Preparation method and application of enzymolysis protein peptide for promoting efficient absorption

Abstract

The invention discloses a preparation method and application of flavor-enhanced enzymolysis protein peptide, and belongs to the technical field of biology. The chicken by-product is subjected to enzymolysis through the compound enzyme, and the prepared enzymolysis product has good flavor and functionality. The prepared enzymolysis protein peptide is excellent in flavor, n-hexyl alcohol reaches 11.45 mu g / g FW or above, 1-octylene-3-alcohol reaches 18.29 mu g / g FW or above, E-2-octenal reaches 42.37 mu g / g FW or above, n-hexanal reaches 187.03 mu g / g FW or above, nonanal reaches 29.64 mu g / g FW or above, n-octanal reaches 14.73 mu g / g FW or above, and 2-amyl furan reaches 17.36 mu g / g FW or above; the stability of intestinal barriers of the mice can be maintained, digestion and absorption are promoted, liver and kidney tissue health is maintained, and support is provided for development of functional food.

Description

Technical Field

[0001] The invention relates to a preparation method of an enzymatic protein peptide for promoting efficient absorption and application thereof, belonging to the field of biotechnology. Background Art

[0002] The poultry industry inevitably produces a large amount of by-products, including heads, legs, bones, offal and feathers. These by-products are usually processed into animal feed, plant fertilizers and spices with low added value, and improper handling of these by-products may lead to harmful consequences, such as environmental pollution and potential risks to human health.

[0003] Many studies have explored enzyme treatment to increase the value of meat by-products and studied their potential biological activities, indicating that biotransformation methods can transform food by-products into various value-added products. The document "Study on the process of preparing easily digestible and absorbable peptides from enzymatic casein" promotes the body's digestion and absorption of nutrients and improves intestinal health. This technology only uses one enzyme for modification and has low efficiency; the document "Study on the optimization of enzymatic conditions for three-yellow chicken skeleton" respectively detects the enzymatic effects of neutral protease, flavor protease and papain. This technology only uses a single enzyme for enzymatic hydrolysis and explores less about the flavor of the product; the document "Study on the preparation of chicken bone peptides and their ACE inhibitory activity" discloses that alkaline protease is the optimal enzyme for enzymatic hydrolysis of chicken by-products, and chicken bone peptides with a higher ACE inhibition rate are prepared. This technology focuses more on the activity of the product and ignores the flavor of the product; Patent CN109055470A discloses the use of 0.3% neutral protease, 0.3% papain and 0.2% flavor protease to enzymatically hydrolyze chicken and chicken skeletons to obtain chicken protein peptides with strong antioxidant properties. It can be seen that the current processing of chicken by-products focuses more on functional development and ignores the flavor of the product itself.

[0004] Among the flavor substances produced by protein hydrolysis, aldehyde substances containing 6 to 10 carbon atoms include hexanal, octanal, nonanal, 2-octenal, etc., which make an important contribution to the formation of meat flavor. These aldehyde compounds have fat, butter and fragrance, and help to form the fat flavor in mature meat; 1-octen-3-ol, hexanol, etc. can present a pleasant mushroom aroma; 2-pentylfuran is an important heterocyclic compound in oxidized lipids, mainly presenting a fruity aroma; propyl nonanolactone has a coconut aroma, and when diluted, it has an almond or peach blossom aroma, which can be coordinated with the aroma of oil; 2-ethylhexanol has a light floral aroma and sweetness, adding good flavor to the product.

[0005] Therefore, on the basis of biological activity, chicken by-product processed products that promote digestion and absorption and have better flavor have extremely high practical and economic value. Summary of the invention

[0006] To solve the above problems, the present invention uses composite enzymes to hydrolyze chicken by-products to prepare enzymatic products, identifies the bioactive short peptides in the enzymatic products, and systematically analyzes the flavor substances of the enzymatic chicken-derived peptides and their effects on intestinal absorption and health, providing support for the development of functional foods.

[0007] The first object of the present invention is to provide a method for preparing enzymatic protein peptides based on chicken processing by-products, the method comprising:

[0008] The chicken processing by-product is ground, papain, flavor protease and bromelain are added, and enzymolysis and enzyme inactivation are performed to obtain an enzymolysis solution; the enzymolysis solution is ultrafiltered, dialyzed and dried to obtain enzymolysis protein peptides.

[0009] In one embodiment, the added amounts of papain, bromelain and flavor protease are 1000-2000 U / g, 1000-2000 U / g, and 5000-6000 U / g, respectively;

[0010] Preferably, the added amounts of papain, bromelain and flavor protease are 1000-1500 U / g, 1000-1500 U / g and 5000-6000 U / g, respectively.

[0011] In one embodiment, the enzymatic hydrolysis is carried out at 38-42° C., pH 7.0-7.5, and for 1-2 h.

[0012] In one embodiment, the molecular cut-off of the ultrafiltration is 1000 Da.

[0013] In one embodiment, the drying is freeze-drying.

[0014] In one embodiment, the centrifugation is at 4000-6000 rpm and 4°C for 10-20 minutes.

[0015] In one embodiment, the dialysis time is 20 to 30 hours.

[0016] The present invention also provides enzymatic protein peptides prepared by the method.

[0017] The second object of the present invention is to provide a method for simultaneously improving the flavor substances and digestion and absorption capacity of enzymatic protein peptides, wherein the flavor substances include n-hexanol, 1-octen-3-ol, E-2-octenal, n-hexanal, n-nonanal, n-octanal, and 2-pentylfuran;

[0018] The method comprises:

[0019] The chicken processing by-product is ground, papain, flavor protease and bromelain are added, and enzymolysis and enzyme inactivation are performed to obtain an enzymolysis solution; the enzymolysis solution is ultrafiltered, dialyzed and dried to obtain enzymolysis protein peptides.

[0020] In one embodiment, the added amounts of papain, bromelain and flavor protease are 1500-2000 U / g, 1500-2000 U / g, and 5000-6000 U / g, respectively.

[0021] In one embodiment, the enzymatic hydrolysis is carried out at 38-42°C, pH 7.0-7.5, and the enzymatic hydrolysis lasts for 1-2 hours;

[0022] In one embodiment, the drying is freeze-drying.

[0023] In one embodiment, the centrifugation is performed at 4000-6000 rpm and 4° C. for 10-20 min.

[0024] In one embodiment, the dialysis time is 20 to 30 hours.

[0025] The third object of the present invention is to provide use of any of the above methods in preparing animal feed.

[0026] The fourth object of the present invention is to provide an animal feed, wherein the feed contains enzymatically hydrolyzed protein peptides; and the preparation method of the enzymatically hydrolyzed protein peptides comprises:

[0027] The chicken processing by-product is ground, papain, flavor protease and bromelain are added, and enzymolysis and enzyme inactivation are performed to obtain an enzymolysis solution; the enzymolysis solution is ultrafiltered, dialyzed and dried to obtain enzymolysis protein peptides.

[0028] In one embodiment, the animal feed comprises:

[0029] The above enzymatic protein peptides, starch, maltodextrin, animal oil, vegetable powder, cellulose, minerals, vitamins and prebiotics.

[0030] In one embodiment, the method for preparing animal feed comprises: preparing animal feed using the above-mentioned enzymatic protein peptide, and the formula is as follows (calculated based on 1000g dry matter): 300g of enzymatic protein peptide, 332.5g of corn starch, 125g of maltodextrin, 40g of chicken fat, 100g of carrot powder, 50g of beet pulp, 20g of mineral mixture, 10g of vitamin mixture, 20g of prebiotics, and 2.5g of choline bitartrate; stirring the above-mentioned raw materials evenly, drying, and sterilizing to obtain animal feed.

[0031] Beneficial Effects of the Invention

[0032] The present invention hydrolyzes chicken by-products with a composite enzyme to prepare enzymatic products, identifies bioactive short peptides in the enzymatic products, and systematically analyzes the flavor substances of the enzymatic products and their effects on intestinal absorption and health, thereby providing support for the development of functional foods.

[0033] Specifically:

[0034] (1) The enzymatic protein peptide prepared by the present invention has excellent flavor, wherein n-hexanol reaches 11.45 μg / g FW or more, 1-octen-3-ol reaches 18.29 μg / g FW or more, E-2-octenal reaches 42.37 μg / g FW or more, n-hexanal reaches 187.03 μg / g FW or more, n-nonanal reaches 29.64 μg / g FW or more, n-octanal reaches 14.73 μg / g FW or more, and 2-pentylfuran reaches 17.36 μg / g FW or more;

[0035] (2) The enzymatic protein peptides prepared by the present invention can maintain the stability of the intestinal barrier of mice, promote digestion and absorption, and maintain the health of liver and kidney tissues;

[0036] (3) The raw material cost of the present invention is low, the preparation method is simple, and it is conducive to large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The molecular weight distribution results of the polypeptides of Comparative Examples 1 to 8 and Example 1;

[0038] Figure 2 These are the physical and chemical indicators of mice; (A) the trend of mouse weight changes; (B) the weight growth rate of mice; (C) the kidney index of mice; (D) the liver index of mice;

[0039] Figure 3 These are sections of mouse small intestine and kidney tissue. DETAILED DESCRIPTION

[0040] The preferred embodiments of the present invention are described below. It should be understood that the embodiments are for better explaining the present invention and are not used to limit the present invention.

[0041] The raw materials used in the examples are:

[0042] Chicken processing by-products: Zhejiang Jichong Trading Co., Ltd.;

[0043] Alkaline protease (40,000 U / g), bromelain (40,000 U / g), papain (40,000 U / g), Shandong Weilan Biotechnology Co., Ltd.;

[0044] Flavor protease (200,000 U / g) was purchased from Wuxi Youpu Biotechnology Co., Ltd.

[0045] Test method:

[0046] 1. Determination of hydrolysis degree

[0047] The degree of hydrolysis is defined as the percentage of the number of peptide bond breaks (h) to the total number of bonds per unit weight (htot), determined by the pH-stat method, the experiment was repeated three times and the average value was taken, and calculated by the following equation:

[0048]

[0049] 2. Determination of peptide mass concentration

[0050] The peptide mass concentration was determined by TCA-biuret method. Glutathione (GSH) was used as the standard sample, and 0-4 mg / mL solutions were prepared. 2 mL of GSH solution was mixed with 3 mL of biuret reagent, and the absorbance of the standard sample was measured at 540 nm after standing for 30 minutes. The standard curve was drawn. When the peptide mass concentration in the sample was determined, 4 mL of the enzymatic hydrolyzate was added with an equal volume of 10% trichloroacetic acid, and the mixture was evenly mixed and centrifuged at 4 ° C and 4000 r / min for 20 minutes to obtain the supernatant. The supernatant was diluted n times and the same determination steps as the standard curve were performed. The experiment was repeated three times to obtain the average value, and finally the peptide mass concentration in the sample solution was obtained by comparing with the standard curve.

[0051] 3. Determination of peptide molecular weight distribution

[0052] The molecular weight distribution of peptides was determined by high performance liquid chromatography (equipped with 2487 UV detector and Empower workstation GPC software). Sample preparation: 100 mg of sample was dissolved in water in a 10 mL volumetric flask, ultrasonicated for 5 min, centrifuged at 10000 r / min for 5 min, and filtered through a 0.22 μm filter membrane before injection. Chromatographic conditions: TSKgel2000SWXL column (300 mm x 7.8 mm); mobile phase composed of acetonitrile / water / trifluoroacetic acid 40 / 60 / 0.1 (v / v / v); flow rate 0.5 mL / min; column temperature 30 ° C, injection volume 10 μL.

[0053] 4. Use headspace solid phase microextraction gas phase high throughput time-of-flight mass spectrometry (HS-SPME-GC-TOF-MS) to separate and identify the volatile flavor components of the enzymatic hydrolysate

[0054] HS-SPME method to extract volatile components in samples: homogenize the above samples with a homogenizer, accurately weigh 4g (accurate to 0.001g) of the sample with an analytical balance, place it in a 20mL extraction bottle containing 5mL of saturated saline, add 10μl of 0.8mg / mL 2-methyl-3-heptanone, tighten the lid, shake it on a rotor, balance it at 40℃ for 15min, insert the DVB-CAR-PDMS solid phase microextraction fiber in a 40℃ constant temperature water bath for extraction for 30min, pull it out and immediately insert it into the GC injection port, analyze it at 260℃ for 2min. Before injection, place the fiber in the 270℃ injection port and adjust it with helium flow for 1h to avoid residual problems between samples.

[0055] 5. GC-TOF-MS technology analyzes volatile flavor components

[0056] GC conditions: chromatographic column is HP-5MS, 30x0.25 mm: helium flow rate: 1.5 mL / min, splitless injection: injection port temperature 250°C; heating program: 35°C for 3 min, increase the temperature to 70°C at a rate of 3°C / min, then increase the temperature to 200°C at a rate of 10°C / min, and finally increase the temperature to 260°C at a rate of 20°C / min and maintain for 5 min.

[0057] MS conditions: ion source: 70 eV; ion temperature 230°C; interface temperature 250°C, mass collection range 30-400 amu.

[0058] Example 1: A method for preparing enzymatic protein peptides

[0059] A method for preparing enzymatic protein peptides, comprising the steps of:

[0060] (1) The chicken processing byproduct is uniformly crushed into minced meat by pressure extrusion in a low-temperature sterile environment at 4°C, 3.75% (1500 U / g) of papain, 3% (6000 U / g) of flavor protease and 3.75% (1500 U / g) of bromelain are added, and enzymolysis is performed at 40°C for 1.5 hours; after enzymolysis, it is heated to 90°C for 15 minutes to inactivate the enzyme, and cooled; centrifuged at 5000 rpm for 15 minutes at 4°C, and filtered to obtain an enzymolysis solution;

[0061] (2) The enzymatic hydrolysate was centrifuged at 5000 × g for 15 min using a PALL ultrafiltration tube with a molecular weight cutoff (MWCO) of 1000 Da to obtain a filtrate, which was lyophilized and dissolved in 5 mL of ultrapure water. The filtrate was dialyzed in 100 mL of ultrapure water for 24 h using a dialysis membrane (MWCO 1000 Da, Spectrum Labs, USA). After dialysis, the hydrolysate was collected and lyophilized to obtain an enzymatic protein peptide sample.

[0062] Example 2: Changing the dosage

[0063] On the basis of Example 1, the dosages of papain, bromelain and flavor protease in step (1) were changed to 1000 U / g, 1000 U / g and 6000 U / g respectively, and the remaining steps were consistent with Example 1 to prepare an enzymatic protein peptide sample.

[0064] Comparative Example 1: Using Flavor Protease Only

[0065] On the basis of Example 1, the enzyme in step (1) was changed to a flavor protease with a consistent total amount, and the remaining steps were consistent with Example 1.

[0066] Comparative Example 2: Using Papain Only

[0067] On the basis of Example 1, the enzyme in step (1) was changed to a consistent total amount of papain, and the remaining steps were consistent with Example 1.

[0068] Comparative Example 3: Using Bromelain Only

[0069] On the basis of Example 1, the enzyme in step (1) was changed to bromelain with the same total amount, and the remaining steps were consistent with Example 1.

[0070] Comparative Example 4: Using Alkaline Protease Only

[0071] On the basis of Example 1, the enzyme in step (1) was changed to alkaline protease with the same total amount, and the remaining steps were the same as in Example 1.

[0072] Comparative Example 5: No papain added

[0073] On the basis of Example 1, the papain in step (1) was omitted and the total amount of enzyme was kept unchanged, and the remaining steps were consistent with Example 1.

[0074] Comparative Example 6: No bromelain added

[0075] On the basis of Example 1, the bromelain in step (1) was omitted and the total amount of enzyme was kept unchanged, and the remaining steps were consistent with Example 1.

[0076] Comparative Example 7: Changing the amount of addition

[0077] On the basis of Example 1, the addition amounts of papain, flavor protease and bromelain in step (1) were changed to 5% (2000 U / g), 4% (8000 U / g) and 5% (2000 U / g), respectively, and the remaining steps were consistent with Example 1.

[0078] Comparative Example 8: Changing the Addition Ratio

[0079] On the basis of Example 1, the addition amounts of papain, flavor protease and bromelain in step (1) were changed to 500 U / g, 6000 U / g and 500 U / g respectively, and the total amount of enzymes was kept unchanged. The remaining steps were consistent with Example 1.

[0080] Example 3: Enzymatic protein peptide composition and flavor detection

[0081] The composition and flavor of the unhydrolyzed protein peptides and the hydrolyzed protein peptides prepared in Examples 1 to 2 and Comparative Examples 1 to 8 were tested.

[0082] (1) Molecular size composition of enzymatic protein peptides

[0083] The nutritional and flavor properties of enzymatic hydrolysates are closely related to the small molecule peptides they contain. The molecular weight of small molecule peptides is about 180-480Da. Compared with the 1k-10kDa of polypeptides and 1kD of oligopeptides, small molecule peptides have a smaller molecular weight and are easier to absorb, so they are called small molecule active peptides.

[0084] The enzymatic protein peptides prepared in Examples 1 to 2 and Comparative Examples 1 to 8 were tested for their molecular size and composition ratio. The results are as follows: Figure 1 The results show that the small peptides in Example 2 are 53.4% ​​higher than those in chicken processing byproducts, 5% to 20.7% higher than those in Comparative Examples 1-4, and 3.7 to 5.6% higher than those in Comparative Examples 7 to 8. In addition, the content of 5 to 10 kDa peptides in the hydrolysate of Example 2 is only 0.48%, while peptides less than 3 kDa account for 99.32%, with more ultra-small short peptides, which are more easily absorbed by the intestine and human cells.

[0085] (2) Flavor Composition

[0086] The enzymatically hydrolyzed protein peptides prepared without enzymatic hydrolysis, Examples 1 to 2, and Comparative Examples 1 to 8 were taken to detect the flavor composition.

[0087] HS-SPME-GCMS was used to detect the types and contents of flavor substances volatilized from unhydrolyzed and hydrolyzed protein peptides. The results showed that a total of 54 compounds with significant differences between the two groups were screened out by p≤0.05 and FC≤0.05 or ≥2, as shown in Table 1, including 2 esters, 8 alcohols, 24 aldehydes and ketones, 3 thioethers, 10 acids and 7 alkanes.

[0088] Among them, aldehydes and alcohols have the highest content. The production of aldehydes mainly comes from fat oxidation, which is one of the main sources of meaty taste. The aldehydes with the highest content are trans-2-heptanal, E-2-octenal, benzaldehyde, hexanal and nonanal. Foods containing aldehydes may have fat, grassy and citrus flavors. The production of alcohols mainly comes from unsaturated fatty acids, and the content of 1-octen-3-ol and hexanol is relatively high, with a mushroom aroma.

[0089] Compared with the unhydrolyzed group, three new volatile compounds were detected in the hydrolyzed protein peptides, and α-nonanolide and 2-ethylhexanol increased significantly after hydrolysis; among them, α-nonanolide has a coconut aroma, and an almond or peach blossom aroma when diluted, which can be coordinated with the aroma of oil, while 2-ethylhexanol has a light floral and sweet taste, adding good flavor to the product.

[0090] The heterocyclic compounds with bean aroma are produced through Maillard reaction and amino acid degradation. Although the heterocyclic content is low, it contributes to the overall flavor, among which 2-pentylfuran exudes the aroma of flowers and fruits.

[0091] On this basis, the above-mentioned flavor substances were detected in the enzymatic protein peptides prepared in Example 2 and Comparative Examples 1 to 8. The results are shown in Table 2. The results show that the types and contents of volatile compounds in the enzymatic protein peptides prepared in Example 1 and Example 2 are significantly increased compared with Comparative Examples 1 to 7, showing a pleasant flavor.

[0092] Table 1 Relative content of volatile flavor substances

[0093]

[0094]

[0095] Table 2 Detection of flavor substances in comparative examples

[0096] (μg / gFW) n-Hexanol 1-Octen-3-ol E-2-Octenal n-Hexanal n-nonanal Octanal 2-Pentylfuran Example 1 11.45 18.29 46.32 187.03 29.64 14.73 17.36 Example 2 11.53 22.23 42.37 214.29 33.65 15.58 18.17 Comparative Example 1 12.25 12.34 32.68 160.33 23.12 11.38 8.46 Comparative Example 2 8.67 3.34 24.71 137.50 33.33 8.54 10.69 Comparative Example 3 7.55 2.09 24.28 134.81 20.56 9.05 10.39 Comparative Example 4 1.18 7.79 22.79 132.20 11.96 9.00 9.20 Comparative Example 5 6.70 10.60 22.45 188.67 30.24 13.97 10.11 Comparative Example 6 8.63 9.43 22.29 197.54 28.10 14.85 10.09 Comparative Example 7 9.36 15.46 42.63 178.51 24.27 13.91 12.07 Comparative Example 8 6.15 16.88 29.50 188.45 26.36 10.91 8.23

[0097] Example 3: Application of enzymatic protein peptides in maintaining intestinal barrier

[0098] The enzymatic protein peptide prepared in Example 1 was used to detect its application in maintaining the intestinal barrier of mice.

[0099] 1. Animal experiments

[0100] Forty male C57BL / 6J mice, 9 weeks old, were provided by Beijing Weitonglihua Experimental Animal Technology Co., Ltd. The mice were placed in a specific pathogen-free (SPF) environment in the Experimental Animal Center of Jiangnan University. After a 7-day adaptation period, the mice were randomly divided into 5 groups: normal diet group, high-protein diet group, non-enzymatic chicken by-product group, enzymatic chicken by-product and short peptide group. All groups had free access to water and food for 4 weeks. The feed of the normal group was based on casein, L-tyrosine, corn starch, maltodextrin, sucrose, cellulose, soybean oil, mixed minerals S10022M, mixed vitamins V10037, and choline bitartrate. Enzymatic chicken by-products and chicken short peptides were used to replace casein and L-tyrosine in the normal group feed (except for the high-protein diet group, the total amount of crude protein in the feed of the other groups was the same). The composition is shown in Table 2. The mice were killed after 4 weeks, and the liver, kidney and intestinal indicators were tested.

[0101] Table 3 Feed composition of each group

[0102]

[0103] 2. Experimental results

[0104] (1) Physical and chemical indicators

[0105] The results of mouse body weight and gain rate are as follows Figure 2 As shown in A and B, the results showed that there was no significant difference between the short peptide group and the enzyme-free chicken by-product group, but the weight gain of the short peptide group was more stable.

[0106] The results of mouse liver and kidney index tests are as follows Figure 2 As shown in Figures C and D, the results showed that the liver and kidney indicators of the enzymatically hydrolyzed chicken by-product group and the short peptide group were significantly lower than those of the non-enzymatically hydrolyzed chicken by-product group, while the liver and kidney indicators of the enzymatically hydrolyzed chicken processing by-product group were not significantly different from those of the short peptide group. This shows that enzymatic hydrolysis can reduce the metabolic burden on the liver and kidneys.

[0107] Short peptides can effectively reduce liver and kidney indexes, but have no significant effect on weight gain. This suggests that compared with non-enzymatic chicken protein, short peptides can reduce the metabolic load of the liver and kidneys due to their higher absorption and metabolic efficiency, thereby supporting the overall health of the liver and kidneys.

[0108] (2) Gut health

[0109] The structural differences of the small intestine and kidney of mice in different diet groups are as follows Figure 3 shown.

[0110] The results showed that the intestinal structure of mice in the normal diet group and the short peptide group was intact, the villi were closely arranged, and the intestinal morphology was healthy. This indicates that the feed containing short peptides does not damage the intestinal barrier. In contrast, the villi structure of mice in the high-protein diet group was slightly disordered, and the spacing between the villi was wider, indicating that the high-protein diet may cause slight damage to the small intestine. The villi and microvilli of the small intestine in the enzymatic hydrolysate group were closely arranged, which increased the absorption area and facilitated the absorption of nutrients.

[0111] In terms of kidney health, the kidneys of mice in the enzymatically hydrolyzed chicken and peptide groups were structurally intact, with tightly arranged tubules and clear glomeruli. No obvious signs of inflammation or tissue damage were observed. No obvious degeneration or damage was found compared with the normal diet group, indicating that the intake of enzymatically hydrolyzed chicken peptides had no negative impact on kidney health. In contrast, the kidneys of mice on a high-protein diet showed signs of mild damage, such as mild tubular dilatation and mild glomerular structural disorder. These findings suggest that a high-protein diet increases the metabolic burden on the kidneys, leading to mild structural damage.

[0112] It can be seen that the intake of enzymatically hydrolyzed chicken and enzymatically hydrolyzed protein peptides does not cause structural damage to the kidneys or small intestine.

[0113] Example 4: Application of enzymatic protein peptides in feed preparation

[0114] The enzymatic protein peptide prepared in Example 1 or Example 2 was used to prepare animal feed, and the formula was as follows (calculated based on 1000 g dry matter):

[0115] Enzymatic protein peptide 300g, corn starch 332.5g, maltodextrin 125g, chicken fat 40g, carrot powder 100g, beet pulp 50g, mineral mixture 20g, vitamin mixture 10g, prebiotics 20g, choline bitartrate 2.5g;

[0116] The above raw materials are stirred evenly, dried and sterilized to obtain animal feed.

[0117] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A method for preparing enzymatic protein peptides based on chicken processing byproducts, characterized in that: The method comprises: The chicken processing by-product is ground, papain, flavor protease and bromelain are added, and enzymolysis and enzyme inactivation are performed to obtain an enzymolysis solution; the enzymolysis solution is ultrafiltered, dialyzed and dried to obtain enzymolysis protein peptides.

2. The method according to claim 1, characterized in that The added amounts of papain, bromelain and flavor protease are 1000-2000U / g, 1000-2000U / g, and 5000-6000U / g, respectively.

3. The method according to claim 1, characterized in that The enzymatic hydrolysis is carried out at 38-42°C, pH 7.0-7.5, and for 1-2 hours.

4. The method according to claim 1, characterized in that: The molecular cut-off of ultrafiltration was 1000 Da; drying was freeze-drying.

5. The enzymatic protein peptide prepared by the method according to any one of claims 1 to 5.

6. A method for simultaneously improving the flavor of enzymatically hydrolyzed protein peptides and promoting nutrient absorption, characterized in that: The flavor substances include one or more of n-hexanol, 1-octen-3-ol, E-2-octenal, n-hexanal, n-nonanal, n-octanal, and 2-pentylfuran; The method comprises: The chicken processing by-product is ground, papain, flavor protease and bromelain are added, and enzymolysis and enzyme inactivation are performed to obtain an enzymolysis solution; the enzymolysis solution is ultrafiltered, dialyzed and dried to obtain enzymolysis protein peptides.

7. The method according to claim 6, characterized in that The added amounts of papain, bromelain and flavor protease are 1000-2000U / g, 1000-2000U / g, and 5000-6000U / g, respectively.

8. The method according to claim 6, characterized in that The enzymatic hydrolysis is at 38-42°C, pH 7.0-7.5, and the enzymatic hydrolysis lasts for 1-2 hours; The molecular cut-off of ultrafiltration is 1000Da.

9. Use of the method according to any one of claims 1 to 4 or claims 6 to 8 in preparing animal feed.

10. An animal feed, characterized in that: The feed contains enzymatic protein peptides; The preparation method of the enzymatic protein peptide comprises: The chicken processing by-product is ground, papain, flavor protease and bromelain are added, and enzymolysis and enzyme inactivation are performed to obtain an enzymolysis solution; the enzymolysis solution is ultrafiltered, dialyzed and dried to obtain enzymolysis protein peptides.

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