JP7178652B2 - Method for producing persimmon polyphenol decomposition product - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a persimmon polyphenol decomposition product that can provide a naturally-derived material with enhanced functionality.

Polyphenols contained in natural products such as tea, grapes, apples, and cacao have various physiological activities, such as antioxidative action, blood pressure lowering action, blood sugar level elevation suppressing action, carcinogenesis suppressing action, and coronary heart disease improving action. has been reported.

On the other hand, the astringent taste of persimmons is due to tannins, which are polyphenols. When you eat astringent persimmons or immature sweet persimmons, their tannins bind to proteins in the tongue and oral mucosa, giving them a strong astringent taste (astringent taste). , Its tannins are insolubilized, and it does not have an astringent taste, so it can be eaten deliciously.

The structure of persimmon tannin has been studied using immature fruits of the cultivar ``Hiratanenashi''. epigallocatechin (EGC), epigallocatechin gallate (EGCg) proanthocyanidin polymer condensed at a predetermined ratio (each constituent unit is polymerized by C-4 and C-6 or C-8 bonds. ) has been reported (see Non-Patent Document 1 below and FIG. 7). In addition, regarding the functionality of persimmon tannin, it has been clarified in rat animal tests and human volunteer evaluations that oral administration has the effect of suppressing the increase in blood sugar level after glucose loading (Non-Patent Document 2 below). .

On the other hand, in Patent Document 1 below, epigallocatechin-3-O-gallate trimer obtained from persimmon tannin, having a pyrogallol rate of 70 to 90% and a galloylation rate of 40 to 70% in the B ring. It is described that the contained persimmon polyphenol oligomer has stronger inhibitory activity against α-glucosidase and/or α-amylase than the tea catechin monomer epigallocatechin-3-O-gallate. there is

Matsuo, T. and Ito, S.,"The chemical structure of kaki-tannin from immature fruit of the persimmon (Diospyros kaki L.)." Agric. Biol. Chem. (1978), 42, 1637-1643. Takashi Kometani and Kumiko Takemori “Polyphenols from Persimmon Fruits as a Functional Foods Material” Nippon Shokuhin Kagaku Kogaku Kaishi (2016), 63(7), 331-337.

JP 2009-001531 A

However, according to the studies of the present inventors, it was difficult to say that the functionality of persimmon tannin as it is is fully utilized. In addition, the persimmon polyphenol oligomer described in Patent Document 1 is fragmented in the presence of tea catechin or epigallocatechin-3-O-gallate as a low-molecular-weight reaction agent under acidic conditions, and then adsorbed on an adsorption resin. , Washed with water, eluted with an aqueous ethanol solution, dried, further passed through a gel filtration column to remove monomers, and have oligomers from dimers to pentamers as main components. It was difficult to say that it was a versatile material because it required complicated work and equipment, and the cost increased.

An object of the present invention is to process persimmon polyphenol so that its functionality can be exhibited sufficiently.

In order to achieve the above object, the present invention firstly provides a method for producing a persimmon polyphenol decomposition product, which comprises treating a persimmon polyphenol-containing material with subcritical water.

In the method for producing a persimmon polyphenol decomposition product, the persimmon polyphenol-containing substance is preferably a water-insoluble substance obtained by removing astringency from persimmon fruit.

Moreover, in the method for producing a persimmon polyphenol decomposition product, the persimmon polyphenol-containing substance is preferably an extract obtained by hot water extraction from a water-insoluble substance obtained by removing astringency from persimmon fruit.

Further, in the method for producing persimmon polyphenol decomposition products, the treatment with subcritical water is preferably performed under a pressure of 1 to 10 MPa.

Further, in the method for producing a decomposition product of persimmon polyphenol, the treatment with subcritical water is preferably carried out under conditions in which the value of R ₀ obtained by the following formula is in the range of 1 to 20,000.

Secondly, the present invention provides a method for producing a composition for suppressing elevation of blood sugar level, which comprises the step of treating persimmon polyphenol-containing material with subcritical water.

In the method for producing a composition for suppressing an increase in blood sugar level, the persimmon polyphenol-containing material is preferably a water-insoluble material obtained by removing astringency from persimmon fruit.

In the method for producing a composition for suppressing an increase in blood sugar level, the persimmon polyphenol-containing material is preferably an extract obtained by hot water extraction from a water-insolubilized material obtained by removing astringency from persimmon fruit.

In the method for producing a composition for suppressing elevation of blood sugar level, the treatment with subcritical water is preferably performed under a pressure of 1 to 10 MPa.

Further, in the method for producing a composition for suppressing elevation of blood sugar level, the treatment with subcritical water is preferably performed under conditions in which the value of R ₀ obtained by the following formula is in the range of 1 to 20,000.

In the method for producing a composition for suppressing an increase in blood sugar level, the composition for suppressing an increase in blood sugar level inhibits one or more enzymes selected from glucosidase, maltase, sucrase, and amylase. is preferred.

Moreover, in the method for producing a composition for suppressing an increase in blood sugar level, it is preferable that the composition for suppressing an increase in blood sugar level is used as a food, drink, or a pharmaceutical product for suppressing an increase in blood sugar level.

According to the present invention, the persimmon polyphenol is processed using subcritical water, so that the functionality of the persimmon-derived natural material can be efficiently enhanced with simple work and equipment. In particular, inhibitory activity against enzymes such as glucosidase, maltase, sucrase, and amylase, which can contribute to suppression of blood sugar level elevation, can be enhanced.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram which shows an example of the subcritical water treatment apparatus which can be used for this invention. 1 is a graph showing the results of evaluation of the molecular weight distribution of persimmon polyphenol solutions obtained by subcritical water treatment under various conditions in Test Example 1. FIG. 4 is a chart showing the results of evaluation of freezing point depression of persimmon polyphenol solutions obtained when subcritical water treatment was performed under various conditions in Test Example 2. FIG. 2 is a chart showing the results of evaluating the pH of persimmon polyphenol solutions obtained when subcritical water treatment was performed under various conditions in Test Example 3. FIG. It is a graph plotting the freezing point depression results of Test Example 2 on the Y axis and the pH results of Test Example 3 on the X axis. Fig. 6a is a chart showing the results of evaluating the glycolytic enzyme inhibitory activity of persimmon polyphenol solutions obtained when subcritical water treatment was performed under various conditions in Test Example 4. Fig. 6a shows the results of α-glucosidase inhibitory activity. 6b shows the results for maltase inhibitory activity, FIG. 6c shows the results for sucrase inhibitory activity, and FIG. 6d shows the results for α-amylase inhibitory activity. It is a chart showing the chemical structure of persimmon tannin.

The present invention provides a method for obtaining a persimmon polyphenol decomposition product rich in functionality by treating a persimmon polyphenol-containing material with subcritical water. Here, the term “functionality” has the same meaning as a normal term that will be understood by those skilled in the art. Technically speaking, it refers to the ability of a substance to affect living organisms or substances related to living organisms. In general, the functions of polyphenols include antioxidant, blood glucose suppression, anti-inflammatory/anti-allergic action, osteoporosis prevention action, visual function regulation action, anti-fatigue action, cognitive function maintenance action, carcinogenesis suppression action, and coronary heart disease improvement action. etc., or an inhibitory activity on sugar-digesting enzymes such as glucosidase, maltase, sucrase, amylase, lactase, and saccharase, which are related to the effect of suppressing elevation of blood sugar. Therefore, the present invention potentially makes it possible to provide persimmon-derived natural materials rich in these functionalities.

In the present invention, the term “subcritical water” has the same meaning as the ordinary term that will be understood by those skilled in the art. to the critical temperature (374.15°C). Subcritical water has the characteristics of increasing the ionic product and decreasing the dielectric constant compared to water in a normal state. In general, an increase in the ionic product enhances the hydrolysis power, and a decrease in the dielectric constant results in properties similar to those of an organic solvent.

In the present invention, the persimmon polyphenol-containing material to be treated with subcritical water is not particularly limited as long as it contains persimmon polyphenol. From the viewpoint of safety when administered, it is preferable to use natural materials such as persimmon tannin and persimmon tannin. Alternatively, a persimmon polyphenol material obtained by extracting such persimmon juice, persimmon tannin, or the like may be used. However, in order to effectively obtain persimmon polyphenol decomposition products rich in functionality, the persimmon polyphenol-containing material needs to contain persimmon polyphenol having a predetermined molecular weight or more. Specifically, the average molecular weight in the molecular weight distribution of the polyphenol is preferably 10,000 to 1,000,000, more preferably 50,000 to 600,000, and even more preferably 100,000 to 400,000. Also, the polyphenol content is preferably 1 to 100% by mass, more preferably 20 to 100% by mass, and even more preferably 50 to 100% by mass in terms of dry solid content. The molecular weight distribution and average molecular weight of polyphenol can be measured by GCP (gel permeation chromatography), viscosity method, mass spectrometry, osmotic pressure method, light scattering method and the like. For example, in GCP (gel permeation chromatography), an elution curve is observed in advance for each molecular weight of a standard molecular weight substance (for example, polyethylene glycol, which is a linear molecule), and the elution position (elution amount) of the elution peak is observed for each molecular weight. is determined, a calibration curve is prepared, and the position of the elution peak of the elution curve actually obtained is applied to the calibration curve, whereby the average molecular weight can be obtained. The polyphenol content can be measured by, for example, the iron tartrate method, the Prussian blue method, the Folin-Denis method, the Folin-Ciocalteu method, the vanillin-hydrochloric acid method, the vanillin-sulfuric acid method, and the like. For the quantification, for example, the amount of polyphenols can be determined by drawing a calibration curve in advance using catechin or the like as an index substance and applying the actually obtained measured values to this curve.

The method for preparing the persimmon polyphenol-containing material from raw material persimmon will be described in more detail below. However, the method for preparing the persimmon polyphenol-containing material to be treated with subcritical water in the present invention is not limited by the following explanation.

There are no particular restrictions on the variety of persimmon used as a raw material, and varieties commonly cultivated in Japan include, for example, ``Tokonwase'', ``Hiratanenashi'', ``Koshu Hyakume'', ``Aizumi Shirazu'', ``Saijo'', ``Atago'', ``Ichida persimmon'', ``Tenno'' and the like can be mentioned. The parts to be used are not particularly limited, such as fruits, peels, pulps, seeds, leaves, rhizomes, branches, barks, etc., but fruits contain many tannin cells in which polyphenols are accumulated. Since it is naturally renewable, it is preferably used. The fruit may be used as a raw material in a state in which it contains any part other than the pulp such as the calyx, peel, and seeds, or in a state in which any or all of them are removed. It can be used as a raw material.

When extracting polyphenols from persimmons as a raw material, it is preferable to subject them to natural and/or artificial astringency removal. As a result, persimmon polyphenol is water-insolubilized by acetaldehyde condensation/polymerization reaction, etc., and the formed water-insolubilized product can be easily washed with water, other isotonic solutions, buffer solutions, etc., so that washing is more effective and effective. Impurities can be removed efficiently. After washing, the polyphenol can be re-solubilized by applying heat, ultrasonic waves, or the like, and if this is treated with subcritical water, a more pure persimmon polyphenol decomposition product can be obtained. In addition, the treatment with subcritical water may serve as the re-solubilization treatment of the polyphenol. That is, when the water-insolubilized substance is directly treated with subcritical water, the water-insolubilized polyphenol is eluted into the water by the treatment. At the same time, decomposition also proceeds.

Fermentation etc. are mentioned as a process of natural astringency removal. However, it takes 1 to 3 years or more to produce, and the fermentation produces a strong odor that causes a unique unpleasant feeling, so the occasions where it can be used tend to be limited.

As the artificial treatment for removing astringency, a conventional method for the purpose of removing astringency to sweeten astringent persimmons can be appropriately employed. For example, persimmons, which are raw materials, are placed in a container such as a polyethylene bag with ethanol or dry ice, sealed, and stored for a predetermined period of time. A constant temperature short-term deastringency method or a low-temperature deastringency method in which astringency removal and storage are carried out simultaneously may be adopted as appropriate. Alternatively, in order to promote the water insolubilization of persimmon polyphenol more simply, the raw material persimmon is crushed or homogenized, and then placed in a container, bag, etc. that can be sealed, and 1 to 1 per 1 kg of the weight of the raw material persimmon 5 mL of ethanol may be added, sealed and allowed to stand for 24 hours to 3 days. The degree of astringency removal can also be confirmed by the tannin printing method well known to those skilled in the art.

After the astringency removal treatment, the water-insoluble matter formed is washed with water, an isotonic solution, a buffer solution, or the like, as described above, to increase the purity of the persimmon polyphenol. Although there is no particular limitation on the manner of washing, persimmon polyphenol, more specifically, for example, tannin cells present as tannin-accumulating cells in persimmon fruit, can be separated and sedimented in water when subjected to sufficient deastringency treatment. sexuality increases. Therefore, in consideration of efficiently performing the washing treatment at the lowest possible cost, the embodiment is to pulverize or homogenize the raw material persimmon and sufficiently remove the astringency with ethanol, dry ice, or the like. Then, add 1 to 20 times the amount of water, stir or mix, then allow to stand, remove the supernatant, repeat this 5 to 20 times, in some cases, over a period of 5 hours to 3 days, It is a method such as filtering out the final precipitate. In this way relatively large amounts of raw material can be efficiently processed.

After the washing treatment, the water-insolubilized persimmon polyphenol is re-solubilized, but as described above, the treatment with subcritical water may also serve as the re-solubilization treatment. However, in order to obtain a more homogeneous or more stable persimmon polyphenol decomposition product, the water-insolubilized product after the above-mentioned deastringency treatment is once extracted with a solvent such as hot water to obtain an extract, which is then used as a sub- Critical water treatment is recommended. According to this, the persimmon polyphenol contained in the water-insolubilized material after the astringency removal treatment can more uniformly receive the effect of the subcritical water treatment. Specifically, 5 to 20 times, preferably 8 to 15 times the amount of the extraction solvent, particularly preferably water, is added to the water-insolubilized material after the insolubilization treatment, and the mixture is added for 30 minutes to 1 hour. The extraction can be carried out in the range of 90-120°C. For example, the hot water extraction may be performed under the heating and pressurizing conditions (120° C., 0.2 MPa) normally used in autoclaves. As the extraction solvent, water may be used, or an organic solvent or a water-containing organic solvent obtained by mixing water and an organic solvent in an arbitrary mixing ratio may be used. Examples of organic solvents include ethanol, methanol, ethyl acetate, acetone and hexane. Ultrasonic treatment may be used during extraction. After extraction, the moisture is removed by vacuum drying, vacuum concentration, freeze drying, hot air drying, fluidized bed drying, spray drying, drum drying, low temperature drying, pressure drying, natural drying, or the like, or the total weight is reduced, or the moisture content is reduced. may be obtained as a dry matter remaining after removal of Furthermore, if necessary, the microscopic Residues such as insolubles or aggregates may be removed. According to this, even when a device such as a tubular reactor is used for subcritical water treatment, clogging in the tube can be eliminated and a stable flow rate can be maintained.

Although it depends on the type of persimmon and the harvest time, persimmon polyphenol-containing substances prepared by hot water extraction after deastringency treatment from persimmon fruit, for example, usually have an average molecular weight distribution of the polyphenol Molecular weights are in the ranges described above. That is, specifically, the average molecular weight in the molecular weight distribution of the polyphenol typically exhibits 10,000 to 1,000,000, more typically 50,000 to 600,000, and still more typically 100,000 to 400,000. In addition, the polyphenol content is about 50 to 90% by mass, more typically about 60 to 80% by mass in terms of dry solid content.

(Subcritical water treatment)
Below, a method for treating the persimmon polyphenol-containing material with subcritical water will be described with reference to the drawings. However, the method of treating persimmon polyphenol-containing material with subcritical water in the present invention is not limited by the following explanation.

FIG. 1 shows an example of a subcritical water treatment apparatus that can be used in the present invention. The sub-critical water treatment apparatus 1 shown in this example is a so-called tubular reactor, and is composed of a raw material solution container 10 for holding and supplying the raw material solution, a tube 11 for feeding the raw material solution, and a high-pressure pump. 12, a coiled tube 13 connected to the tube 11 via a high-pressure pump 12 and immersed in an oil bath 14 that can be heated to a predetermined temperature, and a stirrer 15 (magnet stirrer) for stirring the heat medium in the oil bath 14. , the coiled tube 13 is connected to the tube portion coming out of the oil bath 14, and the coiled tube 16 is immersed in the cooling water tank 17, and the coiled tube 16 is interposed in the tube portion coming out of the cooling water tank 17, It is equipped with a back pressure valve 18 capable of adjusting the pressure of the solution and a sampling container 19 for sampling the treated solution.

A persimmon polyphenol-containing material is put into the raw material solution container 10 of the subcritical water treatment apparatus 1, and the high-pressure pump 12 is driven to apply pressure by the high-pressure pump 12 and the back pressure valve 18 to adjust the water pressure of the liquid flowing through the tube. When the solution is sent to the coiled tube 13 immersed in the oil bath 14 adjusted to a predetermined temperature, the persimmon polyphenol-containing material is exposed to the temperature and pressure conditions formed in the coiled tube 13 for a predetermined period of time. . After that, the material is cooled through a coiled tube 16 immersed in a cooling water tank 17 to end the subcritical state, and the material to be treated is collected in a sampling container 19 . The liquid may be fed continuously through the tube, or may be intermittently fed by repeating the flow of the liquid for a predetermined period of time and the suspension of the liquid for a predetermined period of time.

In the subcritical water treatment apparatus 1 of the example shown in FIG. 1, a tube having an inner diameter of about 0.5 to 1 mm and a total length of about 2 to 5 m can be used because of its configuration. In this case, typically a subcritical state under a pressure of 1 to 10 MPa, more typically a subcritical state under a pressure of 3 to 10 MPa, still more typically a subcritical state under a pressure of 8 to 9 MPa. It can be said that the apparatus is suitable for producing subcritical water and treating the object to be treated with subcritical water at a treatment rate of about 5 to 50 mL/min. If the treatment pressure is less than 1 MPa, the treatment with subcritical water will be insufficient, and the functionality of the persimmon polyphenol-treated product will tend not to be enhanced. Moreover, when the processing pressure is 10 MPa or more, it is necessary to prepare equipment such as specially designed tubes and back pressure valves that can withstand the pressure, which tends to increase costs, which is not preferable. Also, the residence time in the coiled tube 13 is typically 1 second to 60 minutes, more typically 10 seconds to 30 minutes, still more typically 30 seconds to 10 minutes, and the like. Further, the temperature conditions are typically 120 to 250°C, more typically 130 to 240°C, still more typically 140 to 220°C, and the like.

Here, in the subcritical water treatment, the treatment temperature and time are the factors that greatly affect the properties of the obtained treated material, and these are considered to be operating variables specific to the equipment that is generally used. Therefore, it is more desirable to use as an index not only the treatment temperature and time but also the heat history experienced by the object to be treated, which reflects them together. According to this, it becomes easy to optimize the conditions of the subcritical water treatment regardless of the equipment to be used. As a parameter that reflects the heat history experienced by the object to be treated in subcritical water treatment, there is R ₀ : Severity factor (unit: min) obtained by the following formula (Heitz M., Carrasco F., Rubio M. , Brown A., Chornet E., and Overend RP. Physico-chemical characterization of lignocellulosic substrates pretreated via autohydrolysis: an application to tropical woods. Biomass, 13, 255-273.

where T(t) is the treatment temperature (°C) at time t (minutes) from the start of treatment, the value of 100 is the base temperature (°C), and 14.75 is the activation energy for the pseudo-temporal reaction. It is the value used as the corresponding quantity. It is also possible to define the amount corresponding to R ₀ using a value other than 100 and 14.75 in the formula, and optimize the conditions for subcritical water treatment based on that amount.

In _fact , in the sub-critical water treatment apparatus 1 described in FIG. When the value of R ₀ is 100 or more and 1000 or less, it corresponds to 160 to 200° C. _and 0.5 minutes to 10 minutes. Equivalent to 5 to 10 minutes.

When the above heat history is used as an index, the conditions for the subcritical water treatment in the present invention are preferably conditions in which the value of R ₀ is 1 to 20,000, and the value of R ₀ is 50 to 1,000. It is more preferable to carry out the treatment under conditions within the range, and it is even more preferable to carry out the treatment under conditions in which the value of R ₀ is in the range of 100 to 500. Even if the value of R ₀ is less than 1, the treatment with subcritical water becomes insufficient, and the functionality of the persimmon polyphenol treated product tends to be not enhanced. In addition, if the value of R ₀ exceeds the above range, persimmon polyphenol will be excessively decomposed, and in particular, the activity of inhibiting enzymes such as glucosidase, maltase, sucrase, and amylase will be shown in the examples below. Thus, the functionality of the obtained persimmon polyphenol-treated product may not be enhanced.

As described above, for example, when an extract is obtained by hot water extraction from persimmon fruit through deastringency treatment and subcritical water treatment, it depends on the treatment conditions with subcritical water, but as described above. The persimmon polyphenol decomposition product obtained by the method usually exhibits an average molecular weight of about 1,000 to 100,000, more typically about 5,000 to 50,000 in the molecular weight distribution of the polyphenol. In addition, the polyphenol content is about 50 to 90% by mass, more typically about 60 to 80% by mass in terms of dry solid content.

As the persimmon polyphenol decomposition product, the product treated with subcritical water may be used as it is, or residues such as microscopic insolubles or aggregates may be removed by filter filtration or the like. Furthermore, it may be used after being diluted, may be used after concentration such as concentration under reduced pressure, or may be used as a dry powder. As a specific example, the material treated with subcritical water is filtered to remove the residue, followed by vacuum drying, vacuum concentration, freeze drying, hot air drying, fluidized bed drying, spray drying, drum drying, low temperature drying, heating. Moisture is removed by pressure drying, air drying, or the like, and the resulting dried product can be pulverized to prepare a powder.

(Composition for suppressing elevation of blood sugar level)
In the following, the form of utilization of the persimmon polyphenol decomposition product obtained as described above will be described in more detail. However, the utilization form of the persimmon polyphenol decomposition product according to the present invention is not limited by the following explanation.

The persimmon polyphenol decomposition product according to the present invention is useful as an active ingredient for suppressing elevation of blood sugar level. For example, such a composition for use may be provided as containing the persimmon polyphenol decomposition product according to the present invention alone, or may be provided as containing it in combination with other materials. For example, it may be a composition for suppressing an increase in blood sugar level containing 0.1 to 100% by mass of the persimmon polyphenol decomposition product, and more typically a composition for suppressing an increase in blood sugar level containing 1 to 80% by mass. More typically, it may be a composition for suppressing elevation of blood sugar level containing 30 to 70% by mass. The method for preparing the composition is not particularly limited, and the persimmon polyphenol decomposed product may at least be included in the composition together with other ingredients as necessary. It may also contain other ingredients in combination that are effective in suppressing elevation of blood sugar level.

The composition for suppressing elevation of blood sugar level is not particularly limited in its product form. (capsules), soft capsules (soft capsules), solids, semi-liquids (jelly), creams, pastes, and the like.

The composition for suppressing elevation of blood sugar level includes food and drink, pharmaceuticals, quasi-drugs, functional foods, dietary supplements, supplements, health foods, veterinary drugs, quasi-drugs for animals, functional foods for animals, It can be used in the form of nutritional supplements for animals, supplements for animals, health foods for animals, etc., or in combination with these forms.

If necessary, the composition for suppressing elevation of blood sugar level may contain excipients, binders, disintegrants, lubricants, stabilizers, surfactants, and solubilizers that are commonly used in the above products. , reducing agents, buffers, adsorbents, flow agents, antistatic agents, antioxidants, sweeteners, corrigents, cooling agents, light shielding agents, flavoring agents, fragrances, fragrances, coating agents, plasticizers, etc. can be added and used.

The composition for suppressing elevation of blood sugar level exerts the action and effect of suppressing elevation of blood sugar level by ingestion by humans and animals. That is, as shown in the examples below, the persimmon polyphenol degradation product according to the present invention is excellent in the activity of inhibiting enzymes such as glucosidase, maltase, sucrase and amylase. These enzymes are involved in the absorption of sugar from food, and more specifically, they are enzymes that have the action of decomposing polysaccharides and oligosaccharides to facilitate the absorption of sugar into the body. Therefore, by inhibiting these activities, it is possible to suppress, for example, an increase in blood sugar level after a meal.

The persimmon polyphenol decomposition product according to the present invention can be orally ingested by humans and animals without any problems in terms of the experience of eating persimmons. The amount of intake effective for suppressing the rise in blood sugar level as described above can be appropriately determined according to the sex, age, physique, etc. of the intake person, but for example, the amount of polyphenols per day for adults is 50 mg to 5 g. preferably 100 mg to 3 g. It can be taken once to several times a day, or at any period and interval, but if the purpose is to suppress the absorption of sugar from meals, a more desirable form of use is during meals or within 30 minutes after meals. It is preferably used so as to be orally ingested within 15 minutes, and more preferably used so as to be orally ingested within 15 minutes.

EXAMPLES The present invention will be described in more detail below with reference to examples, but these examples are not intended to limit the present invention in any way. In addition, in the following test examples, R ₀ : Severity factor (unit: min) obtained by the following formula was used as an index of the condition of the subcritical water treatment.

where T(t) is the treatment temperature (°C) at time t (minutes) from the start of treatment, the value of 100 is the base temperature (°C), and 14.75 is the activation energy for the pseudo-temporal reaction. It is the value used as the corresponding quantity. It is also possible to define the amount corresponding to R ₀ using a value other than 100 and 14.75 in the formula, and optimize the conditions for subcritical water treatment based on that amount.

[Preparation Example 1] (Preparation of persimmon polyphenol Part 1)
Persimmon polyphenol was prepared according to the method of Hamasaki et al. . Specifically, it was prepared as follows.

Harvest the fruit of "Tokonwase", one of the persimmon varieties cultivated in Japan, immediately seal it with a 0.02 mm thick polyethylene film after harvesting, add 2 mL of ethanol per 1 kg of fruit, and add 25 C. for 5 days to remove astringency. The stalks of the de-astringent fruit were removed, and the fruit was homogenized with a mixer. When the homogenate was placed in a centrifuge tube with a capacity of 50 mL and centrifuged at 1,630 x g for 15 minutes, tannin cells formed a layer at least below the middle height or near the bottom of the contents in the centrifuge tube. To concentrate, the fraction was collected from the centrifuge tube and lyophilized. Then, 10 mL of water is added to 100 mg of the dry powder, heated in an autoclave (heating and pressurizing conditions: 120 ° C., 0.2 MPa) for 15 minutes, and after heating, centrifuged at 1,630 × g for 15 minutes. The supernatant is no. 2 qualitative filter paper (manufactured by Advantech) to obtain a filtrate. This was freeze-dried again and prepared as a powder. The polyphenol content of the obtained powdery persimmon polyphenol-containing material was separately quantified by the Folin-Ciocalteu method using D-(+) catechin as an index, and the polyphenol content was about 70% by mass. In addition, the sugar content measured by the phenol-sulfuric acid method was about 20% by mass, and 10% by mass of unidentified components were included.

[Preparation Example 2] (Preparation of persimmon polyphenol Part 2)
Persimmon polyphenol was prepared as follows.

(removes astringency)
Persimmons with skins and stems were pulverized and deastringent treated in the same manner as in Preparation Example 1. As a result, the persimmon polyphenol is made insoluble in water by acetaldehyde condensation/polymerization reaction. In addition, the separability and sedimentation properties of tannin cells in water are improved.

(water wash)
About 10 times the amount of water was added to the water-insolubilized material after the removal of astringency, and the material was washed. Washing was repeated a total of 10 times over 2 days. As a result, components other than persimmon polyphenol can be removed well.

(Adding water/heating)
About 10 times the amount of water was added to the water-insolubilized material after washing, and the mixture was treated in an autoclave (heating and pressurizing conditions: 120°C, 0.2 MPa) for 1 hour. As a result, bonds such as aldehyde condensation and polymerization are broken, and the persimmon polyphenol is solubilized in water.

(Squeezing/filtration)
Strain with a cloth, pass through a 50 μm filter and finally through a 1 μm filter. The Brix value of the obtained filter-passed liquid was about 1 Brix.

(concentration/powdering)
The filter-passing liquid was concentrated about 15 times with a vacuum concentrator. This was drum-dried, pulverized and sieved to obtain a 250 μm mesh pass powder. Separately, when quantified by the Folin-Ciocalteu method using D-(+) catechin as an index, the polyphenol concentration of this powder was found to be 70% by weight in terms of catechin.

[Preparation Example 3] (Subcritical water treatment)
Using the subcritical water treatment apparatus 1 illustrated in FIG. 1, the persimmon polyphenol-containing material obtained in Preparation Example 1 was subjected to subcritical water treatment. As a specific device configuration, the tube 11 is a SUS 316 HPLC tube (0.8 mm ID x 4 m), the high-pressure pump 12 is an LC-10AT HPLC pump (Shimadzu Corporation), and the back pressure valve 18 is a back pressure adjustment valve (P-880, Upchurch Scientific, Oak Harbor, WA, USA), and a silicone oil bath (temperature can be set in the range of 140 to 220°C) is used for the oil bath 14, and part of the tube immersed in the oil bath (Coil-shaped tube 13: length 2 m) is subjected to subcritical water treatment. It was configured to completely stop the reaction due to the treatment.

The persimmon polyphenol-containing material obtained in Preparation Example 1 was dissolved in pure water to a concentration of 5% (w/v), and this solution was centrifuged at 4°C and 7,100 x g for 15 minutes to obtain the supernatant. to No. 1 qualitative filter paper (manufactured by Advantech) and further passed through a membrane filter (DISMIC-25CS, 0.8 μm, manufactured by Advantech) to obtain a polyphenol solution. This polyphenol solution was applied to the above apparatus and subcritical water treatment was performed for a residence time of 0.5 to 10 minutes. During the test, it was confirmed that the pressure inside the tube of the above device was in the range of 8 to 9 MPa under any conditions.

<Test Example 1> (Change in molecular weight distribution)
The molecular weight distribution of the subcritical water-treated product of Preparation Example 3 was measured by gel permeation chromatography (GPC) to evaluate changes in the molecular weight distribution of persimmon polyphenol under various subcritical water treatment conditions. Specifically, an untreated control (Control) or a solution (1 mL) after subcritical water treatment was centrifuged at 6,100×g for 2 minutes, and the supernatant was subjected to GPC analysis. GPC analysis was performed using a diol column (YMC-pack Diol-60, 8.0 mm ID × 500 mm, YMC, Kyoto, Japan) equipped with an LC-20AD HPLC pump (Shimadzu Corporation) and a RID-10A refractive index detector (Shimadzu Corporation). was used, and the eluent was distilled water at a flow rate of 1.0 mL/min. calibration curve using a certain polyethylene glycol as a standard molecular weight substance).

FIG. 2 shows the GPC chromatograms of the solutions after the treatment when the severity factor _R0 of the subcritical water treatment is 2.3×10 ² , 4.5×10 ² , and 1.1×10 ³ . are shown together with the control.

As shown in Figure 2, the Control chromatogram contained a single peak (Mw: 1 x ¹⁰⁵ ). On the other hand, in the chromatogram of the solution after subcritical water treatment, the molecular weight near the peak top is as small as Mw: 4 × 10 ⁴ , and several _broad peaks are observed. Significant progress of depolymerization was observed.

<Test Example 2> (Change in freezing point depression)
The degree of decomposition of the subcritical water-treated product of Preparation Example 3 was evaluated using freezing point depression as an index. Specifically, the freezing point depression values (K) of the treated solutions under various subcritical water treatment conditions were measured using an osmometer (OM802, Vogel, Kevelaer, Germany), and the untreated control Changes in freezing point depression when compared to (Control) were evaluated.

In FIG. 3, when the value of Severity factor R ₀ of subcritical water treatment is 1 × 10 ¹ to 1.7 × 10 ⁴ , the value of Severity factor R ₀ is on the X axis, and the freezing point after treatment under each condition Fig. 4 shows a graph plotting the results of the descent.

As shown in FIG. 3, up to a severity factor R ₀ value of 1×10 ² , the value of freezing point depression is almost the same as the control (Control), and low molecules that affect freezing point depression are not produced. could be guessed. When the value of severity factor R ₀ exceeded 1×10 ² , the value of freezing point depression began to rise upward, and when it exceeded 1×10 ³ , it further increased sharply. Therefore, it was considered that many low-molecular-weight compounds were produced that would affect the freezing point depression.

<Test Example 3> (Change in pH)
The degree of decomposition of the subcritical water-treated product of Preparation Example 3 was evaluated using pH as an index. Specifically, the pH of the treated solution was measured under various subcritical water treatment conditions, and the change in pH compared to an untreated control (Control) was evaluated.

In FIG. 4, when the value of Severity factor R ₀ of subcritical water treatment is 1 × 10 ¹ to 1.7 × 10 ⁴ , the value of Severity factor R ₀ is on the X axis and the pH after treatment under each condition shows a graph plotting the results of

As shown in FIG. 4, the pH value decreased from around 4.4 to around 3.9 as the value of severity factor R ₀ increased from 1×10 ² to 1×10 ³ . On the other hand, when the value of severity factor R ₀ exceeded 1×10 ³ , the rate of decrease in pH decreased. FIG. 5 is a graph re-plotted with the freezing point depression results of Test Example 2 on the Y axis and the pH results of Test Example 3 on the X axis. As can be seen in this graph, in the range of pH 4.4 to pH 4.0, the pH decreased without much effect on the freezing point depression, while after the pH value reached 3.9, the freezing point depression abruptly occurred. values have also risen. It was thought that this is because the factor that lowers the pH and the factor that raises the value of the freezing point depression exist independently of each other. Moreover, it was thought that such a phenomenon of pH drop may be a phenomenon resulting in the formation of acidic compounds such as organic acids due to the decomposition of polyphenols and sugars.

<Test Example 4> (Change in glycolytic enzyme inhibitory activity)
The subcritical water-treated product of Preparation Example 3 was evaluated for carbohydrate decomposition inhibitory activity. Specifically, the inhibitory activity against each of the enzymes α-glucosidase, maltase, sucrase, and α-amylase was tested using solutions after treatment under various conditions of subcritical water treatment as samples, using the assay system shown below. to evaluate changes in inhibitory activity when compared to untreated controls (Control).

(1) α-glucosidase inhibitory activity Yeast-derived α-glucosidase solution (69.4 Units/mg, prepared to 0.1 Unit/μL by Toyobo) 10 μL, sample or 0.2 M phosphate buffer (pH 6.8) 100 μL, distilled water 390 μL Mixed and pre-incubated at 37°C for 5 minutes. After that, 500 μL of 4% (w/v) maltose solution was added, incubated at 37° C. for 30 minutes, 1 mL of 1N HCl was added to stop the reaction, and 1 mL of 1N NaOH was added for neutralization. The amount of glucose produced in the reaction solution was measured using a commercially available kit (Glucose C-II Test Wako: Wako Pure Chemical Industries) based on the glucose oxidase method.

The inhibition rate was calculated as follows.

Inhibition rate (%) = (1-glucose amount in sample addition group/glucose amount in buffer addition group) x 100

(2) Maltase Inhibitory Activity To 0.5 g of acetone powder derived from rat small intestine (Sigma), 4.5 mL of 0.2 M phosphate buffer (pH 6.0) was added and homogenized in ice using a glass homogenizer. Then, it was centrifuged (800×g, 10 min, 4° C.), the supernatant was used as a crude enzyme solution, and this crude enzyme solution was diluted 20-fold and used.

400 μL of enzyme solution and 400 μL of sample or 0.2 M phosphate buffer (pH 6.0) were mixed and pre-incubated at 37° C. for 5 minutes. After that, 400 μL of 5% (w/v) maltose solution was added, incubated at 37° C. for 60 minutes, and then heated in boiling water for 10 minutes to terminate the reaction. The amount of glucose produced in the reaction solution was measured using a commercially available kit (Glucose C-II Test Wako: Wako Pure Chemical Industries) based on the glucose oxidase method.

The inhibition rate was calculated as follows.

Inhibition rate (%) = (1-glucose amount in sample addition group/glucose amount in buffer addition group) x 100

(3) Sucrase inhibitory activity The crude enzyme solution prepared in (2) above was diluted two-fold and used.

400 μL of enzyme solution and 400 μL of sample or 0.2 M phosphate buffer (pH 6.0) were mixed and pre-incubated at 37° C. for 5 minutes. After that, 400 μL of 5% (w/v) sucrose solution was added, incubated at 37° C. for 60 minutes, and then heated in boiling water for 10 minutes to terminate the reaction. The amount of glucose produced in the reaction solution was measured using a commercially available kit (Glucose C-II Test Wako: Wako Pure Chemical Industries) based on the glucose oxidase method.

The inhibition rate was calculated as follows.

Inhibition rate (%) = (1-glucose amount in sample addition group/glucose amount in buffer addition group) x 100

(4) α-amylase inhibitory activity Mix 20 µL of a porcine pancreatic α-amylase solution (Sigma, prepared to 19.5 Units/mg, 0.25 Units/µL) and 1 mL of a sample or 0.2 M phosphate buffer (pH 6.9), Preincubated at 37°C for 5 minutes. Then, 1 mL of 4% starch (Wako Pure Chemical Industries) solution was added, incubated at 37°C for 60 minutes, and then heated in boiling water for 10 minutes to stop the reaction. The amount of reducing sugar produced in the reaction solution was measured using the Somogyi-Nelson method.

The inhibition rate was calculated as follows.

Inhibition rate (%) = (1-amount of reducing sugar in sample addition group/amount of reducing sugar in buffer addition group) x 100

In FIG. 6, when the value of Severity factor R ₀ for subcritical water treatment is 1 × 10 ¹ to 1.7 × 10 ⁴ , the value of Severity factor R ₀ is taken as the X axis, and polyphenols after treatment under each condition FIG. 6 shows a graph plotting the results of the percentage inhibition of α-glucosidase (FIG. 6a), maltase (FIG. 6b), sucrase (FIG. 6c), and α-amylase (FIG. 6d) by the containing solution.

As shown in FIG. 6a, the α-glucosidase inhibitory activity by the untreated control (Control) was about 61%, but the value of the severity factor R ₀ of the subcritical water treatment increased beyond 1×10 ² . The inhibition rate increased to about 79% at the maximum. However, when the value of severity factor R ₀ exceeded 1×10 ³ , the inhibition rate tended to decrease.

As shown in FIG. 6b, the maltase inhibitory activity by the untreated control (Control) was around 56%, but as the value of Severity factor _R0 of subcritical water treatment increased beyond ¹ ×10 The inhibition rate increased to about 82% at maximum. However, when the value of severity factor R ₀ exceeded 1×10 ⁴ , the inhibition rate tended to decrease.

As shown in FIG. 6c, the sucrase inhibitory activity by the untreated control (Control) was about 37%, but as the value of Severity factor R ₀ of subcritical water treatment increased beyond 3 × 10 ¹ The inhibition rate increased to about 99% at maximum.

As shown in FIG. 6d, the α-amylase inhibitory activity of the untreated control (Control) was about 70%, but the value of Severity factor R ₀ of subcritical water treatment was 1 × 10 ¹ to 3 × 10 In the range of ² , the inhibition rate tended to increase. However, when the value of severity factor R ₀ exceeded 1×10 ² , the inhibition rate tended to decrease.

1 subcritical water treatment device 10 raw material solution container 11 tube 12 high pressure pump 13 coiled tube 14 oil bath 15 stirrer (magnet stirrer)
16 coiled tube 17 cooling water tank 18 back pressure valve 19 sampling container

Claims (8)

A method for producing a persimmon polyphenol decomposition product, characterized by treating a persimmon polyphenol-containing material with subcritical water, wherein the persimmon polyphenol decomposition product has an average molecular weight of 5000 to 100000 in the molecular weight distribution of the polyphenol, and the A method for producing the persimmon polyphenol decomposition product, wherein the polyphenol content is 50 to 90% by mass in terms of dry solid content . 2. The method for producing a persimmon polyphenol decomposition product according to claim 1, wherein the persimmon polyphenol-containing material is a water-insoluble material obtained by removing astringency from persimmon fruit. 2. The method for producing a persimmon polyphenol decomposition product according to claim 1, wherein the persimmon polyphenol-containing material is an extract obtained by hot water extraction from a water-insolubilized material obtained by removing astringency of persimmon fruit. The method for producing a persimmon polyphenol decomposition product according to any one of claims 1 to 3, wherein the treatment with subcritical water is performed under a pressure of 1 to 10 MPa. The method for producing a persimmon polyphenol decomposition product according to any one of claims 1 to 4, wherein the treatment with subcritical water is performed under conditions in which the value of R0 obtained by the following formula is 1 to 20000.

A composition for suppressing an increase in blood sugar level, containing a persimmon polyphenol decomposition product produced by the production method according to any one of claims 1 to 5. 7. The composition for suppressing elevation of blood sugar level according to claim 6, which inhibits one or more enzymes selected from glucosidase, maltase, sucrase and amylase. 8. The composition for suppressing elevation of blood sugar level according to claim 6 or 7, which is used as a food, drink or pharmaceutical for suppressing elevation of blood sugar level.

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