Chestnut skin powder, drink obtained by dissolving chestnut skin powder in hot water, and method for manufacturing chestnut skin powder

Abstract

To reduce waste by utilizing the outer skin and astringent skin of chestnuts all at once, and to realize a drink made from chestnut skin powder that is healthy and easy to drink. [Solution] Chestnut skin powder is made primarily from the outer and inner skins of chestnuts, and is characterized by containing at least 50% by weight of dietary fiber. Also, a beverage is made primarily from chestnut skin powder, which is caffeine-free and has antioxidant properties.

Description

[Technical Field]

[0001] The present invention relates to chestnut skin powder containing chestnut skin as a main ingredient, a beverage containing chestnut skin powder as an ingredient, and a method for producing chestnut skin powder. [Background technology]

[0002] After using the edible part of chestnuts, the skin, which makes up 50% of the chestnut, is discarded. In order to reduce this waste, some research is being conducted into utilizing chestnut skin.

[0003] Chestnut skin is rich in polyphenols, which are known to suppress inflammation and contribute to the prevention of diseases such as cardiovascular disease and cancer.

[0004] Patent Document 1 describes the powdering of chestnut outer skins and the use of the powder in foods such as baked goods. [Prior art documents] [Patent documents]

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2022-175270 Summary of the Invention [Problem to be solved by the invention]

[0006] However, although Patent Document 1 describes the production of baked goods and other confectioneries with the aim of reusing the chestnut skins, it does not describe the active use of the chestnut skins or the production of beverages using chestnut skins, and there is a problem in that it is unclear how to produce chestnut skins and beverages whose main ingredients are chestnut skins.

[0007] The present invention aims to solve the above problems and to realize a drink made from chestnut skin powder, which is healthy and easy to drink, by utilizing both the outer skin and the inner skin of chestnuts together. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides a method for producing chestnuts. After using the seeds The outer skin and astringent skin include Chestnut skin powder, Based on the weight of the dried chestnut skin powder Contains at least 50% by weight of dietary fiber; By heating The present invention provides chestnut skin powder characterized by containing at least 5% by weight of total polyphenols.

[0009] This structure allows the production of a drink using both the outer skin and the inner skin of chestnuts as a raw material for chestnut skin powder, and provides chestnut skin powder containing chestnut skin as a main component, which is very rich in dietary fiber. Furthermore, the high content of total polyphenols provides the chestnut skin powder with antioxidant properties. The astringent skin is said to contain polyphenols and flavonoids equivalent to those of the outer skin, and it is possible to provide chestnut skin powder containing chestnut skin as the main component, which contains a much higher amount of total polyphenols than the outer skin alone.

[0012] In order to solve the above problems, the present invention also provides a method for producing chestnuts. After using the seeds The outer skin and astringent skin Including flat The present invention provides a drink in which chestnut skin powder having an average particle size of 50 μm or less is dissolved in hot water, the drink being characterized by being caffeine-free and having antioxidant properties.

[0013] This composition makes it healthy due to its antioxidant properties, and since it does not contain caffeine, it can be safely consumed by pregnant women and children.

[0014] The beverage may be made from chestnut skin powder and contain sugar.

[0015] This configuration reduces the astringency, making the beverage easier to drink.

[0016] Furthermore, in order to solve the above problems, the present invention provides a method for producing chestnuts. After using the seeds The outer skin and astringent skin include A method for producing chestnut skin powder, A heating step of heating chestnut skins including at least the outer skin and the inner skin of chestnuts; A drying step of drying the chestnut skin heated in the heating step; A roasting step of roasting the chestnut skins dried in the drying step; A crushing step of crushing the chestnut skin roasted in the roasting step; The present invention provides a method for producing chestnut skin powder that carries out the above steps.

[0017] This method significantly reduces the moisture content of chestnut skins by heating and then drying them, making them easier to crush. Furthermore, chestnut skin powder produced through a heating process has superior antioxidant properties compared to chestnut skin powder produced without a heating process. Furthermore, the roasting process imparts a roasted aroma, making the beverage easier to drink, and also gives it a distinctive sour taste, resulting in a beverage with better antioxidant properties.

[0020] The method for producing chestnut skin powder may be configured such that, after the crushing step, a sieving step is carried out in which the crushed chestnut skin is sieved.

[0021] This configuration allows chestnut skin powder to be produced with a uniform particle size, reducing the unpleasant taste when made into a beverage. [Effects of the Invention]

[0022] The present invention aims to provide a chestnut skin powder containing chestnut skin as a main component, a drink made from chestnut skin powder, and a method for producing chestnut skin powder, which reduces waste by utilizing the outer skin and astringent skin of chestnuts all at once, and also to provide a drink made from chestnut skin powder that is healthy and easy to drink. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is an explanatory diagram of a method for producing chestnut skin powder containing chestnut skin as the main ingredient in Example 1 of the present invention. [Figure 2] Component analysis results of chestnut skin powder containing chestnut skin as the main component in Example 1 of the present invention. [Figure 3] 1 is a graph showing the antioxidant properties of chestnut skin powder containing chestnut skin as the main component in Example 1 of the present invention. [Figure 4] 2 is a graph showing the taste response of a beverage made from chestnut skin powder in Example 1 of the present invention based on the taste recognition device. [Figure 5] 1 is a graph showing the antioxidant properties of a beverage made from chestnut skin powder in Example 1 of the present invention. [Figure 6] 1 is a graph showing the caffeine content of a beverage made from chestnut skin powder in Example 1 of the present invention. [Figure 7] 2 is a graph showing the antioxidant properties of a beverage made from chestnut skin powder in Example 2 of the present invention. [Figure 8] Graph showing the caffeine content of a beverage made from chestnut skin powder in Example 2 of the present invention. DETAILED DESCRIPTION OF THE INVENTION [Example]

[0024] (Method for producing chestnut skin powder having chestnut skin as the main ingredient) A method for producing chestnut skin powder having chestnut skin as the main ingredient in Example 1 of the present invention will be described with reference to Fig. 1. Fig. 1 is an explanatory diagram of a method for producing chestnut skin powder having chestnut skin as the main ingredient in Example 1 of the present invention.

[0025] First, a heating step 10 is carried out, in which the chestnut outer shell and the chestnut skin containing the astringent skin are heated after the chestnut seeds have been used. In this case, a portion of the chestnut seeds may also be included in addition to the chestnut outer shell and astringent skin. In heating step 10 in Example 1, heating was performed using steam at 100°C for 60 minutes. However, heating may be performed at different temperatures and for different times, or by a method other than steam. By carrying out heating step 10 (heating), the antioxidant properties (total polyphenols, DPPH radical scavenging activity) of the chestnut skin powder were improved compared to when no heating was performed (non-heating). In particular, the total polyphenols were increased by nearly two times (see Figure 3).

[0026] Next, a drying step 20 is carried out to dry the chestnut skins heated in the heating step 10. In the drying step 20 in Example 1, a low-temperature drying method was carried out in which the chestnut skins were dried at 70°C for 15 hours using a food dryer, Petit Marenghi DX, manufactured by Tomei Tech Co., Ltd. As a result, the weight after drying was approximately half of the weight before drying.

[0027] In the drying step 20 in Example 1, drying was performed at 70°C for 15 hours, but this is not necessarily limited to this and can be changed as appropriate. For example, the temperature may be 60°C or 80°C, and the drying time may be 14 hours or less or 16 hours or more.

[0028] Furthermore, in Example 1, a low-temperature drying method was used, but the method is not necessarily limited to this and can be modified as appropriate. For example, a vacuum freeze-drying method may be used, although it is expensive.

[0029] The drying step 20 is followed by the roasting step 30. In the roasting step 30 in Example 1, the beans were roasted in a TAYTHI coffee roaster at a rotation speed of 20 rpm at 190°C for 15 minutes, and then at 200°C for 5 minutes. By carrying out the roasting step 30, the antioxidant properties of the beverage made from chestnut skin powder were improved compared to the beverage without roasting, as will be described later.

[0030] In Example 1, the coffee was roasted at 190°C for 15 minutes at a rotation speed of 20 rpm, followed by roasting at 200°C for 5 minutes, but this is not necessarily limited to this and can be modified as appropriate. For example, the coffee may be roasted at 190°C for 20 minutes, or at 200°C for 10 minutes. Furthermore, the roasting step 30 is not necessarily required and may not be performed.

[0031] The roasting step 30 is followed by the crushing step 40. In the crushing step 40 in Example 1, a household crusher, Conappy, manufactured by LabNect Co., Ltd., was operated for 60 seconds to crush the chestnut skins.

[0032] In Example 1, the crusher was operated for 60 seconds to crush the chestnut skins, but this is not necessarily limited to this and can be changed as appropriate. For example, the operation time may be 50 seconds or less, or 70 seconds or more.

[0033] Finally, a sieving step 50 was carried out to adjust the particle size. In the sieving step 50 in Example 1, the particles were sieved through a 32 mesh to adjust the particle size to approximately 500 μm or less. This allows the beverage described below to have less unpleasant flavors and to have consistent physical properties by removing large particles, but the sieving step 50 is not necessarily carried out. As described below, when dissolving the powder in hot water to make a beverage, it is desirable to further refine the particles. This improves the texture when dissolved in hot water.

[0034] (Chestnut skin powder, the main ingredient of which is chestnut skin) The chestnut skin powder containing chestnut skin as the main ingredient, produced by the above-mentioned production method, will be described with reference to Figures 2 and 3. Figure 2 shows the results of component analysis of the chestnut skin powder containing chestnut skin as the main ingredient in Example 1 of the present invention, and Figure 3 is a graph showing the antioxidant properties of the chestnut skin powder containing chestnut skin as the main ingredient in Example 1 of the present invention.

[0035] First, a component analysis of 100 g of chestnut skin powder produced by a method using chestnut skin as the main ingredient was performed by the Food Analysis and Development Center (SUNATEC). The results are shown in Figure 2 for the cases produced using the heating step 10 (heated) and the cases produced without the heating step 10 (unheated). A wheat flour composition table is also shown for reference. As shown in Figure 2, 100 g of chestnut skin powder containing chestnut skin as the main ingredient in Example 1 contained 53.6 g of dietary fiber when produced using the heating step 10, and 50.7 g when produced using the method without the heating step 10. This indicates that the chestnut skin powder containing chestnut skin as the main ingredient in Example 1 contains at least 50% by weight of dietary fiber. Although not shown in Figure 2, cocoa powder, which is considered to contain a relatively high amount of dietary fiber, also contained 23.9% by weight, which is significantly higher than other powders used as beverage ingredients.

[0036] Dietary fiber is said to be "the total amount of food that cannot be broken down by human digestive enzymes." Most of it is a type of polysaccharide, which is made up of many monosaccharides linked together. However, because it is difficult to digest, it is not a good source of energy. Instead, it is fermented and broken down by bacteria in the large intestine, and becomes food for beneficial intestinal bacteria such as bifidobacteria, which is said to increase the number of beneficial bacteria and improve the intestinal environment. It also promotes bowel movements and is effective in preventing constipation.

[0037] (Antioxidant properties of chestnut skin powder, whose main ingredient is chestnut skin) Figure 3 shows the antioxidant properties of chestnut skin powder, which contains chestnut skin as the main ingredient in Example 1. Figure 3(a) shows comparative data on total polyphenol content between chestnut skin powder that underwent the heating step 10 (heated) and chestnut skin powder that did not underwent the heating step 10 (unheated), and Figure 3(b) shows comparative data on DPPH radical scavenging activity between chestnut skin powder that underwent the heating step 10 and chestnut skin powder that did not underwent the heating step 10. Values ​​represent the mean ± standard deviation of three experiments. There is a significant difference between the different signs (a-f) (p < 0.05, Tukey's HSD test).

[0038] As shown in Figure 3(a), the chestnut skin powder that underwent heating step 10 contained nearly twice as much (1.6 times) the total polyphenols as chestnut skin powder that did not undergo heating step 10. Furthermore, as shown in Figure 3(b), it was confirmed that the chestnut skin powder that underwent heating step 10 also had higher antioxidant properties in terms of DPPH radical scavenging activity than chestnut skin powder that did not undergo heating step 10.

[0039] Antioxidant properties refer to the ability to remove active oxygen that has increased in the body, and high antioxidant properties are said to help prevent aging, cancer, lifestyle-related diseases, and other conditions. Active oxygen is usually broken down by enzymes in the body, but if a large amount of active oxygen is produced, the body is unable to detoxify it in time, resulting in damage. Highly antioxidant substances are effective in this detoxification. In Example 1 of the present invention, both the outer shell and the inner shell are used. The inner shell is said to contain polyphenols and flavonoids equivalent to those of the outer shell, and a chestnut skin powder containing chestnut skin as the main ingredient can be provided, which contains significantly more total polyphenols than the outer shell alone.

[0040] (Drink made from chestnut skin powder) The beverage made from chestnut skin powder in Example 1 of the present invention will be described with reference to Figures 4 to 6. Figure 4 is a graph showing the taste response of the beverage made from chestnut skin powder in Example 1 of the present invention based on a taste recognition device, Figure 5 is a graph showing the antioxidant properties of the beverage made from chestnut skin powder in Example 1 of the present invention, and Figure 6 is a graph showing the caffeine content of the beverage made from chestnut skin powder in Example 1 of the present invention.

[0041] 10 g of the chestnut skin powder was dissolved in 500 g of boiling water, steamed for 2 minutes, and filtered through a coffee filter to produce a beverage. The taste response, antioxidant activity, and caffeine content of this beverage were evaluated.

[0042] (Taste response of drinks made from chestnut skin powder) Figure 4 shows the results of evaluation of taste response using the taste recognition device TS-5000Z. Figure 4 shows a comparison between a beverage extracted using chestnut skin powder that has undergone the roasting process 30 as an ingredient and barley tea (the values ​​show the average values ​​of three experiments). The results show that the beverage extracted using chestnut skin powder that has undergone the roasting process 30 in Example 1 as an ingredient had a lower bitterness and off-flavor value and a higher astringency stimulation value.

[0043] (Antioxidant properties of drinks made from chestnut skin powder) Figure 5 shows the evaluation results of the antioxidant properties of the beverage extracted using chestnut skin powder in Example 1. Figure 5(a) shows the amount of total polyphenols, and it was found that the beverage contained the same level of total polyphenols as green tea and black tea, and more total polyphenols than oolong tea, roasted green tea, and barley tea. It was also found that in the chestnut skin powder manufacturing process, the beverage that underwent the roasting step 30 (roasted) contained more total polyphenols than the beverage that did not undergo the roasting step 30 (unroasted). Values ​​represent the mean ± standard deviation of three experiments. There was a significant difference between the different signs (a-f) (p < 0.05, Tukey's HSD test).

[0044] Figure 5(b) shows the evaluation results of the DPPH radical scavenging activity of beverages containing chestnut skin powder, which showed values ​​at the same level as black tea and coffee, and higher than oolong tea, roasted green tea, and barley tea. It was also found that the DPPH radical scavenging activity of beverages that underwent the roasting process 30 (with roasting) in the chestnut skin powder manufacturing process was higher than that of beverages that did not undergo the roasting process 30 (without roasting).

[0045] In other words, the antioxidant activity of the beverage extracted with the chestnut skin powder in Example 1 is at the same level as green tea and black tea, and higher than oolong tea, roasted green tea, and barley tea. Furthermore, in the chestnut skin powder production process, the antioxidant activity is improved in the chestnut skin powder that has undergone the roasting step 30 compared to the chestnut skin powder that has not undergone the roasting step 30. Furthermore, both the outer skin and the astringent skin are used in the beverage. The astringent skin is said to contain polyphenols and flavonoids equivalent to those of the outer skin, and a beverage can be provided that uses chestnut skin powder, whose main ingredient is chestnut skin, containing significantly more total polyphenols than the outer skin alone.

[0046] (Amount of caffeine in drinks made from chestnut skin powder) Next, the caffeine content of the beverage extracted using chestnut skin powder as an ingredient in Example 1 will be described with reference to Figure 6. As shown in Figure 6, no caffeine was detected in the beverages made from chestnut skin powder, whether they underwent the roasting process 30 (with roasting) or did not undergo the roasting process 30 (without roasting). Values ​​indicate the average value ± standard deviation of three experiments. There is a significant difference between values ​​with different signs (a-f) (p < 0.05, Tukey's HSD test).

[0047] In other words, coffee contains a lot of caffeine, and green tea, black tea, oolong tea, and roasted green tea also contain caffeine, but the beverage made from chestnut skin powder in Example 1 does not contain caffeine and can be safely consumed by pregnant women and children.

[0048] (Sugar content) The beverage extracted using chestnut skin powder in Example 1 may contain sugar or other sugars, which makes it easier to drink. As a result of the sensory evaluation by eight people, when evaluated by sum of ranks using the Newell & Farlane test table, the astringency of the beverage containing chestnut skin powder before adding sugar was significantly improved, reaching a value equivalent to that of roasted green tea or barley tea.

[0049] (Mix with other health drinks) The chestnut skin powder extract or the chestnut skin powder in Example 1 can also be mixed with other health drinks (young barley leaf tea, green juice, Angelica keiskei tea, etc.) and consumed.

[0050] Thus, in Example 1 of the present invention, a chestnut skin powder containing chestnut outer skin and astringent skin as main components is provided. The chestnut skin powder, which is characterized by containing at least 50% by weight of dietary fiber, reduces waste by utilizing the outer skin and the inner skin of chestnuts together, and also makes it possible to realize a drink made from chestnut skin powder that contains the nutrients of chestnut skin, is healthy, and is easy to drink.

[0051] Furthermore, in Example 1 of the present invention, a beverage is made from chestnut skin powder, the main components of which are the outer skin and astringent skin of chestnuts, and is characterized by not containing caffeine and having antioxidant properties, making it good for health and, because it does not contain caffeine, it can be safely consumed by pregnant women and children.

[0052] Furthermore, in Example 1 of the present invention, a method for producing chestnut skin powder containing chestnut skin as a main component is provided, A heating step of heating chestnut skins including at least the outer skin and the inner skin of chestnuts; A drying step of drying the chestnut skin heated in the heating step; A crushing step of crushing the chestnut skin dried in the drying step; By using this method for producing chestnut skin powder, the moisture content of the chestnut skin can be significantly reduced by heating and then drying it, making it easier to grind. In addition, the antioxidant properties can be improved. [Example]

[0053] The beverage made from chestnut skin powder in Example 2 of the present invention differs from Example 1 in that the beverage is made by mixing finely pulverized chestnut skin powder (average particle size of 50 μm or less) with hot water.

[0054] In Example 2, 20 g of chestnut skin powder pulverized to an average particle size of 37 μm was roasted in a frying pan over medium heat for 1 minute, and then 6 g of the chestnut skin powder was mixed with 300 ml of boiling water to prepare a beverage. This beverage dissolved well in the hot water because the chestnut skin powder was finely pulverized. Some precipitated, but this was at a similar level to other tea beverages, such as green tea powder. Note that in Example 2, the average particle size was 37 μm, but it may be 37 μm or less or 38 μm or more. However, to achieve the effect of easy solubility in hot water, an average particle size of 50 μm or less is preferable.

[0055] (sensory evaluation) A sensory evaluation was conducted on the beverage made from chestnut skin powder in Example 2 (hereinafter also referred to as the "chestnut skin beverage") along with other beverages: roasted green tea, persimmon leaf tea, guava leaf tea, and mulberry leaf tea. Samples other than the chestnut skin beverage were also evaluated by mixing 6 g of each powder with 300 ml of hot water. The sensory evaluation was conducted by six panelists, and the results were evaluated by summing the rankings using the Newell & Farlane test table. This evaluation method involves having the panel rank the attributes of three beverages, including the chestnut skin beverage, from 1st to 3rd place, and then comparing the sums of the rankings. A higher proportion of responses in the first place, i.e., a lower total ranking, indicates a better evaluation. A difference of 9 or more between the total rankings is considered to be statistically significant. Table 1 shows the evaluation results for the chestnut skin beverage, roasted green tea, and persimmon leaf tea, and Table 2 shows the evaluation results for the chestnut skin beverage, guava leaf tea, and mulberry leaf tea.

[0056] Table 1 JPEG0007774271000002.jpg56141

[0057] The results shown in Table 1 show that the chestnut skin powder drink (chestnut skin drink) was significantly preferred over persimmon leaf tea in terms of appearance. Furthermore, it was comparable to roasted green tea and persimmon leaf tea in terms of texture strength, texture preference, taste preference, and overall evaluation. The chestnut skin powder drink was highly rated for texture strength and texture preference, likely due to its fine particle size of 37 μm on average.

[0058] Table 2 JPEG0007774271000003.jpg57148

[0059] The results shown in Table 2 show that the chestnut skin powder drink (chestnut skin drink) was equivalent to guava leaf tea and mulberry leaf tea in terms of appearance, texture strength, texture preference, taste preference, and overall evaluation. The chestnut skin powder drink was highly rated for texture strength and texture preference, likely due to its fine particle size of 37 μm on average.

[0060] As a result of the above, it can be said that the tea is not particularly tasty compared to other beverages, but it is still within the range of what can be consumed as a healthy tea.

[0061] (Antioxidant properties of drinks made from chestnut skin powder) Figure 7 shows the results of an evaluation of the antioxidant properties of the beverage made from chestnut skin powder in Example 2 (a beverage made by mixing chestnut skin powder with hot water) compared with other health drinks. Values ​​indicate the mean ± standard deviation of three experiments. There is a significant difference between the different signs (a-f) (p < 0.05, Tukey's HSD test). Figure 7(a) shows the amount of total polyphenols, and it was found that the beverage contains a level of total polyphenols equivalent to that of guava leaf tea, and more total polyphenols than roasted green tea, persimmon leaf tea, loquat leaf tea, and mulberry leaf tea. The beverage made from chestnut skin powder in Example 2 underwent a roasting step 30 (with roasting) during the chestnut skin powder manufacturing process.

[0062] Figure 7(b) shows the evaluation results of the DPPH radical scavenging activity of the beverage made from chestnut skin powder in Example 2, which shows values ​​at the same level as guava leaf tea and higher values ​​than roasted green tea, persimmon leaf tea, loquat leaf tea, and mulberry leaf tea.

[0063] In other words, the antioxidant activity of the beverage made from chestnut skin powder in Example 2 is at the same level as guava leaf tea, and higher than roasted green tea, persimmon leaf tea, loquat leaf tea, and mulberry leaf tea. The beverage in Example 2 also uses both the outer skin and the astringent skin. The astringent skin is said to contain polyphenols and flavonoids equivalent to those of the outer skin, and a beverage made from chestnut skin powder, primarily containing chestnut skin, can be provided that contains significantly more total polyphenols than the outer skin alone.

[0064] (Amount of caffeine in drinks made from chestnut skin powder) Figure 8 shows the results of an evaluation of the caffeine content of the beverage made from chestnut skin powder in Example 2 (a beverage made by mixing chestnut skin powder with hot water) compared with other health drinks. Values ​​indicate the mean ± standard deviation of three experiments. There is a significant difference between the different signs (a-f) (p < 0.05, Tukey's HSD test). According to this, only green tea and roasted green tea contained caffeine, while no caffeine was detected in guava leaf tea, persimmon leaf tea, loquat leaf tea, or mulberry leaf tea. Note that the beverage made from chestnut skin powder in Example 2 was subjected to a roasting step 30 (roasted) in the chestnut skin powder manufacturing process.

[0065] In other words, the beverage made from chestnut skin powder in Example 1 (a beverage made by filtering chestnut skin powder through a coffee filter) and the beverage made from chestnut skin powder in Example 2 (a beverage made by mixing chestnut skin powder with hot water) do not contain caffeine and can be safely consumed by pregnant women and children.

[0066] Furthermore, the beverage made from chestnut skin powder in Example 2 was not made by filtering the chestnut skin powder through a coffee filter, etc. Most of the dietary fiber contained in chestnut skin powder is insoluble, and the beverage in Example 2 was made by directly mixing it with hot water, so it is believed to contain a large amount of dietary fiber.

[0067] Thus, in Example 2 of the present invention, a beverage is produced from chestnut skin powder, the main components of which are the outer skin and astringent skin of chestnuts, and is characterized by being caffeine-free and having antioxidant properties, making it healthy and suitable for consumption as chestnut tea by pregnant women and children. [Industrial Applicability]

[0068] The chestnut skin powder containing chestnut skin as the main ingredient, the beverage using chestnut skin powder as an ingredient, and the method for producing chestnut skin powder of the present invention can be widely applied to fields that utilize chestnut outer skin and astringent skin. [Explanation of symbols]

[0069] 10: Heating process 20: Drying process 30: Roasting process 40: Grinding process 50: Sieving process

Claims

1. A chestnut skin powder containing outer skin and astringent skin after using chestnut seeds, The dried chestnut skin powder contains at least 50% by weight of dietary fiber, This chestnut skin powder is characterized by containing at least 5% by weight of total polyphenols when heated.

2. This drink is made by dissolving chestnut skin powder having an average particle size of 50 μm or less, including the outer skin and astringent skin after using the chestnut seeds, in hot water, and is characterized by not containing caffeine and having antioxidant properties.

3. 3. A beverage prepared by dissolving the chestnut skin powder according to claim 2 in hot water, which contains sugar.

4. A method for producing chestnut skin powder containing outer skin and astringent skin after using chestnut seeds, A heating step of heating chestnut skins including at least the outer skin and the inner skin of chestnuts; A drying step of drying the chestnut skin heated in the heating step; A roasting step of roasting the chestnut skins dried in the drying step; A crushing step of crushing the chestnut skin roasted in the roasting step; A method for producing chestnut skin powder.

5. 5. The method for producing chestnut skin powder according to claim 4, further comprising the step of sieving the pulverized chestnut skin after the pulverizing step.

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