A umami peptide with ACE inhibitory activity, its preparation method and application

Abstract

The present invention discloses a umami peptide with ACE inhibitory activity, its preparation method and application, belonging to the field of active peptide biotechnology. The present invention prepares and identifies a umami peptide with ACE inhibitory activity from sea cucumber viscera. It can not only enhance umami perception in the presence of salt, playing the role of reducing salt and increasing umami, but also has ACE inhibitory activity, playing a role in alleviating cardiovascular diseases such as hypertension, and has application value in the preparation of products with blood pressure lowering efficacy. The umami peptide involved in the present invention enhances umami perception in the presence of salt, playing the role of reducing salt and increasing umami, and at the same time has ACE inhibitory activity. It has the characteristics of simple structure, safety, strong activity, etc., can play a nutritional and health care role, and is expected to provide effective active ingredients for the development of foods, food seasonings and blood pressure lowering efficacy products without side effects, and has broad application prospects.

Description

Technical Field

[0001] The present invention relates to the field of active peptide biotechnology, and particularly to a umami peptide with ACE inhibitory activity, its preparation method and application. Background Art

[0002] As a class of short peptides generated by hydrolysis of natural proteins, umami peptides have received extensive attention due to their umami taste and diverse functions. Umami peptides are mainly rich in glutamic acid, aspartic acid and other amino acids with umami properties, and they are widely used in the food industry to enhance flavor, reduce salt addition, etc. The significance of umami peptides not only lies in enhancing food flavor, but also in their potential multifunctionality, including specific physiological regulatory functions such as antioxidant, anti-inflammatory, blood pressure lowering and blood sugar lowering. Moreover, umami peptides can have certain functions while reducing salt and increasing umami, which is an important direction for developing umami peptides from natural raw materials at present.

[0003] Hypertension is one of the main risk factors leading to cardiovascular diseases. In its pathogenesis, angiotensin-converting enzyme (ACE) plays an important role. ACE catalyzes the conversion of angiotensin I into angiotensin II (a potent vasoconstrictor), and at the same time degrades bradykinin (a vasodilator), thus promoting blood pressure elevation. Therefore, inhibiting ACE activity is considered an important therapeutic means for controlling blood pressure. Although chemically synthesized ACE inhibitors (such as captopril, enalapril) show good antihypertensive effects clinically, their potential side effects limit the long-term use of patients. In contrast, functional peptides with ACE inhibitory activity derived from natural proteins have become a more ideal choice due to their high safety and low side effects.

[0004] Sea cucumbers, as a kind of marine organism with high protein and low fat, are rich in various nutrients, including collagen, sulfated polysaccharides, sea cucumber saponins and abundant trace elements. Especially the protein in sea cucumbers has a unique amino acid composition, containing a relatively high proportion of hydrophobic amino acids (such as alanine, leucine) and aromatic amino acids (such as phenylalanine, tyrosine), and these characteristics provide the possibility for the protein to generate functional peptides with ACE inhibitory activity after hydrolysis. In addition, sea cucumbers, as a traditional food, have long been considered safe and reliable, and their processing by-products (such as viscera and skin) have also been proven to contain a large amount of protein resources. These characteristics make sea cucumbers an important potential source for developing umami peptides with ACE inhibitory activity. Existing studies have shown that through appropriate enzymatic hydrolysis treatment, multifunctional peptides with both umami properties and the ability to inhibit ACE activity can be isolated from sea cucumber proteins. This not only helps to develop high-value-added functional foods, but also provides a new direction for natural intervention means for hypertension. Therefore, providing new sea cucumber umami peptides has become a research hotspot. Summary of the Invention

[0005] The object of the present invention is to provide a umami peptide with angiotensin-converting enzyme (ACE) inhibitory activity, its preparation method and application, so as to solve the problems existing in the above-mentioned prior art.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] One of the technical solutions of the present invention is a umami peptide with angiotensin-converting enzyme inhibitory activity, and its amino acid sequence is IDGAVFP.

[0008] Another technical solution of the present invention is the preparation method of the umami peptide, which includes the following steps:

[0009] (1) Using aminopeptidase and flavor protease to enzymatically hydrolyze sea cucumber viscera to obtain a sea cucumber viscera enzymatic hydrolysis product;

[0010] (2) After the sea cucumber viscera enzymatic hydrolysis product is ultrafiltered and desalted, the LC-MS / MS liquid chromatography-mass spectrometry method is used to identify the sequences of the peptide segments in the sea cucumber viscera hydrolysate, construct a sea cucumber viscera hydrolysate peptide segment database, and obtain an enzymatic hydrolysate containing the umami peptide with ACE inhibitory activity;

[0011] (3) Screening out umami peptides with potential ACE inhibitory activity.

[0012] Another technical solution of the present invention is the application of the umami peptide in the preparation of an angiotensin-converting enzyme inhibitor.

[0013] Another technical solution of the present invention is an angiotensin-converting enzyme inhibitor containing the umami peptide.

[0014] Another technical solution of the present invention is the application of the umami peptide in the preparation of a hypotensive drug.

[0015] Another technical solution of the present invention is a hypotensive drug containing the umami peptide.

[0016] Another technical solution of the present invention is the application of the umami peptide in enhancing the umami taste of food or in the preparation of products for enhancing the umami taste of food.

[0017] Another technical solution of the present invention is a food condiment containing the umami peptide.

[0018] Based on the above technical solutions, the present invention has the following technical effects:

[0019] The present invention prepares and identifies a umami peptide with ACE inhibitory activity from sea cucumber viscera, which can not only enhance the umami perception in the presence of salt, play the role of reducing salt and increasing umami, but also has ACE inhibitory activity, relieve cardiovascular diseases such as hypertension, and has application value in the preparation of products with hypotensive efficacy.

[0020] The umami peptide involved in the present invention enhances umami perception in the presence of salt, plays the role of reducing salt and increasing umami, and at the same time has ACE inhibitory activity. It has the characteristics of simple structure, safety, strong activity, etc., can play the roles of nutrition and health care, and is expected to provide effective active ingredients for the development of foods, food seasonings and antihypertensive products without side effects, etc., and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 It is the amino acid structure and sequence secondary mass spectrometry identification diagram of the umami peptide with ACE inhibitory activity.

[0023] Figure 2 It is the docking interaction diagram of the umami peptide IDGAVFP with ACE inhibitory activity and the umami receptor. Among them, A is the overall three-dimensional conformation schematic diagram of the docking of the umami peptide IDGAVFP and the umami receptor, B is the partial enlarged view of the boxed part in A, and C is the two-dimensional schematic diagram of the docking interaction force of the umami peptide IDGAVFP and the umami receptor.

[0024] Figure 3 It is the sensory score diagram of the umami peptide IDGAVFP with ACE inhibitory activity in the presence of different salt concentrations.

[0025] Figure 4 It is the inhibition rate diagram of the umami peptide IDGAVFP with ACE inhibitory activity against ACE at different concentrations.

[0026] Figure 5 It is the molecular simulation docking diagram of the umami peptide IDGAVFP with ACE inhibitory activity and ACE. Among them, A is the three-dimensional conformation schematic diagram of the docking site amino acids and interaction forces of the umami peptide IDGAVFP and ACE, and B is the two-dimensional schematic diagram of the docking interaction force of the umami peptide IDGAVFP and the umami receptor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] Now, various exemplary embodiments of the present invention will be described in detail. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and implementation schemes of the present invention.

[0028] It should be understood that the terms used in the present invention are only for describing specific embodiments and are not intended to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0029] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to those documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0030] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific embodiments of the present invention specification, which are obvious to those skilled in the art. Other embodiments obtained from the specification of the present invention are obvious to those skilled in the art. The specification and examples of this application are merely exemplary.

[0031] Regarding the use of "comprising", "including", "having", "containing", etc. herein, they are all open-ended terms, meaning including but not limited to.

[0032] The technical solutions described in the present invention are all conventional solutions in the art unless otherwise specified. The reagents or raw materials used are all purchased from commercial channels or have been disclosed unless otherwise specified.

[0033] An embodiment of the present invention provides a umami peptide having angiotensin-converting enzyme inhibitory activity, and its amino acid sequence is IDGAVFP (SEQ ID NO.1).

[0034] An embodiment of the present invention also provides a preparation method of the umami peptide, including the following steps:

[0035] (1) Using aminopeptidase and flavor protease to enzymatically hydrolyze sea cucumber viscera to obtain a sea cucumber viscera enzymatic hydrolysis product;

[0036] (2) After the sea cucumber viscera enzymatic hydrolysis product is subjected to ultrafiltration and desalting treatment, the LC-MS / MS liquid chromatography-mass spectrometry tandem method is used to identify the sequences of the peptide segments in the sea cucumber viscera hydrolysate, construct a sea cucumber viscera hydrolysate peptide segment database, and obtain an enzymatic hydrolysate containing the umami peptide with ACE inhibitory activity;

[0037] (3) Screen out umami peptides with potential ACE inhibitory activity.

[0038] In some specific embodiments, the enzymatic hydrolysis conditions are as follows: the dosage of aminopeptidase is 1000 U / g, the dosage of flavor protease is 500 U / g, the dosage of sea cucumber viscera substrate is 10%, enzymatic hydrolysis is carried out at 50 °C for 18 h, and the pH of enzymatic hydrolysis is 7.

[0039] In some specific embodiments, the screening method is as follows: identify the molecular weight and sequence of peptide segments in the enzymatic hydrolysis product of sea cucumber viscera, and screen out peptide segments of 5 ppm; further predict the ACE inhibitory activity and umami of the peptide segments, and based on the umami score, screen out umami peptides with potential ACE inhibitory activity, and analyze the secondary mass spectrometry structure thereof to obtain the amino acid sequence and structure of the umami peptide.

[0040] The embodiment of the present invention also provides the application of the umami peptide in the preparation of an angiotensin-converting enzyme inhibitor.

[0041] The embodiment of the present invention also provides an angiotensin-converting enzyme inhibitor containing the umami peptide.

[0042] The embodiment of the present invention also provides the application of the umami peptide in the preparation of a hypotensive drug.

[0043] The embodiment of the present invention also provides a hypotensive drug containing the umami peptide.

[0044] The embodiment of the present invention also provides the application of the umami peptide in enhancing the umami of food or in the preparation of products for enhancing the umami of food.

[0045] The embodiment of the present invention also provides a food condiment containing the umami peptide.

[0046] The umami peptide with ACE inhibitory activity provided by the present invention can not only significantly feel umami in the presence of salt, increase the palatability, achieve the effect of reducing salt and increasing umami, but also effectively inhibit the activity of ACE, play a role in preventing and even alleviating diseases such as hypertension, and is of great significance to the actual production and theoretical research of functional umami peptides.

[0047] Example 1

[0048] Preparation of umami peptides in sea cucumber viscera

[0049] After homogenizing and performing other pretreatment on sea cucumber viscera, compound enzymatic hydrolysis was carried out using aminopeptidase and flavor protease. The dosage of aminopeptidase was 1000 U / g, the dosage of flavor protease was 500 U / g, the dosage of sea cucumber viscera substrate was 10%, the enzymatic hydrolysis conditions were enzymatic hydrolysis at 50 °C for 18 h, and the pH value of the enzymatic hydrolysis system was continuously monitored and adjusted to 7 during the enzymatic hydrolysis process. The sea cucumber viscera hydrolysate was ultrafiltered and desalted using a solid-phase extraction column (SEP-PAK C18 solid-phase extraction column, Waters, USA) to prepare a sea cucumber viscera hydrolysate containing umami peptides. Further, LC-MS / MS liquid chromatography-mass spectrometry was used to determine the molecular weights and sequences of the peptide segments obtained from the enzymatic hydrolysis of sea cucumber viscera, and a peptide segment database of sea cucumber viscera hydrolysate was constructed.

[0050] Example 2

[0051] Screening and Mining of Umami Peptide IDGAVFP with ACE Inhibitory Activity

[0052] According to the molecular weights and sequences of the peptide segments in the sea cucumber viscera hydrolysate identified by LC-MS / MS liquid chromatography-mass spectrometry, 1222 peptide segments with 5 ppm were screened using the DeltaM tool. Further, the ACE inhibitory activity and umami of the peptide segments were predicted using the TastePeptidesDM and UMPred-FRL umami scoring predictors, the PeptideRanker functional activity predictor, and the Toixinpred safety and toxicity evaluation predictor. Based on the umami score, umami peptides with potential ACE inhibitory activity were screened, and the secondary mass spectrometry structure of the umami peptide was analyzed to obtain the amino acid sequence and structure of the umami peptide. The results are as Figure 1 shown. The secondary mass spectrometry diagram of the screened umami peptide shows that the amino acid sequence and arrangement of the umami peptide are IDGAVFP.

[0053] Example 3

[0054] Molecular Simulation Docking of Umami Peptide IDGAVFP with ACE Inhibitory Activity and Umami Receptor T1R1 / R1R3

[0055] The umami peptide with ACE activity prepared and mined from sea cucumber viscera was subjected to molecular simulation docking with the umami receptor T1R1 / R1R3 to further determine the umami characteristics and taste mechanism of the umami peptide. The Discovery studio software was used to draw the three-dimensional conformation diagram of the umami peptide IDGAVFP, and molecular simulation docking was performed with the active center, i.e., the cavity hairpin binding region, of the constructed umami receptor T1R1 / R1R3. Based on the docking results, the interaction forces between the umami peptide IDGAVFP and the key amino acid residues in the active center of the umami receptor T1R1 / R1R3 were analyzed.

[0056] The results are as follows Figure 2 shown. The umami peptide IDGAVFP forms 6 conventional hydrogen bond forces, 1 pi-pi stacking force, 1 pi-alkyl force and various van der Waals forces with the receptor binding cavity region in the umami receptor T1R1 / R1R3. Moreover, the amino acids in the umami peptide IDGAVFP sequence bind to the key amino acid residues in the umami receptor T1R1 / R1R3, such as Ala170, Asp147, His71, Ser276, Gln278 and Arg277, etc., and then present umami characteristics. Therefore, through the molecular simulation docking of the umami peptide IDGAVFP and the umami receptor T1R1 / R1R3, it is further determined that the umami peptide IDGAVFP prepared and identified from sea cucumber viscera has umami characteristics.

[0057] Example 4

[0058] Umami sensory evaluation of the umami peptide IDGAVFP with ACE inhibitory activity at different salt concentrations

[0059] 10 healthy sensory evaluation panel members (6 females and 4 males, aged 24 - 30 years) with sensory evaluation experience were recruited from the laboratory. First, the sensory evaluation panel members were trained for 2 weeks. The training content was to present the aqueous solutions of six sour, sweet, bitter, salty, umami and astringent taste standards to the sensory evaluation personnel. The umami standard was sodium glutamate, which was the main sensory evaluation index of the present invention. Different solutions were prepared by taking different concentrations (0.5, 1, 1.5 mg / mL) of the umami peptide IDGAVFP of the present invention and different concentrations of NaCl (1, 1.5, 2, 3 mg / mL), and presented to the sensory evaluation personnel to taste and rank the umami intensity and record the scores.

[0060] The results are as follows Figure 3 shown. Different concentrations of the umami peptide IDGAVFP can show a certain umami enhancement effect in the presence of different concentrations of NaCl, that is, when the concentration of the umami peptide IDGAVFP is 0.5 - 1 mg / mL, only a low salt concentration (1 - 1.5 mg / mL) is required to provide a relatively high level of umami; and at a higher concentration of the umami peptide IDGAVFP, in the case of low salt (1 - 1.5 mg / mL), compared with high salt (2 - 3 mg / mL), a comparable umami level can be produced. The above results indicate that the umami peptide IDGAVFP has a certain effect of reducing salt and enhancing umami.

[0061] Example 5

[0062] Verification of the ACE inhibitory activity of the umami peptide IDGAVFP with ACE inhibitory activity

[0063] The ACE inhibitory activity of the umami peptide IDGAVFP was determined using a visible spectrophotometer method with a 96-well plate. 1 mM N-[3-(2-furyl)acryloyl]-L-phenylalanylglycylglycine (FAPPG) was used as the substrate; 0.1 U / mL angiotensin-converting enzyme (ACE); HEPES was used as the buffer matrix (weigh 1.901 g of HEPES reagent and 1.755 g of NaCl reagent, dissolve in an appropriate amount of deionized water, then adjust the pH of the buffer to 8.3 with NaOH solution, and make up to 100 mL for standby) to determine the ACE inhibition rate. The measurement steps are as follows: Add different concentrations of the umami peptide IDGAVFP samples (0.5, 1, 1.5, 2 mg / mL) to the 96-well plate in sequence, as well as FAPPG substrate, ACE, and buffer, etc.; Use a microplate reader to measure the absorbance value of the sample addition system at 340 nm and record it; Place the sample addition system in a shaker incubator at 37 °C and shake for 30 min, and then use the microplate reader to measure the absorbance value at 340 nm again for the reacted sample addition system; The ACE inhibition rate of the sample is determined by calculating the change in absorbance value before and after the reaction.

[0064] The calculation formula is:

[0065] The ACE inhibition rate of the sample % = 1 - change in absorbance value of the sample / change in absorbance value of the blank.

[0066] The results are as Figure 4 shown. When the concentration of the umami peptide IDGAVFP is 0.5 mg / mL, the inhibition rate of the umami peptide IDGAVFP is 92.5%; when the concentration of the umami peptide IDGAVFP is 1 mg / mL, the inhibition rate of ACE is 102.7%; when the concentration of the umami peptide IDGAVFP is 1.5 mg / mL, the inhibition rate of ACE is 100.6%; when the concentration of the umami peptide IDGAVFP is 2 mg / mL, the inhibition rate of the umami peptide IDGAVFP is 99.8% (see Figure 4 ). And according to the results of the ACE inhibitory activity determination, when the concentration of the umami peptide IDGAVFP is greater than 0.5 mg / mL, it can completely inhibit ACE. And combined with the sensory evaluation results in Example 4, when the concentration of the umami peptide IDGAVFP is 0.5 - 1 mg / mL, it can provide a comparable level of umami for solutions with high and low salt concentrations, and in this concentration range, this umami peptide IDGAVFP can also completely inhibit ACE, indicating that the umami peptide IDGAVFP can also have a certain ACE inhibitory effect at the concentration that can achieve the umami characteristics of reducing salt and enhancing umami.

[0067] In summary, the umami peptide IDGAVFP of the present invention has certain ACE inhibitory activity, and at the concentration at which it can reduce salt and enhance umami and exhibit umami characteristics, it can also effectively inhibit the activity of ACE.

[0068] Example 6

[0069] Molecular simulation docking of the umami peptide IDGAVFP with ACE having ACE inhibitory activity

[0070] The umami peptide with ACE activity prepared and mined from sea cucumber viscera was subjected to molecular simulation docking with ACE to further determine the mechanism of action when the umami peptide exerts its ACE inhibitory activity. The Discovery studio software was used to draw the three-dimensional conformation diagram of the umami peptide IDGAVFP, and molecular simulation docking was performed with the catalytic active center of ACE (PDB: 1o8a), and the interaction forces between the umami peptide IDGAVFP and the key amino acid residues in the ACE active center were analyzed based on the docking results.

[0071] The results are as Figure 5 shown. The umami peptide IDGAVFP with ACE inhibitory activity can tightly bind to the ACE active center and can perform simulation docking within the normal analysis time. And the umami peptide IDGAVFP with ACE inhibitory activity interacts with a variety of amino acid residues in the ACE active center, and the main amino acid residues are Phe527, Try520, His383, Glu384, Gln281, His513, Tyr523, Glu403, His410, Pro407, Val379, His353, Lys511 and Zn 2+ .

[0072] The analysis results of the interaction forces between the umami peptide IDGAVFP with ACE inhibitory activity and the amino acid residues in the ACE active center are as Figure 5 shown. The umami peptide IDGAVFP with ACE inhibitory activity forms 4 hydrogen bond interaction forces, 5 alkyl-alkyl interaction forces and π-alkyl interaction forces, 1 salt bridge and 1 attractive interaction force, 2 carbon-hydrogen interaction forces, and Zn 2+ binding.

[0073] All in all, the umami peptide IDGAVFP with ACE inhibitory activity can bind to ACE, and mainly interacts with the residues in the ACE active center through hydrogen bonds, hydrophobic interactions and Zn 2+ binding to inhibit the activity of ACE. That is, from the perspective of molecular simulation docking, it is further proved that the umami peptide IDGAVFP has significant ACE inhibitory activity.

[0074] In summary, through the method of enzymatic hydrolysis with composite enzymes, a umami peptide IDGAVFP with ACE inhibitory activity was prepared and identified from sea cucumber viscera. The amino acid sequence and structure of this umami peptide were obtained through secondary mass spectrometry analysis. The umami characteristics and flavor formation mechanism were illustrated by molecular simulation docking with the umami receptor T1R1 / T1R3 and its umami sensory evaluation under different salt concentrations. Furthermore, the ACE inhibitory activity of the umami peptide IDGAVFP was verified, and the inhibitory mechanism of the umami peptide on ACE activity was illustrated by molecular simulation docking of the umami peptide with the ACE active center.

[0075] The umami peptide IDGAVFP with ACE inhibitory activity provided by the present invention can exhibit a relatively high level of umami at a certain concentration, and the umami levels presented at low and high salt concentrations are quite similar, showing a certain effect of reducing salt and enhancing umami. Moreover, at this flavor-forming concentration, the umami peptide IDGAVFP can also significantly inhibit the activity of ACE, having a certain blood pressure-lowering effect.

[0076] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly explaining the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. An umami peptide having ACE inhibitory activity, characterized in that: Its amino acid sequence is IDGAVFP.

2. The method for preparing the umami peptide according to claim 1, characterized in that: The following steps are involved: (1) Using aminopeptidase and flavor protease to enzymatically hydrolyze the sea cucumber viscera to obtain a sea cucumber viscera enzymatic hydrolyzate; the enzymatic hydrolysis conditions are: the amount of aminopeptidase used is 1000 U / g, the amount of flavor protease used is 500 U / g, the amount of sea cucumber viscera substrate is 10%, the enzymatic hydrolysis is carried out at 50°C for 18 h, and the enzymatic hydrolysis pH is 7; (2) After the sea cucumber viscera hydrolysate is subjected to ultrafiltration and desalting treatment, the peptide sequences in the sea cucumber viscera hydrolysate are identified by LC-MS / MS liquid chromatography-mass spectrometry to construct a sea cucumber viscera hydrolysate peptide database, and an enzymatic hydrolysate containing the umami peptide with ACE inhibitory activity is obtained; (3) Screening out umami peptides with potential ACE inhibitory activity; the screening method is: identifying the molecular weight and sequence of peptides in the sea cucumber viscera hydrolysate, and using the DeltaM tool to screen out 5 ppm peptides; further predicting the ACE inhibitory activity and umami taste of the peptides, and based on the umami taste score, screening out umami peptides with potential ACE inhibitory activity, and analyzing their secondary mass spectrometry structures to obtain the amino acid sequence and structure of the umami peptides.

3. An angiotensin converting enzyme inhibitor, characterized in that The method comprises the umami peptide according to claim 1.

4. Use of the umami peptide as claimed in claim 1 in the preparation of blood pressure lowering drugs.

5. A blood pressure lowering drug, characterized in that: The method comprises the umami peptide according to claim 1.

6. Use of the umami peptide according to claim 1 in improving the umami taste of food or in preparing a product for improving the umami taste of food.

7. A food seasoning, characterized in that: The method comprises the umami peptide according to claim 1.

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