etc.).

[0015] Here, "black tea leaves" refers to the buds, leaves or stems of the tea plant (Camellia sinensis var.), an evergreen tree of the Theaceae family, which are withered, rolled, fermented and then dried.

[0016] The black tea leaves are not particularly limited in terms of tea season, shape, origin, variety, type, or grade, and can be commercially available dried tea leaves for drinking. Examples of tea leaf types include Sri Lankan tea leaves (e.g., Uva, Dimbula, Kandy, Ratnapura, Gyal, and Ruhuna), Indian tea leaves (e.g., Assam, Darjeeling, and Nilgiri), Kenyan, Keemun, and Java tea leaves. In this embodiment, Darjeeling tea leaves are preferred in terms of compatibility with dairy ingredients.

[0017] The extraction treatment is not particularly limited, and various extraction methods commonly used in the food processing field can be used. Examples include solvent extraction, air flow extraction, and squeeze extraction. In addition to these extraction treatments, if necessary, further treatments such as solid-liquid separation (e.g., precipitation or filtration), concentration, centrifugation, drying (e.g., spray drying or freeze drying), dilution, and powderization may be performed.

[0018] Examples of the extraction solvent used in the extraction treatment include water, glycerin, propylene glycol, methanol, ethanol, 1-propanol, 2-propanol, acetone, triacetin, etc. At least one selected from these groups can be used. Among these, water or ethanol is preferred, and water is more preferred, considering food safety and cost.

[0019] The polyphenols are those quantified by the Folin-Ciocalteu method shown below, and are preferably polyphenols derived from black tea extract. Examples of the polyphenols include catechins such as catechin, epicatechin, gallocatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate, and epigallocatechin gallate; theaflavins, which are oxidized dimers of catechins; and polymeric tannins composed of catechins or theaflavins as building blocks.

[0020] The Folin-Ciocalteu method is based on the official ISO method (ISO 14502-1:2005). Specifically, the sample solution is adjusted to volume with 50% ethanol, diluted appropriately, and then mixed with Folin-Ciocalteu reagent and 0.4 mmol / L sodium carbonate solution. The mixture is left at 30°C for 30 minutes, centrifuged, and the absorbance at 660 nm is measured using a UV-Vis spectrophotometer. The polyphenol content is calculated as a (+)-catechin equivalent.

[0021] The total content of the polyphenols in the black tea extract-containing milk beverage is preferably 0.09 to 0.19% by weight, more preferably 0.1 to 0.18% by weight, and even more preferably 0.12 to 0.16% by weight. If the total polyphenol content is less than 0.09% by weight, the black tea flavor may be weak or the balance between the black tea flavor and the milk flavor may be poor. On the other hand, if the total polyphenol content is more than 0.19% by weight, the black tea flavor may be perceived as being too astringent or the balance between the black tea flavor and the milk flavor may be poor.

[0022] The catechins are a collective term for eight types of catechins: catechin (C), gallocatechin (GC), catechin gallate (CG), gallocatechin gallate (GCG), epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG), and epigallocatechin gallate (EGCG). Catechins derived from black tea extracts are preferred as catechins.

[0023] The content of the catechins in the black tea extract-containing milk beverage is preferably 0.0045 to 0.012% by weight, more preferably 0.006 to 0.011% by weight, and even more preferably 0.007 to 0.0105% by weight. If the content of catechins is less than 0.0045% by weight, the black tea flavor may be weak, or the balance between the black tea flavor and the milk flavor may be poor. On the other hand, if the content is more than 0.012% by weight, the bitterness may be strong, or the balance between the black tea flavor and the milk flavor may be poor.

[0024] Examples of methods for measuring the catechin content include high-performance liquid chromatography (HPLC) and liquid chromatography tandem mass spectrometry (LC / MS / MS). Specifically, the sample solution is extracted with a mixture (8:2) of methanol and an aqueous oxalic acid solution, centrifuged, and then the volume is determined and analyzed by HPLC and LC / MS / MS. The contents of epicatechin, epicatechin gallate, and epigallocatechin gallate are measured by HPLC analysis, and the contents of catechin, gallocatechin, epigallocatechin, gallocatechin gallate, and catechin gallate are measured by LC / MS / MS analysis. The measurement conditions are as follows:

[0025] (HPLC operating conditions) Column: YMC-Pack ODS-A, φ6.0mmx150mm, particle size 5μm Mobile phase: A mixture of water, methanol, and 0.02 mmol / L phosphate buffer (pH 3.0) Flow rate: 1.0mL / min Column temperature: 40℃ Measurement wavelength: 270nm Fluorescence excitation wavelength: 280 nm Fluorescence measurement wavelength: 310 nm

[0026] (LC / MS / MS operating conditions) Column: InertSustain C18, φ2.1mm x 150mm, particle size 3μm Mobile phase: 1% acetic acid and acetonitrile mixture Flow rate: 0.2mL / min Column temperature: 40℃ Ionization method: Electrospray (positive ion detection mode) Set mass number (m / z): Catechin; 291.2 → 139.0 Gallocatechin: 307.2 → 139.1 Epigallocatechin: 307.2 → 139.1 Gallocatechin gallate: 459.0 → 138.9 Catechin gallate: 443.2 → 122.9

[0027] The catechins preferably satisfy the following conditions in the entire black tea extract-containing milk beverage: (total amount of C+GC+EC+EGC) 0.0011 to 0.0024 wt%, (total amount of CG+GCG+ECG+EGCG) 0.004 to 0.01 wt%, and (total amount of C+GC+EC+EGC) / (total amount of CG+GCG+ECG+EGCG) 0.2 to 0.34. The (total amount of C+GC+EC+EGC) is more preferably 0.0014 to 0.002 wt%, and even more preferably 0.0016 to 0.002 wt%. If the amount is less than 0.0011 wt%, the black tea flavor may be too weak or the balance between the black tea flavor and the milk flavor may be poor. If the amount is more than 0.0024 wt%, the black tea flavor may be too strong or the balance between the black tea flavor and the milk flavor may be poor. The (total amount of CG+GCG+ECG+EGCG) is more preferably 0.005 to 0.009% by weight, and even more preferably 0.006 to 0.0085% by weight. If it is less than 0.004% by weight, the black tea flavor may be too weak, or the balance between the black tea flavor and the milk flavor may be poor. If it is more than 0.01% by weight, the black tea flavor may be too strong, or the balance between the black tea flavor and the milk flavor may be poor. The (total amount of C+GC+EC+EGC) / (total amount of CG+GCG+ECG+EGCG) is more preferably 0.2 to 0.32, and even more preferably 0.2 to 0.3. If it is outside the above range, the balance between the black tea flavor and the milk flavor may be poor.

[0028] The caffeine is a type of purine alkaloid having a purine ring, and its chemical name is 1,3,7-trimethylxanthine, CAS registration number 58-08-2. Caffeine derived from black tea extract is preferred.

[0029] The caffeine content of the black tea extract-containing milk beverage is preferably 0.01 to 0.024% by weight, more preferably 0.012 to 0.022% by weight, and even more preferably 0.014 to 0.02% by weight. If the caffeine content is less than 0.01% by weight, the black tea flavor may be weak or the balance between the black tea flavor and the milk flavor may be poor. On the other hand, if the caffeine content is more than 0.024% by weight, the bitterness may be strong or the balance between the black tea flavor and the milk flavor may be poor.

[0030] The caffeine content can be measured by HPLC analysis, etc. Specifically, the sample solution is extracted with methanol, filtered through a membrane filter (pore size: 0.45 μm), and then analyzed by HPLC. The measurement conditions are as follows:

[0031] (HPLC operating conditions) Model: LC-20AD (Shimadzu Corporation) Detector: UV-visible spectrophotometer SPD-20A (Shimadzu Corporation) Column: CAPCELL PAK C18 MG, φ3.0 mm x 150 mm, particle size 5 μm (Osaka Soda Co., Ltd.) Column temperature: 50℃ Mobile phase: 0.01 mmol / L ammonium acetate solution and methanol mixture (10:1) Flow rate: 0.8mL / min Measurement wavelength: 270nm Injection amount: 5μm

[0032] In the black tea extract-containing milk beverage according to this embodiment, {(total content of the polyphenols)-(content of the catechins)} / (content of the catechins) preferably satisfies a ratio of 10 to 20, more preferably 11 to 19, and even more preferably 12 to 17. If the ratio is outside this range, the balance between the black tea flavor and the milk flavor may be poor.

[0033] In the black tea extract-containing milk beverage according to this embodiment, the ratio (total content of the polyphenols) / (content of the milk solids) is preferably 0.01 to 0.02, more preferably 0.012 to 0.018, and even more preferably 0.014 to 0.016. If the ratio is outside this range, the balance between the black tea flavor and the milk flavor may be poor.

[0034] From the viewpoint of flavor, the polyphenols and caffeine are preferably derived from the black tea extract. However, polyphenols extracted from sources other than black tea or synthetic polyphenols may also be blended. However, when polyphenols derived from sources other than black tea extract are blended, the amount used is preferably less than 10% by weight of the total content of each component.

[0035] In this embodiment, from the viewpoint of the balance between the astringency and acidity of black tea, it is preferable that 70% by weight or more of the total content of the polyphenols and the caffeine in the black tea extract-containing milk beverage be polyphenols and caffeine derived from Darjeeling tea leaves, more preferably 80% by weight or more, even more preferably 90% by weight or more, and particularly preferably 100% by weight.

[0036] In addition to the milk solids and the black tea extract, the black tea extract-containing milk beverage of this embodiment may contain water, sweeteners (sucrose, isomerized sugar, glucose, fructose, lactose, maltose, xylose, isomerized lactose, fructooligosaccharides, maltooligosaccharides, isomaltooligosaccharides, galactooligosaccharides, coupling sugar, palatinose, maltitol, sorbitol, erythritol, xylitol, lactitol, palatinit, reduced starch saccharides, stevia, glycyrrhizin, thaumatin, monellin, aspartame, alitame, saccharin, acesulfame K, sucralose, dulcin, etc.), antioxidants (sodium erythorbate, etc.), emulsifiers (sucrose fatty acid esters, sorbitan fatty acid esters, polyglycerin fatty acid esters, etc.), flavorings (black tea flavors, etc.), etc., as long as the effects of the invention are not impaired.

[0037] The sweetener is preferably sucrose. Examples of sucrose include white sugar and granulated sugar. The amount of sweetener blended is preferably 0 to 8% by weight, more preferably 1 to 8% by weight, even more preferably 2 to 6% by weight, and particularly preferably 3 to 5% by weight, of the total amount of the black tea extract-containing milk beverage. If the amount of sweetener blended is more than 8% by weight, the sweetness may be too strong.

[0038] The method for producing the black tea extract-containing milk beverage according to this embodiment will be described below. The black tea extract-containing milk beverage can be produced by heating a mixture containing black tea extract and dairy ingredients under predetermined conditions, or by heating dairy ingredients under predetermined conditions and then mixing the dairy ingredients with black tea extract.

[0039] First, we will explain a production method by heat-treating a mixture containing black tea extract and milk ingredients. The mixture contains 8.4 to 12.3 wt% milk solids, 0.09 to 0.19 wt% total polyphenols, 0.0045 to 0.012 wt% catechins, and 0.01 to 0.024 wt% caffeine, and the black tea extract and milk ingredients are blended so that the ratio {(total content of polyphenols) - (content of catechins)} / (content of catechins) is 10 to 20, and the ratio (total content of polyphenols) / (content of milk solids) is 0.01 to 0.02. The mixture preferably has a total content of C+GC+EC+EGC of 0.0011 to 0.0024% by weight, a total content of CG+GCG+ECG+EGCG of 0.004 to 0.01% by weight, and a ratio of (C+GC+EC+EGC) / (CG+GCG+ECG+EGCG) of 0.2 to 0.34. The components and their contents are the same as those described for the black tea extract-containing milk beverage. The mixture may be a blend of black tea extract and raw milk, or a blend of black tea extract, milk solids, and water. The mixture may further contain optional ingredients such as a sweetener.

[0040] The mixture is heated in the first heating step from a temperature below 10°C to 50 to 95°C at a rate of 0.1 to 5°C / second, and held at that temperature for 15 to 300 seconds. Thereafter, the mixture is heated in the second heating step at a rate of 0.1 to 5°C / second to 110 to 135°C, and heated at that temperature for 2 to 10 seconds, thereby producing a milk beverage containing black tea extract.

[0041] The temperature rise rate during the primary heating is preferably 0.1 to 5°C / second. If the temperature rise rate is slower than 0.1°C / second, heat sterilization takes a long time, resulting in reduced productivity. On the other hand, if the temperature rise rate is faster than 5°C / second, the amount of utilities such as steam required for heating increases, resulting in increased production costs, and proteins in the dairy ingredients may adhere to the heating surface, resulting in a loss of flavor due to burning. The temperature rise rate during the primary heating is more preferably 0.5 to 2.5°C / second, and even more preferably 1.3 to 1.8°C / second.

[0042] The holding temperature during the primary heating is preferably 50 to 95°C. If the holding temperature is lower than 50°C, it may be difficult to obtain the effect of the sterilization treatment by the primary heating, and if it is higher than 95°C, it may be difficult to achieve the effect of having high titers of both the black tea flavor and the milk flavor and an excellent balance between them. The holding temperature during the primary heating is more preferably 60 to 70°C, and even more preferably 60 to 65°C. The temperature during heating refers to the temperature of the mixture containing the black tea extract and the milk ingredients during the heating.

[0043] The holding time during the primary heating is preferably 15 to 300 seconds. If the holding time is shorter than 15 seconds, it becomes difficult to secure the piping length required for homogenization during the primary heating, while if it is longer than 300 seconds, it may become difficult to achieve the effect of achieving high levels of both black tea flavor and milk flavor with an excellent balance between the two. The holding time during the primary heating is more preferably 15 to 120 seconds, even more preferably 15 to 80 seconds, and particularly preferably 15 to 60 seconds. Note that the heating holding time refers to the time during which the temperature of the mixture containing the black tea extract and the milk ingredients is maintained within a predetermined temperature range during heating, and does not include the time required for the temperature to rise.

[0044] The apparatus for carrying out the primary heat treatment is not particularly limited, and an apparatus used for thermal sterilization of raw milk can be appropriately selected, but in consideration of productivity, a channel-type sterilizer is preferred. Examples of such sterilizers include, but are not limited to, a plate-type sterilizer, a tube-type sterilizer, a spin-injection sterilizer, and a Joule-type sterilizer.

[0045] During the primary heating, a conventionally known homogenization treatment may be carried out in order to make the diameter of the fat globules contained in the dairy raw material uniform and stabilize the quality. In this case, a device such as a homogenizer, a microfluidizer, or a colloid mill can be used. Note that such a homogenization treatment can also be carried out during cooling after the secondary heating.

[0046] The temperature rise rate during the secondary heating is preferably 0.1 to 5°C / second. If the temperature rise rate is slower than 0.1°C / second, heat sterilization takes a long time, and productivity may be reduced too much. On the other hand, if the temperature rise rate is faster than 5°C / second, the amount of utilities such as steam required for heating increases, which may increase production costs, or proteins in the dairy ingredients may adhere to the heating surface, causing a deterioration in flavor due to burning. The temperature rise rate during the secondary heating is more preferably 0.5 to 2.5°C / second, and even more preferably 0.8 to 1.3°C / second.

[0047] The holding temperature during the secondary heating is preferably 110 to 135°C. If the holding temperature is lower than 110°C, it may be difficult to obtain the effect of the sterilization treatment by the secondary heating, and if it is higher than 135°C, it may be difficult to achieve the effect of having high titers of both the black tea flavor and the milk flavor and an excellent balance between them. The holding temperature during the secondary heating is more preferably 115 to 132°C, and even more preferably 115 to 125°C.

[0048] The holding time during the secondary heating is preferably 2 to 10 seconds. If the holding time is shorter than 2 seconds, it may be difficult to obtain the effect of the sterilization treatment by the secondary heating, and if it is longer than 10 seconds, it may be difficult to obtain the effect of having high titers of both black tea flavor and milk flavor and an excellent balance between the two. The holding time during the secondary heating is more preferably 2 to 8 seconds, and even more preferably 2 to 5 seconds. Furthermore, it is preferable to immediately cool the black tea extract-containing milk beverage after the completion of the secondary heating.

[0049] Next, a method for producing the black tea extract by heat-treating a milk raw material under predetermined conditions and then mixing the milk raw material with a black tea extract will be described. From the viewpoint of flavor, the milk raw material used in this method is preferably raw milk.

[0050] When heat-treating the milk raw material, it is preferable to first heat the raw material from a temperature below 10°C to 50 to 95°C at a rate of 0.1 to 5°C / second, hold the raw material at that temperature for 15 to 300 seconds, and then second heat the raw material at a rate of 0.1 to 5°C / second to 110 to 135°C, and heat-treat the raw material at that temperature for 2 to 10 seconds. The detailed conditions for the heat treatment are the same as those for heat-treating the mixture described above. The milk raw material heat-treated in this manner can easily satisfy the requirements of a protein reduction value of 4 to 9 and a denatured whey protein ratio of 70 to 90%.

[0051] The protein reducing value is measured by the ferricyanide reduction method, which measures the reducing power that increases when dairy raw materials are heated due to an increase in SH groups caused by protein denaturation and compounds formed by browning reactions. The protein reducing value can be measured in accordance with "Examination Methods for Dairy Products, Commentary, edited by the Pharmaceutical Society of Japan" (Kanbara Publishing Co., Ltd., p. 131, published March 20, 1984). The protein reducing value in the dairy raw materials is preferably 4 to 9. This can suppress the cooked odor that occurs due to excessive heat denaturation in conventional heat sterilization treatments, and can achieve the effects of high black tea flavor and milk flavor, with a good balance between the two. The protein reducing value is more preferably 5 to 9, even more preferably 5.5 to 9, and particularly preferably 6 to 9.

[0052] The denatured whey protein percentage is an index showing the proportion of whey protein denatured by heating to the total whey protein in the milk raw material. The lower the denatured whey protein percentage, the less the whey protein is denatured by heating. Generally, the denatured whey protein percentage is 20 to 45% in raw milk and about 85 to 95% in UHT pasteurized milk.

[0053] The denatured whey protein percentage is measured as follows: Place 20 mL of dairy ingredients in a lidded test tube, add 8.0 g of NaCl, then cover and place in a water bath at 37°C ± 1°C for 30 minutes. During this time, shake the test tube well to completely saturate the dairy ingredients with NaCl. Then, without cooling, immediately perform suction filtration using a Kiriyama funnel with quantitative filter paper (No. 7) and collect 3 mL of filtrate. If the filtrate is cloudy, filter it again with filter paper to obtain a clear solution. Add 1.0 mL of the filtrate to the test tube containing 10 mL of saturated NaCl solution and mix. Then, add two drops of 23% HCl solution using a 5 mL pipette and mix to make the liquid cloudy.

[0054] The turbidity (N 100) is measured at a wavelength of 420 nm. The turbidity (N) measured at a wavelength of 420 nm within 5 to 10 minutes after the addition of the HCl solution is also used to calculate the denatured whey protein percentage using the following formula. The measurement can be performed using a U-2900 spectrophotometer (manufactured by Hitachi, Ltd.) in the %T mode. Denatured whey protein rate (%) = {(N / N 100 )×100}

[0055] The filtrate is tested twice, and if the error between the two measurements is within 2%, the average of the two is used as the denatured whey protein percentage. If the error between the two measurements exceeds 2%, the test is repeated to obtain four measurements, and the average of the four measurements is used as the denatured whey protein percentage.

[0056] As described above, the black tea extract-containing milk beverage according to the present embodiment can be easily obtained by mixing a milk raw material having a protein reduction value of 4 to 9 and a denatured whey protein ratio of 70 to 90% with a black tea extract. When mixing the milk raw material with the black tea extract, optional ingredients such as a sweetener may also be added.

[0057] The milk drink containing black tea extract produced as described above can be commercialized by packaging it in a container such as a box or a bottle. [Example]

[0058] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples, "parts" and "%" are by weight. The raw materials used in the examples and comparative examples are as follows: 1) Raw milk (milk solids content: 13.0%) 2) San-ei Gen F.F.I. Co., Ltd. "FD Black Tea Extract Powder No. 17259": Powdered extract of Darjeeling tea leaves 3) Honey Coffee Co., Ltd. "Assam Aroma Tea" 4) "Spoon Brand Granulated Sugar" manufactured by Mitsui Sugar Co., Ltd.

[0059] <Method for measuring each content> The milk solids content was measured according to the method described in the Ministerial Ordinance on the Compositional Standards of Milk and Dairy Products. The total polyphenol content was determined based on the Folin-Ciocalteu method described previously. The catechin content and caffeine content were measured by the above-mentioned HPLC analysis method and LC / MS / MS analysis method, respectively.

[0060] <Sensory evaluation of milk drinks containing black tea extract> The milk drinks containing black tea extract obtained in the Examples and Comparative Examples were adjusted to 10°C, and then 10 experienced panelists drank them, and each panelist performed a sensory evaluation in terms of the black tea flavor, the milk flavor, and the balance between the black tea flavor and the milk flavor. The average scores are shown in each table as the evaluation score of the sensory evaluation. The evaluation criteria were as follows:

[0061] (Tea feeling) 5 points: Better than the milk drink containing black tea extract of Example 3, with a very strong black tea flavor 4 points: Equivalent to the milk drink containing black tea extract of Example 3, with a strong black tea flavor 3 points: Slightly inferior to the milk drink containing black tea extract of Example 3, but still has a black tea flavor 2 points: Worse than the milk drink containing black tea extract of Example 3, with almost no black tea flavor 1 point: Much worse than the milk drink containing black tea extract of Example 3, no black tea flavor at all

[0062] (Milky) 5 points: Better than the milk drink containing black tea extract of Example 3, with a very strong milky taste 4 points: Equivalent to the milk drink containing black tea extract of Example 3, with a strong milky taste 3 points: Slightly inferior to the milk drink containing black tea extract of Example 3, but still has a milky taste 2 points: Worse than the milk drink containing black tea extract of Example 3, with almost no milky taste 1 point: Much worse than the milk drink containing black tea extract of Example 3, no milky taste at all

[0063] (Balance of tea and milk flavor) 5 points: Better than the milk drink containing black tea extract of Example 3, with an extremely good balance of black tea flavor and milk flavor 4 points: Equivalent to the milk drink containing black tea extract of Example 3, with an excellent balance of black tea flavor and milk flavor 3 points: Slightly inferior to the milk drink containing black tea extract of Example 3, but the balance between the black tea flavor and the milk flavor is good 2 points: Worse than the milk drink containing black tea extract of Example 3, with a poor balance between the black tea flavor and the milk flavor 1 point: Much worse than the milk drink containing black tea extract of Example 3, with an extremely poor balance between the black tea flavor and the milk flavor

[0064] (Overall evaluation of milk drinks containing black tea extract) An overall evaluation was made based on the evaluation results of the black tea flavor, the milk flavor, and the balance between the black tea flavor and the milk flavor. The evaluation criteria were as follows: A: The black tea flavor, milk flavor, and balance of black tea flavor and milk flavor all meet the criteria of 4.5 to 5.0 points. B: The black tea flavor, milk flavor, and balance of black tea flavor and milk flavor are all 4.0 points or more and 5.0 points or less, and at least one is 4.0 points or more and less than 4.5 points. C: The black tea flavor, milk flavor, and balance of black tea flavor and milk flavor are all 3.0 points or more and 5.0 points or less, and at least one is 3.0 points or more and less than 4.0 points. D: The black tea flavor, milk flavor, and balance of black tea flavor and milk flavor are all 2.0 points or more and 5.0 points or less, and at least one is 2.0 points or more and less than 3.0 points. E: In the evaluation of black tea flavor, milk flavor, and balance of black tea flavor and milk flavor, at least one item was less than 2.0

[0065] Example 1: Preparation of milk drink containing black tea extract According to the formulation in Table 1, 70.0 parts by weight of raw milk, 0.3 parts by weight of black tea extract powder, 4.0 parts by weight of granulated sugar, and 25.7 parts by weight of water were mixed to obtain a mixture. The mixture was heated from 5°C to 63°C at a heating rate of 1.5°C / sec in a tubular heat exchanger and held at this temperature for 17 seconds to perform primary heating. During primary heating, the mixture was homogenized under a pressure of 17 MPa in a homogenizer, then heated to 125°C at a heating rate of 0.9°C / sec in a tubular heat exchanger and held at this temperature for 2 seconds to perform sterilization (secondary heating). The mixture was then cooled to 4°C in the same tubular heat exchanger to obtain a black tea extract-containing milk beverage. The milk solids, total polyphenols, catechins, and caffeine contents of the resulting black tea extract-containing milk beverage were measured, and sensory evaluations were performed on the black tea flavor, milk flavor, and balance of the black tea flavor and milk flavor. The results are shown in Table 1.

[0066] [Table 1]

[0067] (Examples 2 to 5 and Comparative Examples 1 to 4) A black tea extract-containing milk beverage was obtained in the same manner as in Example 1, except that the amounts of raw milk, black tea extract powder, granulated sugar, and water were changed according to the formulation in Table 1. The obtained black tea extract-containing milk beverage was subjected to measurement of the milk solids content, total polyphenols, catechins, and caffeine content, and sensory evaluation of the black tea flavor, milk flavor, and balance between the black tea flavor and the milk flavor. The results are shown in Table 1.

[0068] (Comparative Example 5) A milk beverage containing black tea extract was obtained in the same manner as in Example 1, except that the amounts of black tea extract powder and water were changed according to the formulation in Table 1, and 3.0 parts by weight of black tea extract was further mixed in. The milk solids, total polyphenols, catechins, and caffeine contents of the obtained milk beverage containing black tea extract were measured, and a sensory evaluation was conducted on the black tea flavor, milk flavor, and balance between the black tea flavor and milk flavor. The results are shown in Table 1.

[0069] From Table 1, it can be seen that in Examples 1 to 5, the black tea flavor and the milk flavor were both strongly felt, and the balance between the black tea flavor and the milk flavor was good, resulting in an overall rating of C or higher. On the other hand, in Comparative Example 1, the black tea flavor was weak, and the balance between the black tea flavor and the milk flavor was poor, resulting in an overall rating of D. In Comparative Examples 2 and 3, the milk flavor was not felt sufficiently, resulting in an overall rating of D. Furthermore, in Comparative Examples 4 and 5, the milk flavor was not felt sufficiently, and the balance between the black tea flavor and the milk flavor was poor, resulting in an overall rating of E or D.

[0070] Example 6: Preparation of milk drink containing black tea extract A mixture was obtained by mixing 70.0 parts by weight of raw milk, 0.3 parts by weight of black tea extract powder, 4.0 parts by weight of granulated sugar, and 25.7 parts by weight of water in the same manner as in Example 1. A milk beverage containing black tea extract was obtained by heating and cooling the mixture in the same manner as in Example 1, except that the heating conditions were changed to those shown in Table 2. The milk solids, total polyphenols, catechins, and caffeine contents of the obtained milk beverage containing black tea extract were measured, and a sensory evaluation was conducted on the black tea flavor, milk flavor, and balance between the black tea flavor and the milk flavor. The results are shown in Table 2.

[0071] [Table 2]

[0072] Examples 7 to 11 A black tea extract-containing milk beverage was obtained in the same manner as in Example 6, except that the heat treatment conditions for heat-treating the mixed liquid were changed according to the description in Table 2. The obtained black tea extract-containing milk beverage was subjected to measurement of the contents of milk solids, total polyphenols, catechins, and caffeine, and a sensory evaluation of the black tea flavor, milk flavor, and balance between the black tea flavor and the milk flavor. The results are shown in Table 2.

[0073] From Table 2, it can be seen that in Examples 6 to 11, the black tea flavor and the milk flavor were both strong, and the balance between the black tea flavor and the milk flavor was good, and the overall evaluation was C or higher.

[0074] Example 12 Raw milk alone was heated from 5°C to 63°C at a heating rate of 1.5°C / sec in a tubular heat exchanger and held at this temperature for 17 seconds to perform primary heating. During primary heating, the milk was homogenized under a pressure of 17 MPa in a homogenizer, then heated to 125°C at a heating rate of 0.9°C / sec in a tubular heat exchanger and held at this temperature for 2 seconds to perform sterilization (secondary heating). The milk was then cooled to 4°C in the same tubular heat exchanger to obtain sterilized milk. 70.0 parts by weight of the resulting milk was mixed with a mixture of 0.3 parts by weight of black tea extract powder and 4.0 parts by weight of granulated sugar dissolved in 25.7 parts by weight of water to obtain a black tea extract-containing milk beverage. The resulting black tea extract-containing milk beverage was subjected to measurement of milk solids, total polyphenols, catechins, and caffeine content, and sensory evaluation of the black tea flavor, milk flavor, and balance of the black tea flavor and milk flavor.

[0075] As a result, the milk solids content was 9.1 wt%, the total polyphenols content was 0.14 wt%, the catechins content was 0.0087 wt%, the caffeine content was 0.017 wt%, {(the total polyphenols content) - (the catechins content)} / (the catechins content) was 15.1, (the total polyphenols content) / (the milk solids content) was 0.015, (the total amount of C + GC + EC + EGC) was 0.0017 wt%, (the total amount of CG + GCG + ECG + EGCG) was 0.007 wt%, and (the total amount of C + GC + EC + EGC) / (the total amount of CG + GCG + ECG + EGCG) was 0.24. In addition, in the sensory evaluation, the black tea flavor was 4.8 points, the milk flavor was 4.1 points, and the balance between the black tea flavor and the milk flavor was 4.7 points, and the overall rating was B.

Claims

1. The black tea extract-containing milk beverage as a whole has a milk solid content of 8.4 to 12.3% by weight, a total polyphenol content of 0.09 to 0.19% by weight, a catechin content of 0.0045 to 0.012% by weight, and a caffeine content of 0.01 to 0.024% by weight, {(the total content of the polyphenols) - (the content of the catechins)} / (the content of the catechins) is 10 to 20, (the total content of the polyphenols) / (the content of the milk solids) is 0.01 to 0.02, The black tea extract-containing milk drink is a Darjeeling tea extract.

2. 2. The milk beverage containing black tea extract according to claim 1, wherein the total amount of C+GC+EC+EGC in the entire milk beverage containing black tea extract is 0.0011 to 0.0024% by weight, the total amount of CG+GCG+ECG+EGCG is 0.004 to 0.01% by weight, and the ratio of (total amount of C+GC+EC+EGC) / (total amount of CG+GCG+ECG+EGCG) is 0.2 to 0.

34. C: Catechin GC: Gallocatechin EC: epicatechin EGC: epigallocatechin CG: Catechin gallate GCG: gallocatechin gallate ECG: epicatechin gallate EGCG: epigallocatechin gallate

3. 3. The black tea extract-containing milk beverage according to claim 1 or 2, wherein a mixture containing black tea extract and milk ingredients is heated in a primary heating step from a temperature below 10°C to 50 to 95°C at a rate of 0.1 to 5°C / second, and maintained at that temperature for 15 to 300 seconds. Thereafter, in a secondary heating step, the mixture is heated in a secondary heating step at a rate of 0.1 to 5°C / second to 110 to 135°C, and maintained at that temperature for 2 to 10 seconds.

4. 4. The black tea extract-containing milk beverage according to claim 1, wherein the milk ingredient is raw milk that has been heated in a primary heating step from a temperature below 10°C to 50 to 95°C at a rate of 0.1 to 5°C / second, maintained at that temperature for 15 to 300 seconds, and then heated in a secondary heating step at a rate of 0.1 to 5°C / second to 110 to 135°C, and then heat-treated at that temperature for 2 to 10 seconds.

5. a mixture of black tea extract and milk raw materials blended together such that the total mixture has a milk solid content of 8.4 to 12.3% by weight, a total polyphenol content of 0.09 to 0.19% by weight, a catechin content of 0.0045 to 0.012% by weight, and a caffeine content of 0.01 to 0.024% by weight, and the ratio {(the total polyphenol content) - (the catechin content)} / (the catechin content) is 10 to 20, and the ratio (the total polyphenol content) / (the milk solid content) is 0.01 to 0.02; The method includes a step of first heating, raising the temperature from a temperature below 10°C to 50-95°C at a rate of 0.1-5°C / second, holding the temperature at that temperature for 15-300 seconds, and then second heating, raising the temperature to 110-135°C at a rate of 0.1-5°C / second, and heat-treating the material at that temperature for 2-10 seconds; The method for producing a milk drink containing black tea extract, wherein the black tea extract is Darjeeling tea extract.

6. 6. The method for producing a milk beverage containing black tea extract according to claim 5, wherein, in the entire mixture, (the total amount of C+GC+EC+EGC) is 0.0011 to 0.0024% by weight, (the total amount of CG+GCG+ECG+EGCG) is 0.004 to 0.01% by weight, and (the total amount of C+GC+EC+EGC) / (the total amount of CG+GCG+ECG+EGCG) is 0.2 to 0.

34. C: Catechin GC: Gallocatechin EC: epicatechin EGC: epigallocatechin CG: Catechin gallate GCG: gallocatechin gallate ECG: epicatechin gallate EGCG: epigallocatechin gallate

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