Functional protein peptide product and preparation method thereof

Abstract

The invention provides a functional protein peptide product and a preparation method thereof, and belongs to the technical field of protein peptides. Comprising the following steps: S1, performing enzymolysis on loaches and prinsepia utilis royle, and precipitating a protein composition; s2, fermenting the filter residues with selenium-enriched saccharomycetes, and precipitating to obtain selenium-enriched protein; s3, performing enzymolysis on the yeast mud to obtain an enzymolysis product; s4, separating and purifying the enzymolysis product to obtain 2-10kDa antibacterial peptide; s5, chelating the antibacterial peptide with Zn / Cu ions; s6, malic acid / salicylic acid condensation chelating Zn / Cu antibacterial peptide is prepared; s7, the malic acid / salicylic acid condensation chelating Zn / Cu antibacterial peptide, the protein composition and the selenium-rich protein are evenly mixed to obtain a functional protein peptide product, the functional protein peptide product can promote growth and development of livestock, promote lactation, improve the nutritional value of meat, inhibit tumor, resist aging, resist oxidation, resist inflammation and antibacterial activity, reduce the pathogenic rate and improve the quality of the livestock. Meanwhile, the compound has a very strong inhibition effect on enteropathogenic bacteria and has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of protein peptides, and specifically relates to a functional protein peptide product and a preparation method thereof. Background Art

[0002] Protein components in feed raw materials are generally relatively rich and generally need to be degraded into peptides and amino acids by proteases for reuse; many probiotics, such as Bacillus spp. and Aspergillus niger or Aspergillus oryzae, etc., will secrete proteases to decompose and utilize protein components in the environment, thereby promoting the growth of the probiotic bacteria themselves. However, Saccharomyces cerevisiae or lactic acid bacteria secrete less proteases and have a low ability to degrade protein materials. Generally, peptone and other protein degradation metabolites need to be supplemented to grow well; acidic or neutral proteases are generally used in feed. Proteases are classified into endopeptidases and exopeptidases according to their action modes, and general microbial proteases are usually a mixture of endopeptidases and exopeptidases. Most feeding animals need to supplement proteases. For example, early-weaned piglets often need to add proteases to make up for the deficiency of digestive enzymes secreted in the body.

[0003] Antimicrobial peptides originally referred to a class of basic polypeptide substances with antibacterial activity induced in insects, with a molecular weight of about 2,000 - 7,000 and consisting of 20 - 60 amino acid residues. Most of these active polypeptides have characteristics such as strong basicity, thermal stability, and broad-spectrum antibacterial properties. Antimicrobial peptides inhibit the growth of pathogenic bacteria, and different antimicrobial peptides have different killing abilities against bacteria, fungi, protozoa, and viruses, etc.; antimicrobial peptides also have selective immune activation and regulatory functions. Summary of the Invention

[0004] The purpose of the present invention is to provide a functional protein peptide product and a preparation method thereof, which can promote the growth and development of livestock and poultry, promote lactation, improve the nutritional value of meat quality, inhibit tumors, resist aging, have antioxidant, anti-inflammatory and antibacterial activities, reduce the morbidity rate, and at the same time have a strong inhibitory effect on intestinal pathogenic bacteria, and have broad application prospects.

[0005] The technical solution of the present invention is realized as follows:

[0006] The present invention provides a preparation method of a functional protein peptide product, comprising the following steps:

[0007] S1. Enzymatic hydrolysis of loach and Prinsepia utilis Royle, and precipitation of a protein composition;

[0008] S2. Fermentation of the filter residue with selenium-enriched yeast, precipitation, and obtaining selenium-enriched protein;

[0009] S3. Enzymatic hydrolysis of the yeast mud to obtain an enzymatic hydrolysis product;

[0010] S4. Isolate and purify an antibacterial peptide with a molecular weight of 2 - 10 kDa from the enzymatic hydrolysate obtained in step S3;

[0011] S5. Chelate the antibacterial peptide prepared in step S4 with Zn / Cu ions;

[0012] S6. Prepare a malic acid / salicylic acid condensed chelated Zn / Cu antibacterial peptide;

[0013] S7. Mix the malic acid / salicylic acid condensed chelated Zn / Cu antibacterial peptide prepared in step S6 with the protein composition prepared in step S1 and the selenium - rich protein prepared in step S2 evenly to obtain a functional protein - peptide product.

[0014] As a further improvement of the present invention, it includes the following steps:

[0015] S1. Remove the internal organs of loaches, mince them to obtain minced meat, wash, dry, and pulverize Prinsepia utilis Royle fruits to obtain Prinsepia utilis Royle fruit powder. Mix the minced meat and Prinsepia utilis Royle fruit powder, add them to water, add a complex enzyme for enzymatic hydrolysis, filter, and keep the filter residue for use. Precipitate proteins by ammonium sulfate multi - stage precipitation to obtain a protein composition;

[0016] S2. Add the filter residue obtained in step S1 to water, add glucose, sucrose, and peptone, sterilize, inoculate with a selenium - rich yeast strain seed liquid, ferment, filter, wash the filter residue, concentrate, and collect the concentrated bacterial liquid. The filtrate is subjected to ammonium sulfate multi - stage precipitation to obtain selenium - rich protein;

[0017] S3. Add lysozyme and snail enzyme to the concentrated bacterial liquid obtained in step S2, carry out enzymatic hydrolysis, and inactivate the enzyme to obtain an enzymatic hydrolysate;

[0018] S4. Ultrafilter and collect the protein peptide with a molecular weight of 2 - 10 kDa from the enzymatic hydrolysate in step S3, and freeze - dry it to prepare an antibacterial peptide;

[0019] S5. Dissolve the antibacterial peptide prepared in step S4 in water, add zinc salt and copper salt, stir and react, dialyze, and freeze - dry to prepare an antibacterial peptide chelated with Zn / Cu ions;

[0020] S6. After activating malic acid and salicylic acid with N - hydroxysuccinimide and 1 - (3 - dimethylaminopropyl) - 3 - ethylcarbodiimide hydrochloride, add the antibacterial peptide chelated with Zn / Cu ions prepared in step S5, heat and stir to react, and dialyze to prepare a malic acid / salicylic acid condensed chelated Zn / Cu antibacterial peptide;

[0021] S7. Mix the malic acid / salicylic acid condensed chelated Zn / Cu antibacterial peptide prepared in step S6 with the protein composition prepared in step S1 and the selenium - rich protein prepared in step S2 evenly to obtain a functional protein - peptide product.

[0022] As a further improvement of the present invention, the mass ratio of loach, Prinsepia utilis Royle fruit and the composite enzyme in step S1 is 10-15:4-7:1-2. The composite enzyme includes trypsin and cellulase, and the mass ratio is 12-15:3-5. The conditions for enzymatic hydrolysis are that the pH value is 8.5-9, the temperature is 40-45 °C, and the time is 1-3 h.

[0023] As a further improvement of the present invention, the mass ratio of the filter residue, water, glucose, sucrose, and peptone in step S2 is 15-20:200-400:7-10:3-5:6-8. The inoculation amount of the selenium-enriched yeast strain seed liquid is 2-4 v / v%. The bacteria content of the selenium-enriched yeast strain seed liquid is 10 8 -10 9 cfu / mL. The conditions for fermentation are 45-55 °C, 100-200 r / min, and fermentation culture for 48-56 h. The bacteria content of the concentrated bacterial liquid is 10 10 -10 11 cfu / mL.

[0024] As a further improvement of the present invention, the mass ratio of the concentrated bacterial liquid, lysozyme and snail enzyme in step S3 is 1000:1-2:2-3. The temperature for enzymatic hydrolysis is 45-55 °C, and the time is 2-4 h.

[0025] As a further improvement of the present invention, the mass ratio of the antimicrobial peptide, zinc salt and copper salt in step S5 is 100:3-5:2-4. The zinc salt is selected from at least one of zinc chloride, zinc sulfate, and zinc nitrate. The copper salt is selected from at least one of copper chloride, copper sulfate, and copper nitrate. The pore size of the dialysis bag used for dialysis is 1-2 kDa, and the dialysis time is 5-7 h.

[0026] As a further improvement of the present invention, the mass ratio of malic acid, salicylic acid, N-hydroxysuccinimide, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and the antimicrobial peptide chelating Zn / Cu ions in step S6 is 6-7:12-14:25-27:42-47:15-20. The activation conditions are 0-4 °C, and the activation reaction is 30-50 min. The temperature for the heating and stirring reaction is 30-35 °C, and the time is 10-15 h. The pore size of the dialysis bag used for dialysis is 1-2 kDa, and the dialysis time is 3-5 h; in step S7, the mass ratio of the malic acid / salicylic acid condensed chelating Zn / Cu antimicrobial peptide, protein composition, and selenium-enriched protein is 15-20:12-15:7-10.

[0027] As a further improvement of the present invention, it specifically includes the following steps:

[0028] S1. Remove the internal organs of 10 - 15 parts by weight of loaches, mince them to obtain minced meat. Wash 4 - 7 parts by weight of Prinsepia utilis Royle fruits, dry them, and powder them to obtain Prinsepia utilis Royle fruit powder. Mix the minced meat and Prinsepia utilis Royle fruit powder, add them to 200 parts by weight of water, add 1 - 2 parts by weight of a composite enzyme, with a pH value of 8.5 - 9 and a temperature of 40 - 45 °C, enzymatically hydrolyze for 1 - 3 h, filter, and retain the filter residue. Precipitate proteins by ammonium sulfate multi - stage precipitation to obtain a protein composition;

[0029] The composite enzyme includes trypsin and cellulase, and the mass ratio is 12 - 15:3 - 5;

[0030] S2. Add 15 - 20 parts by weight of the filter residue prepared in step S1 to 200 - 400 parts by weight of water, add 7 - 10 parts by weight of glucose, 3 - 5 parts by weight of sucrose, and 6 - 8 parts by weight of peptone, sterilize, inoculate with a selenium - rich yeast strain seed solution with a bacterial content of 10 8 -10 9 cfu / mL, with an inoculation amount of 2 - 4 v / v%, at 45 - 55 °C, 100 - 200 r / min, ferment and culture for 48 - 56 h, filter, wash the filter residue, concentrate, and collect a concentrated bacterial solution with a bacterial content of 10 10 -10 11 cfu / mL. The filtrate is subjected to ammonium sulfate multi - stage precipitation to obtain selenium - rich protein;

[0031] S3. Add 1 - 2 parts by weight of lysozyme and 2 - 3 parts by weight of snail enzyme to 1000 parts by weight of the concentrated bacterial solution prepared in step S2, enzymatically hydrolyze at 45 - 55 °C for 2 - 4 h, and inactivate the enzyme to obtain an enzymatic hydrolysis product;

[0032] S4. Ultrafilter the enzymatic hydrolysis product in step S3 to collect protein peptides with a molecular weight of 2 - 10 kDa, and freeze - dry to prepare an antibacterial peptide;

[0033] S5. Dissolve 100 parts by weight of the antibacterial peptide prepared in step S4 in 1000 parts by weight of water, add 3 - 5 parts by weight of zinc salt and 2 - 4 parts by weight of copper salt, stir and react for 20 - 30 min, use a dialysis bag with a pore size of 1 - 2 kDa for dialysis for 5 - 7 h, and freeze - dry to prepare an antibacterial peptide chelated with Zn / Cu ions;

[0034] S6. Add 6 - 7 parts by weight of malic acid and 12 - 14 parts by weight of salicylic acid to 500 parts by weight of water. Then add 25 - 27 parts by weight of N - hydroxysuccinimide and 42 - 47 parts by weight of 1 - (3 - dimethylaminopropyl) - 3 - ethylcarbodiimide hydrochloride. Stir and activate at 0 - 4 °C for 30 - 50 min. Add 15 - 20 parts by weight of the antibacterial peptide chelating Zn / Cu ions prepared in step S5, heat to 30 - 35 °C, and stir and react for 10 - 15 h. Dialyze for 3 - 5 h using a dialysis bag with a pore size of 1 - 2 kDa to obtain the malic acid / salicylic acid - condensed chelated Zn / Cu antibacterial peptide;

[0035] S7. Mix 15 - 20 parts by weight of the malic acid / salicylic acid - condensed chelated Zn / Cu antibacterial peptide prepared in step S6, 12 - 15 parts by weight of the protein composition prepared in step S1, and 7 - 10 parts by weight of the selenium - rich protein prepared in step S2 evenly to obtain the functional protein - peptide product.

[0036] The present invention further protects a functional protein - peptide product prepared by the above - mentioned preparation method.

[0037] The present invention further protects the application of the above - mentioned functional protein - peptide product in the preparation of products for improving animal immunity, increasing poultry meat production rate, and reducing poultry disease incidence.

[0038] The present invention has the following beneficial effects:

[0039] Loach and Prinsepia utilis Royle contain rich proteins, vitamins, and trace elements. In the protein - peptide composition obtained after enzymatic hydrolysis, there are not only rich protein - peptides, but also the protein - peptides chelate trace metal elements, having good physiological regulatory functions, including improving immunity, promoting growth and development, reducing disease incidence, promoting lactation, and other effects.

[0040] After enzymatic hydrolysis, macromolecular proteins are degraded into small - molecular protein compositions. The filter residue is further fermented by selenium - rich yeast to obtain selenium - rich proteins, which have good anti - tumor effects, improve the immunity of livestock and poultry, reduce blood sugar and blood lipids, improve the appetite of livestock and poultry, improve palatability, thus promoting their growth and increasing the meat production rate.

[0041] The present invention further enzymatically lyses and breaks the cell walls of selenium-rich yeast. Under the synergistic action of lysozyme and snail enzyme, a large amount of protein peptides in the yeast are dissolved out. Protein peptides with a molecular weight of 2 - 10 kDa are further collected, mainly antibacterial peptides. Antibacterial peptides can cause the death of bacteria by destroying the bacterial membrane structure. After chelating Zn and Cu ions, the antibacterial performance of the antibacterial peptides is improved, and the immunity of livestock and poultry is also enhanced, reducing the morbidity rate. At the same time, the absorption rate of trace elements Zn and Cu by livestock and poultry is increased. Chelating Zn and Cu ions with protein peptides helps the intestinal cell wall to absorb antibacterial peptides and also increases the absorption rate of Zn and Cu, thus better exerting the physiological activity of trace elements, promoting the growth and development of livestock and poultry, inhibiting tumors, anti-aging, increasing antioxidant activity, and at the same time having a strong inhibitory effect on intestinal pathogenic bacteria.

[0042] The antibacterial peptides chelating Zn / Cu ions prepared by the present invention are further condensed with malic acid and salicylic acid to form a condensate, greatly improving the heat resistance and storage stability of the protein peptides, avoiding the irritation and damage of malic acid and salicylic acid to the gastrointestinal tract, reducing their sensitization performance, further enhancing the antioxidant, anti-inflammatory and antibacterial activities of the prepared malic acid / salicylic acid condensed chelating Zn / Cu antibacterial peptides, reducing the morbidity rate, and having a good anti-tumor effect.

[0043] The functional protein peptide product prepared by the present invention has good application value, promoting the growth and development of livestock and poultry, promoting lactation, improving the nutritional value of meat quality, inhibiting tumors, anti-aging, having antioxidant, anti-inflammatory and antibacterial activities, reducing the morbidity rate, and at the same time having a strong inhibitory effect on intestinal pathogenic bacteria, with broad application prospects. Detailed implementation methods

[0044] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0045] Trypsin, 200,000 U / g, cellulase, 50,000 U / g, lysozyme, 2,000,000 U / g, purchased from Cangzhou Xiasheng Enzyme Biotechnology Co., Ltd.; snail enzyme, with a cell wall breaking rate of 98%, purchased from Shaanxi Zhenghe Pharmaceutical Biotechnology Co., Ltd.

[0046] Selenium-rich yeast, 10 billion cfu / g, purchased from Angel Yeast Co., Ltd.

[0047] Preparation method of the selenium-rich yeast strain seed solution: Inoculate the selenium-rich yeast into the Gao's medium, culture at 55 °C and 100 r / min for 24 h to obtain a bacterial content of 10 8 -109 Selenium-enriched yeast strain seed solution with cfu / mL.

[0048] Example 1

[0049] This example provides a method for preparing a functional protein peptide product, which specifically includes the following steps:

[0050] S1. Remove the internal organs of 10 parts by weight of loach, mince it to obtain minced meat, wash 4 parts by weight of Prinsepia utilis Royle, dry it, and pulverize it to obtain Prinsepia utilis Royle powder. Mix the minced meat and Prinsepia utilis Royle powder, add 200 parts by weight of water, add 1 part by weight of a composite enzyme, with a pH value of 8.5 and a temperature of 40 °C, enzymatically hydrolyze for 1 h, filter, and keep the filter residue for use. Precipitate the protein by ammonium sulfate multi-stage precipitation to obtain a protein composition;

[0051] The composite enzyme includes trypsin and cellulase, with a mass ratio of 12:3;

[0052] S2. Add 15 parts by weight of the filter residue obtained in step S1 to 200 parts by weight of water, add 7 parts by weight of glucose, 3 parts by weight of sucrose, and 6 parts by weight of peptone, sterilize, inoculate with a selenium-enriched yeast strain seed solution with a bacterial content of 10 8 -10 9 cfu / mL, with an inoculation amount of 2 v / v%, at 45 °C, 100 r / min, ferment and culture for 48 h, filter, wash the filter residue, concentrate, and collect a concentrated bacterial solution with a bacterial content of 10 10 -10 11 cfu / mL, and subject the filtrate to ammonium sulfate multi-stage precipitation to obtain selenium-enriched protein;

[0053] S3. Add 1 part by weight of lysozyme and 2 parts by weight of snail enzyme to 1000 parts by weight of the concentrated bacterial solution obtained in step S2, enzymatically hydrolyze at 45 °C for 2 h, and inactivate the enzyme to obtain an enzymatic hydrolysis product;

[0054] S4. Ultrafilter and collect the enzymatic hydrolysis product in step S3 to obtain protein peptides with a molecular weight of 2 - 10 kDa, and freeze-dry to prepare antibacterial peptides;

[0055] S5. Dissolve 100 parts by weight of the antibacterial peptides obtained in step S4 in 1000 parts by weight of water, add 3 parts by weight of zinc chloride and 2 parts by weight of copper chloride, stir and react for 20 min, use a dialysis bag with a pore size of 1 kDa for dialysis for 5 h, and freeze-dry to prepare antibacterial peptides chelated with Zn / Cu ions;

[0056] S6. Add 6 parts by weight of malic acid and 12 parts by weight of salicylic acid to 500 parts by weight of water. Add 25 parts by weight of N-hydroxysuccinimide and 42 parts by weight of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride. Stir and activate at 0 °C for 30 min. Add 15 parts by weight of the antibacterial peptide chelating Zn / Cu ions prepared in step S5. Heat to 30 °C and stir and react for 10 h. Dialyze for 3 h using a dialysis bag with a pore size of 1 kDa to obtain the malic acid / salicylic acid condensed chelating Zn / Cu antibacterial peptide;

[0057] S7. Stir and mix 15 parts by weight of the malic acid / salicylic acid condensed chelating Zn / Cu antibacterial peptide prepared in step S6, 12 parts by weight of the protein composition prepared in step S1, and 7 parts by weight of the selenium-rich protein prepared in step S2 for 30 min to obtain the functional protein peptide product.

[0058] Example 2

[0059] This example provides a preparation method of a functional protein peptide product, which specifically includes the following steps:

[0060] S1. Remove the internal organs of 15 parts by weight of loach, crush it to obtain minced meat. Wash 7 parts by weight of Prinsepia utilis Royle, dry it, and pulverize it to obtain Prinsepia utilis Royle powder. Mix the minced meat and Prinsepia utilis Royle powder and add them to 200 parts by weight of water. Add 2 parts by weight of a composite enzyme, with a pH value of 9 and a temperature of 45 °C, and enzymatically hydrolyze for 3 h. Filter, and keep the filter residue for use. Precipitate the protein by ammonium sulfate multiple precipitation to obtain a protein composition;

[0061] The composite enzyme includes trypsin and cellulase, and the mass ratio is 15:5;

[0062] S2. Add 20 parts by weight of the filter residue prepared in step S1 to 400 parts by weight of water. Add 10 parts by weight of glucose, 5 parts by weight of sucrose, and 8 parts by weight of peptone. Sterilize, inoculate with a selenium-rich yeast strain seed liquid with a bacterial content of 10 8 -10 9 cfu / mL, with an inoculation amount of 4 v / v%, at 55 °C and 200 r / min, ferment and culture for 56 h. Filter, wash the filter residue, concentrate, and collect a concentrated bacterial liquid with a bacterial content of 10 10 -10 11 cfu / mL. The filtrate is subjected to ammonium sulfate multiple precipitation to obtain selenium-rich protein;

[0063] S3. Add 2 parts by weight of lysozyme and 3 parts by weight of snail enzyme to 1000 parts by weight of the concentrated bacterial liquid prepared in step S2. Enzymatically hydrolyze at 55 °C for 4 h to inactivate the enzyme and obtain an enzymatic hydrolysis product;

[0064] S4. Ultrafilter and collect the protein peptides with a molecular weight of 2-10 kDa from the enzymatic hydrolysis product in step S3, and freeze-dry to obtain the antibacterial peptide;

[0065] S5. Dissolve 100 parts by weight of the antimicrobial peptide prepared in step S4 in 1000 parts by weight of water, add 5 parts by weight of zinc sulfate and 4 parts by weight of copper sulfate, stir and react for 30 min. Dialyze for 7 h using a dialysis bag with a pore size of 2 kDa, and then freeze-dry to obtain an antimicrobial peptide chelated with Zn / Cu ions.

[0066] S6. Add 7 parts by weight of malic acid and 14 parts by weight of salicylic acid to 500 parts by weight of water, add 27 parts by weight of N-hydroxysuccinimide and 47 parts by weight of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, stir and activate at 4°C for 50 min. Then add 20 parts by weight of the antimicrobial peptide chelated with Zn / Cu ions prepared in step S5, heat to 35°C, and stir and react for 15 h. Dialyze for 5 h using a dialysis bag with a pore size of 2 kDa to obtain a malic acid / salicylic acid condensed antimicrobial peptide chelated with Zn / Cu.

[0067] S7. Stir and mix 20 parts by weight of the malic acid / salicylic acid condensed antimicrobial peptide chelated with Zn / Cu prepared in step S6, 15 parts by weight of the protein composition prepared in step S1, and 10 parts by weight of the selenium-enriched protein prepared in step S2 for 30 min to obtain a functional protein peptide product.

[0068] Example 3

[0069] This example provides a preparation method of a functional protein peptide product, which specifically includes the following steps:

[0070] S1. Remove the internal organs of 12 parts by weight of loaches, mince them to obtain minced meat. Wash 5.5 parts by weight of Prinsepia utilis Royle fruits, dry them, and pulverize them to obtain Prinsepia utilis Royle fruit powder. Mix the minced meat and Prinsepia utilis Royle fruit powder and add them to 200 parts by weight of water. Add 1.5 parts by weight of a complex enzyme, with a pH value of 8.7 and a temperature of 42°C, and enzymatically hydrolyze for 2 h. Filter, and keep the filter residue for use. Precipitate proteins by ammonium sulfate multi-stage precipitation to obtain a protein composition.

[0071] The complex enzyme includes trypsin and cellulase, and the mass ratio is 13:4.

[0072] S2. Add 17 parts by weight of the filter residue prepared in step S1 to 300 parts by weight of water, add 8.5 parts by weight of glucose, 4 parts by weight of sucrose, and 7 parts by weight of peptone, sterilize, inoculate with a selenium-enriched yeast strain seed solution with a bacterial content of 10 8 -10 9 cfu / mL, with an inoculation amount of 3 v / v%, at 50°C, 150 r / min, ferment and culture for 52 h, filter, wash the filter residue, concentrate, and collect a concentrated bacterial solution with a bacterial content of 10 10 -10 11 cfu / mL. The filtrate is subjected to ammonium sulfate multi-stage precipitation to obtain selenium-enriched protein.

[0073] S3. Add 1.5 parts by weight of lysozyme and 2.5 parts by weight of snailase to 1000 parts by weight of the concentrated bacterial solution prepared in step S2, enzymatically hydrolyze at 50 °C for 3 h, inactivate the enzyme, and obtain an enzymolysis product;

[0074] S4. Ultrafilter and collect the enzymolysis product in step S3 to obtain protein peptides with a molecular weight of 2 - 10 kDa, and freeze-dry to prepare antibacterial peptides;

[0075] S5. Dissolve 100 parts by weight of the antibacterial peptides prepared in step S4 in 1000 parts by weight of water, add 4 parts by weight of zinc nitrate and 3 parts by weight of copper nitrate, stir and react for 25 min. Use a dialysis bag with a pore size of 1.5 kDa for dialysis for 6 h, and freeze-dry to prepare antibacterial peptides chelated with Zn / Cu ions;

[0076] S6. Add 6.5 parts by weight of malic acid and 13 parts by weight of salicylic acid to 500 parts by weight of water, add 26 parts by weight of N-hydroxysuccinimide and 45 parts by weight of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, stir and activate at 2 °C for 40 min, add 17 parts by weight of the antibacterial peptides chelated with Zn / Cu ions prepared in step S5, heat to 32 °C, stir and react for 12 h. Use a dialysis bag with a pore size of 1.5 kDa for dialysis for 4 h to prepare malic acid / salicylic acid condensed chelated Zn / Cu antibacterial peptides;

[0077] S7. Stir and mix 17 parts by weight of the malic acid / salicylic acid condensed chelated Zn / Cu antibacterial peptides prepared in step S6, 13.5 parts by weight of the protein composition prepared in step S1, and 8.5 parts by weight of the selenium-rich protein prepared in step S2 for 30 min to obtain a functional protein peptide product.

[0078] Example 4

[0079] Compared with Example 3, the difference is that the complex enzyme is a single trypsin.

[0080] Example 5

[0081] Compared with Example 3, the difference is that the complex enzyme is a single cellulase.

[0082] Comparative Example 1

[0083] Compared with Example 3, the difference is that no complex enzyme was added in step S1.

[0084] Specifically as follows:

[0085] S1. Remove the internal organs of 12 parts by weight of loach, crush it to obtain minced meat, wash 5.5 parts by weight of Prinsepia utilis Royle, dry it, and pulverize it to obtain Prinsepia utilis Royle powder. Mix the minced meat and Prinsepia utilis Royle powder, add them to 200 parts by weight of water, filter, and keep the filter residue for use. Precipitate proteins by ammonium sulfate multi-stage precipitation to obtain a protein composition.

[0086] Comparative Example 2

[0087] Compared with Example 3, the difference is that step S2 is not carried out.

[0088] Specifically as follows:

[0089] S1. Remove the internal organs of 12 parts by weight of loach, crush it to obtain minced meat, wash 5.5 parts by weight of Prinsepia utilis Royle, dry it, and pulverize it to obtain Prinsepia utilis Royle powder. Mix the minced meat and Prinsepia utilis Royle powder, add them to 200 parts by weight of water, add 1.5 parts by weight of a composite enzyme, with a pH value of 8.7 and a temperature of 42 °C, enzymatically hydrolyze for 2 h, filter, and keep the filter residue for use. Precipitate proteins by ammonium sulfate multi-stage precipitation to obtain a protein composition;

[0090] The composite enzyme includes trypsin and cellulase, with a mass ratio of 13:4;

[0091] S2. Add 1.5 parts by weight of lysozyme and 2.5 parts by weight of snail enzyme to 1000 parts by weight of a concentrated bacterial solution containing Se-enriched yeast with a bacterial count of 10 10 -10 11 cfu / mL, enzymatically hydrolyze at 50 °C for 3 h, inactivate the enzyme, and obtain an enzymolysis product;

[0092] S3. Ultrafilter and collect the enzymolysis product in step S2 to obtain protein peptides with a molecular weight of 2 - 10 kDa, and freeze-dry to prepare an antibacterial peptide;

[0093] S4. Dissolve 100 parts by weight of the antibacterial peptide prepared in step S3 in 1000 parts by weight of water, add 4 parts by weight of zinc nitrate and 3 parts by weight of copper nitrate, stir and react for 25 min, use a dialysis bag with a pore size of 1.5 kDa for dialysis for 6 h, and freeze-dry to prepare an antibacterial peptide chelated with Zn / Cu ions;

[0094] S5. Add 6.5 parts by weight of malic acid and 13 parts by weight of salicylic acid to 500 parts by weight of water, add 26 parts by weight of N-hydroxysuccinimide and 45 parts by weight of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, stir and activate at 2 °C for 40 min, add 17 parts by weight of the antibacterial peptide chelated with Zn / Cu ions prepared in step S4, heat to 32 °C, stir and react for 12 h, use a dialysis bag with a pore size of 1.5 kDa for dialysis for 4 h, and prepare a malic acid / salicylic acid condensation chelated Zn / Cu antibacterial peptide;

[0095] S6. Mix 17 parts by weight of the malic acid / salicylic acid condensed chelated Zn / Cu antibacterial peptide prepared in step S5, 13.5 parts by weight of the protein composition prepared in step S1, and 8.5 parts by weight of the selenium-enriched protein prepared in step S2 and stir and mix them for 30 min to obtain a functional protein peptide product.

[0096] Comparative Example 3

[0097] Compared with Example 3, the difference lies in that lysozyme was not added in step S3.

[0098] Specifically as follows:

[0099] S3. Add 4 parts by weight of snailase to 1000 parts by weight of the concentrated bacterial solution prepared in step S2, enzymatically hydrolyze at 50 °C for 3 h, and inactivate the enzyme to obtain an enzymolysis product.

[0100] Comparative Example 4

[0101] Compared with Example 3, the difference lies in that snailase was not added in step S3.

[0102] Specifically as follows:

[0103] S3. Add 4 parts by weight of lysozyme to 1000 parts by weight of the concentrated bacterial solution prepared in step S2, enzymatically hydrolyze at 50 °C for 3 h, and inactivate the enzyme to obtain an enzymolysis product.

[0104] Comparative Example 5

[0105] Compared with Example 3, the difference lies in that step S5 was not carried out.

[0106] Specifically as follows:

[0107] S1. Remove the internal organs of 12 parts by weight of loaches, crush them to obtain minced meat, wash 5.5 parts by weight of pricklyash fruits, dry them, and powder them to obtain pricklyash fruit powder. Mix the minced meat and pricklyash fruit powder, add 200 parts by weight of water, add 1.5 parts by weight of a composite enzyme, with a pH value of 8.7 and a temperature of 42 °C, enzymatically hydrolyze for 2 h, filter, and keep the filter residue for use. Precipitate the protein by ammonium sulfate multiple precipitation to obtain a protein composition;

[0108] The composite enzyme includes trypsin and cellulase, and the mass ratio is 13:4;

[0109] S2. Add 17 parts by weight of the filter residue prepared in step S1 to 300 parts by weight of water, add 8.5 parts by weight of glucose, 4 parts by weight of sucrose, and 7 parts by weight of peptone, sterilize, inoculate with a selenium-enriched yeast strain seed solution with a bacterial content of 10 8 -10 9 cfu / mL, the inoculation amount is 3 v / v%, 50 °C, 150 r / min, ferment and culture for 52 h, filter, wash the filter residue, concentrate, and collect to obtain a bacterial content of 1010 -10 11 a concentrated bacterial solution of cfu / mL, and the filtrate is subjected to ammonium sulfate multi-stage precipitation to obtain selenium-rich protein;

[0110] S3. Add 1.5 parts by weight of lysozyme and 2.5 parts by weight of snail enzyme to 1000 parts by weight of the concentrated bacterial solution prepared in step S2, enzymatically hydrolyze at 50 °C for 3 h, inactivate the enzyme, and obtain an enzymatic hydrolysis product;

[0111] S4. Ultrafilter and collect the enzymatic hydrolysis product in step S3 to obtain protein peptides with a molecular weight of 2-10 kDa, and freeze-dry to prepare antibacterial peptides;

[0112] S5. Add 6.5 parts by weight of malic acid and 13 parts by weight of salicylic acid to 500 parts by weight of water, add 26 parts by weight of N-hydroxysuccinimide and 45 parts by weight of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, stir and activate at 2 °C for 40 min, add 17 parts by weight of the antibacterial peptide prepared in step S4, heat to 32 °C, stir and react for 12 h, and dialyze with a dialysis bag with a pore size of 1.5 kDa for 4 h to prepare a malic acid / salicylic acid condensation chelated antibacterial peptide;

[0113] S6. Stir and mix 17 parts by weight of the malic acid / salicylic acid condensation chelated antibacterial peptide prepared in step S6, 13.5 parts by weight of the protein composition prepared in step S1, and 8.5 parts by weight of the selenium-rich protein prepared in step S2 for 30 min to obtain a functional protein peptide product.

[0114] Comparative Example 6

[0115] Compared with Example 3, the difference is that malic acid is not added in step S6.

[0116] Specifically as follows:

[0117] S6. Add 19.5 parts by weight of salicylic acid to 500 parts by weight of water, add 26 parts by weight of N-hydroxysuccinimide and 45 parts by weight of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, stir and activate at 2 °C for 40 min, add 17 parts by weight of the antibacterial peptide chelated with Zn / Cu ions prepared in step S5, heat to 32 °C, stir and react for 12 h, and dialyze with a dialysis bag with a pore size of 1.5 kDa for 4 h to prepare a salicylic acid condensation chelated Zn / Cu antibacterial peptide.

[0118] Comparative Example 7

[0119] Compared with Example 3, the difference is that salicylic acid is not added in step S6.

[0120] Specifically as follows:

[0121] S6. Add 19.5 parts by weight of malic acid to 500 parts by weight of water, add 26 parts by weight of N-hydroxysuccinimide and 45 parts by weight of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, stir and activate at 2 °C for 40 min, add 17 parts by weight of the antibacterial peptide chelating Zn / Cu ions prepared in step S5, heat to 32 °C, stir and react for 12 h, and dialyze for 4 h using a dialysis bag with a pore size of 1.5 kDa to obtain a malic acid-condensed chelating Zn / Cu antibacterial peptide.

[0122] Comparative Example 8

[0123] Compared with Example 3, the difference lies in that step S6 was not carried out.

[0124] Specifically as follows:

[0125] S1. Remove the internal organs of 12 parts by weight of loach, crush it to obtain minced meat, wash 5.5 parts by weight of Prinsepia utilis Royle, dry it, and pulverize it to obtain Prinsepia utilis Royle powder. Mix the minced meat and Prinsepia utilis Royle powder and add them to 200 parts by weight of water, add 1.5 parts by weight of a composite enzyme, with a pH value of 8.7 and a temperature of 42 °C, enzymatically hydrolyze for 2 h, filter, and keep the filter residue for use. Precipitate the protein by ammonium sulfate multi-stage precipitation to obtain a protein composition;

[0126] The composite enzyme includes trypsin and cellulase, and the mass ratio is 13:4;

[0127] S2. Add 17 parts by weight of the filter residue prepared in step S1 to 300 parts by weight of water, add 8.5 parts by weight of glucose, 4 parts by weight of sucrose, and 7 parts by weight of peptone, sterilize, inoculate with a selenium-rich yeast strain seed solution with a bacterial content of 10 8 -10 9 cfu / mL, with an inoculation amount of 3 v / v%, at 50 °C and 150 r / min, ferment and culture for 52 h, filter, wash the filter residue, concentrate, and collect a concentrated bacterial solution with a bacterial content of 10 10 -10 11 cfu / mL. The filtrate is subjected to ammonium sulfate multi-stage precipitation to obtain selenium-rich protein;

[0128] S3. Add 1.5 parts by weight of lysozyme and 2.5 parts by weight of snail enzyme to 1000 parts by weight of the concentrated bacterial solution prepared in step S2, enzymatically hydrolyze at 50 °C for 3 h, and inactivate the enzyme to obtain an enzymatic hydrolysis product;

[0129] S4. Ultrafilter and collect the enzymatic hydrolysis product in step S3 to obtain a protein peptide with a molecular weight of 2-10 kDa, and freeze-dry it to obtain an antibacterial peptide;

[0130] S5. Dissolve 100 parts by weight of the antibacterial peptide prepared in step S4 in 1000 parts by weight of water, add 4 parts by weight of zinc nitrate and 3 parts by weight of copper nitrate, stir and react for 25 min. Dialyze for 6 h using a dialysis bag with a pore size of 1.5 kDa, and then freeze-dry to obtain an antibacterial peptide chelated with Zn / Cu ions.

[0131] S6. Stir and mix 17 parts by weight of the antibacterial peptide chelated with Zn / Cu ions prepared in step S5, 13.5 parts by weight of the protein composition prepared in step S1, and 8.5 parts by weight of the selenium-rich protein prepared in step S2 for 30 min to obtain a functional protein peptide product.

[0132] Comparative Example 9

[0133] Compared with Example 3, the difference lies in that malic acid / salicylic acid condensed chelated Zn / Cu antibacterial peptide was not added in step S7.

[0134] Specifically as follows:

[0135] S7. Stir and mix 13.5 parts by weight of the protein composition prepared in step S1 and 8.5 parts by weight of the selenium-rich protein prepared in step S2 for 30 min to obtain a functional protein peptide product.

[0136] Comparative Example 10

[0137] Compared with Example 3, the difference lies in that selenium-rich protein was not added in step S7.

[0138] Specifically as follows:

[0139] S7. Stir and mix 17 parts by weight of the malic acid / salicylic acid condensed chelated Zn / Cu antibacterial peptide prepared in step S6 and 13.5 parts by weight of the protein composition prepared in step S1 for 30 min to obtain a functional protein peptide product.

[0140] Test Example 1

[0141] Select 160 Holstein cows in mid-lactation. According to the principle of similar milk yield, body weight, parity [(1.49 ± 0.92) parity] and lactation time, divide them into 16 groups, namely the control group and the groups of Examples 1 - 5 and Comparative Examples 1 - 10, with 10 cows in each group. The control group is fed a basal diet, and the test groups are supplemented with 21 g / head / d of the corresponding functional protein peptide product on the basis of the basal diet. The test period is 25 d, including a 10-day pre-feeding period and a 15-day formal period. Feed 3 times a day. For the test groups, 7 g, 7 g, and 7 g of the functional protein peptide product are mixed with 100 g of concentrate before feeding in the morning, noon, and evening respectively, and then fed to ensure complete intake. During the test, the test basal diet is the conventional mid-lactation diet of dairy cows in the dairy farm. The management of dairy cows refers to the conventional feeding and management of the dairy farm.

[0142] Measurement of milk yield and milk quality:

[0143] Automated milking machines were collected on the 0th, 7th, and 15th days of the formal period respectively, and the milk yields of dairy cows in each group were recorded. Meanwhile, on the 15th day of the formal period, milk samples from the experimental dairy cows were collected in 3 batches continuously: 20 mL in the morning, 15 mL at noon, and 15 mL in the evening. After being fully mixed, they were stored refrigerated for the determination of milk fat rate, milk protein, lactose, and selenium content.

[0144] The results are shown in Table 1 and Table 2.

[0145] Table 1 Effects on milk yield of dairy cows

[0146] Group Day 0 Day 7 Day 15 Control Group 30.23 29.92 27.10 Example 1 30.31 32.13 31.59 Example 2 30.28 32.59 32.01 Example 3 30.15 32.84 32.46 Example 4 30.22 31.98 31.42 Example 5 30.28 31.87 31.36 Comparative Example 1 30.32 31.65 31.24 Comparative Example 2 30.19 31.78 31.30 Comparative Example 3 30.25 31.39 30.89 Comparative Example 4 30.23 31.24 30.76 Comparative Example 5 30.20 31.21 31.04 Comparative Example 6 30.35 31.88 31.35 Comparative Example 7 30.21 31.92 31.42 Comparative Example 8 30.16 31.56 31.18 Comparative Example 9 30.24 31.02 30.45 Comparative Example 10 30.30 31.71 31.28

[0147] Table 2 Effects on milk components of dairy cows

[0148]

[0149]

[0150] As can be seen from the above table, the functional protein peptide products prepared in Examples 1-3 of the present invention can significantly increase the milk yield of dairy cows and improve the quality of milk.

[0151] Determination of serum biochemical indexes:

[0152] At 8:00 am on the day after the end of the experiment, 10 mL of blood samples of dairy cows during the experiment were collected by the method of collecting blood from the tail root, placed in heparin anticoagulant tubes, centrifuged to separate serum, stored refrigerated, and the total superoxide dismutase (T-SOD), alanine aminotransferase activity, and malondialdehyde (MDA) content in the serum were determined by ELISA kits. The results are shown in Table 3.

[0153] Table 3

[0154]

[0155]

[0156] As can be seen from the above table, the functional protein peptide products prepared in Examples 1-3 of the present invention can significantly increase the activity of total superoxide dismutase (T-SOD), reduce the activity of alanine aminotransferase, and reduce the content of malondialdehyde (MDA).

[0157] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A preparation method of a functional protein peptide product, characterized in that, It includes the following steps: S1. Enzymatic hydrolysis of loach and Prinsepia utilis Royle, and precipitation of protein composition; S2. Fermentation of filter residue with selenium-enriched yeast, precipitation, and obtaining selenium-enriched protein; S3. Enzymatic hydrolysis of yeast mud to obtain enzymatic hydrolysate; S4. Isolating and purifying antibacterial peptides with a molecular weight of 2 - 10 kDa from the enzymatic hydrolysate in step S3; S5. Chelating Zn / Cu ions with the antibacterial peptides prepared in step S4; S6. Preparing malic acid / salicylic acid condensation chelated Zn / Cu antibacterial peptides; S7. Mixing the malic acid / salicylic acid condensation chelated Zn / Cu antibacterial peptides prepared in step S6 evenly with the protein composition prepared in step S1 and the selenium-enriched protein prepared in step S2 to obtain a functional protein peptide product.

2. The preparation method according to claim 1, characterized in that, It includes the following steps: S1. Removing the internal organs of loach, mincing it to obtain minced meat, washing Prinsepia utilis Royle, drying it, and pulverizing it to obtain Prinsepia utilis Royle powder. Mixing the minced meat and Prinsepia utilis Royle powder and adding them to water, adding a composite enzyme for enzymatic hydrolysis, filtering, retaining the filter residue, and performing multi-stage ammonium sulfate precipitation of proteins to obtain a protein composition; S2. Adding the filter residue prepared in step S1 to water, adding glucose, sucrose, peptone, sterilizing, inoculating with a seed solution of selenium-enriched yeast strain, fermenting, filtering, washing the filter residue, concentrating, collecting the concentrated bacterial solution, and performing multi-stage ammonium sulfate precipitation on the filtrate to obtain selenium-enriched protein; S3. Adding lysozyme and snail enzyme to the concentrated bacterial solution prepared in step S2 for enzymatic hydrolysis and inactivating the enzyme to obtain an enzymatic hydrolysate; S4. Ultrafiltrating and collecting the protein peptides with a molecular weight of 2 - 10 kDa from the enzymatic hydrolysate in step S3, and freeze-drying to prepare antibacterial peptides; S5. Dissolving the antibacterial peptides prepared in step S4 in water, adding zinc salt and copper salt, stirring for reaction, dialyzing, and freeze-drying to prepare antibacterial peptides chelated with Zn / Cu ions; S6. After activating malic acid and salicylic acid with N-hydroxysuccinimide and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, adding the antibacterial peptides chelated with Zn / Cu ions prepared in step S5, heating and stirring for reaction, and dialyzing to prepare malic acid / salicylic acid condensation chelated Zn / Cu antibacterial peptides; S7. Mixing the malic acid / salicylic acid condensation chelated Zn / Cu antibacterial peptides prepared in step S6 evenly with the protein composition prepared in step S1 and the selenium-enriched protein prepared in step S2 to obtain a functional protein peptide product.

3. The preparation method according to claim 2, characterized in that, In step S1, the mass ratio of loach, Prinsepia utilis Royle, and the composite enzyme is 10 - 15:4 - 7:1 - 2. The composite enzyme includes trypsin and cellulase, and the mass ratio is 12 - 15:3 - 5. The conditions for enzymatic hydrolysis are a pH value of 8.5 - 9, a temperature of 40 - 45 °C, and a time of 1 - 3 h.

4. The preparation method according to claim 2, wherein In step S2, the mass ratio of the filter residue, water, glucose, sucrose, and peptone is 15-20:200-400:7-10:3-5:6-8. The inoculation amount of the selenium-enriched yeast strain seed liquid is 2-4 v / v%. The bacteria content of the selenium-enriched yeast strain seed liquid is 10 8 -10 9 cfu / mL. The fermentation conditions are 45-55 °C, 100-200 r / min, and fermentation culture for 48-56 h. The bacteria content of the concentrated bacterial liquid is 10 10 -10 11 cfu / mL.

5. The preparation method according to claim 2, wherein In step S3, the mass ratio of the concentrated bacterial solution, lysozyme, and snail enzyme is 1000:1 - 2:2 - 3. The temperature for enzymatic hydrolysis is 45 - 55 °C, and the time is 2 - 4 h.

6. The preparation method according to claim 2, characterized in that, In step S5, the mass ratio of the antimicrobial peptide, zinc salt and copper salt is 100:3 - 5:2 - 4. The zinc salt is selected from at least one of zinc chloride, zinc sulfate, and zinc nitrate. The copper salt is selected from at least one of copper chloride, copper sulfate, and copper nitrate. The dialysis bag used for dialysis has a pore size of 1 - 2 kDa, and the dialysis time is 5 - 7 h.

7. The preparation method according to claim 2, characterized in that, In step S6, the mass ratio of malic acid, salicylic acid, N-hydroxysuccinimide, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and the antimicrobial peptide chelating Zn / Cu ions is 6 - 7:12 - 14:25 - 27:42 - 47:15 - 20. The activation condition is 0 - 4 °C, and the activation reaction is carried out for 30 - 50 min. The temperature of the heating and stirring reaction is 30 - 35 °C, and the time is 10 - 15 h. The dialysis bag used for dialysis has a pore size of 1 - 2 kDa, and the dialysis time is 3 - 5 h. In step S7, the mass ratio of the malic acid / salicylic acid condensed chelating Zn / Cu antimicrobial peptide, protein composition, and selenium-rich protein is 15 - 20:12 - 15:7 - 10.

8. The preparation method according to claim 2, wherein Specifically, it includes the following steps: S1. Remove the internal organs of 10 - 15 parts by weight of loaches, crush them to obtain minced meat. Wash 4 - 7 parts by weight of pricklyash fruits, dry them, and powder them to obtain pricklyash fruit powder. Mix the minced meat and pricklyash fruit powder, add 200 parts by weight of water, add 1 - 2 parts by weight of a composite enzyme, with a pH value of 8.5 - 9 and a temperature of 40 - 45 °C, enzymatically hydrolyze for 1 - 3 h, filter, and keep the filter residue for use. Precipitate proteins by ammonium sulfate multi-stage precipitation to obtain a protein composition. The composite enzyme includes trypsin and cellulase, and the mass ratio is 12 - 15:3 - 5. S2. Add 15 - 20 parts by weight of the filter residue obtained in step S1 to 200 - 400 parts by weight of water, add 7 - 10 parts by weight of glucose, 3 - 5 parts by weight of sucrose, and 6 - 8 parts by weight of peptone, sterilize, inoculate with a selenium - rich yeast strain seed liquid with a bacterial content of 10 8 -10 9 cfu / mL, with an inoculation amount of 2 - 4 v / v%, at 45 - 55 °C, 100 - 200 r / min, ferment and culture for 48 - 56 h, filter, wash the filter residue, concentrate, and collect a concentrated bacterial liquid with a bacterial content of 10 10 -10 11 cfu / mL. The filtrate is subjected to multi - stage ammonium sulfate precipitation to obtain selenium - rich protein; S3. Add 1 - 2 parts by weight of lysozyme and 2 - 3 parts by weight of snail enzyme to 1000 parts by weight of the concentrated bacterial liquid prepared in step S2, enzymatically hydrolyze at 45 - 55 °C for 2 - 4 h, and inactivate the enzyme to obtain an enzymatic hydrolysis product. S4. Collect the protein peptides with a molecular weight of 2 - 10 kDa from the enzymatic hydrolysis product in step S3 by ultrafiltration, and freeze-dry to obtain an antimicrobial peptide. S5. Dissolve 100 parts by weight of the antimicrobial peptide prepared in step S4 in 1000 parts by weight of water, add 3 - 5 parts by weight of zinc salt and 2 - 4 parts by weight of copper salt, stir and react for 20 - 30 min, dialyze with a dialysis bag having a pore size of 1 - 2 kDa for 5 - 7 h, and freeze-dry to obtain an antimicrobial peptide chelating Zn / Cu ions. S6. Add 6 - 7 parts by weight of malic acid and 12 - 14 parts by weight of salicylic acid to 500 parts by weight of water, add 25 - 27 parts by weight of N-hydroxysuccinimide and 42 - 47 parts by weight of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, stir and activate at 0 - 4 °C for 30 - 50 min, add 15 - 20 parts by weight of the antimicrobial peptide chelating Zn / Cu ions prepared in step S5, heat to 30 - 35 °C, stir and react for 10 - 15 h, and dialyze with a dialysis bag having a pore size of 1 - 2 kDa for 3 - 5 h to obtain a malic acid / salicylic acid condensed chelating Zn / Cu antimicrobial peptide. S7. Mix 15 - 20 parts by weight of the malic acid / salicylic acid condensed chelated Zn / Cu antibacterial peptide prepared in step S6, 12 - 15 parts by weight of the protein composition prepared in step S1, and 7 - 10 parts by weight of the selenium - rich protein prepared in step S2 evenly to obtain a functional protein - peptide product.

9. A functional protein - peptide product prepared by the preparation method according to any one of claims 1 - 8.

10. Use of the functional protein - peptide product according to claim 9 in the preparation of products for improving animal immunity, increasing the meat production rate of poultry, and reducing the disease incidence rate of poultry.

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