Sea cucumber peptide powder as well as preparation method and application thereof

Abstract

The invention discloses sea cucumber peptide powder as well as a preparation method and application thereof, and belongs to the technical field of marine byproduct processing. Comprising the following steps: (1) mashing sea cucumber viscera, adding water, flavourzyme and aminopeptidase for enzymolysis, after enzymolysis is completed, performing enzyme deactivation, and performing centrifugation to collect supernatant; (2) adding a chitosan-acetic acid solution, stirring and mixing, centrifuging again, and collecting supernatant; and (3) carrying out rotary evaporation and drying to obtain the sea cucumber peptide powder. According to the preparation method disclosed by the invention, protein is dissolved out to the greatest extent by virtue of an enzymolysis process of cutting off different amino acid targets through double-enzyme compounding, and the proportion of components with molecular weights of 1000Da or below in the obtained fresh-flavor sea cucumber oligopeptide is 72%. Through a double-enzyme composite enzymolysis process, the obtained fresh sea cucumber oligopeptide is obvious in fresh taste, free of peculiar smell, good in solubility and rich in free amino acids and flavor nucleotides. The purpose of adsorbing and removing lipid is achieved by adding chitosan, so that the enzymatic hydrolysate is clarified.

Description

Technical Field

[0001] The invention relates to the technical field of marine by-product processing, and in particular to sea cucumber peptide powder and a preparation method and application thereof. Background Art

[0002] In recent years, China's sea cucumber industry has developed rapidly, and the market and breeding scale have continued to expand. In 2022, my country's total sea cucumber output was about 248,500 tons, a year-on-year increase of 13.3%. The sea cucumber processing industry has developed rapidly, but sea cucumber processing is limited to the sea cucumber body wall. The sea cucumber viscera, which account for 10-30% of the total sea cucumber weight, are often discarded as waste during processing because they carry a lot of mud and heavy metals. They have not been fully developed and utilized, resulting in waste of resources.

[0003] Modern research has shown that sea cucumber viscera not only contain rich protein like the body wall, but also contain umami amino acids, accounting for 41-43% of the total amino acids. Umami amino acids give the product a unique flavor. In general, glutamic acid, aspartic acid, glycine, alanine and threonine, which can present a special umami flavor, are called flavor amino acids.

[0004] According to the World Health Organization (WHO), the average salt intake of people is 9-12g / day, which greatly exceeds the highest recommended level of 5g / day. A high-salt diet can lead to organ damage and chronic diseases. Finding salt-reducing and flavor-enhancing peptides is a promising strategy. Sea cucumber peptides are made using advanced peptide molecular biotechnology, which not only completely retains the unique nutrients of sea cucumbers, but also converts large molecular proteins into more easily absorbed and more functional small molecular active peptides, which are easier to pass through the intestinal wall and be absorbed and utilized by the human body. However, the release of bitter peptides during the degradation process will aggravate the unpleasant sensory experience of sea cucumber peptides. This is a problem that needs to be solved urgently. Summary of the invention

[0005] The purpose of the present invention is to provide a sea cucumber peptide powder and a preparation method and application thereof, so as to solve the problems existing in the above-mentioned prior art. An enzymatic hydrolysis process is used to ensure that large molecular proteins are converted into small molecular umami oligopeptides and free amino acids and are dissolved to the maximum extent, and at the same time, the fat in the sea cucumber peptides is removed by chitosan adsorption, and finally the sea cucumber oligopeptide powder is obtained by drying. The enzymatic hydrolysis technology of the present invention releases a large amount of umami oligopeptides, free amino acids and umami nucleotides, so that the sea cucumber by-products are utilized to the maximum extent.

[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 method for preparing sea cucumber peptide powder, comprising the following steps:

[0008] (1) After the sea cucumber viscera are crushed, water, flavor protease and aminopeptidase are added for enzymolysis, and after the enzymolysis is completed, the enzyme is inactivated, and the supernatant is collected by centrifugation;

[0009] (2) adding chitosan-acetic acid solution, stirring and mixing, and centrifuging again to collect the supernatant;

[0010] (3) Rotary evaporation and drying to obtain the sea cucumber peptide powder.

[0011] The second technical solution of the present invention is the sea cucumber peptide powder prepared by the above preparation method.

[0012] The third technical solution of the present invention is an umami oligopeptide derived from sea cucumber, wherein the umami oligopeptide includes NSPGDSFP, DFLDDGPG, SDTGNFGF, FGSLGNP and / or PDAILP.

[0013] A fourth technical solution of the present invention is the use of the sea cucumber peptide powder or the umami oligopeptide in the preparation of food seasonings.

[0014] A fifth technical solution of the present invention is a food seasoning for increasing umami taste, comprising the sea cucumber peptide powder or the umami oligopeptide.

[0015] The sixth technical solution of the present invention is a method for preparing sea cucumber peptide powder rich in free amino acids and flavor nucleotides GMP and IMP, utilizing the above-mentioned preparation method.

[0016] Based on the above technical solution, the present invention has the following technical effects:

[0017] 1. The present invention uses a double-enzyme compound to cut off the enzymatic hydrolysis process of different amino acid targets to maximize the dissolution of protein, and the proportion of components with a molecular weight of less than 1000Da in the obtained umami sea cucumber oligopeptide is 72%.

[0018] 2. The present invention uses a double-enzyme complex enzymatic hydrolysis process to obtain a umami sea cucumber oligopeptide with obvious umami taste, no peculiar smell, good solubility, and rich in free amino acids and flavor nucleotides.

[0019] 3. The present invention adds chitosan to achieve the purpose of adsorbing and removing lipids, thereby clarifying the enzymatic hydrolyzate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1This is an electronic tongue scoring diagram of the umami sea cucumber oligopeptides produced in Example 3 of the present invention and Comparative Example 1 at the same concentration.

[0022] Figure 2 This is the LC / MS total ion current diagram for the identification of the umami sea cucumber oligopeptide peptide segment produced in Example 3 of the present invention.

[0023] Figure 3 This is a schematic diagram of the 3D docking effect of the NSPGDSFP screened for the effect example of the present invention and the T1R1 / T1R3 receptor molecule.

[0024] Figure 4 This is a schematic diagram of the 3D docking effect of DFLDDGPG screened for the effect example of the present invention and the T1R1 / T1R3 receptor molecule.

[0025] Figure 5 This is a schematic diagram of the 3D docking effect of SDTGNFGF and T1R1 / T1R3 receptor molecules screened for the effect examples of the present invention.

[0026] Figure 6 This is a schematic diagram of the 3D docking effect of FGSLGNP screened for the effect example of the present invention and T1R1 / T1R3 receptor molecules.

[0027] Figure 7 This is a schematic diagram of the 3D docking effect of PDAILP and T1R1 / T1R3 receptor molecules screened for the effect examples of the present invention.

[0028] Figure 8 3D schematic diagram of the T1R1 / T1R3 umami taste receptor model.

[0029] Fig. 9 The radar chart is a sensory evaluation of 5 synthetic peptides and standards. DETAILED DESCRIPTION

[0030] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0031] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0032] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation 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 associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0033] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present application description and examples are exemplary only.

[0034] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0035] The technical solutions described in the present invention, unless otherwise specified, are all conventional solutions in the art, and the reagents or raw materials used, unless otherwise specified, are purchased from commercial channels or have been disclosed.

[0036] The embodiment of the present invention provides a method for preparing sea cucumber peptide powder, comprising the following steps:

[0037] (1) After the sea cucumber viscera are crushed, water, flavor protease and aminopeptidase are added for enzymolysis, and after the enzymolysis is completed, the enzyme is inactivated, and the supernatant is collected by centrifugation;

[0038] (2) adding chitosan-acetic acid solution, stirring and mixing, and centrifuging again to collect the supernatant;

[0039] (3) Rotary evaporation and drying to obtain the sea cucumber peptide powder.

[0040] In some specific embodiments, the mass ratio of the sea cucumber viscera to water is (10-13):100.

[0041] In some specific embodiments, the added amount of the flavor protease is 900-1100 U / g; the added amount of the aminopeptidase is 450-550 U / g; and the conditions for the enzymatic hydrolysis are: temperature of 50-55° C., and time of 15-20 h.

[0042] In some specific embodiments, the mass concentration of the chitosan-acetic acid solution is 1%, and the added amount is 6%-10% (v:v).

[0043] In some specific embodiments, the centrifugation condition is centrifugation at 4000-5000 r / min for 15-20 min; the second centrifugation condition is centrifugation at 4000-5000 r / min for 5-10 min.

[0044] In some specific embodiments, the enzyme inactivation method is heating to 90°C for 10 min.

[0045] In some specific embodiments, the rotary evaporation is for concentration to 30-50% of the original volume; and the drying is spray drying or freeze drying.

[0046] In some specific implementation schemes, LC-MS / MS liquid phase mass spectrometry is used to determine the molecular weight and sequence of the sea cucumber oligopeptide powder peptide segment, and then the umami learning predictor and T1R1 / T1R3 receptor molecular docking model are used to screen the umami peptides.

[0047] The present invention utilizes double enzyme collaboration to obtain an umami oligopeptide product with a molecular weight lower than 1000Da, and identifies 5 peptide segment amino acid sequences that mainly contribute to the umami taste.

[0048] The embodiment of the present invention also provides an enzymatic preparation process of umami oligopeptides rich in free amino acids and flavor nucleotides GMP and IMP.

[0049] The embodiment of the present invention also provides sea cucumber peptide powder prepared by the above preparation method.

[0050] The embodiment of the present invention also provides umami oligopeptides derived from sea cucumber, wherein the umami oligopeptides include NSPGDSFP, DFLDDGPG, SDTGNFGF, FGSLGNP and / or PDAILP.

[0051] The embodiment of the present invention also provides the use of the sea cucumber peptide powder or the umami oligopeptide in preparing a food seasoning.

[0052] The embodiment of the present invention further provides a food seasoning for increasing umami taste, comprising the sea cucumber peptide powder or the umami oligopeptide.

[0053] The embodiment of the present invention also provides a method for preparing sea cucumber peptide powder rich in free amino acids and flavor nucleotides GMP and IMP, using the above preparation method.

[0054] Example 1

[0055] (1) Take 50 g of frozen unprocessed sea cucumber viscera, add water until the sea cucumber viscera are just submerged, gently stir until the sea cucumber viscera are thawed and evenly distributed in the water, change the water and continue stirring and rinsing for 1 min, and repeat the above operation 5 times;

[0056] (2) filtering the sea cucumber viscera rinsed in step (1) through double-layer gauze and draining to separate the sea cucumber viscera from the rinsing liquid;

[0057] (3) grinding the sea cucumber viscera drained in step (2) in a colloid mill and determining the water content and solid content for calculating the amount of water and enzyme to be added;

[0058] (4) 30 g of the sea cucumber viscera minced in step (3) was placed in a 250 mL beaker, 50 mL of water, 0.072 g of flavor protease, and 0.036 g of aminopeptidase were added, and the mixture was enzymolyzed in a stirring water bath at 50° C. for 18 h;

[0059] (5) heating the enzymatic hydrolyzate of step (4) to 90° C. and maintaining it for 10 min, cooling it to room temperature, centrifuging it at 5000 rpm for 10 min, and collecting the supernatant;

[0060] (6) adding 1% chitosan-acetic acid solution to the supernatant of step (5) in an amount of 6% of the supernatant volume, stirring and mixing for 30 seconds, centrifuging at 5000 r / min for 10 minutes, and collecting the supernatant;

[0061] (7) The supernatant collected in step (6) was concentrated by rotary evaporation to a substrate concentration of 30%, placed on a glass plate, pre-frozen at -40°C overnight, and freeze-dried for 48 hours to obtain sea cucumber peptide powder.

[0062] The solid extraction rate of the sea cucumber oligopeptide powder prepared according to the above method reaches 41.21%, the protein extraction rate reaches 48.86%, the total sugar extraction rate reaches 51.46%; the protein content reaches 78.92%, and the fat content reaches 7.71%.

[0063] Example 2

[0064] (1) Take 100 g of frozen unprocessed sea cucumber viscera, add water until the sea cucumber viscera are just submerged, gently stir until the sea cucumber viscera are thawed and evenly distributed in the water, change the water and continue stirring and rinsing for 1 min, and repeat the above operation 5 times;

[0065] (2) filtering the sea cucumber viscera rinsed in step (1) through double-layer gauze and draining to separate the sea cucumber viscera from the rinsing liquid;

[0066] (3) grinding the sea cucumber viscera drained in step (2) in a colloid mill and determining the water content and solid content for calculating the amount of water and enzyme to be added;

[0067] (4) 60 g of the sea cucumber viscera minced in step (3) was placed in a 500 mL beaker, 100 mL of water, 0.15 g of flavor protease, and 0.075 g of aminopeptidase were added, and the mixture was enzymolyzed in a stirring water bath at 50° C. for 16 h;

[0068] (5) heating the enzymatic hydrolyzate of step (4) to 90° C. and maintaining it for 10 min, cooling it to room temperature, centrifuging it at 5000 rpm for 10 min, and collecting the supernatant;

[0069] (6) The supernatant collected in step (5) was concentrated by rotary evaporation to a substrate concentration of 30%, placed on a glass plate, pre-frozen at -40°C overnight, and freeze-dried for 48 hours to obtain sea cucumber peptide powder.

[0070] The solid extraction rate of the sea cucumber oligopeptide powder prepared according to the above method reaches 68.34%, the protein extraction rate reaches 68.74%, the total sugar extraction rate reaches 60.08%; the protein content reaches 64.23%, and the fat content reaches 20.01%.

[0071] Example 3

[0072] (1) Take 4.5 kg of frozen unprocessed sea cucumber viscera, add water until the sea cucumber viscera are just submerged, gently stir until the sea cucumber viscera are thawed and evenly distributed in the water, change the water and continue stirring and rinsing for 2 minutes, and repeat the above operation 5 times;

[0073] (2) filtering the sea cucumber viscera rinsed in step (1) through double-layer gauze and draining to separate the sea cucumber viscera from the rinsing liquid;

[0074] (3) grinding the sea cucumber viscera drained in step (2) in a colloid mill and determining the water content and solid content for calculating the amount of water and enzyme to be added;

[0075] (4) putting the sea cucumber viscera crushed in step (3) into a 20 L enzymatic hydrolysis tank, adding 6.67 L of water, 10.5 g of flavor protease, and 5 g of aminopeptidase, and maintaining the liquid temperature at 50 ° C for 18 h;

[0076] (5) heating the enzymatic hydrolyzate of step (4) to 85° C. and maintaining it for 15 min, cooling it to 40° C., centrifuging it at 4000 r / min for 15 min, and collecting the supernatant;

[0077] (6) The supernatant collected in step (5) was concentrated by rotary evaporation to a substrate concentration of 35%, placed on a glass plate, pre-frozen at -40°C overnight, and freeze-dried for 72 hours to obtain sea cucumber peptide powder.

[0078] The solid extraction rate of the sea cucumber oligopeptide powder prepared according to the above method reaches 60.6%, the protein extraction rate reaches 66.23%, the total sugar extraction rate reaches 63.55%; the protein content is 64.56%, and the fat content reaches 22.04%.

[0079] The sea cucumber oligopeptide produced in Example 3 has an orange-yellow powder appearance, good solubility, fresh taste, no peculiar smell and impurities. The general nutritional composition table is shown in Table 1, the total amino acid composition of the umami sea cucumber oligopeptide and sea cucumber viscera raw materials is shown in Table 2, and the flavor nucleotide composition is shown in Table 3.

[0080] Table 1 General nutritional components of umami sea cucumber oligopeptide powder

[0081]

[0082] Table 2 Total amino acid composition of umami sea cucumber oligopeptides and sea cucumber viscera raw materials

[0083]

[0084]

[0085] Note: TAA = total amino acid; EAA = essential amino acid; FAA = umami amino acid; E / T = essential amino acid / total amino acid; F / T = umami amino acid / total amino acid.

[0086] Table 3 Flavor nucleotide composition of umami sea cucumber oligopeptides and sea cucumber viscera raw materials

[0087]

[0088] Note: “——” not detected.

[0089] Comparative Example 1

[0090] (1) Take 100 g of frozen unprocessed sea cucumber viscera, add water until the sea cucumber viscera are just submerged, gently stir until the sea cucumber viscera are thawed and evenly distributed in the water, change the water and continue stirring and rinsing for 1 min, and repeat the above operation 5 times;

[0091] (2) filtering the sea cucumber viscera rinsed in step (1) through double-layer gauze and draining to separate the sea cucumber viscera from the rinsing liquid;

[0092] (3) grinding the sea cucumber viscera drained in step (2) in a colloid mill and determining the water content and solid content for calculating the amount of water and enzyme to be added;

[0093] (4) 60 g of the sea cucumber viscera minced in step (3) was placed in a 500 mL beaker, 100 mL of water and 0.15 g of flavor protease were added, and the mixture was enzymatically treated in a stirring water bath at 50° C. for 16 h;

[0094] (5) heating the enzymatic hydrolyzate of step (4) to 90° C. and maintaining it for 10 min, cooling it to room temperature, centrifuging it at 5000 rpm for 10 min, and collecting the supernatant;

[0095] (6) The supernatant collected in step (5) was concentrated by rotary evaporation to a substrate concentration of 30%, placed on a glass plate, pre-frozen at -40°C overnight, and freeze-dried for 48 hours to obtain sea cucumber peptide powder.

[0096] The solid extraction rate of the sea cucumber oligopeptide powder prepared according to the above method reaches 57.62%, the protein extraction rate reaches 60.00%, the total sugar extraction rate reaches 46.01%; the protein content reaches 58.56%, and the fat content reaches 20.97%.

[0097] Effect example

[0098] 1. Taste analysis of umami oligopeptides

[0099] Method: Weigh 1 g of the freeze-dried sea cucumber oligopeptide products of Example 3 and Comparative Example 1, dissolve them in 70 mL of distilled water, and perform taste measurement using the INSENT taste analysis system (electronic tongue).

[0100] Result: Passed Figure 1 Based on the difference in scores between Example 3 and Comparative Example 1 in terms of richness and umami value, it is concluded that the dual-enzyme composite process significantly improves the richness and umami value of the oligopeptides compared with the use of a single flavor protease.

[0101] 2 Peptide sequence analysis

[0102] Method: The sea cucumber umami oligopeptide product obtained in Example 3 was subjected to pretreatment steps such as ultrafiltration and desalting, and the peptide sequence was analyzed by nanoliter high performance liquid chromatography tandem with high resolution mass spectrometry.

[0103] Results: Peptide identification LC / MS total ion current diagram is as follows Figure 2 As shown in the figure, the molecular weight distribution is shown in Table 4. The peptides with a molecular weight of less than 1000Da account for 72.08% of the total number of peptides, and the peptides with a molecular weight of less than 2000Da account for 87.68% of the total number of peptides, which proves that the process can fully cleave large molecular proteins and convert them into oligopeptides that are more conducive to human absorption.

[0104] Table 4 Molecular weight distribution of umami sea cucumber oligopeptides

[0105]

[0106] 3. Docking of umami sea cucumber oligopeptides with T1R1 / T1R3 molecules

[0107] Method: All peptides obtained in Example 5 were screened, and the steps included umami prediction, molecular weight screening, activity prediction, and toxicity prediction, and 34 umami oligopeptides with activity, non-toxicity, and molecular weight below 1000Da were screened. The molecular structures of the 34 umami oligopeptide ligands were drawn, and a human taste receptor T1R1 / T1R3 model was established. The receptor model was modified by dehydration and hydrogenation, and the ligand molecules were molecularly docked with the receptor molecules to simulate molecular docking, and the 5 peptides with the highest docking scores were screened. The molecular docking results of the 5 peptides were visualized and their binding sites with the receptors were analyzed.

[0108] Results: The docking scores, i.e., docking binding affinity scores, are shown in Table 5. The scores of the first five sequences are all -7.5 or below, indicating that the docking effect is good. The sequences are: NSPGDSFP, DFLDDGPG, SDTGNFGF, FGSLGNP, and PDAILP. The visualization results are shown in Figure 3-8 As shown, there are many hydrogen bonds and the binding is tight. The binding sites between the ligand and the receptor are shown in Table 6. The most important binding sites are GLU-301 and THR-149.

[0109] Table 5 Binding affinity scores of 34 umami peptides screened by the predictor and docked with umami receptor molecules

[0110]

[0111]

[0112] Table 6 Analysis of five umami oligopeptides and receptor binding sites

[0113]

[0114] 4 Synthesis and verification of umami oligopeptides

[0115] Method: The present invention commissioned a biological company to synthesize the 5 umami oligopeptides identified in Example 2 by solid phase synthesis, and conducted sensory evaluation on their taste indicators such as freshness value. The synthesized peptide samples were prepared into a 1 mg / mL aqueous solution for standby use; citric acid, sucrose, tannin, sodium chloride and sodium glutamate were used as standard samples, corresponding to the five tastes of sour, sweet, bitter, salty and umami, respectively. The samples were evaluated using a 10-point intensity scale, where 1 point means no taste and 10 points means strong taste.

[0116] Results: Sensory evaluation radar chart Fig. 9 As shown, the freshness values ​​are ranked from high to low as follows: DFLDDGPG, NSPGDSFP, PDAILP, SDTGNFGF, and FGSLGNP.

[0117] In summary, the present invention provides a method for preparing umami sea cucumber oligopeptides, wherein the protected umami oligopeptide amino acid sequence is NSPGDSFP, DFLDDGPG, SDTGNFGF, FGSLGNP, and PDAILP, and the oligopeptides are prepared by enzymatic hydrolysis, the method comprising: soaking and thawing frozen sea cucumber intestines and eggs in water, rinsing and desalting, draining and crushing, and then putting them into an enzymatic hydrolysis tank, adding water and heating to maintain the temperature of the feed liquid at 50-55°C, adding a 1.6:1-2.5:1 composite enzyme, maintaining the temperature for 15-20 hours, and killing the enzyme. , collect the supernatant after centrifugation; mix 1-2% chitosan solution with 6-8% of the supernatant volume to remove lipids, and centrifuge again to collect the supernatant; concentrate and dry the supernatant to make sea cucumber oligopeptide powder; use LC-MS / MS liquid phase mass spectrometry to determine the molecular weight and sequence of the sea cucumber oligopeptide powder peptide segment, and then use the umami learning predictor and T1R1 / T1R3 receptor molecular docking model to screen umami peptides, obtain 5 umami oligopeptides and their amino acid sequences, and obtain 5 umami oligopeptides by means of solid phase synthesis and evaluate their freshness values. The outstanding feature of the present invention is to use dual enzymes to cooperate to obtain umami oligopeptide products with a molecular weight of less than 1000Da, and identify 5 peptide amino acid sequences that mainly contribute to umami, which is a new direction for the high-value utilization of sea cucumber by-products.

[0118] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For ordinary technical users in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to list all the implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for preparing sea cucumber peptide powder, characterized in that: The following steps are involved: (1) After the sea cucumber viscera are crushed, water, flavor protease and aminopeptidase are added for enzymolysis, and after the enzymolysis is completed, the enzyme is inactivated, and the supernatant is collected by centrifugation; (2) adding chitosan-acetic acid solution, stirring and mixing, and centrifuging again to collect the supernatant; (3) Rotary evaporation and drying to obtain the sea cucumber peptide powder.

2. The preparation method according to claim 1, characterized in that: The mass ratio of the sea cucumber viscera to water is (10-13):

100.

3. The preparation method according to claim 1, characterized in that: The added amount of the flavor protease is 900-1100 U / g; the added amount of the aminopeptidase is 450-550 U / g; and the conditions for the enzymolysis are: temperature of 50-55° C. and time of 15-20 hours.

4. The preparation method according to claim 1, characterized in that: The mass concentration of the chitosan-acetic acid solution is 1%, and the added amount is 6%-10% (v:v).

5. The preparation method according to claim 1, characterized in that: The centrifugation condition is 15-20 min at 4000-5000 r / min; the re-centrifugation condition is 5-10 min at 4000-5000 r / min.

6. The sea cucumber peptide powder prepared by the preparation method according to any one of claims 1 to 5.

7. Umami oligopeptide derived from sea cucumber, characterized in that: The umami oligopeptides include NSPGDSFP, DFLDDGPG, SDTGNFGF, FGSLGNP and / or PDAILP.

8. Use of the sea cucumber peptide powder according to claim 6 or the umami oligopeptide according to claim 7 in the preparation of food flavoring.

9. A food flavoring agent for increasing umami taste, characterized in that: It comprises the sea cucumber peptide powder as described in claim 6 or the umami oligopeptide as described in claim 7.

10. A method for preparing sea cucumber peptide powder rich in free amino acids and flavor nucleotides GMP and IMP, characterized in that: Utilize the preparation method described in any one of claims 1 to 5.

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