JPWO2005120541A1 - Method for producing protein with enhanced antihypertensive effect - Google Patents

Abstract

It takes time and cost to prepare and purify functional peptides by enzymatically decomposing foods, and it becomes a relatively expensive product even at the stage of rough purification. In addition, the produced functional peptide may be further decomposed in the digestive juice to lose its efficacy.
By binding reducing sugars to meat or protein, the reactivity as a substrate for digestive enzymes is changed, thereby imparting an excellent blood pressure regulating action.

Description

  The present invention relates to the field of food processing such as fishery processing and meat processing, as well as the fields of health foods, pharmaceuticals and chemical products.

  Proteins, together with lipids and sugars, are basic nutrients for the survival of animals and have traditionally been positioned as a source of amino acids that compose the living body.

  However, in recent years, it has become clear that proteins have various functions that regulate not only the value as a nutrient but also the metabolic activity of the living body. The bioregulatory function of this protein is often attributed to the bioactive peptides derived from food proteins by the action of digestive tract proteases.

For example, a steroid-binding peptide that regulates serum cholesterol metabolism (derived from soybean protein: Sugano, bioregulatory function of food, pp33-41, Academic Publishing Center, 1992), exogenous opioid peptide (casein: Yoshikawa) involved in analgesic/sedative action. Agric. Biol. Chem. 48, 3185-, 1984. (Non-patent document 1), plant protein: Fukudome et al. FEBS Lett. 296, 107-111, 1984 (Non-patent document 2), Angiotensin that suppresses blood pressure increase I-converting enzyme (ACE) inhibitory peptide, milk casein: Maruyama et al. Agric. Biol. Chem., 46, 1393-1394 1982. (Non-patent document 3), plant protein: Miyoshi et al. Agric. Biol. Chem., 55, 1313. -1318, 1991 (Non-patent document 4). Skipjack section: Suetsuna, Nissui 65, 92-96, 1999 (Non-patent document 5), Wakame: Suetsuna et al. J. Nutr. Biochem, 11, 450-454, 2000. (Non-patent document 6). The following patent documents 1-7, etc.) are known and used for various health and functional foods.
Japanese Patent Laid-Open No. 05-306296 Patent No. 3401280 Derived from seafood JP 05-331191 Derived from bonito flakes JP 06-345664 Derived from cheese whey Patent No. 3129523 Derived from ovalbumin Tokurei 2001-884948 Milk origin JP 06-277090 Casein origin Yoshikawa et al. Agric. Biol. Chem., 48, 3185-, 1984. Fukudome et al. FEBS Lett. 296, 107-111, 1984 Maruyama et al. Agric. Biol. Chem., 46, 1393-1394, 1982. Miyoshi et al. Agric. Biol. Chem., 55, 1313-1318, 1991 Suetsuna, Nissui 65, 92-96, 1999 Suetsuna et al. J. Nutr. Biochem

  There are two problems in utilizing the bioregulatory function of conventional digestive peptides derived from proteins.

  First, in order to ingest a functional peptide as a dietary supplement, it is necessary to first prepare a functional peptide from a protein. However, it takes time and cost to prepare and purify a functional peptide by enzymatically decomposing food, and it is a relatively expensive product even at the rough purification stage. In addition, the produced functional peptide may be further decomposed in the digestive juice to lose its efficacy.

  On the other hand, in order to habitually eat foods that produce functional digestive peptides in vivo and produce functional peptides by digestion in the body, first, functional peptides that efficiently express the desired function in the body. You have to search for foods that produce. Furthermore, since it is taken as a food, it is necessary to be able to take an amount that can be expected to be effective on a daily basis.

  As described above, the preparation of digestive peptides by the existing technology has many points to be overcome, and in order to solve these restrictions all at once, it is necessary to improve the bioregulatory function of protein foods that are commonly eaten. Technology development is considered necessary.

  Therefore, the inventors focused on muscle proteins, which are the most common source of animal protein, and enhanced the functions of the above-mentioned functional digestive peptides as much as possible, and examined whether they could effectively utilize the functional peptides. As a result, we have developed a method that can effectively improve blood pressure regulation.

  The inventors of the present invention have realized the solubilization, stabilization, modification of emulsifying ability, etc. of various saccharides by binding them to muscle proteins via the Maillard reaction. Various uses of this sugar-modified protein as food are considered.

  When developing and using a new food material, it is necessary to confirm its safety and at the same time evaluate its digestibility. Therefore, the present inventors examined the digestibility of this sugar-modified protein. As a result, it has some digestive resistance to the major digestive enzyme secreted in the digestive tract, that is, pepsin secreted in the stomach, while it is almost completely digested by the action of trypsin digested in the small intestine. I found the characteristic that it is done (Fig. 1).

  This finding indicates that the susceptibility to digestive enzymes was changed by binding sugar molecules, although the "digestibility" of muscle proteins was hardly impaired. That is, it is clear that the digestive peptides produced during the digestion/absorption process are different. In fact, gel filtration analysis (FIG. 2) could easily confirm that the digestion patterns were different. This indicates the possibility that new functional digestive peptides can be produced in the body by sugar modification. Therefore, the present inventors have examined in detail the blood pressure regulating action of this sugar-modified protein.

  As a result, as shown in FIG. 3, a new fact has been found that the blood pressure regulating action inherent to fish meat protein is remarkably enhanced, which has never been reported before.

  It was also confirmed that the blood pressure elevation suppressing effect obtained lasted for at least 8 hours. This lasting effect is characteristic of the fish meat protein obtained in the present invention.

  According to the present invention, a protein or meat having an excellent blood pressure regulating function can be efficiently prepared. When the protein of the present invention is eaten in a state of being contained in food, it produces a functional peptide having an excellent blood pressure regulating action in the digestive tract to regulate blood pressure. Therefore, it is not necessary to prepare digested peptides in advance, and by enhancing the bioregulatory function of daily familiar foods such as meat and muscle proteins, it can be used for various processed foods, You can provide a diet that benefits from its effects without being aware of it.

  This specification includes the content described in the Japan patent application 2004-173963 and/or drawing which are the foundations of the priority of this application.

Changes in susceptibility of muscle proteins to digestive enzymes caused by sugar modification. Sugar-modified muscle protein (8.0% lysine modification rate) to which alginic acid oligosaccharide corresponding to 7.8% weight of salmon muscle was bound was digested with pepsin for 3 hours (pH 2.0) and then with trypsin for 3 hours (pH 7.0). )did. The digestibility of each was calculated from the amount of nitrogen in the digested fraction. This result indicates that the susceptibility to digestive enzymes was changed by binding sugar molecules, although the "digestibility" of muscle proteins was hardly impaired. Changes in digestibility of fish meat protein caused by alginate oligosaccharide modification. Sugar-modified muscle protein (●: lysine modification rate 8.0%) to which alginic acid oligosaccharide corresponding to 7.8% weight of salmon muscle was bound was digested with pepsin for 3 hours (pH 2.0) and then with trypsin for 3 hours (pH 7). Then, the molecular weight distribution of the digest was examined by gel filtration analysis (Vo: exclusion limit molecular weight 2500). It can be seen that the peptide distribution in the arrow portion is greatly different from that of normal fish meat (○). Blood Pressure Modulating Function of Sugar-Modified Muscle Protein Obtained by the Present Invention Weight of sugar-modified muscle protein (bonded sugar equivalent to 7.8% weight of salmon muscle) to systolic blood pressure (□) of SHR rat before administration After oral administration of 170 (○) and 670 mg (△) per kg, a rapid decrease in blood pressure was observed. When the same amount of sugar is mixed with untreated salmon meat (●: dose of protein as 670 mg/kg body weight), the blood pressure is slightly decreased, and the effect of the present invention can be remarkably observed. The blood pressure increase suppressing function of the sugar-modified muscle protein obtained in the present invention. To 10-week old SHR rats, sugar-modified muscle protein (conjugated with sugar corresponding to 7.8% weight of salmon muscle) was orally administered daily for 15 and 28 days. First, in untreated SHR rats (◯), a gradual increase in systolic blood pressure was observed with aging. On the other hand, when 70 mg (kg) per 1 kg of body weight was administered daily, the increase in blood pressure was suppressed. Furthermore, when 170 mg (□) was administered daily, no increase in blood pressure occurred. (*: Danger rate 5%, **: Danger rate 1%)

  The present invention is to change the reactivity of a digestive enzyme as a substrate by binding reducing saccharides to meat or protein, thereby imparting an excellent blood pressure regulating action.

  In the present invention, for example, (1) a protein is mixed with a reducing saccharide and then dehydrated to maintain a water content of 0.25 to 6% under an environment of 30 to 70° C. And (2) mixing the protein with reducing sugars, dehydrating the mixture, and maintaining it in an environment with a relative humidity of 70% or less and 30 to 70°C. Included.

  Hereinafter, a specific method for enhancing the blood pressure lowering action of protein by binding reducing sugars to meat or protein will be described.

[Method of modifying protein with reducing sugar]
As a method for binding a reducing sugar to meat or protein, a Maillard reaction is caused between the reactive lysine residue of the protein and the reducing end of the reducing sugar to form a covalent bond between the two. At this time, it is desirable to adjust the water content of the meat or the mixture of protein and sugar to 6% or less, or to keep it in an environment with relative humidity of 35% or less at 40°C or more in order to accelerate the reaction (this researcher Patent Publication: 2003-169634), but the relative humidity is not limited to this depending on the kind of protein, and the relative humidity can be 70% or less (Example 5).

  As a method for controlling water content, for example, a mixture of protein and sugar is dehydrated, and specifically, heat treatment under low humidity of 10% relative humidity, or treatment such as freeze-drying, spray-drying, and vacuum drying. Alternatively, by treating them in combination, the water content of the meat or the mixture of protein and sugar can be reduced to 6% or less. Freeze-drying is preferred. Even if the water content of meat or a mixture of protein and sugar exceeds 6% at the end of the dehydration treatment, the relative humidity is 35% or less, 30 to 70°C, more specifically, 40°C, for example. By maintaining the temperature at 70° C. or lower, the water content can be controlled within the range of 6% or lower. Meat and muscle proteins are solubilized by binding reducing sugars under the conditions of this treatment.

  Regarding the control of the Maillard reaction, for example, the protein is mixed with reducing sugar in the range of 1:0.5 to 10 and lyophilized to adjust the water content to about 0.6-3%. This is kept at a constant temperature and constant humidity of 40 to 60° C. and a relative humidity of about 35% for several hours to 4 days. This allows a Maillard reaction to occur between the lysine residue of the protein and the reducing end of the sugar. When the lysine modification ratio in the protein reaches about 4-40%, the reaction is stopped by cooling (freezing) to bind the reducing sugar in an amount suitable for the purpose (that is, sugar modification). You can

[Hypotensive effect]
When the reducing sugar is bound to the reactive lysine residue of meat or protein in this way, the conformation of the protein is changed, and various properties of the protein are affected. For example, when an alginic acid oligosaccharide is linked, the digestibility of fish meat protein is changed by the binding of 2% or more sugar chains of the reactive lysine residue, and as a result, Example 1 described below is used. As shown in 2, an enhancing effect of the blood pressure lowering regulating action is recognized. Therefore, the meat or sugar-modified protein sugar-modified by the method of the present invention can be used for lowering blood pressure.

  It was also confirmed that if the sugar modification reaction is continued, polymerization between proteins occurs via the Maillard reaction product, resulting in a gradual decrease in the blood pressure-regulating effect that was enhanced with the decrease in digestibility (Implementation) Example 2).

[raw materials]
Examples of the protein that can be used in the present invention include various proteins, and specific examples thereof include muscle protein, ovalbumin, protamine, and soybean protein. Examples of muscle proteins include muscle proteins of all living things such as fish meat, meat, shellfish and squid. Of course, these may be used even if they are thoroughly washed, and there is no problem even if they contain food components other than muscle proteins such as lipids and water-soluble low-molecular components. Muscle proteins include myosin, actin, tropomyosin, troponin and the like. Examples of protamine include fish testis-derived protamine, and specifically salmon testis-derived protamine.

  The meats that can be used in the present invention include muscles obtained by slicing all the muscles of the above-mentioned fish meat, livestock meat, shellfish, squid and the like. Shredded means cutting the above-mentioned meat by various means, and includes, for example, homogenization treatment and minced meat treatment, and the like, preferably to a degree of passing a mesh of 5 mm, more preferably 3 mm or less. It is desirable to chop up or mince.

  As examples of reducing sugars that can be used in the present invention, the results of alginic acid oligosaccharides having an average degree of polymerization of 6 are shown in Examples 1 and 2, but as shown in Example 3, other reducing sugars (reducing sugars Similar effects can be expected for sugar). Which reducing sugar is used may be determined according to the purpose of product development and the cost-effectiveness associated therewith.

  The reducing sugars that can be used in the present invention include monosaccharides (glucose, ribose, etc.), those having an average degree of polymerization of 20 or less and having a reducing end, such as alginic acid oligosaccharides and chitosan oligosaccharides An oligosaccharide is mentioned.

  When a thermally unstable protein (for example, a fish muscle protein that lives in cold water) is used in the present invention, a reducing sugar is used to suppress protein denaturation in the process of water regulation and sugar modification. It is desirable to mix the denaturing agent at the same time. Examples of the protein denaturation inhibitor in the present invention include sorbitol and trehalose. The protein denaturation inhibitor is particularly effective when the reducing saccharide to be added has a small protein denaturation preventing effect (eg, alginic acid oligosaccharide). When a reducing saccharide having a denaturing preventing effect such as glucose is used, it is not necessary to use it together with another denaturing preventing agent.

  The mixing ratio (weight) of the meat or muscle protein and the alginic acid oligosaccharide (reducing sugar) in the preparation process of the sugar-modified protein is preferably in the range of 1:0.1 to 1:10. There is no special designation, and it is essential only that the sugar modification causes a change in digestibility of the protein.

[Usage and usage]
The sugar-modified protein or sugar-modified meat prepared by the method of the present invention can be basically used as a food material since reagents are not used in the production process thereof, and is therefore the object of the present invention. , It is consistent with the advanced utilization of the bioregulatory function of proteins obtained when eaten as food.

  Further, since the sugar-modified protein or sugar-modified meat treated by the method of the present invention can be water-soluble, it has good digestion and absorption properties and can be easily mixed with other food and beverage materials.

  The blood pressure-lowering protein or meat for lowering blood pressure of the present invention acts as a blood pressure-lowering factor. The antihypertensive protein or antihypertensive meat of the present invention can be orally administered as it is.

  Furthermore, the protein for lowering blood pressure or the meat for lowering blood pressure of the present invention can be added to or mixed with other foods to be ingested as a food, or added to or mixed with a beverage to be ingested as a beverage. Is. When used as a blood pressure lowering agent, it can be mixed with a preparation-like carrier to prepare a preparation. For example, it can be a tablet, capsule, granule, or powder. As additives, sugars/sugar alcohols (for example, lactose, glucose, mannitol, dextrin, cyclodextrin, sucrose), polysaccharides (starch, sodium carboxymethyl cellulose, hydroxypropyl starch, carboxymethyl cellulose calcium, methyl cellulose, hydroxypropyl cellulose) , Hydroxypropylmethylcellulose, ), gelatin, gums (gum arabic), synthetic polymers (polyvinylpyrrolidone, polyvinyl alcohol), talc, tragacanth, bentonite, veegum, sorbitan fatty acid ester, sodium lauryl sulfate, glycerin, fatty acid glycerin ester, propylene Examples thereof include glycol.

  The blood pressure-lowering protein or the blood pressure-lowering meat of the present invention is preferably ingested in a protein amount of 0.05 g to 2 g, preferably 0.1 g to 1 g per 1 kg of body weight per day. The protein for lowering blood pressure of the present invention can be ingested continuously for 7 to 21 days or at intervals of about 2 days.

  Furthermore, the present invention also includes an antihypertensive agent or an antihypertensive agent containing the antihypertensive protein or the antihypertensive meat produced by the above-mentioned preparation method as an active ingredient. The administration method is the same as the above-mentioned intake method of the blood pressure-lowering protein or the blood pressure-lowering meat.

  Next, the method of the present invention will be described in detail with reference to examples.

Addition of blood pressure regulation function to salmon muscle (safety of sugar-modified protein, influence of dose of sugar-modified protein on the effect of the present invention)
The salmon muscle was shredded with a meat chopper to a size that passed through a 2 mm (JIS-8811) sieve. 100 g of this fish meat was mixed with alginic acid oligosaccharide (14 g) in an amount equal to the amount of muscle protein (14% wet weight) contained in it, and sorbitol (14 g) as a protein freezing denaturation inhibitor was mixed, and then the water content was 4.2% by freeze-drying. Adjusted to %. Subsequently, when kept at 60°C (35% relative humidity) for 3 hours, alginic acid oligosaccharides reacted with 8% of lysine residues in salmon muscle to react with sugar-modified protein (a sugar corresponding to 7.8% by weight was bound). ) Was formed.

  The sensitivity of this sugar-modified protein to digestive enzymes was examined. First, after digesting with pepsin for 3 hours (pH 2.0), it was further digested with trypsin for 3 hours (pH 7.0). The digestibility of each was calculated from the amount of nitrogen in the digested fraction. The results are shown in Fig. 1, and it can be seen that the sensitivity of salmon muscle protein was modified by alginate oligosaccharide modification. Furthermore, the molecular weight distribution of the digest was examined by gel filtration analysis (Vo: exclusion limit molecular weight 2500). The results are shown in Fig. 2, and thus it was confirmed that the distribution of the digest was different before and after sugar modification.

  Further, the digestive absorbability of this sugar-modified protein was examined in a breeding test using 4-week-old male SD rats. As a result, it was confirmed that during the 4-week breeding, there was no difference in weight gain from the normal mixed feed.

  Therefore, in order to investigate the blood pressure regulation function of this glycosylated protein, 170 mg/body weight was orally administered to 10-week-old male SHR rats (body weight 220-260 g) exhibiting hypertension, and systolic blood pressure was found 2 hours later. It decreased by 24 mmHg, and this effect was maintained for at least 6 hours. Furthermore, in the experimental group to which 670 mg per body weight was orally administered, the systolic blood pressure decreased by a maximum of 35 mmHg, and the effect of decreasing 30 mmHg was maintained even after 8 hours. When SHR rats were loaded with the same amount of sugar as that contained in the above sample, which was not modified with sugar, the maximum systolic blood pressure decrease range was 6 mmHg, which was between the experimental section. Showed a significant difference (risk rate 1%). The above results show that the blood pressure regulation function of fish meat protein was remarkably enhanced by the alginate oligosaccharide modification (FIG. 3).

Addition of blood pressure control function to salmon muscle (2) (Effect of the amount of reducing sugar bound to protein on the effect of the present invention)
In the same manner as in Example 1, the reaction time was changed for 1.5 hours, 3 hours, and 48 hours, and the sugar binding amounts were 3.0% (P-3.0), 7.8% (P-7.8), and 13.0% of the protein weight, respectively. (P-13.0), 20.4% (P-20.4) glycosylated proteins were prepared and these were orally administered to male SHR rats aged 10 weeks (body weight 240 to 260 g) at 170 mg per body weight (the sugar binding amount was The sugar-modified protein was once purified and then measured by the phenol-sulfuric acid method). As a result, in P-3.0 and P-7.8, the systolic blood pressure decreased by 16 mmHg and 22 mmHg, respectively, 1 hour after administration, and further, the maximum decreased by 28 mmHg after 4 hours. Furthermore, it was confirmed that P-13.0 with an increased amount of sugar bond had a completely similar blood pressure elevation inhibitory effect. On the other hand, when the same amount of saccharide as that contained in the above sample was mixed with the protein without modification of sugar and loaded into SHR rats, systolic blood pressure did not change at 1 hour after administration, and 8 hours after administration. The maximum decrease was 7 mmHg. With P-20.4, the systolic blood pressure decreased to 17 mmHg one hour after administration, but no further decrease was observed. The lysine modification rates of sugars of P-3.0, P-7.8, P-13.0 and P-20.4 were 4.0%, 8.2%, 14.8% and 26.0%, respectively, and especially in P-20.4, a remarkable browning change as the Maillard reaction progressed. Could be observed. Unlike the other 3 samples, P-20.4 showed protein polymerization by SDS-polyacrylamide gel electrophoretic analysis, resulting in a decrease in digestibility by trypsin-chymotrypsin (performed in accordance with Example 1). . In this way, it was confirmed that the protein with a lysine modification rate of 4.0% (P-3.0) enhanced the blood pressure regulation function of the muscle protein by sugar modification, but when it browned like P-20.4 and the Maillard reaction proceeded excessively. , It became clear that the effect gradually diminished.

Cows, glucose, and cows of cows that had been stored at 4°C for 7 days after slaughter were trimmed into minced meat, which was washed three times with 5 times the amount of physiological saline. To 100 g of the washed meat obtained, 200 mL of an aqueous solution containing glucose corresponding to 5 times the weight of the muscle protein content (10.2% wet weight) was added, kneaded, spread thinly and freeze-dried (water content 1.4% ). Then, when it was kept at 50° C. (5% relative humidity) for 12 hours, 61% of the lysine residues in the protein reacted with glucose. In order to investigate the blood pressure regulation function of this glycosylated protein, 700 mg/body weight was orally administered to 10-week-old male SHR rats (body weight 230-288 g) exhibiting hypertension, and systolic blood pressure was 21 mmHg after 2 hours. Decreased and this effect lasted for at least 6 hours. On the other hand, even when the unmodified protein was mixed with the same amount of sugar as that contained in the above sample and loaded on SHR rats, the systolic blood pressure did not show a significant decrease. From this result, it was confirmed that the blood glucose control function of the cow beef protein was enhanced by glucose modification.

Effect of continuous long-term administration (suppressive effect on blood pressure increase with aging)
The SHR rat is a model animal in which blood pressure gradually rises as it grows. When the male SHR rats aged 10 weeks were bred for 4 weeks, the same sugar-modified fish meat (P-7.8) as in Example 2 was orally administered at 70 and 170 mg per body weight once a day, and changes in blood pressure were investigated. As a result, as shown in FIG. 4, the systolic blood pressure of normal SHR rats increased by 13 mmHg in 4 weeks, whereas in rats continuously administered with sugar-modified fish meat, the blood pressure elevation was significantly suppressed. did it. Furthermore, even if such continuous administration was performed, the blood pressure lowering effect immediately after administration of the sugar-modified fish meat was not impaired.

Addition of blood pressure control function to egg protein
Ovalbumin (mainly ovalbumin) was obtained by acid precipitation of white leghorn egg white at pH 5.6, and then recovered by centrifugation, suspended in 10 mM NaCl, neutralized with HCl, and recovered. This protein solution was prepared at 100 mg/ml, and then 0.1 M maltose was dissolved and freeze-dried. Then, it was immediately kept at 60° C. and 65% relative humidity for 4 days to bind maltose to the ovalbumin molecule. Furthermore, unreacted maltose was removed from this sugar-modified protein by ammonium sulfate fractionation.

  SDS-polyacrylamide gel electrophoresis analysis showed that the ovalbumin obtained above had 53% less effective lysine, and that it was treated with pepsin at a 1/500 weight ratio and the protein degradation pattern was different. Confirmed by. Therefore, in order to investigate the blood pressure regulation function of this glycosylated protein, 1000 mg/body weight was orally administered to 10-week-old male SHR rats (body weight 240 to 260 g) exhibiting hypertension, and systolic blood pressure was found 2 hours later. It decreased by 22 mmHg, and this effect was maintained for at least 6 hours. Even when maltose in an amount similar to that contained in the above sample was mixed with unmodified sugar ovalbumin, the maximum systolic blood pressure decrease range was 8 mmHg even when loaded on SHR rats. Showed a significant difference (risk rate 1%).

  The above results indicate that the blood pressure control function was added to ovalbumin by sugar modification.

  All publications, patents and patent applications cited in this specification are incorporated herein by reference as they are.

Claims (17)

  A method for preparing a sugar-modified protein for lowering blood pressure, which comprises mixing a protein with a reducing sugar, dehydrating the mixture, and maintaining the water content at 0.25 to 6% under an environment of 30 to 70°C.   A method for preparing a sugar-modified protein for lowering blood pressure, which comprises mixing a protein with a reducing saccharide, dehydrating the mixture, and maintaining the mixture in an environment having a relative humidity of 70% or less and 30 to 70°C.   The method for preparing a sugar-modified protein for lowering blood pressure according to claim 1 or 2, wherein the protein is selected from albumin, myosin, protamine, soybean protein and muscle protein.   The method according to any one of claims 1 to 3, wherein dehydration is performed until the water content becomes 10% or less.   The method according to claim 1, wherein the reducing saccharide is a reducing monosaccharide or a reducing oligosaccharide.   A sugar-modified protein for lowering blood pressure, which is prepared by the method according to claim 1.   Muscles of molluscs or crustaceans, minced meat selected from fish meat, or livestock meat, mixed with reducing sugars, dehydrated, including maintaining in an environment of relative humidity 70% or less and 30 ~ 70 ℃, A method for preparing sugar-modified meat for lowering blood pressure.   Sugar-reducing sugar that comprises mixing muscle protein derived from mollusc or crustacean muscle, fish meat, or livestock meat with reducing sugars, dehydrating the mixture, and maintaining it in an environment with a relative humidity of 70% or less and 30 to 70°C. Method for preparing modified meat.   The method according to claim 7 or 8, wherein dehydration is performed until the water content becomes 10% or less.   10. The method according to claim 7, wherein the reducing sugar is a reducing monosaccharide or a reducing oligosaccharide.   Sugar-modified meat for lowering blood pressure prepared by the method according to claim 7.   A food or drink containing the sugar-modified protein for lowering blood pressure according to claim 6.   A food or drink comprising the sugar-modified meat for lowering blood pressure according to claim 11.   An antihypertensive agent comprising the sugar-modified protein for lowering blood pressure according to claim 6 or the sugar-modified meat for lowering blood pressure according to claim 11 as an active ingredient.   An antihypertensive agent containing, as an active ingredient, a sugar-modified protein produced by a Maillard reaction of a protein and sugar.   An antihypertensive agent containing sugar-modified meat produced by the Maillard reaction of meat and sugar as an active ingredient.   The food or drink according to claim 12 or 13, which is labeled with an indication that it is effective in lowering blood pressure.

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