Powder composition

Abstract

The purpose of the present invention is to provide a powder composition having excellent ability to retain an aromatic component derived from tea leaves.　Provided is a powder composition containing a tea leaf extract, wherein dextrin is blended and the molecular weight distribution of the composition is controlled so that the proportion having molecular weights of 250,000 or more is 0.5 to 10%.

Description

Technical Field

[0001] The present invention relates to a powder composition, and more specifically, to a powder composition containing a tea extract and dextrin.

Background Art

[0002] For a general powdering method for obtaining instant tea, a spray drying method suitable for continuous mass production is adopted. Spray drying is a method of instantaneously evaporating moisture by spraying fine droplets into hot air. Since the residence time exposed to high temperature is short and the given amount of heat is consumed as latent heat of evaporation, the heat load on the liquid content is suppressed, and a powder with less quality deterioration can be obtained. And the higher the concentration of the liquid content to be spray-dried, the higher the retention rate of the aroma components contained in the liquid after spray drying. This can be explained by the selective diffusion theory. In the liquid droplets during drying, when the solute concentration is low, the diffusion coefficient of the aroma components is low, and the aroma components also volatilize simultaneously with the evaporation of water. However, the higher the solute concentration, the higher the diffusion coefficient of the aroma components, and the aroma remains because water evaporates faster than the transfer of the aroma components. Therefore, in order to obtain high-quality instant tea, it is important to produce a tea concentrate containing a high concentration of aroma components.

[0003] Regarding the method of concentrating a tea extract, from the perspective of the principle of separating water into any of the solid, liquid, or gas phases, it can be classified into three types: freeze concentration (water phase - solid), membrane concentration (water phase - liquid), and evaporation concentration (water phase - gas). Among these, for evaporation concentration, since the heat load on the liquid content is large, it is difficult to obtain a concentrate that retains aroma components that are easily thermally deteriorated like tea. Also, freeze concentration has high hurdles to practical application such as long concentration time and high cost, and in addition, it is difficult to increase the concentration in the first place. Therefore, concentration by these two methods has not been adopted very much. On the other hand, for membrane concentration, since it is a method of increasing the solute concentration by applying pressure while keeping water through a membrane with fine pores, evaporation and freezing are not required, so it can be concentrated at low cost without changing the quality.

[0004] Furthermore, as a method for producing a concentrated tea solution, it is known to add dextrin, which is a kind of excipient and has a molecular structure in which sugars are linked in a chain, to a tea extract. For example, when non-cyclic dextrin or cyclic dextrin with an average degree of polymerization of 4 to 10 is added to the extract of tea leaves, roasted grains, or roasted beans before concentration, and then membrane concentration is performed at 40°C, it has been reported that the extract can be concentrated without reducing the concentration efficiency (Patent Document 1).

[0005] Also, regarding specific dextrin, it is known to improve the solubility of instant tea after spray drying. For example, it has been reported that an instant tea with excellent flavor and instant solubility can be produced by spray drying tea containing dextrin with an average degree of polymerization of 4 to 10 or a combination thereof with cyclic dextrin in a state where carbon dioxide gas is dissolved (Patent Document 2). In addition, it has been reported that an instant tea with excellent flavor and solubility can be provided by adding indigestible dextrin to a tea extract and spray drying (Patent Document 3).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] Since the aromatic components that contribute to the aroma derived from tea leaves are usually volatile, in the production of a powder composition containing a tea leaf extract, it has not always been sufficient to retain the tea leaf-derived aroma in the powder composition. Therefore, an object of the present invention is to provide a powder composition having excellent retention power for aromatic components derived from tea leaves. [Means for Solving the Problems]

[0008] As a result of intensive studies to solve the above problems, the present inventors focused on the dextrin used in the production of the powder composition, and by adjusting its type and amount to set the molecular weight distribution in the powder composition to predetermined conditions, it was found that a powder composition that effectively retains the aroma components derived from tea leaves can be obtained. Based on such findings, the present inventors have completed the present invention.

[0009] The present invention relates to the following, although not limited thereto. (1) A powder composition containing a tea leaf extract and dextrin, The above composition, wherein the ratio of the molecular weight of 250,000 or more in the molecular weight distribution of the composition is 0.5 to 10%. (2) The composition according to (1), wherein the ratio of the molecular weight of 300,000 or more in the molecular weight distribution is 0.2 to 5%. (3) The composition according to (1) or (2), wherein the ratio b / a of the ratio (a) of the molecular weight of 250,000 or more and less than 300,000 in the molecular weight distribution to the ratio (b) of the molecular weight of 300,000 or more and less than 350,000 in the molecular weight distribution is 0.3 or more. (4) The composition according to any one of (1) to (3), wherein the ratio c / a of the ratio (a) of the molecular weight of 250,000 or more and less than 300,000 in the molecular weight distribution to the ratio (c) of the molecular weight of 350,000 or more and less than 400,000 in the molecular weight distribution is 0.1 or more. (5) The composition according to any one of (1) to (4), wherein the dextrin contains linear dextrin and cyclic dextrin. (6) The composition according to (5), wherein the dextrin further contains helical dextrin. (7) Use of dextrin for improving the retention power of tea leaf-derived aroma components in a powder composition containing a tea leaf extract, The above use, wherein the ratio of the molecular weight of 250,000 or more in the molecular weight distribution of the dextrin is 10% or more. [Effects of the Invention]

[0010] According to the present invention, a powder composition excellent in the retention power of aroma components derived from tea leaves can be provided. The powder composition of the present invention can retain a large amount of aroma components derived from tea leaves contained in the solution before drying in the manufacturing process in the composition after drying. Therefore, by utilizing the present invention, it becomes possible to provide a powder composition having a strong aroma derived from tea leaves.

[0011] The powder composition of the present invention can be made into a tea beverage using water or hot water, and can bring about an aroma derived from tea leaves when consumed. Since the powder composition of the present invention is very lightweight compared to beverages, it is excellent in convenience during transportation.

[0012] Further, the powder composition of the present invention can also be used as a raw material for foods. The number and types of foods having a tea flavor have been increasing in recent years. By using the powder composition of the present invention, for example, confectioneries such as cakes, castella, candies, cookies, jellies, puddings, and chocolates can be imparted with an aroma derived from tea leaves.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2-1

Figure 2-2

Figure 2-3

BEST MODE FOR CARRYING OUT THE INVENTION

[0014] The powder composition of the present invention will be described below. Unless otherwise specified, "ppm", "ppb", and "wt%" used in this specification mean ppm, ppb, and wt% of weight / weight (w / w), respectively.

[0015] One aspect of the present invention is a powder composition containing a tea leaf extract and dextrin, wherein the proportion of a molecular weight of 250,000 or more in the molecular weight distribution of the composition is 0.5 to 10%. By adopting such a configuration, the retention power of the aroma components derived from tea leaves can be enhanced.

[0016] The powder composition of the present invention contains a tea leaf extract. Here, in this specification, "tea leaf extract" means a component extracted from tea leaves. In the present invention, as the tea leaves, leaves obtained from plants of the genus Camellia (such as Camellia sinensis (L) O. Kuntze) can be used. The tea leaves used in the present invention can be classified into non-fermented tea, semi-fermented tea, and fermented tea according to the processing method. Examples of non-fermented tea include green teas such as aracha, sencha, gyokuro, kabusecha, matcha, bancha, houjicha, kamairi-cha, kucha, bouchacha, and mecha. Examples of semi-fermented tea include oolong teas such as Tieguanyin, Sezhong, Huangjingui, and Wuyi rock tea. Examples of fermented tea include black teas such as Darjeeling, Assam, and Sri Lanka. In the present invention, only one type of tea leaf may be used alone, or a plurality of types of tea leaves may be blended and used. Further, as the tea leaves, there is no particular limitation as long as it is a part from which aroma components can be extracted, and leaves, stems, etc. can be appropriately used, and the form thereof is also not limited to large leaves, powder, etc. In the present invention, although not particularly limited, preferably green tea leaves are used.

[0017] The powder composition of the present invention contains dextrin. Dextrin is a general term for carbohydrates obtained by hydrolysis of starch or glycogen. In the present invention, dextrin can be used as an excipient for forming the powder composition, and the molecular weight distribution in the powder composition of the present invention can be adjusted according to the weight average molecular weight of the dextrin used and its content in the composition. The content of dextrin in the powder composition of the present invention is not particularly limited, but is, for example, 10 to 70% by weight, preferably 20 to 65% by weight, more preferably 30 to 60% by weight. In the present invention, commercially available products can be used as dextrin. The content of dextrin in the powder composition can be measured by performing sugar analysis using methods known to those skilled in the art.

[0018] In the molecular weight distribution of the powder composition of the present invention, the proportion of components with a molecular weight of 250,000 or more is 0.5 to 10%. It is considered that the retention power of the tea leaf-derived aromatic components in the powder composition is enhanced by the presence of such large-molecular-weight molecules in a predetermined proportion. On the other hand, when there are too many large-molecular-weight molecules, for example, when the proportion of components with a molecular weight of 250,000 or more exceeds 10%, the viscosity of the composition before powdering becomes too high, making it difficult to perform a drying process, and the powder tends to be difficult to obtain. In the molecular weight distribution of the powder composition of the present invention, the proportion of components with a molecular weight of 250,000 or more is preferably 1 to 7%, more preferably 1 to 5%.

[0019] In the present invention, the molecular weight distribution in the powder composition can be examined by using gel permeation chromatography (GPC) analysis method. Specifically, the molecular weight distribution in the powder composition can be examined under the following conditions. Apparatus: Sampling injector: 231 XL (GILSON) Pump: 305 (GILSON) Column oven: CTO-10AS VP (Shimadzu Corporation) Detector: RID-10A (Shimadzu Corporation) Column: Connected in series in the following order [Pump] → TSKgel Guard Column PWxl (6.0 mm I.D. × 4 cm) (Tosoh) → TSKgel G4000PWxl (particle size 10 μm, 7.8 mm I.D. × 30 cm) (Tosoh) → TSKgel G3000PWxl (particle size 7 μm, 7.8 mm I.D. × 30 cm) (Tosoh) → [Detector] Analysis data system: LabSolutions (Shimadzu Corporation) Flow rate: 1 mL / min Injection volume: 50 μL Mobile phase: 0.1 mol / L sodium nitrate solution Column temperature: 50 °C The preparation of the analysis sample can be carried out as shown in the examples described below. Also, the ratio of components of various molecular weights in the molecular weight distribution can be determined as shown in the examples described below. Specifically, it can be determined by calculating the ratio of the target peak area to the total value of the obtained peak areas (total peak area).

[0020] The further compositional ratio of the components with a molecular weight of 250,000 or more in the powder composition of the present invention is not particularly limited. However, in the range of a molecular weight of 250,000 or more and less than 500,000, it is preferable that the ratio decreases as the molecular weight increases. That is, the ratio of the components with a molecular weight of 300,000 or more and less than 350,000 is smaller than the ratio of the components with a molecular weight of 250,000 or more and less than 300,000, the ratio of the components with a molecular weight of 350,000 or more and less than 400,000 is smaller than the ratio of the components with a molecular weight of 300,000 or more and less than 350,000, the ratio of the components with a molecular weight of 400,000 or more and less than 450,000 is smaller than the ratio of the components with a molecular weight of 350,000 or more and less than 400,000, and the ratio of the components with a molecular weight of 450,000 or more and less than 500,000 is smaller than the ratio of the components with a molecular weight of 400,000 or more and less than 450,000.

[0021] The proportion of components with a molecular weight of more than 250,000 and less than 300,000 is, for example, 0.3 to 2%, preferably 0.3 to 1.5%, more preferably 0.3 to 1.2%. The proportion of components with a molecular weight of more than 300,000 and less than 350,000 is, for example, 0.1 to 1.2%, preferably 0.2 to 1%, more preferably 0.2 to 0.8%. The proportion of components with a molecular weight of more than 350,000 and less than 400,000 is, for example, 0.1 to 0.8%, preferably 0.1 to 0.7%, more preferably 0.1 to 0.5%. The proportion of components with a molecular weight of more than 400,000 and less than 450,000 is, for example, 0.05 to 0.5%, preferably 0.05 to 0.4%, more preferably 0.1 to 0.4%. The proportion of components with a molecular weight of more than 450,000 and less than 500,000 is, for example, 0.04 to 0.4%, preferably 0.05 to 0.3%, more preferably 0.07 to 0.3%.

[0022] In the molecular weight distribution of the powder composition of the present invention, the proportion of components with a molecular weight of 300,000 or more is not particularly limited, but is, for example, 0.2 to 5%, preferably 0.3 to 3%, more preferably 0.5 to 2%. Also, in the molecular weight distribution of the powder composition of the present invention, the proportion of components with a molecular weight of 350,000 or more is not particularly limited, but is, for example, 0.2 to 2.5%, preferably 0.3 to 2%, more preferably 0.4 to 1.5%. Also, in the molecular weight distribution of the powder composition of the present invention, the proportion of components with a molecular weight of 400,000 or more is not particularly limited, but is, for example, 0.2 to 1.5%, preferably 0.3 to 1.2%, more preferably 0.3 to 1%.

[0023] In the molecular weight distribution of the powder composition of the present invention, the proportion of components having a molecular weight of less than 250,000 is not particularly limited. In the molecular weight distribution of the powder composition of the present invention, the proportion of components having a molecular weight of less than 3,000 is, for example, 35% or more, preferably 40% or more, more preferably 45% or more. In the molecular weight distribution of the powder composition of the present invention, the proportion of components having a molecular weight of 3,000 or more and less than 50,000 is, for example, 15 to 30%, preferably 17 to 27%, more preferably 20 to 25%. In the molecular weight distribution of the powder composition of the present invention, the proportion of components having a molecular weight of 50,000 or more and less than 150,000 is, for example, 2 to 25%, preferably 5 to 22%, more preferably 6.5 to 20%. In the molecular weight distribution of the powder composition of the present invention, the proportion of components having a molecular weight of 150,000 or more and less than 250,000 is, for example, 1 to 10%, preferably 2 to 8%, more preferably 3 to 5%.

[0024] Further, in the molecular weight distribution of the powder composition of the present invention, the ratio b / a of the proportion (a) of components having a molecular weight of 250,000 or more and less than 300,000 and the proportion (b) of components having a molecular weight of 300,000 or more and less than 350,000 is not particularly limited, but is, for example, 0.3 or more. The ratio b / a is preferably 0.3 to 0.9, more preferably 0.35 to 0.85, still more preferably 0.4 to 0.8.

[0025] Further, in the molecular weight distribution of the powder composition of the present invention, the ratio c / a of the proportion (a) of components having a molecular weight of 250,000 or more and less than 300,000 and the proportion (c) of components having a molecular weight of 350,000 or more and less than 400,000 is not particularly limited, but is, for example, 0.1 or more. The ratio c / a is preferably 0.1 to 0.9, more preferably 0.15 to 0.7, still more preferably 0.2 to 0.5.

[0026] As described above, in the present invention, the molecular weight distribution in the powder composition can be adjusted depending on the type of dextrin used. The dextrin used in the present invention preferably includes linear dextrin and cyclic dextrin. Here, in the present specification, "linear dextrin" means dextrin in which glucose is linearly bonded or chain-bonded with no branched chains, and does not form a ring structure or a helical structure. Further, in the present specification, "cyclic dextrin" means dextrin in which glucose is bonded to form a ring structure and does not form a helical structure.

[0027] The linear dextrin is not particularly limited, and for example, linear dextrin with a DE (dextrose equivalent) of 1 to 25 or linear dextrin with a weight average molecular weight of 500 to 160,000 can be used. Further, in the present invention, not only one kind of linear dextrin but also a combination of two or more kinds can be used. A preferred embodiment in the present invention is the use of two kinds of linear dextrin. When using two kinds of linear dextrin, for example, a combination of linear dextrin with a DE of 2 to 5 and linear dextrin with a DE of 16 to 20, or a combination of linear dextrin with a weight average molecular weight of 90,000 to 140,000 and linear dextrin with a weight average molecular weight of 600 to 1,200 can be utilized.

[0028] When using linear dextrin, the content of linear dextrin in the powder composition of the present invention is, for example, 30 to 65% by weight, preferably 35 to 60% by weight, more preferably 40 to 55% by weight. When using linear dextrin with DE2 - 5 and linear dextrin with DE16 - 20 as the two types of linear dextrins, the content of linear dextrin with DE2 - 5 in the powder composition of the present invention is, for example, 5 to 45% by weight, preferably 15 to 40% by weight, more preferably 25 to 35% by weight, and the content of linear dextrin with DE16 - 20 is, for example, 5 to 40% by weight, preferably 7 to 30% by weight, more preferably 10 to 20% by weight. Also, the content ratio (weight ratio) of linear dextrin with DE2 - 5 to linear dextrin with DE16 - 20 is, for example, 4:1 to 1:5, preferably 3:1 to 1:5, more preferably 2:1 to 1:4.

[0029] When using linear dextrin with a weight - average molecular weight of 90,000 to 140,000 and linear dextrin with a weight - average molecular weight of 600 to 1,200 as the two types of linear dextrins, the content of linear dextrin with a weight - average molecular weight of 90,000 to 140,000 in the powder composition of the present invention is, for example, 5 to 45% by weight, preferably 15 to 40% by weight, more preferably 25 to 35% by weight, and the content of linear dextrin with a weight - average molecular weight of 600 to 1,200 is, for example, 5 to 40% by weight, preferably 7 to 30% by weight, more preferably 10 to 20% by weight. Also, the content ratio (weight ratio) of linear dextrin with a weight - average molecular weight of 90,000 to 140,000 to linear dextrin with a weight - average molecular weight of 600 to 1,200 is, for example, 5:1 to 1:3, preferably 3:1 to 1:2, more preferably 2:1 to 1:1.

[0030] As the cyclic dextrin, for example, cyclodextrin can be used. In the present invention, any of α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin can be used, but α-cyclodextrin is preferably used. The weight average molecular weight of the cyclic dextrin used in the present invention is not particularly limited, but is, for example, 700 to 1,300, preferably 800 to 1,200, more preferably 900 to 1,100. When using cyclic dextrin, the content of cyclic dextrin in the powder composition of the present invention is, for example, 0.5 to 15% by weight, preferably 1 to 12% by weight, more preferably 3 to 10% by weight.

[0031] When linear dextrin and cyclic dextrin are used, the content ratio (weight ratio) of linear dextrin to cyclic dextrin is, for example, 20:1 to 2:1, preferably 15:1 to 3:1, more preferably 12:1 to 5:1.

[0032] In addition, the dextrin used in the present invention preferably further contains helical dextrin. Here, in the present specification, "helical dextrin" means a dextrin in which glucose is bonded to form a helical structure. The DE of the helical dextrin used in the present invention is not particularly limited, but is, for example, less than 7, preferably less than 6, more preferably less than 5.

[0033] As the helical dextrin, for example, cluster dextrin (Ezaki Glico) can be used. When using helical dextrin, the content of helical dextrin in the powder composition of the present invention is, for example, 1 to 30% by weight, preferably 5 to 25% by weight, more preferably 10 to 20% by weight. Also, when helical dextrin is used, the content ratio (weight ratio) of linear dextrin to helical dextrin is, for example, 1:3 to 3:1, preferably 1:2 to 2:1, more preferably 1:1.5 to 1.5:1.

[0034] Since the powder composition of the present invention contains a tea leaf extract, the powder composition of the present invention may contain aroma components derived from tea leaves. Such aroma components are not particularly limited, and examples thereof include pentanal (valeraldehyde), 2-methylpropanal (isobutyraldehyde), nonanal, trimethylpyrazine, 1-octen-3-ol, 2-ethyl-3,5-dimethylpyrazine, 2-ethyl-3,6-dimethylpyrazine, 2,4-heptadien-6-one, 2,3-diethyl-5-methylpyrazine, 2-methyl-3-n-propylpyrazine, benzaldehyde, ethyl decanoate, acetylthiazoline, ethyl acetophenone, p-cresol, and the like.

[0035] In addition to the various components shown above, the powder composition of the present invention can be added with additives commonly used in foods and beverages, such as antioxidants, preservatives, pH adjusters, sweeteners, nutritional fortifiers, thickening stabilizers, emulsifiers, dietary fibers, quality stabilizers, etc., within a range that does not impair the effects of the present invention.

[0036] The powder composition of the present invention is in a powder form and is usually solid. The particle size of the powder composition of the present invention is not particularly limited, but is, for example, 0.1 to 500 μm, preferably 1 to 300 μm, more preferably 10 to 200 μm.

[0037] The powder composition of the present invention can be eaten or drunk as it is, but it is preferably dissolved in water or hot water and drunk as a tea beverage. Therefore, the powder composition of the present invention can be provided as instant tea. Here, in this specification, "instant tea" means a powdered beverage obtained by drying a solution using an extract of tea leaves as a raw material and processing it into a powder form. Tea beverages include non-fermented tea (such as green tea), semi-fermented tea (such as oolong tea), and fermented tea (such as black tea). Specifically, steamed non-fermented tea (green tea) such as sencha, bancha, houjicha, gyokuro, kabusecha, and sweet tea; non-fermented tea such as kettle-fried tea like yukinotcha and aoyagi tea and various Chinese teas; semi-fermented tea such as baozhong tea, tieguanyin tea, and oolong tea; and fermented tea such as black tea, awa-bancha, and pu-erh tea can be mentioned. The tea beverage in which the powder composition of the present invention is used is preferably green tea. That is, the powder composition of the present invention can be provided as instant green tea.

[0038] The powder composition of the present invention can also be added to foods. Such foods include, for example, both Japanese and Western confectionery, such as cakes, castella, candies, cookies, jelly, pudding, chocolate, etc. as confectionery, ice cream, ice candy, sherbet, etc. as frozen desserts, or snacks, etc., and can also be used in bread and dairy products. When adding the powder composition of the present invention to foods, the addition amount can be appropriately set according to the type of food, etc.

[0039] The powder composition of the present invention can be produced through the steps of preparing a solution containing the above-mentioned tea leaf extract and dextrin, and drying the obtained solution. In addition to the tea leaf extract and dextrin, the above-mentioned various components may be included in the solution. The blending amount of any component can be appropriately set as long as the effects of the present invention are not impaired, and the order of blending the various components is not particularly limited. Also, water may be used as the solvent of the solution, or the extract of tea leaves may be used as it is. In addition, the blending amount of dextrin in the solution before powdering can be adjusted so that the content of dextrin in the soluble solids of the solution becomes the content in the above-mentioned powder composition.

[0040] The drying of the solution can be carried out by methods conventionally known to those skilled in the art. For example, methods such as spray drying, freeze drying, hot air drying, and vacuum drying can be mentioned, but in the present invention, it is preferable to use spray drying. In addition, conditions such as temperature and time in spray drying are not particularly limited and can be appropriately adjusted for powdering the solution.

[0041] In the production of the powder composition of the present invention, in addition to the above steps, steps such as concentrating a solution containing a tea extract and dextrin and sterilizing the solution can be included. Any of these steps can be carried out using methods conventionally known to those skilled in the art.

[0042] Another aspect of the present invention is the use of dextrin for improving the retention of tea-derived aromatic components in a powder composition containing a tea extract, wherein the ratio of the molecular weight of 250,000 or more in the molecular weight distribution of the dextrin is 10% or more. The elements such as the tea extract and dextrin employed in such use are as described above, and the molecular weight distribution in the powder composition is also as described above. Further, the use of dextrin in the present invention is preferably for improving the retention of tea-derived aromatic components in the powdering of the above powder composition.

Examples

[0043] The present invention will be described below based on examples, but the present invention is not limited to these examples.

[0044] (1) Preparation of powder composition Solid raw material of tea extract (trade name: GT204S, raw material: green tea (produced in China)), linear dextrin A (Matsutani Chemical, TK-16, weight average molecular weight: 910, DE: 18), linear dextrin B (Sanwa Starch Industry, Sandex #30, weight average molecular weight: 120,000, DE: 2 - 5), helical dextrin (Ezaki Glico, Cluster Dextrin, weight average molecular weight: 400,000, DE: less than 5), and cyclic dextrin (Cyclochem, α-cyclodextrin, weight average molecular weight: 973) were used to prepare powder compositions respectively. Specifically, various raw materials were blended at the ratios shown in the following table to prepare a total of 6,000 g of powder mixture, and 14,000 g of water was added to this to prepare a powder composition stock solution of a total of 20,000 g (Brix 30%). Note that the above solid raw material of tea extract is obtained by drying the tea extract to powder and does not contain dextrin.

[0045]

Table 1

[0046] A part of the powder composition stock solution prepared as described above was taken out as a sample for measuring the aromatic component concentration, and then, each stock solution was subjected to spray drying treatment using a spray dryer to prepare powder compositions. Note that the drying conditions were an inlet hot air temperature of 160°C and an outlet hot air temperature of 110°C.

[0047] (2) Evaluation of Aromatic Component Retention Both the powder composition stock solution and the powder composition obtained as described above were diluted or dissolved with water so that the Brix value became 4%. 10 mL of the obtained solution was put into a vial containing 3 g of sodium chloride, and this vial was sealed and introduced into a gas chromatography analyzer (Alpha Mos Japan, Flash GC Nose HERACLES II). The aromatic components in various solutions were analyzed under the conditions shown below. Incubation: 60°C, 15 minutes Syringe: Temperature: 70°C, post-injection wash: 90 seconds Headspace injection: 5000 μl at 250 μl / second Column 1: MXT-5 (weakly polar, 10 m, 180 μm ID, 0.4 μm) Column 2: MXT-WAX (highly polar, 10 m, 180 μm ID, 0.4 μm) Carrier gas flow rate: Hydrogen 1.6 mL / min Hydrogen flame ionization detector (FID) temperature: 260 °C Injector temperature: 200 °C Oven temperature: 40 °C (5 s) ~ 1.5 °C / s ~ 250 °C (90 s) Injection time: 125 s Trap temperature: Adsorption 50 °C, desorption 240 °C Trap time: Adsorption 130 s, preheating 35 s

[0048] From the data obtained by the analysis, the integrated value of the total peak areas was calculated, and by dividing this integrated value by the measured value of the Brix value of the solution subjected to the analysis, the total value of the peak areas detected per solid content was calculated. Then, for each sample, the retention rate of the tea aroma components before and after spray drying was calculated by obtaining (total peak area value per solid content detected in the powder composition) / (total peak area value per solid content detected in the stock solution).

[0049] The results of examining the retention rate of the tea aroma components are as shown in Fig. 1. It was shown that adding linear dextrin B with a larger molecular weight resulted in a higher aroma retention rate than adding spiral dextrin (cluster dextrin) which was known to have a high aroma retention effect. Furthermore, unexpectedly, it was found that the sample in which spiral dextrin and linear dextrin B were mixed had the highest retention rate of the tea aroma components.

[0050] (3) Molecular weight distribution in the powder composition For each of the above various powder compositions, the molecular weight distribution of the soluble molecules contained in the composition was measured. Each powder composition was diluted with a 0.1 mol / L sodium nitrate solution to a concentration of 1% (w / v) to prepare an analysis sample, and the molecular weight distribution was measured using gel permeation chromatography (GPC) analysis. Similarly, the molecular weight distribution in linear dextrin B was also measured. The conditions for gel permeation chromatography analysis were as follows. Apparatus: Sampling injector: 231 XL (GILSON) Pump: 305 (GILSON) Column oven: CTO-10AS VP (Shimadzu Corporation) Detector: RID-10A (Shimadzu Corporation) Columns: Connected in series in the following order [Pump] → TSKgel Guard Column PWxl (6.0 mm I.D. × 4 cm) (Tosoh) → TSKgel G4000PWxl (particle size 10 μm, 7.8 mm I.D. × 30 cm) (Tosoh) → TSKgel G3000PWxl (particle size 7 μm, 7.8 mm I.D. × 30 cm) (Tosoh) → [Detector] Analysis data system: LabSolutions (Shimadzu Corporation) Flow rate: 1 mL / min Injection volume: 50 μL Mobile phase: 0.1 mol / L sodium nitrate solution Column temperature: 50 °C

[0051] Using STANDARD P-82 (Shodex, Showa Denko) as the standard solution, the retention times of eight molecular weights were first detected, and a calibration curve was created based on the detection results. Then, from the total value of the peak areas detected at each retention time in the analysis sample, the ratio of the peak area (ratio to the total peak area) for each molecular size contained in the sample was calculated. The results of the molecular weight distribution in various samples and linear dextrin B are shown in the following table.

[0052]

Table 2

[0053] In the above molecular weight distribution, the ratios of the molecular weight of 250,000 or more, the molecular weight of 300,000 or more, and the molecular weight of less than 50,000 are shown in the following table. Further, in the above molecular weight distribution, the ratio b / a of the ratio (a) of the molecular weight of 250,000 or more and less than 300,000 to the ratio (b) of the molecular weight of 300,000 or more and less than 350,000, and the ratio c / a of the ratio (a) of the molecular weight of 250,000 or more and less than 300,000 to the ratio (c) of the molecular weight of 350,000 or more and less than 400,000 are shown in the following table.

[0054]

Table 3

[0055] As shown in the above results, it was revealed that in Samples 1, 2, 3, and 8, which showed a high aroma retention rate, the ratio of the molecular weight of 250,000 or more was higher than that of the other samples. From this result, it was suggested that when the component with a molecular weight of 250,000 or more in the molecular weight distribution of the powder composition is at a predetermined ratio or more, the retention rate of the aromatic component derived from tea leaves is improved.

Claims

1. A powder composition containing a tea extract and dextrin, wherein the proportion of a molecular weight of 250,000 or more in the molecular weight distribution of the composition is 0.5 to 10%, and the dextrin includes a linear dextrin with a DE of 2 to 5, a linear dextrin with a DE of 16 to 20, and a cyclic dextrin. The above composition.

2. The composition according to claim 1, wherein the proportion of a molecular weight of 300,000 or more in the molecular weight distribution is 0.2 to 5%.

3. The composition according to claim 1 or 2, wherein the ratio b / a of the proportion (a) of a molecular weight of 250,000 or more and less than 300,000 in the molecular weight distribution to the proportion (b) of a molecular weight of 300,000 or more and less than 350,000 in the molecular weight distribution is 0.3 or more.

4. The composition according to any one of claims 1 to 3, wherein the ratio c / a of the proportion (a) of a molecular weight of 250,000 or more and less than 300,000 in the molecular weight distribution to the proportion (c) of a molecular weight of 350,000 or more and less than 400,000 in the molecular weight distribution is 0.1 or more.

5. The composition according to any one of claims 1 to 4, further containing helical dextrin.

6. The composition according to any one of claims 1 to 5, wherein the content of the linear dextrin with a DE of 2 to 5 is 5 to 45% by weight.

7. The composition according to any one of claims 1 to 6, wherein the content of the linear dextrin with a DE of 16 to 20 is 5 to 40% by weight.

8. The composition according to any one of claims 1 to 7, wherein the content ratio (weight ratio) of the linear dextrin with a DE of 2 to 5 to the linear dextrin with a DE of 16 to 20 is 4:1 to 1:5.

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