Antioxidant mackerel intestine pet snack and preparation method thereof

Abstract

The invention provides an anti-oxidation mackerel intestine pet snack and a preparation method thereof, the anti-oxidation mackerel intestine pet snack is prepared by uniformly mixing a main raw material mackerel surimi and auxiliary materials corn starch, anti-oxidation peptide and water, filling the mixture into a sausage, cooking and processing, and the anti-oxidation peptide is extracted from a product obtained after mackerel meat and by-products thereof are subjected to protease enzymolysis. The antioxidant mackerel intestine provided by the invention is high in protein content, low in fat content and rich in nutritional value, antioxidant components of the antioxidant mackerel intestine not only can prolong the shelf life of pet snacks, but also can effectively remove free radicals in bodies of pets after the pets eat the antioxidant mackerel intestine, reduce damage of the free radicals to immune cells and enhance immunity, so that the antioxidant mackerel intestine is suitable for being eaten by pets. And the elasticity and health of pet fur are kept. According to the invention, the variety and enzymolysis conditions of protease, the variety of a taste improver and the mixing ratio of raw materials are screened, so that the prepared anti-oxidation mackerel intestine pet snack has higher anti-oxidation activity and better texture.

Description

Technical Field

[0001] The present invention belongs to the field of pet food processing, and more specifically, relates to an antioxidant mackerel sausage pet snack and a preparation method thereof. Background Art

[0002] In recent years, the scale of the pet market in China has been continuously expanding, and the number of pets has been growing steadily. According to relevant data, the number of pets in China has exceeded 200 million, and the pet owner population is becoming increasingly large. With the improvement of the status of pets and the booming development of the pet industry, the pet food market is also expanding continuously. Pet owners have higher and higher requirements for pet food, not only paying attention to the taste and deliciousness of food, but also attaching more importance to its nutritional value and health benefits. Therefore, pet snacks with health care functions are becoming more and more popular.

[0003] Antioxidant peptides are small molecule active peptides composed of 2 to 100 amino acids. They can effectively scavenge free radicals and have the advantages of high antioxidant activity, simple structure, easy digestion and absorption, safety and no toxic side effects. They have broad application prospects in industries such as biology, medicine, and functional foods. Therefore, antioxidant properties have become a research hotspot in pet food. Antioxidant components can protect the fat and other nutrients in pet food from being oxidized, extend the shelf life of food, and at the same time can effectively scavenge free radicals in the body, reduce the damage of free radicals to immune cells, slow down cell aging, protect cells, enhance immunity, improve digestion, maintain the elasticity and health of pet fur, and are very beneficial to the health of pets.

[0004] Mackerel, also known as Spanish mackerel, is a common economic fish in the coastal areas of China. Mackerel is rich in nutrients, including high-quality protein, unsaturated fatty acids, vitamins, and minerals. These nutrients are an important material basis for the normal operation of the pet body's immune system. In particular, its high content of Omega-3 fatty acids not only has a positive effect on the growth and gloss of pet hair, can effectively improve and maintain the health of pet skin and hair, but also has good health care effects on the cardiovascular health of pets. In addition, mackerel sausage has a unique taste and is deeply loved by pets. As a marine fish, its fish skin, minced fish, fish bones, etc. are often regarded as by-products and discarded during the processing process, which not only causes waste of resources, but also may cause environmental pollution. Research shows that mackerel is an important biological source of highly active antioxidant peptides. Mackerel and its by-products are rich in amino acids and high-quality proteins, and are good sources for preparing antioxidant peptides. By enzymatically hydrolyzing the proteins in mackerel minced meat, peptide segments with antioxidant activity can be released. Mackerel minced meat is usually a by-product in the processing of marine aquatic products. Using these by-products to extract antioxidant peptides can not only increase their added value, but also reduce waste, and has good economic efficiency and sustainability.

[0005] Currently, there are few relevant studies and applications on extracting antioxidant peptides from Spanish mackerel meat for making pet snacks, and it is in the initial development stage. Spanish mackerel meat itself is a high-quality protein source and is rich in various nutritional elements. The antioxidant peptides extracted from Spanish mackerel meat have the characteristics of being natural and safe, meeting the demand for natural ingredients in the pet food market. Moreover, antioxidant peptides can scavenge free radicals in the pet's body, reduce oxidative stress, and are beneficial to the pet's health. For example, they help maintain the pet's immune function, skin health, etc. This enables pet snacks to not only provide nutrition but also have certain health care functions, increasing the added value of the product. Summary of the Invention

[0006] The present invention provides an antioxidant Spanish mackerel sausage pet snack and a preparation method thereof. The antioxidant Spanish mackerel sausage pet snack is prepared by mixing the main raw material of Spanish mackerel mince, auxiliary materials of corn starch and antioxidant peptides, and then performing enema steaming and cooking. The antioxidant peptides are extracted from the product after protease enzymolysis of Spanish mackerel meat and its by-products. The antioxidant Spanish mackerel sausage provided by the present invention has a high protein content and a low fat content, and has rich nutritional value. Its antioxidant components can slow down cell aging, protect cells, enhance immunity, improve digestion, and promote hair health, and it is an excellent snack for pet health. The present invention also screens the types of proteases and their enzymolysis conditions, the types of texture improvers, and the mixing ratio of raw materials, so that the prepared antioxidant Spanish mackerel sausage pet snack has higher antioxidant activity and better texture. The present invention uses Spanish mackerel and its by-products for the production of pet food, which not only improves the comprehensive utilization value of Spanish mackerel, but also promotes the sustainable utilization of marine resources, provides new ideas and directions for the development of related industries, and promotes sustainable development.

[0007] On the one hand, the present invention provides an antioxidant Spanish mackerel sausage pet snack, which includes Spanish mackerel meat and auxiliary materials. The auxiliary materials include antioxidant peptide powder, and the antioxidant peptide powder is extracted from Spanish mackerel.

[0008] The antioxidant peptide is a type of peptide compound with antioxidant effects, widely present in organisms, and has various biological activities and application values. The antioxidant peptide of the present invention is extracted from Spanish mackerel meat and its by-products, and the by-products include fish skin, minced fish meat, fish bones, etc. Currently, there are few related researches and applications on extracting antioxidant peptides from Spanish mackerel meat and its by-products for making pet snacks, and it is in the initial development stage. Adding the antioxidant peptide to Spanish mackerel sausage, as a natural antioxidant, can replace or reduce the use of chemically synthesized antioxidants. The addition of the antioxidant peptide can not only extend the shelf life of Spanish mackerel sausage, prevent oil oxidation, and maintain the sensory quality of the sausage, but also improve the nutritional value and antioxidant capacity of the sausage, effectively scavenge free radicals generated in the pet's body, prevent the damage of free radicals to pet cells, and enhance the pet's immunity and overall health level. In addition, the present invention also provides a method for preparing pet snacks of antioxidant peptide from Spanish mackerel sausage, which includes the step of extracting antioxidant peptide from Spanish mackerel. The operation of this step is simple, and the antioxidant peptide extracted through this step has high purity and strong biological activity of the antioxidant peptide. In addition, the present invention also screens the raw materials and their ratios for preparing pet snacks of antioxidant peptide from Spanish mackerel sausage to make the texture of the prepared sausage the best.

[0009] Furthermore, the auxiliary materials further include a mouthfeel improver, and the mouthfeel improver includes any one or more of corn starch, potato starch, low-gluten wheat flour, soy protein powder, and soy protein isolate.

[0010] The mouthfeel improver is used to improve the palatability of the sausage, attract pets to eat by optimizing the texture and mouthfeel; in addition, it can also adapt to the chewing and digestion abilities of different pets to meet the needs of pets of all ages, breeds, and health conditions.

[0011] Furthermore, the mouthfeel improver is corn starch; calculated by weight, the antioxidant peptide is 3 - 5 parts, the Spanish mackerel meat is 60 - 100 parts, and the corn starch is 24 - 40 parts.

[0012] Furthermore, the auxiliary materials further include water, calculated by weight, the water is 10 - 30 parts by weight; calculated by weight, the antioxidant peptide powder is 5 parts, the Spanish mackerel meat is 60 parts, the corn starch is 40 parts, and the water is 20 parts.

[0013] In some ways, the effects of different addition ratios of moisture content, corn starch content, and antioxidant peptide powder content on the texture and sensory evaluation of antioxidant Spanish mackerel intestine pet snacks were explored, and the optimal ratio was screened based on the texture and sensory evaluation. The moisture content, starch content, and antioxidant peptide powder content all have an impact on their texture and sensory evaluation. Among them, the starch content has the greatest impact, followed by the antioxidant peptide powder content and the moisture content. When the ratio of moisture content, starch content, and antioxidant peptide powder content is 20 parts, 40 parts, and 3 parts, the hardness of the antioxidant Spanish mackerel intestine is the best; when the ratio of moisture content, starch content, and antioxidant peptide powder content is 20 parts, 40 parts, and 3 parts, the viscosity of the antioxidant Spanish mackerel intestine is the best; when the ratio of moisture content, starch content, and antioxidant peptide powder content is 20 parts, 40 parts, and 5 parts, the elasticity of the antioxidant Spanish mackerel intestine is the best; when the ratio of moisture content, starch content, and antioxidant peptide powder content is 20 parts, 40 parts, and 5 parts, the chewiness of the antioxidant Spanish mackerel intestine is the best; when the ratio of moisture content, starch content, and antioxidant peptide powder content is 20 parts, 40 parts, and 5 parts, the sensory evaluation of the antioxidant Spanish mackerel intestine is the best; therefore, the optimal ratio of moisture content, starch content, and antioxidant peptide powder content is screened as 20 parts, 40 parts, and 5 parts based on the comprehensive texture and sensory evaluation.

[0014] On the other hand, the present invention provides a method for preparing the antioxidant Spanish mackerel intestine pet snack as described above, comprising the following steps:

[0015] (1) Crushing Spanish mackerel minced meat and Spanish mackerel by-products and adding water to prepare a raw material homogenate;

[0016] (2) Adding protease to the raw material homogenate for enzymatic hydrolysis, separating and purifying to obtain antioxidant peptide powder;

[0017] (3) Mixing the antioxidant peptide powder with Spanish mackerel meat, texture improver, and water, and then performing enema and steaming to obtain the antioxidant Spanish mackerel intestine pet snack.

[0018] Further, the mass ratio of the Spanish mackerel minced meat, Spanish mackerel by-products, and water in step (1) is 1:6.

[0019] Further, the protease in step (2) includes any one or more of papain, alkaline protease, and neutral protease; the separation and purification include centrifugal ultrafiltration, rotary evaporation, and freeze-drying.

[0020] In some ways, papain, alkaline protease, and neutral protease enzymatically hydrolyze the raw material homogenate under the same conditions, and the antioxidant properties (DPPH free radical scavenging rate and reducing power) of the three enzymatic hydrolysis products are compared. The results show that the antioxidant property of neutral protease is significantly higher than that of the other two proteases. Therefore, the protease is preferably neutral protease.

[0021] In some ways, the specification of the ultrafiltration tube is 10 kD, and the centrifugation conditions are centrifugation at 4°C and 6000 rpm for 5 min; the conditions for rotary evaporation are 40°C, 120 rpm, and 10 min; the freeze-drying time is 1 - 2 d.

[0022] In some ways, the same mass of freeze-dried antioxidant peptide powder after separation and purification and the freeze-dried antioxidant peptide powder without separation and purification are dissolved in the same volume of water, and the contents of antioxidant peptides in the two solutions are compared. The results show that the peptide content of the antioxidant peptide after separation and purification is twice that of the antioxidant peptide without separation and purification.

[0023] Furthermore, the protease is neutral protease, and its enzymatic hydrolysis conditions are: enzyme dosage 1000 - 1800 U / g, temperature 10 - 50°C, pH value 5.0 - 9.0, and enzymatic hydrolysis time 4 - 6 h.

[0024] In some ways, the enzyme dosage, temperature, pH, and enzymatic hydrolysis time of neutral protease are optimized to obtain the optimal enzymatic hydrolysis conditions: enzyme dosage 1600 U / g, temperature 30°C, pH value 7.0, and enzymatic hydrolysis time 6 h.

[0025] Furthermore, the cooking time in step (3) is 30 - 40 min.

[0026] In some ways, the method for extracting antioxidant peptide powder provided by the present invention is compared with the methods provided in the published documents CN114426998A and CN112048534B. The antioxidant peptide concentrations of the antioxidant peptide powders extracted by the three different methods are detected after being formulated into solutions. The results show that the antioxidant peptide content of the antioxidant peptide powder prepared by the method provided by the present invention is significantly higher than that of the other two methods. Further, the antioxidant peptide powders extracted by the three different methods are prepared into antioxidant Spanish mackerel intestines according to the method provided by the present invention, and the DPPH radical scavenging rate and reducing power are detected. The results show that the DPPH radical scavenging rate and reducing power of the antioxidant Spanish mackerel intestines prepared from the antioxidant peptide powder prepared by the method provided by the present invention are significantly higher than those of the other two kinds of fish intestines.

[0027] On the other hand, the present invention provides a use of an antioxidant peptide powder for preparing antioxidant Spanish mackerel intestine pet snacks, and the antioxidant peptide powder is extracted from Spanish mackerel meat.

[0028] In some ways, the nutritional components (moisture, crude ash, crude protein, crude fat, dietary fiber) and antioxidant properties (DPPH radical scavenging rate and reducing power) of the antioxidant Spanish mackerel intestine provided by the present invention were compared with those of two common Spanish mackerel intestines (without adding antioxidant peptides or without adding corn starch). The results showed that the antioxidant Spanish mackerel intestine provided by the present invention had a richer protein content and a lower fat content compared with the two common Spanish mackerel intestines, achieving high protein and low fat. In addition, the antioxidant Spanish mackerel intestine had more excellent antioxidant properties compared with the two common Spanish mackerel intestines, and its DPPH radical scavenging rate and reducing power were much higher than those of the common Spanish mackerel intestine.

[0029] The present invention has the following beneficial effects:

[0030] 1. The present invention provides an antioxidant Spanish mackerel intestine pet snack, which contains Spanish mackerel meat, antioxidant peptides extracted from Spanish mackerel, and corn starch. They provide rich nutritional components for the antioxidant Spanish mackerel intestine, including high-quality protein, essential amino acids, Omega-3 fatty acids, as well as various trace elements and vitamins, and also achieve high protein and low fat.

[0031] 2. The antioxidant Spanish mackerel intestine pet snack has excellent antioxidant properties. The added antioxidant peptide component not only effectively inhibits the oxidation and deterioration of the oil in the antioxidant Spanish mackerel intestine pet snack, prolongs the shelf life of the fish intestine, but also effectively scavenges free radicals in the body, reduces the damage of free radicals to immune cells, thereby helping to maintain and enhance the immune function of pets, and slowing down skin aging, keeping the elasticity and health of the pet's fur.

[0032] 3. The present invention also provides a method for preparing an antioxidant Spanish mackerel intestine pet snack. This method involves extracting antioxidant peptide powder from the product after protease enzymolysis of Spanish mackerel meat and Spanish mackerel by-products. The extracted antioxidant peptide powder has high antioxidant properties. The method is simple to operate, does not add any stabilizers, additives, or chemically synthesized antioxidants additionally, the formula is green and safe, reducing the health risks that pets may have due to ingesting chemical additives. In addition, the method also uses a steaming technology, which is clean, hygienic, time-saving, energy-saving, and reduces costs.

[0033] 4. The present invention also screens the types of proteases and their enzymolysis conditions, the types of texture improvers, and the raw material mixing ratio, so that the prepared antioxidant Spanish mackerel intestine pet snack has higher antioxidant activity and better texture.

[0034] 5. The present invention uses mackerel and its by-products in the production of pet food, which not only improves the comprehensive utilization value of mackerel, but also reduces its environmental pollution. At the same time, it promotes the sustainable utilization of marine resources, provides new ideas and directions for the development of related industries, and promotes sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is the detection result of the antioxidant peptide content concentration before and after the separation and purification of the mackerel antioxidant peptide powder in Example 1;

[0036] Figure 2 It is the physical picture of the antioxidant mackerel intestine pet snack in Example 1;

[0037] Figure 3 It is the detection result of the DPPH free radical scavenging rate and reducing power of the antioxidant mackerel intestine and the ordinary mackerel intestine in Example 2;

[0038] Figure 4 It is the detection result of the DPPH free radical scavenging rate and enzymatic hydrolysis degree of neutral protease, papain and alkaline protease in Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0039] The present invention will be further described in detail below with reference to the drawings and examples. It should be noted that the following examples are intended to facilitate the understanding of the present invention and do not limit it in any way.

[0040] Example 1. A preparation method of an antioxidant mackerel intestine pet snack

[0041] 1. Preparation of antioxidant peptide powder:

[0042] (1) Put the minced mackerel and mackerel by-products (purchased from Ningbo Hongwei Food Company), and the by-products include fish skin, minced fish, fish bones, etc., into a crusher for crushing, calculate the weight, add 6 times the weight of distilled water, and continuously stir evenly in a water bath at 25 °C to obtain a raw material homogenate;

[0043] (2) Adjust the pH of the raw material homogenate to 7.0 with sodium hydroxide or hydrochloric acid, then add neutral protease, and the addition amount is 1600 U / g. After stirring evenly, enzymatically hydrolyze at 30 °C for 6 h, and heat the extracted enzymatic hydrolysate to about 100 °C to inactivate the protease;

[0044] (3) Separate and purify the enzymatic hydrolysate obtained by enzymatic hydrolysis. Specifically, first perform centrifugal ultrafiltration (ultrafiltration tube 10 kD, 4 °C, centrifugation at 6000 rpm for 5 min), then perform rotary evaporation (40 °C, 120 rpm, 10 min), then perform freeze-drying (1-2 d), and finally obtain antioxidant peptide powder.

[0045] Take 1 g of the antioxidant peptide powder after separation and purification in the above step (3) and dissolve it in 9 mL of 0.1 mol / L phosphate buffer solution. Configure the sample using a BCA kit according to the instructions. Put the sample into an enzyme-linked immunosorbent assay (ELISA) reader and measure it at a wavelength of 562 nm. The calculation formula is as follows:

[0046]

[0047] In the formula: A determination represents the absorbance of the sample; A blank represents the absorbance of the blank group; A standard represents the absorbance of the standard group; C standard represents the concentration of the standard solution, μg / mL; N represents the dilution factor of the sample before testing.

[0048] Use the antioxidant peptide powder directly freeze-dried without going through step (3) of separation and purification as a comparison. The test results are as Figure 1 shown, indicating that the purity of the antioxidant peptide powder prepared after separation and purification has doubled.

[0049] 2. Preparation of antioxidant Spanish mackerel intestine:

[0050] (1) Put the minced Spanish mackerel into a meat grinder and grind it into fish paste;

[0051] (2) By weight, add 40 parts of starch, 20 parts of water, and 5 parts of antioxidant peptide powder to 60 parts of Spanish mackerel fish paste, and stir evenly to obtain the raw material;

[0052] (3) Use an enema to inject the raw material into sausage casings (purchased from Walmart Supermarket in Ningbo) to obtain fish intestines;

[0053] (4) Put the filled fish intestines into a steamer and steam for 30 - 40 min to obtain antioxidant Spanish mackerel intestine pet snacks, as Figure 2 shown.

[0054] Example 2. Comparison between antioxidant Spanish mackerel intestine and ordinary Spanish mackerel intestine

[0055] This example will compare the nutritional components and antioxidant properties of the antioxidant Spanish mackerel intestine prepared in Comparative Example 1 with those of ordinary Spanish mackerel intestine (without antioxidant peptide powder or without corn starch).

[0056] The preparation method of Spanish mackerel intestine without antioxidant peptide is as follows: Put the minced Spanish mackerel into a meat grinder and grind it into fish paste; By weight, add 40 parts of starch and 20 parts of water to 60 parts of Spanish mackerel fish paste, and stir evenly to obtain the raw material; Use an enema to inject the raw material into sausage casings to obtain fish intestines; Put the filled fish intestines into a steamer and steam for 30 - 40 min to obtain Spanish mackerel intestine without antioxidant peptide powder.

[0057] The preparation method of Spanish mackerel sausage without corn starch is as follows: Put the minced Spanish mackerel into a meat grinder and grind it into fish paste; Calculate by weight, add 5 parts of antioxidant peptide powder and 20 parts of water to 60 parts of Spanish mackerel fish paste, and stir evenly to obtain the raw material; Use an enema to inject the raw material into the sausage casing to obtain fish sausage; Put the filled fish sausage into a steamer and steam it for 30 - 40 minutes to obtain Spanish mackerel sausage without corn starch.

[0058] Furthermore, detect the moisture, crude ash, crude protein, crude fat, crude fiber and antioxidant properties of the above antioxidant Spanish mackerel sausage and two common Spanish mackerel sausages. The moisture, crude ash, crude protein, crude fat and crude fiber are determined according to the methods of national standards GB5009.3 - 2016, GB 5009.4 - 2016, BCA kit, GB5009.6 - 2016, GB / T 6434 - 2006 respectively. The antioxidant properties include DPPH free radical scavenging rate and reducing power.

[0059] The determination method of DPPH free radical scavenging rate is: Add 1 mL of sample to 1 mL of 0.1 mmol / L DPPH ethanol solution, keep it in the dark and stand for 30 minutes, and measure the absorbance value A1 at 517 nm. Use an equal volume of ethanol solution instead of DPPH as the blank group A2, and an equal volume of distilled water instead of the sample solution as the control group A0. Calculate according to the following formula: DPPH free radical scavenging rate % = (1 - A1 - A2 / A0) × 100%

[0060] The determination method of reducing power is: Add 1 mL of the sample to 1 mL of 0.2 mol / L phosphate buffer solution and 1 mL of 1% potassium ferricyanide solution, water bath at 50 °C for 20 minutes, add 1 mL of 10% TCA solution, centrifuge at 3000 rmp / min for 10 minutes, take 2.5 mL of the supernatant, add 2.5 mL of distilled water and 0.5 mL of 0.1% FeCl3 solution, and measure the absorbance value of the solution at 700 nm.

[0061] The detection results of the nutritional components and antioxidant properties of antioxidant Spanish mackerel sausage and common Spanish mackerel sausage are as shown in Table 1 and Figure 3 shown below.

[0062] Table 1. Detection results of nutritional components and antioxidant properties of antioxidant Spanish mackerel sausage and common Spanish mackerel sausage

[0063]

[0064] As can be seen from Table 1, except for the little difference in moisture and crude ash content, there are significant differences in the other components between the antioxidant Spanish mackerel intestine and the two common Spanish mackerel intestines (without corn starch or without antioxidant peptide powder). The crude protein of the antioxidant Spanish mackerel intestine is much greater than that of the two common Spanish mackerel intestines, and the crude fat content is also much lower than that of the two common Spanish mackerel intestines, achieving high protein and low fat. In addition, the DPPH free radical scavenging rate and reducing power of the antioxidant Spanish mackerel intestine are significantly higher than those of the two common Spanish mackerel intestines, having good antioxidant capacity. In addition, the crude fiber content of the antioxidant Spanish mackerel is also at a relatively low level. High-protein and low-fat pet snacks are more beneficial to the nutrition and health of pets, helping pets maintain an ideal weight, prevent obesity and other related diseases, and protect joints. Good antioxidant capacity can not only extend the shelf life of the pet snacks, but also slow down cell aging, protect cells, enhance immunity, improve digestion, and promote hair health after pets eat them. The low crude fiber content can make the snacks more palatable and easier to digest and absorb after pets eat them.

[0065] In summary, the antioxidant Spanish mackerel intestine provided by the present invention is superior to the common Spanish mackerel intestine.

[0066] Example 3. Protease screening

[0067] In this example, the proteases used for enzymatic hydrolysis of the raw material homogenate in Example 1 will be screened. The different proteases are neutral protease, papain, and alkaline protease. The enzyme activity of the papain is 100000U / g, the enzyme activity of the alkaline protease is 20000U / g, and the enzyme activity of the neutral protease is 100000U / g.

[0068] The specific experimental steps are as follows:

[0069] Put the Spanish mackerel meat and Spanish mackerel by-products into a crusher for crushing, then calculate the weight, add 6 times the same weight of distilled water, mix to obtain the raw material homogenate, continuously stir in a 25°C water bath to reach the optimum enzymatic hydrolysis temperature, maintain for 10 min, and then adjust to pH 7.0 with sodium hydroxide or hydrochloric acid; Prepare 1000U of neutral protease, papain, and alkaline protease and add them to different beakers respectively, add the raw material homogenate, and the ratio of the raw material homogenate (g) to the protease (mL) is 1:20, stir well, and carry out enzymatic hydrolysis for 5 h. During the enzymatic hydrolysis process, take the enzymatic hydrolysate once every 1 h, heat the extracted enzymatic hydrolysate to about 100°C to inactivate the protease; After inactivating the enzymatic hydrolysis product, centrifuge it at 4°C for 10 min, and place the supernatant in a 4°C refrigerator for storage for later use; Detect the antioxidant properties (DPPH free radical scavenging rate and reducing power) and enzymatic hydrolysis degree of the three enzymatic hydrolysis products. The detection methods of the DPPH free radical scavenging rate and reducing power refer to Example 2.

[0070] The detection method of the degree of enzymatic hydrolysis is as follows: The formaldehyde titration method is used to determine the degree of hydrolysis: 1) Pipette a certain volume of the sample before enzymatic hydrolysis into a conical flask, add 2 - 3 drops of phenolphthalein (0.5%) indicator. At this time, the solution is colorless. Titrate with a standard sodium hydroxide solution until the solution turns slightly pink and does not fade within half a minute. Record the volume V1 of the standard sodium hydroxide solution (0.1 mol / L) consumed. This titration is for the free acid in the sample solution and can be used as a blank titration; 2) Pipette the same volume of the sample after enzymatic hydrolysis into a conical flask, add an excessive amount of formaldehyde solution (20%), shake well, and let it stand for a period of time (usually 5 - 15 minutes) to allow formaldehyde to react with the amino groups in the sample. Then continue to titrate with the standard sodium hydroxide solution until the solution turns slightly pink again and does not fade within half a minute. Record the total volume V2 of the standard sodium hydroxide solution consumed at this time; 3) Calculate according to the formula DH / % = (V1 - V2) × 0.1 × 14.008 × 100%, where: DH represents the degree of hydrolysis, %; V1 is the volume of 0.1 mol / L NaOH consumed by the blank solution, mL; V2 is the volume of 0.1 mol / L NaOH consumed by the sample solution, mL; 0.1 is the concentration of the NaOH titrant, mol / L; 14.008 is the mass of nitrogen equivalent to 1 mL of 0.1 mol / L NaOH titrant, mg.

[0071] The DPPH radical scavenging rate and the degree of enzymatic hydrolysis of the enzymatic hydrolysis products of the above three proteases are as Figure 4 shown. The results show that the DPPH radical scavenging rate (48%) and the degree of enzymatic hydrolysis (17%) of the enzymatic hydrolysis product of neutral protease are significantly higher than those of the other two hydrolases. This indicates that the enzymatic hydrolysis efficiency of neutral protease is higher and it has higher specificity for the raw material homogenate as the substrate.

[0072] The detection results of the reducing power of the above three proteases are shown in Table 2 below.

[0073] Table 2. Detection results of the reducing power of the products of enzymatic hydrolysis of Spanish mackerel meat by different proteases

[0074] Protease Reducing power Neutral protease 0.43 Papain 0.31 Alkaline protease 0.35

[0075] According to the data in Table 2, the results show that the reducing power of the enzymatic hydrolysis product of neutral protease is significantly higher than that of the other two proteases. Combining with the fact that the DPPH radical scavenging rate and the degree of enzymatic hydrolysis of the enzymatic hydrolysis product of neutral protease are also the highest, neutral protease is thus preferred.

[0076] Furthermore, the products of enzymatic hydrolysis of the above three different proteases on the raw material homogenate are separated and purified according to the method in Example 1 and made into antioxidant Spanish mackerel intestine, and then their nutritional components and antioxidant properties are detected. The detection results are shown in Table 3 below.

[0077] Table 3. Detection Results of Nutritional Components and Antioxidant Properties of Antioxidant Spanish Mackerel Intestines Prepared by Enzymatic Hydrolysis with Different Proteases

[0078]

[0079] According to the data analysis in Table 3, comparing the nutritional components, the crude fat content of the antioxidant Spanish mackerel intestines prepared from the enzymatic hydrolysis products of the three proteases is very low. However, the crude protein content of the antioxidant Spanish mackerel intestines prepared from the enzymatic hydrolysis products of neutral protease and alkaline protease is much higher than that of papain, achieving high protein and low fat. Then, comparing the antioxidant properties, the DPPH radical scavenging rate and reducing power of the antioxidant Spanish mackerel intestines prepared by enzymatic hydrolysis with neutral protease are higher, and the antioxidant property is stronger. Therefore, considering both the nutritional components and antioxidant properties, neutral protease is preferably selected as the protease.

[0080] Example 4. Screening of the Optimal Enzymatic Hydrolysis Conditions of Neutral Protease

[0081] In this example, the enzymatic hydrolysis temperature, enzyme addition amount, pH, and enzymatic hydrolysis time in step (2) of Example 1 will be changed respectively. The enzymatic hydrolysis temperatures are set at 10°C, 20°C, 30°C, 40°C, 50°C, the enzyme addition amounts are set at 1000 U / g, 1200 U / g, 1400 U / g, 1600 U / g, 1800 U / g, the pH values are set at 5.0, 6.0, 7.0, 8.0, 9.0, and the enzymatic hydrolysis times are set at 4 h, 5 h, 6 h. The radical scavenging rate and reducing power of the products of enzymatic hydrolysis of Spanish mackerel meat with neutral protease under different conditions are detected. The detection results are shown in Tables 4 - 7 below.

[0082] Table 4. Radical Scavenging Rate and Reducing Power of the Products of Enzymatic Hydrolysis of Spanish Mackerel Meat with Neutral Protease at Different Temperatures

[0083] Enzymolysis temperature (°C) Free radical scavenging rate Reducing power 10 27.03 0.24 20 36.85 0.40 30 38.14 0.43 40 32.44 0.38 50 30.69 0.33

[0084] Table 5. Radical Scavenging Rate and Reducing Power of the Products of Enzymatic Hydrolysis of Spanish Mackerel Meat with Neutral Protease at Different Enzyme Addition Amounts

[0085] Enzyme dosage (U / g) Free radical scavenging rate Reducing power 1000 27.53 0.25 1200 31.14 0.33 1400 36.48 0.39 1600 38.53 0.44 1800 35.91 0.36

[0086] Table 6. Radical Scavenging Rate and Reducing Power of the Products of Enzymatic Hydrolysis of Spanish Mackerel Meat with Neutral Protease at Different pH Values

[0087] pH Free radical scavenging rate Reducing power 5.0 25.22 0.21 6.0 31.25 0.34 7.0 42.31 0.52 8.0 36.28 0.41 9.0 20.67 0.18

[0088] Table 7. Radical Scavenging Rate and Reducing Power of the Products of Enzymatic Hydrolysis of Spanish Mackerel Meat with Neutral Protease at Different Enzymatic Hydrolysis Times

[0089] Enzymolysis time (h) Free radical scavenging rate Reducing power 4 28.67 0.27 5 33.23 0.34 6 37.46 0.40

[0090] According to the data in Table 4-7, the free radical scavenging rate and reducing power of the products of neutral protease hydrolysis of Spanish mackerel meat under different enzymatic hydrolysis conditions were compared respectively. It was shown that the optimal enzymatic hydrolysis temperature was 30 °C, the optimal enzyme dosage was 1600 U / g, the optimal pH was 7.0, and the optimal enzymatic hydrolysis time was 6 h. Under the optimal enzymatic hydrolysis conditions, the structure of Spanish mackerel meat protein was more conducive to binding with neutral protease and carrying out specific enzymatic hydrolysis, thus efficiently generating antioxidant peptides.

[0091] Example 5. Screening of texture improvers

[0092] The difference between this example and Example 1 lies in changing the types of texture improvers. The texture improvers include corn starch, potato starch, low-gluten wheat flour, soy protein powder, and soy protein isolate, and all the texture improvers were purchased from Walmart Supermarket in Ningbo.

[0093] The above five different texture improvers were prepared into five antioxidant Spanish mackerel sausage samples according to the method of Example 1, and the texture and sensory properties of these five antioxidant Spanish mackerel sausage samples were evaluated.

[0094] The specific method for texture evaluation is as follows: The TPA measurement of Spanish mackerel sausage was carried out using a texture analyzer. The measurement indexes include hardness, elasticity, adhesiveness, and chewiness. The samples were cut into cylinders with a thickness of about 10 mm, and five samples were randomly taken from each sample for measurement, and the average value was taken. Parameter settings: probe: TA3 / 100, measurement mode: TPA measurement, deformation amount: 70%, test speed: 2 mm / s, interval between two times: 3.00 s, trigger force: 3 g.

[0095] The sensory properties include hardness, adhesiveness, elasticity, and appearance, and the scoring criteria are shown in Table 8 below.

[0096] Table 8. Sensory evaluation indexes of antioxidant Spanish mackerel sausage

[0097]

[0098] The five antioxidant Spanish mackerel sausage samples were evaluated according to the above texture and sensory evaluation methods, and the evaluation results are shown in Table 9 below.

[0099] Table 9. Texture and sensory evaluation results of antioxidant Spanish mackerel sausage prepared with different texture improvers

[0100]

[0101]

[0102] Note: Different lowercase letters abcd in the same row indicate significant differences between groups (P < 0.05).

[0103] According to the data analysis in Table 9, in terms of hardness, among the fish sausages prepared with the five taste improvers, except for soy protein powder, the other four have relatively high hardness. Among them, the fish sausage prepared with potato starch has the highest hardness, followed by corn starch. In terms of viscosity, the fish sausage prepared with low-gluten wheat flour has the highest viscosity, followed by corn starch and potato starch, and finally soy protein isolate and soy protein powder. Among them, the fish sausages prepared with corn starch and potato starch have moderate viscosity, not as hard as those prepared with low-gluten wheat flour, nor as soft as those prepared with soy protein isolate and soy protein powder, so as to ensure that the fish sausages can be shaped without affecting the eating experience due to excessive viscosity. In terms of elasticity, the fish sausages prepared with potato starch, soy protein powder and soy protein isolate all have high elasticity. In contrast, although the elasticity of the fish sausages prepared with corn starch and low-gluten wheat flour is not as good as the former three, it is also relatively ideal. In terms of chewiness, the fish sausages prepared with potato starch and soy protein isolate are too "chewy", while the chewiness of the fish sausages prepared with corn starch, low-gluten wheat flour and soy protein powder is more moderate. Looking at the sensory evaluation scores again, since the fish sausage prepared with corn starch has moderate levels of hardness, viscosity, chewiness and elasticity, its sensory evaluation score is the best, indicating that its overall quality better meets the quality expectations of antioxidant mackerel fish sausage.

[0104] Based on the above indicators, the antioxidant mackerel fish sausage made of corn starch performs the most balanced in terms of hardness, viscosity, elasticity, chewiness and sensory evaluation. It is neither too hard nor too soft, nor too sticky or loose, and has been highly recognized in the sensory evaluation. Therefore, the antioxidant mackerel fish sausage made of corn starch has the best quality for pet snacks.

[0105] Furthermore, the nutritional components and antioxidant properties of the antioxidant mackerel fish sausages prepared with the above five different taste improvers were detected. The detection method refers to Example 2, and the detection results are shown in Table 10 below.

[0106] Table 10. Detection results of nutritional components and antioxidant properties of antioxidant mackerel fish sausages prepared with different taste improvers

[0107]

[0108] According to the data analysis in Table 10, in terms of antioxidant properties, the DPPH free radical scavenging rate and reducing power of the antioxidant mackerel fish sausage prepared with corn starch are the highest among the five taste improvers. In terms of nutritional components, only the antioxidant mackerel fish sausage prepared with corn starch has high protein and low fat. The crude protein content of the antioxidant mackerel fish sausage prepared with low-gluten wheat flour is lower than that of corn starch, while the antioxidant mackerel fish sausages prepared with potato starch, soy protein powder and soy protein isolate have low protein and high fat, which is not conducive to pet health.

[0109] Based on the above analysis, the preferred taste improver is corn starch.

[0110] Example 6: Optimization of the Proportions of Corn Starch, Water, and Antioxidant Peptides

[0111] The difference between this example and Example 1 lies in changing the proportions of corn starch, water, and antioxidant peptides, and the proportions of corn starch, water, and antioxidant peptides are shown in Table 11 below.

[0112] Table 11: Different Proportions of Corn Starch, Water, and Antioxidant Peptides

[0113] Test number A Water % B Starch % C Peptide % 1 20 20 1 2 20 30 3 3 20 40 5 4 10 20 5 5 10 30 1 6 10 40 3 7 30 20 3 8 30 30 5 9 30 40 1

[0114] Nine groups of excipients with different proportions in the above table were prepared into nine kinds of antioxidant Spanish mackerel sausages according to the method of Example 1, and then the texture and sensory evaluation were carried out on them with reference to the method provided in Example 4. The evaluation results are shown in Table 12 below.

[0115] Table 12: Texture and Sensory Evaluation Results of Antioxidant Spanish Mackerel Sausages Prepared with Different Proportions of Excipients

[0116]

[0117] According to the data analysis in Table 12, it can be seen that the sensory score of Test No. 9 is the best. In addition, with the increase in the content of peptide powder and starch, the hardness, elasticity, and chewiness of the fish sausage show an upward trend, and the viscosity first increases and then decreases, enhancing the texture of the fish sausage; with the increase in the amount of water added, the hardness, viscosity, elasticity, and chewiness of the fish sausage all show a downward trend, reducing its overall texture.

[0118] Furthermore, according to the data in Table 12 above, explore which one of water, starch, and antioxidant peptides is the key excipient that affects the hardness, viscosity, elasticity, chewiness, and sensory properties of antioxidant Spanish mackerel sausage respectively. The specific analysis method is as follows:

[0119] Add the hardness, viscosity, elasticity, chewiness, and sensory evaluation measured when the water ratio, starch ratio, or peptide ratio in Table 12 above is the same, and obtain the horizontal total values K1, K2, and K3 respectively. Then calculate the average values k1, k2, and k3 of K1, K2, and K3, and finally calculate the range R of k1, k2, and k3. The calculation results of the horizontal total values K1, K2, K3, the average values k1, k2, and k3, and the range R are shown in Table 13 below.

[0120] Table 13: Factors Affecting the Texture and Sensory Evaluation of Antioxidant Spanish Mackerel Sausage

[0121]

[0122]

[0123] According to the data analysis of Table 12 and Table 13, by comparing the ranges R of hardness, adhesiveness, elasticity, chewiness, and sensory evaluation respectively, it is found that the factors affecting hardness are B starch% > C antioxidant peptide% > A water%. Therefore, the optimal combination for hardness in Table 12 is A2B3C2 (water 20%, starch 40%, peptide 3%); the factors affecting adhesiveness are B starch% > C antioxidant peptide% > A water%. Therefore, the optimal combination for adhesiveness in Table 12 is A2B3C2 (water 20%, starch 40%, peptide 3%); the factors affecting elasticity are C antioxidant peptide% > A water% > B starch%. Therefore, the optimal combination for elasticity in Table 12 is A3B3C3 (water 20%, starch 40%, peptide 5%); the factors affecting chewiness are B starch% > C antioxidant peptide% > A water%. Therefore, the optimal combination for chewiness in Table 12 is A1B3C3 (water 20%, starch 40%, peptide 5%); the factors affecting sensory evaluation are B starch% > A water% > C antioxidant peptide%. Therefore, the optimal combination for sensory evaluation in Table 12 is A2B3C3 (water 20%, starch 40%, peptide 5%). Based on the above analysis, the factors affecting the quality of fish sausage are B starch% > C antioxidant peptide% > A water%. Combining the texture and sensory scores, the optimal combination is A2B3C3 (water 20%, starch 40%, peptide 5%). Therefore, the best process parameters are: water addition amount is 20%, starch addition amount is 40%, and peptide addition amount is 5%.

[0124] Example 7. Comparison of antioxidant activities of antioxidant peptides extracted by different methods

[0125] In this example, the antioxidant activities of antioxidant peptide powders extracted from Spanish mackerel by different extraction methods and the prepared antioxidant Spanish mackerel sausages will be compared.

[0126] Method 1: Prepare antioxidant peptide powder according to the extraction method provided in Example 1.

[0127] Method 2: Refer to the method provided in the published document CN114426998A. The specific steps are as follows: 1) Remove miscellaneous proteins: Cut the Spanish mackerel meat into small pieces and add it to a 7.5 g / 100 mL NaCl solution (the ratio of Spanish mackerel meat to NaCl solution is 1 g:10 mL). Stir for 12 h at an environmental temperature of 4°C to remove miscellaneous proteins, and then wash it with distilled water; 2) Degrease: After removing miscellaneous proteins, add 10% n-butanol solution (the volume ratio of Spanish mackerel meat to 10% n-butanol is 1:10) to the fish meat for degreasing. The degreasing condition is to stir at 4°C for 24 h and change the solution every 8 h. Finally, wash the Spanish mackerel meat with distilled water; 3) Prepare a homogenate: Accurately weigh the degreased and impurity-removed Spanish mackerel meat, add water, and put it into a homogenizer for homogenization. The mass ratio of water to raw material is 2:1 to obtain a Spanish mackerel homogenate; 4) Enzymolysis: Add an alkaline protease solution accounting for 0.8% of the mass of Spanish mackerel meat to the homogenate (the volume ratio of 0.8% alkaline protease to the homogenate is 1:20), add NaHCO3 to adjust the pH to 9.0, and enzymolyze at 47°C for 2 h; 5) Inactivate the enzyme and centrifuge: Put the solution after enzymolysis into 95°C to inactivate the enzyme for 10 min, cool the inactivated solution to 5°C, and centrifuge the cooled solution at a centrifugation speed of 10000 r / min for 20 min; 6) Ultrafiltration membrane filtration: Take the solution after inactivating the enzyme and centrifuging and perform ultrafiltration treatment through an ultrafiltration membrane. The molecular weight retained after filtration is above 10 kD; 7) Concentration and drying: Take the liquid after ultrafiltration membrane filtration and perform rotary evaporation at a rotary evaporation temperature of 60°C for 25 min to obtain an antioxidant peptide powder.

[0128] Method 3: Refer to the method provided in the published document CN112048534B. The specific steps are as follows: Use a meat grinder to grind Spanish mackerel meat with 10% crushed ice added into meat paste to obtain Spanish mackerel meat paste. Add deionized water according to a solid-liquid ratio of 1:5 (g / mL), where the mass of Spanish mackerel meat paste is 10 g and the volume of deionized water is 50 mL, and the pH value is 7 to form suspension 1; Add 2000 U / g of alkaline protease to suspension 1 and carry out an enzymolysis reaction under the condition of constant temperature at 45°C for 6 h to obtain suspension 2; Then heat suspension 2, the heating temperature is 90°C, and the heating time is 15 min. After cooling to room temperature, carry out centrifugation treatment at a low temperature of 4°C. The rotation speed of centrifugation treatment is 8000 rpm, and the centrifugation treatment time is 15 min. Take the supernatant to obtain extract 1. Use DEAE-cellulose (52) to separate extract 1 to obtain extract 2; Use Sephadex G-100 to separate extract 2 to obtain extract 3; Carry out freeze-drying on extract 3 to obtain an antioxidant peptide powder.

[0129] Furthermore, the antioxidant peptide powders prepared by the above three different methods were formulated into solutions to detect the concentration of antioxidant peptides. The detection method was referred to Example 1, and the detection results are shown in Table 14 below. Then, these three antioxidant peptide powders were prepared into antioxidant Spanish mackerel intestines according to the method in Example 1, and their DPPH free radical scavenging rate and reducing power were detected. The detection method was referred to Example 2, and the detection results are shown in Table 15 below.

[0130] Table 14. Concentrations of antioxidant peptide solutions extracted by different methods

[0131] Preparation method of antioxidant peptide powder Concentration of antioxidant peptide solution μg / mL Method 1 (This invention) 1703 Method 2 (CN114426998A) 1324 Method 3 (CN112048534B) 1269

[0132] Table 15. Antioxidant activities of antioxidant Spanish mackerel intestines prepared from antioxidant peptide powders extracted by different methods

[0133] Preparation method of antioxidant peptide powder DPPH free radical scavenging rate Reducing power Method 1 (This invention) 76.34％ 0.65 Method 2 (CN114426998A) 51.36％ 0.42 Method 3 (CN112048534B) 44.39％ 0.35

[0134] According to the data analysis in Tables 14 - 15, in the antioxidant peptide powder extracted by the antioxidant peptide extraction method provided by the present invention, in addition to the content of antioxidant peptides being significantly higher than the other two methods, the DPPH free radical scavenging rate and reducing power in the antioxidant Spanish mackerel intestines prepared therefrom are also significantly higher than the other two methods. In addition, the antioxidant peptide extraction method provided by the present invention is simple to operate and does not require complex pretreatment of Spanish mackerel meat or complex multiple ion exchange column chromatography for the enzymolysate. Instead, the complex steps reduce the extraction yield of antioxidant peptides. For Method 1 provided by the present invention, the protease used is neutral protease and its enzymolysis temperature is 30°C. For Method 2 and Method 3, the protease used is alkaline protease, and their enzymolysis temperatures are 47°C and 45°C respectively. Too high enzymolysis temperature may cause chemical changes in amino acid residues in fish meat, such as oxidation, deamination, etc. These changes will affect the amino acid composition of antioxidant peptides, and then change their physicochemical properties and biological activities. In addition, too high enzymolysis temperature may also cause aggregation or denaturation of fish meat proteins, change their structures and properties, making it difficult for proteases to approach and act on substrates, which will also affect the progress of the enzymolysis reaction and then reduce the extraction efficiency of antioxidant peptides.

[0135] Furthermore, the above three antioxidant peptides were prepared into antioxidant Spanish mackerel intestines according to the method in Example 1, and their nutritional components and antioxidant properties were detected. The detection method was referred to Example 2, and the detection results are shown in Table 16 below.

[0136] Table 16. Detection results of nutritional components and antioxidant properties of antioxidant Spanish mackerel intestines prepared from antioxidant peptide powders extracted by different methods

[0137]

[0138] According to the data analysis in Table 16, there are little differences in the moisture and crude ash contents of the antioxidant mackerel intestines prepared with the antioxidant peptide powders extracted by three different methods. However, the crude protein content of the fish intestines prepared by Method 1 (the present invention) is higher than the other two methods, while the crude fat and crude fiber contents are lower than the other two methods. In addition, the DPPH free radical scavenging rate and reducing power are higher, indicating stronger antioxidant ability. This shows that the antioxidant mackerel intestines prepared by the method provided by the present invention have the advantages of high protein, low fat and strong antioxidant ability.

[0139] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be subject to the scope defined by the claims.

Claims

1. An antioxidant mackerel sausage pet snack, characterized in that: The invention comprises mackerel meat and auxiliary materials, wherein the auxiliary materials comprise antioxidant peptide powder, and the antioxidant peptide powder is extracted from mackerel.

2. The antioxidant mackerel sausage pet snack according to claim 1, characterized in that: The auxiliary materials also include a taste improver, and the taste improver includes any one or more of corn starch, potato starch, low-gluten wheat flour, soy protein powder, and soy protein isolate.

3. The antioxidant mackerel sausage pet snack according to claim 2, characterized in that: The mouthfeel improver is corn starch; calculated by weight, the antioxidant peptide powder is 3-5 parts, the mackerel meat is 60-100 parts, and the corn starch is 24-40 parts.

4. The antioxidant mackerel sausage pet snack according to claim 3, characterized in that: The auxiliary materials also include water, which is 10-30 parts by weight. The antioxidant peptide powder is 5 parts, the mackerel meat is 60 parts, the corn starch is 40 parts, and the water is 20 parts.

5. The method for preparing the antioxidant mackerel sausage pet snack according to any one of claims 1 to 4, characterized in that: The following steps are involved: (1) grinding mackerel minced meat and mackerel by-products and adding water to prepare a raw material homogenate; (2) adding protease to the raw material homogenate for enzymatic hydrolysis, separation and purification to obtain antioxidant peptide powder; (3) The antioxidant peptide powder is mixed with mackerel meat, a taste improver and water, and then enema and steaming are performed to obtain antioxidant mackerel sausage pet snacks.

6. The preparation method according to claim 5, characterized in that: The mass ratio of the mackerel minced meat and mackerel by-products to water in step (1) is 1:

6.

7. The preparation method according to claim 5, characterized in that: The protease in step (2) includes any one or more of papain, alkaline protease and neutral protease; and the separation and purification includes centrifugal ultrafiltration, rotary evaporation and freeze drying.

8. The preparation method according to claim 7, characterized in that: The protease is a neutral protease, and the enzymolysis conditions are: enzyme addition amount 1000-1800U / g, temperature 10-50°C, pH value 5.0-9.0, and enzymolysis time 4-6h.

9. The preparation method according to claim 8, characterized in that: The cooking time in step (3) is 30-40 minutes.

10. Use of an antioxidant peptide powder for preparing antioxidant mackerel sausage pet snacks, characterized in that: The antioxidant peptide powder is extracted from mackerel meat.

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