Method for producing polyphenol-containing gelatin

Abstract

To provide a method for producing a polyphenol-containing material with reduced bitterness and astringency by using a substance that specifically adsorbs polyphenols without any limit on the allowable intake amount. [Solution] This method for producing solid polyphenol-containing gelatin with reduced bitterness and astringency uses solid polyphenols or an extract of a polyphenol-containing plant as a raw material, and includes the steps of adding solid gelatin to an aqueous solution containing water-soluble polyphenols under heating and mixing, and allowing the water-soluble polyphenols to be adsorbed onto the solid gelatin.

Description

Technical Field

[0001] The present invention relates to an industrial production method of polyphenol-containing gelatin with reduced bitterness and astringency.

Background Art

[0002] So far, it has been reported that polyphenols have many physiological activities such as antioxidant activity, blood pressure-lowering activity, and anti-cancer activity. In addition, it has been recognized that polyphenols have effects such as blood sugar-lowering activity and blood cholesterol concentration-lowering activity that promote the metabolism of sugars and lipids, which are the causes of obesity and diabetes, and various products and beverages containing polyphenols are commercially available. Recently, it has been reported and attracted attention that polyphenols affect the maintenance and improvement of the intestinal flora homeostasis.

[0003] Polyphenols are a general term for plant components having a plurality of phenolic hydroxyl groups in their molecules, and flavonoids, phenolic acids, ellagic acid, lignans, curcumin, coumarin, etc. are known as typical polyphenols (Non-Patent Document 1: Wikipedia). The above-mentioned flavonoids include catechin (abundant in wine, tea, apples, blueberries, etc.), anthocyanidin (abundant in grape skins, purple sweet potatoes, blueberries, etc.), rutin (contained in buckwheat), or isoflavone (contained in soybeans, kudzu, etc.), etc., and non-flavonoids include tannins (astringent components contained in tea, red wine, persimmons, bananas, etc.), phenolic acids (chlorogenic acid contained in coffee), ellagic acid (contained in strawberries), sesamin, a kind of lignan (contained in sesame), curcumin (contained in turmeric), coumarin (abundant in cherry leaves, parsley, peaches, citrus fruits, etc.), etc. (Non-Patent Document 1).

[0004] Currently, examples of polyphenols used in foods, beverages, etc. include tea catechins, olive fruit polyphenols, red wine polyphenols, grape seed polyphenols, apple polyphenols, soybean polyphenols, blackcurrant polyphenols, perilla polyphenols, cocoa polyphenols, raw coffee extract, walnut polyphenols, chestnut husk polyphenols, peanut skin polyphenols, pine bark polyphenols, seaweed polyphenols, ginkgo leaf polyphenols, camellia (Theaceae) polyphenols, and the like.

[0005] However, foods and beverages with increased polyphenol concentration to an extent where their physiological activity can be expected have strong bitterness and astringency and are not in line with taste preferences, so improvement is desired.

[0006] As a method for reducing these bitterness and astringency, for example, a method of adding cyclodextrin to tea-based beverages has been reported (for example, Patent Documents 1 to 8). However, the method of adding cyclodextrin has a problem that the reduction effect of bitterness and astringency varies depending on the addition timing in the manufacturing process, etc., and a uniform and stable reduction effect of bitterness and astringency cannot be obtained. In addition, since the ADI value (acceptable daily intake) of β-cyclodextrin is set at 5 mg / kg body weight / day, there is a problem that the usage amount is limited.

[0007] The fact that polyphenols bind to proteins to form water-insoluble complexes has long been a phenomenon known as haze in wine and beer brewing. It has been reported that haze is a water-insoluble complex formed by the binding of a proline-rich region of a protein and a hydrophobic region of a polyphenol (Non-Patent Document 2).

[0008] It has been reported that hydrophobic forces and hydrogen bonds are involved in the precipitation formation of polyphenol tannins and proteins, and that proteins with a high proline content are likely to bind to polyphenols (Non-Patent Document 3).

[0009] Regarding the masking effect of various food materials on the astringency of chestnut pericarp polyphenols, evaluation was carried out based on the ability to form a precipitate with polyphenols, and it has been reported that gelatin, milk-derived proteins, methylcellulose, etc. show high effects (Non-Patent Document 4).

[0010] Methods for producing water-insoluble complexes of polyphenols and proteins have been reported. For example, a method of adding a polyphenol solution to a protein solution while stirring and mixing to form a complex (Patent Document 8), a method of adjusting the pH to 4.5 after mixing a soybean protein extract and a tea extract in a beaker to precipitate the complex (Patent Document 9), or a method of obtaining a complex by suspending milk protein dialyzed with green tea polyphenols and skim milk powder in physiological saline using a dialysis membrane (Patent Document 10) have been reported as examples. However, since no specific examples suitable for scale-up are described for the method of producing a complex of polyphenols and proteins, problems to be solved remain for the industrial production method of the complex.

[0011] Also, as an industrial production method of a complex of polyphenols and proteins, a method of forming a lipid film on the surface of a polyphenol-containing powder and a protein powder in advance and then applying a shearing force and mixing in an aqueous solution to produce a complex with reduced bitterness and astringency has been reported (Patent Document 11). However, this method requires a special powder lipid film production apparatus for forming the lipid film on the polyphenol-containing powder and the protein powder.

Prior Art Documents

Patent Documents

[0012]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Patent Document 8

Patent Document 9

Patent Document 10

Patent Document 11

Non-Patent Document

[0013]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Non-Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0014] An object of the present invention is to provide a method for producing a polyphenol-containing material with reduced bitterness and astringency, which specifically adsorbs polyphenols and uses a substance with no limit on the acceptable intake amount.

Means for Solving the Problems

[0015] Therefore, the present inventor has found that by adding solid gelatin to an aqueous solution containing polyphenols under heating and mixing and adsorbing water-soluble polyphenols to the solid gelatin, a solid polyphenol-containing gelatin with reduced bitterness and astringency can be easily produced at low cost, and the present invention has been completed.

[0016] That is, the present invention provides the following [1] to [3].

[0017] [1] A method for producing polyphenol-containing gelatin with low bitterness and astringency using water-soluble polyphenols as a raw material, a first step of preparing an aqueous solution containing polyphenols by extraction from a polyphenol-containing raw material, or by dissolving solid polyphenols in water to prepare an aqueous solution containing polyphenols, and adding solid gelatin to the aqueous solution containing polyphenols obtained in the first step under heating and mixing at 40 to 100°C to adsorb water-soluble polyphenols to the solid gelatin (provided that a water-insoluble complex of polyphenols and proteins is not formed by mixing a polyphenol-containing powder and a protein-containing powder with a lipid film formed in an aqueous solution and destroying the lipid film Shi Po except in the case of forming a water-insoluble complex of polyphenols and proteins) a second step, and a third step of separating the gelatin fraction adsorbed with water-soluble polyphenols in the second step, and A 4a step of drying the precipitate fraction containing moisture obtained in the third step and finely pulverizing it to obtain a polyphenol-containing gelatin powder; A method for producing a polyphenol-containing gelatin, comprising .

[0018] [2] The method for producing a polyphenol-containing gelatin according to [1], wherein the solid gelatin is gelatin powder.

[0019] [3] The method for producing a polyphenol-containing gelatin according to [1] or [2], wherein the amount of the solid gelatin used is 0.3 parts by mass or more with respect to 1 part by mass of the water-soluble polyphenol contained in the polyphenol-containing solution. Water

Advantages of the Invention

[0020] According to the present invention, a polyphenol-containing gelatin containing polyphenols without restriction on the allowable intake amount and having reduced bitterness and astringency, and a composition containing the same can be produced simply and at low cost.

Brief Description of the Drawings

[0021]

Figure 1

Modes for Carrying Out the Invention

[0022] Hereinafter, the present invention will be described in detail based on its embodiments, but the present invention is not limited to these embodiments.

[0023] <Method for Producing Polyphenol-Containing Gelatin with Reduced Bitterness and Astringency> The method for producing the polyphenol-containing gelatin of the present invention is a method for producing polyphenol-containing gelatin with reduced bitterness and astringency, using water-soluble polyphenols as raw materials and solid gelatin as an adsorbent. The method includes a step (hereinafter also referred to as the second step) of adding solid gelatin to an aqueous polyphenol-containing solution containing water-soluble polyphenols under heating and mixing to adsorb the water-soluble polyphenols in the aqueous polyphenol-containing solution to the solid gelatin.

[0024] Further, the aqueous polyphenol-containing solution can be prepared by dissolving solid polyphenols in water or using a solution extracted from a plant raw material containing polyphenols with an aqueous solvent.

[0025] Next, the first to fourth steps in the present invention will be described in detail. First, each step of the present invention will be briefly described with reference to FIG. 1.

[0026] When "starting", first, a "polyphenol-containing raw material" is prepared, and an "aqueous polyphenol-containing solution" is prepared by extraction, or an "aqueous polyphenol-containing solution" is prepared by dissolving solid polyphenols in water (first step). Next, solid gelatin is added to the aqueous polyphenol-containing solution obtained in the first step under heating and mixing to adsorb water-soluble polyphenols to the solid gelatin (second step). Further, the gelatin fraction adsorbed with water-soluble polyphenols in the second step is separated (third step), and the precipitate fraction obtained in the third step is dried and finely pulverized to recover polyphenol-containing gelatin powder (fourth step), and then "ending".

[0027] (First step) The aqueous polyphenol-containing solution used in the present invention is prepared by dissolving solid polyphenols in water. Alternatively, it can be prepared by extraction with an aqueous solvent from a polyphenol-containing raw material such as a plant raw material containing water-soluble polyphenols.

[0028] Examples of solid polyphenols used as raw materials in the present invention include polyphenols commercially available as food raw materials, such as catechin, proanthocyanidin, and isoflavone. Examples of plant raw materials containing water-soluble polyphenols include persimmon, grape, tea, peanut, and coffee, but the variety is not limited.

[0029] (2nd process) This process is a process in which solid gelatin is added to a polyphenol-containing aqueous solution under heating and mixing to adsorb water-soluble polyphenols to the solid gelatin. By the operation of this process, polyphenols, which are bitter and astringent components, are specifically adsorbed to the solid gelatin. In this way, a gelatin fraction with water-soluble polyphenols adsorbed thereto can be obtained. The gelatin fraction with water-soluble polyphenols adsorbed thereto produced by this process is produced as a solid with good separation characteristics and sedimentation properties, so it is easy to separate. In addition, heat-sensitive microorganisms present in the polyphenol raw material and gelatin are also sterilized by heating, so the quality of polyphenol-containing gelatin can be expected to improve.

[0030] Here, the mechanism by which water-soluble polyphenols are adsorbed to solid gelatin is not entirely clear, but the present inventors speculate that when solid gelatin is added to water-soluble polyphenols such as heated persimmon juice, the helical structure of the gelatin molecules on the surface of the solid gelatin becomes a random coil molecular structure depending on the temperature, to which water-soluble polyphenol molecules are quickly adsorbed. In addition, solid gelatin with water-soluble polyphenols adsorbed is formed as a precipitate without gelling, and the present inventors speculate that this is because the water-soluble polyphenols are quickly adsorbed to the solid gelatin, making it unable to form a normal gelatin sol, and suppressing swelling due to the binding of water molecules, so that the gelatin cannot take on its original helical structure even when cooled.

[0031] The content of the water-soluble polyphenol contained in the aqueous solution containing polyphenol used in this process is preferably more than 0.1% (w / v), more preferably more than 1% (w / v) in terms of tannic acid conversion, and preferably 10% (w / v) or less, more preferably 7.5% (w / v) or less, particularly preferably 5% (w / v) or less.

[0032] In this specification, the content of the water-soluble polyphenol refers to the value measured using tannic acid as a standard product by the Folin-Ciocalteu method. Specifically, it may be measured in the same manner as the method of the examples.

[0033] In this process, solid gelatin is used. Therefore, there is no dilution of the polyphenol solution as in the case of adding a gelatin solution, and it can be easily and efficiently produced from 100% raw materials such as plant extracts. In addition, since the process of preparing the gelatin solution in advance can be omitted, it is simple and industrially advantageous. Further, when a gelatin solution is used instead of solid gelatin, fine precipitates with poor separation characteristics and sedimentation properties are generated.

[0034] The solid gelatin used in this process is not particularly limited as long as it adsorbs water-soluble polyphenol when heated. However, in terms of easy availability of commercially available products for food use, acid-treated gelatin and alkali-treated gelatin are preferred. Examples of such gelatin include those derived from pigs (skin, bones), cows (skin, bones), fish (skin, scales), etc. Note that one of these may be used alone or two or more of them may be used in combination.

[0035] Examples of the solid gelatin also include gelatin powder, gelatin granules, sheet gelatin, etc. Note that one of these may be used alone or two or more of them may be used in combination. Among these, gelatin powder is preferred from the viewpoints of the taste of the polyphenol-containing gelatin, production efficiency, handleability, etc. Note that the solid gelatin may be prepared according to a known method or a commercially available product may be used.

[0036] The amount of solid gelatin used may be determined according to the amount of water-soluble polyphenols contained in the aqueous polyphenol-containing solution. The amount of solid gelatin used is preferably 0.3 parts by mass or more, more preferably 0.7 parts by mass or more, particularly preferably 1 part by mass or more, based on 1 part by mass (in terms of tannic acid) of water-soluble polyphenols. Also, from the viewpoints of production cost and production efficiency, it is preferably 3 parts by mass or less, more preferably 2 parts by mass or less, based on 1 part by mass (in terms of tannic acid) of water-soluble polyphenols contained in the aqueous polyphenol-containing solution.

[0037] In addition, the amount of solid gelatin used such that the polyphenol content in the obtained polyphenol-containing gelatin becomes the desired content can be determined based on the results of preliminary tests from the water-soluble polyphenol concentration in the aqueous polyphenol-containing solution, whereby the polyphenol content of the obtained polyphenol-containing gelatin can also be finely adjusted, and a polyphenol-containing gelatin with a complex taste with a slightly astringent taste can also be obtained.

[0038] Also, the temperature when adding solid gelatin to the aqueous polyphenol-containing solution is 40°C or higher, more preferably 50°C or higher, particularly preferably 60°C or higher, from the viewpoint of the adsorption rate of water-soluble polyphenols to solid gelatin. Also, from the viewpoints of production cost and production efficiency, it is 100°C or lower, more preferably 90°C or lower, still more preferably 80°C or lower, particularly preferably 70°C or lower.

[0039] Heating of the aqueous polyphenol-containing solution can be carried out using a heat exchanger such as a plate-type heat exchanger or a tubular heat exchanger. Also, during heating and mixing, it is preferable to maintain the treatment temperature constant through the jacket of the mixing tank. The mixing time for mixing the solid gelatin added to the heated aqueous polyphenol-containing solution may be appropriately adjusted according to the liquid volume of the aqueous polyphenol-containing solution.

[0040] In addition, as a specific operation of "adding solid gelatin under heating and mixing to the aqueous solution containing polyphenol", for example, an operation of adding solid gelatin (gradually) to the aqueous solution containing polyphenol being heated and mixed can be mentioned. By thus preheating and then bringing the aqueous solution containing polyphenol into contact with solid gelatin, the generation of aggregates is suppressed, and the adsorption of water-soluble polyphenol proceeds more easily.

[0041] Further, as a mixing operation of the aqueous solution containing polyphenol, a mixing operation by stirring using an ordinary stirrer can be mentioned.

[0042] (Step 3) As a method for producing the gelatin containing polyphenol of the present invention, a method further including a third step of separating the gelatin fraction adsorbed with the water-soluble polyphenol in the second step is preferable. Since the gelatin fraction adsorbed with the water-soluble polyphenol is a solid having good separation characteristics and sedimentation properties, it can be easily separated by a solid-liquid separation operation such as centrifugation, filtration, or screw press.

[0043] Among the above solid-liquid separation operations, centrifugation can be performed using an ordinary centrifuge such as a separation plate type, cylindrical type, or decanter type. As the rotation speed of centrifugation, 3,000 to 100,000 rpm is preferable, 5,000 to 20,000 rpm is more preferable, and 5,000 to 10,000 rpm is particularly preferable. Also, when mass-producing, it is preferable to use a continuous centrifuge, but a batch centrifuge can also be used.

[0044] In addition, the gelatin fraction adsorbed with the water-soluble polyphenol separated in the third step can be separated into the water-soluble polyphenol and gelatin by solvent extraction or the like, in addition to being used as the original food raw material. This gelatin can be reused for the adsorption of the water-soluble polyphenol, and the water-soluble polyphenol separated from the gelatin can also be used as a raw material for bactericides, kaki astringent, soap, deodorants, cosmetics, paints, etc.

[0045] (Step 4a) The polyphenol-containing gelatin separated in the third step is a wet precipitate cake (precipitation fraction) containing moisture, which is dried and pulverized to obtain polyphenol-containing gelatin powder.

[0046] As the drying method, it can be carried out using ordinary dryers such as freeze dryers, vacuum dryers, hot air dryers, infrared dryers, and microwave heating dryers. As the drying temperature, 50°C or lower is preferable, 40°C or lower is more preferable, and 30°C or lower is particularly preferable.

[0047] After drying, fine pulverization is carried out using a fine pulverizer such as a bead mill, ball mill, rod mill, jet mill, or a grinding machine such as a rotary mortar to obtain polyphenol-containing gelatin powder.

[0048] <Composition containing polyphenol-containing gelatin> The composition containing polyphenol-containing gelatin described in this specification contains the polyphenol-containing gelatin produced by the production method of the polyphenol-containing gelatin described above and a dispersant. This composition has reduced bitterness and astringency of polyphenols and also has good extractability from gelatin. That is, gelatin is used to reduce the bitterness and astringency of polyphenols, and polyphenols are adsorbed on this gelatin. On the other hand, when polyphenols are ingested, the ingested polyphenols need to be sufficiently released from the gelatin. If the release from gelatin is not sufficient, for example, when using polyphenol-containing gelatin powder in health foods, etc., the sustained release property of polyphenols from the powder particles may decrease. As a result, there may be problems such as an increase in the intake amount. Therefore, by suspending the wet precipitate of polyphenol-containing gelatin containing moisture in a dispersant and atomizing it into fine particles like the composition containing polyphenol-containing gelatin described in this specification, it becomes possible to easily release the polyphenols adsorbed on the gelatin.

[0049] Examples of the dispersant include water-soluble polymers having functions such as an anti-precipitation function, an anti-aggregation function, and an emulsification function. The water-soluble polymer is not particularly limited as long as it has the above functions. Examples include thickening polysaccharides such as xanthan gum and guar gum, natural polymers such as sodium alginate, corn starch, sodium chondroitin sulfate, and sodium hyaluronate, semi-synthetic polymers such as carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose, and cationized guar gum, and synthetic polymers such as carboxyvinyl polymer, polyacrylic acid, polyvinyl pyrrolidone, and polyvinyl alcohol. The aqueous solution of the thickening polysaccharide is characterized by high non-Newtonian fluidity and pseudoplastic fluidity. That is, the aqueous solution of the thickening polysaccharide has a high static viscosity (good sedimentation suppression effect for fine particles), but the viscosity decreases significantly when sheared.

[0050] <Method for producing a composition containing polyphenol-containing gelatin with reduced bitterness and astringency> The method for producing a composition containing polyphenol-containing gelatin according to the present specification is a method for producing a composition containing polyphenol-containing gelatin with reduced bitterness and astringency using a water-soluble polyphenol as a raw material and solid gelatin as an adsorbent. The method includes a first step of preparing an aqueous solution containing polyphenol by extraction from a polyphenol-containing raw material or dissolving solid polyphenol in water to prepare an aqueous solution containing polyphenol, a second step of adding solid gelatin to the aqueous solution containing polyphenol obtained in the first step under heating and mixing to adsorb the water-soluble polyphenol to the solid gelatin, a third step of separating the gelatin fraction adsorbed with the water-soluble polyphenol in the second step, and a fourth b step of suspending the precipitate fraction containing water obtained in the third step in a dispersant to form fine particles and obtaining a suspension solution of polyphenol-containing gelatin.

[0051] By this method, a composition with reduced bitterness and astringency of polyphenols can be obtained, and a composition with good extractability of polyphenols from gelatin can also be obtained. That is, as described above, the bitterness and astringency of polyphenols can be reduced by using gelatin. On the other hand, after ingesting polyphenol-containing gelatin, the ingested polyphenols need to be sufficiently released from the gelatin in an effective state. However, if the effective polyphenols are not released from the gelatin, for example, when using polyphenol-containing gelatin powder in health foods, etc., the sustained release of polyphenols from the powder particles may decrease. As a result, problems such as an increase in the intake amount may occur. According to the production method of the present specification, a composition with reduced bitterness and astringency during ingestion and release of polyphenols in an effective state after ingestion can be produced.

[0052] (Steps 1 to 3) For Steps 1 to 3, the same steps as those in the above-described <Method for Producing Polyphenol-Containing Gelatin with Reduced Bitterness and Astringency> can be adopted.

[0053] (Step 4b) Step 4b is a step of suspending the precipitate fraction containing moisture obtained in Step 3 in a dispersant to form fine particles and obtaining a suspension solution of polyphenol-containing gelatin. As the dispersant used in this step, the dispersants described in the above <Composition Containing Polyphenol-Containing Gelatin> can be appropriately adopted.

[0054] As a suspension method for suspending the precipitate fraction in the dispersant, examples include a method of suspending a wet precipitate cake containing moisture in a dispersant (for example, a water-soluble polymer having a precipitation prevention function, an aggregation inhibition function, an emulsification function, etc.) and using a wet pulverizer such as a wet bead mill or a wet ball mill to form fine particles. In this way, a suspension solution of wet polyphenol-containing gelatin can be obtained.

Examples

[0055] Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

[0056] The water-soluble polyphenol concentration was measured by the Folin-Ciocalteu method using tannic acid (manufactured by Yoneyama Pharmaceutical Co., Ltd.) as a standard product and a phenol reagent (manufactured by Nacalai Tesque).

[0057] (Preparation Example 1: Preparation of Persimmon Tannin-Containing Gelatin from Astringent Persimmon Extract) [Preparation of Extract] From about 10 kg of astringent persimmons (Aitai produced in Ehime Prefecture), about 8 kg (7.4 L) of squeezed juice was obtained using a juicer (Panasonic "MJ-L500-S"). Since the squeezed juice exhibited an orange color derived from carotenoids and had turbidity, centrifugation was performed at 9,500 rpm for 30 minutes using a high-speed cooling centrifuge to remove the water-insoluble carotenoid-containing precipitate fraction.

[0058] As a result, about 7.5 kg of a clear astringent persimmon extract containing water-soluble persimmon tannin (persimmon polyphenol) was obtained (total recovery rate: about 75%). As a result of measuring the water-soluble persimmon tannin concentration in the extract by the Folin-Ciocalteu method, the water-soluble persimmon tannin concentration was 24.2 mg / mL (in terms of tannic acid).

[0059] [Examination of Gelatin Addition Conditions (Temperature)] To 100 mL of the astringent persimmon extract obtained above, 3.6 g of gelatin powder (manufactured by Nitta Gelatin Co., Ltd.) was gradually added under the temperature and mixing conditions shown in Table 1, and after sufficiently mixing and stirring for about 10 minutes at that temperature, it was left at room temperature. Then, centrifugation was performed at 4 - 8°C and 6,800 rpm for 30 minutes. The remaining water-soluble persimmon tannin concentration in the obtained centrifuged supernatant was measured and evaluated. The results are shown in Table 1.

[0060] [Table 1]

[0061] As shown in Table 1, when water-soluble persimmon tannin begins to be adsorbed by solid gelatin at a temperature of 40°C or higher, a precipitate that can be easily separated from the extract is formed, and the adsorption rate is approximately 97% at 60°C or higher, indicating that almost all of the water-soluble persimmon tannin in the extract is adsorbed by gelatin.

[0062] [Examination of Gelatin Addition Amount] To 100 mL of the astringent persimmon extract (water-soluble persimmon tannin concentration: 24.2 mg / mL) obtained above, under heating and mixing at 60 - 70°C, 0.5 part by mass, 0.75 part by mass, 1.0 part by mass, or 1.5 part by mass of gelatin powder (manufactured by Nitta Gelatin Inc.) was gradually added per 1 part by mass (in terms of tannic acid) of water-soluble persimmon tannin. After thoroughly mixing and stirring for about 10 minutes at that temperature, it was left at room temperature. Then, centrifugation was performed at 4 - 8°C and 6,800 rpm for 30 minutes.

[0063] The concentration of water-soluble persimmon tannin remaining in the obtained centrifuged supernatant was measured to determine the adsorption rate to gelatin. The results are shown in Table 2.

[0064]

Table 2

[0065] When the amount of solid gelatin used was 1 part by mass or more per 1 part by mass of water-soluble persimmon tannin, almost all of the water-soluble persimmon tannin was adsorbed by gelatin.

[0066] [Production of Gelatin Containing Persimmon Tannin] To 2 L of the astringent persimmon extract obtained above, under heating and mixing at 60 - 70°C, 50 g of gelatin powder (manufactured by Nitta Gelatin Inc.) was gradually added. After thoroughly mixing and stirring for about 10 minutes at that temperature, it was left at room temperature. Then, centrifugation was performed at 4 - 8°C and 6,800 rpm for 30 minutes. After freeze-drying the precipitate fraction and then finely pulverizing it, about 60 g of gelatin powder containing persimmon tannin was obtained. No astringency was felt when this powder was put in the mouth.

[0067] [Production of Suspension Solution Containing Moist Gelatin Containing Persimmon Tannin] To 2 L of the astringent persimmon extract obtained above, 50 g of gelatin powder (manufactured by Nitta Gelatin Inc.) was gradually added under heating and mixing at 60 to 70°C, and after thoroughly mixing and stirring for about 10 minutes at that temperature, it was left at room temperature. Then, centrifugation was performed at 4 to 8°C and 6,800 rpm for 30 minutes. The precipitate fraction was dispersed in 2 L of a dispersant / 0.5% xanthan gum aqueous solution (xanthan gum: KIMICA CORPORATION "KIMICA XANTHAN PH-EC"), and then micronized using a wet ball mill (Shimal Enterprises Co., Ltd. "DYNO-MILL MULTI-LAB type") to obtain about 2 L of a suspension solution of wet persimmon tannin-containing gelatin. No astringency was felt when this suspension solution was held in the mouth.

[0068] (Preparation Example 2: Production of Catechin-Containing Gelatin from Catechin Raw Material) Using commercially available tea catechin powder (Taiyo Kagaku Co., Ltd. "SUNPHENOL 90S": polyphenol 80% or more) as a catechin raw material, 1000 mL of a 2% aqueous solution was prepared. To this aqueous solution, 20 g of gelatin powder (manufactured by Nitta Gelatin Inc.) was gradually added under heating and mixing at 60 to 70°C, and after thoroughly mixing and stirring for about 10 minutes at that temperature, it was left at room temperature. Then, centrifugation was performed at 4 to 8°C and 6,800 rpm for 30 minutes. The residual catechin concentration in the supernatant was 0.8 mg / mL, and most of it was adsorbed by gelatin. After freeze-drying the precipitate fraction, it was finely pulverized to obtain about 25 g of tea catechin-containing gelatin powder. No bitterness or astringency was felt when this powder was held in the mouth.

[0069] (Preparation Example 3: Production of Proanthocyanidin-Containing Gelatin from Proanthocyanidin Raw Material) Using commercially available grape seed polyphenols (Kikkoman Biochemifa Co., Ltd.'s "Gravinol-SE") as a proanthocyanidin raw material, 1000 mL of a 2% aqueous solution was prepared. To this aqueous solution, 20 g of gelatin powder (manufactured by Nitta Gelatin Inc.) was gradually added under heating and mixing at 40°C to 50°C, and after sufficiently mixing and stirring at that temperature for about 10 minutes, it was left at room temperature. Then, centrifugation was performed at 6,800 rpm for 30 minutes at 4°C to 8°C. The residual proanthocyanidin concentration in the supernatant was 0.7 mg / mL, and most of it was adsorbed by the gelatin. After freeze-drying the precipitate fraction and finely pulverizing it, about 2 g of gelatin powder containing grape seed proanthocyanidin was obtained. No bitter or astringent taste was felt when this powder was held in the mouth.

Industrial Applicability

[0070] According to the present invention, since it is possible to provide a polyphenol-containing material with reduced bitterness and astringency by using a substance that specifically adsorbs polyphenols and has no limit on the allowable intake, it can be used extremely beneficially industrially.

Claims

1. A method for producing polyphenol-containing gelatin with low bitterness and astringency using water-soluble polyphenol as a raw material, a first step of preparing an aqueous polyphenol-containing solution by extraction from a polyphenol-containing raw material or dissolving solid polyphenol in water to prepare an aqueous polyphenol-containing solution; adding solid gelatin to the aqueous polyphenol-containing solution obtained in the first step under heating and mixing at 40 to 100 °C to adsorb water-soluble polyphenol to the solid gelatin (however, except when a polyphenol-containing powder and a protein-containing powder having a lipid coating are mixed in an aqueous solution to break the lipid coating and form a water-insoluble complex of polyphenol and protein), a second step; a third step of separating the gelatin fraction adsorbed with water-soluble polyphenol in the second step; a fourth a step of drying the precipitate fraction containing water obtained in the third step and finely pulverizing it to obtain polyphenol-containing gelatin powder; A method for producing polyphenol-containing gelatin, comprising:

2. The method for producing polyphenol-containing gelatin according to claim 1, wherein the solid gelatin is gelatin powder.

3. The method for producing polyphenol-containing gelatin according to claim 1 or 2, wherein the amount of the solid gelatin used is 0.3 parts by mass or more with respect to 1 part by mass of water-soluble polyphenol contained in the aqueous polyphenol-containing solution.

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