Preparation method of enzymolysis anchovy cream for feed

Abstract

The invention discloses a preparation method of enzymolysis anchovy cream for feed. The preparation method comprises the following steps: directly preparing low-temperature minced fillet by taking an anchovy frozen plate as a unique raw material; transferring the low-temperature minced fillet into a fermentation container, and uniformly heating to a fermentation temperature for compound enzyme fermentation; in the fermentation process, an emulsification pump is synchronously adopted for first circulation emulsification; performing enzymolysis to obtain enzymolysis fish paste; performing high-temperature sterilization on the enzymolysis fish cream to obtain sterile fish cream; reducing the temperature of the sterile fish cream to medium temperature, adding a preservative and an emulsifier, and carrying out second circulation emulsification and homogenization by adopting an emulsification pump to obtain sterile homogenized fish cream; and cooling the sterile homogenized anchovy cream to room temperature, and sieving to obtain the enzymolysis anchovy cream product for feeding. According to the invention, through circulating emulsification and proper addition of the emulsifier and the preservative, the fish cream product has good stability and homogeneity and long preservation time, which not only is helpful for improving the processing and use efficiency of the feed, but also is helpful for ensuring the quality of the feed in the storage and use process.

Description

Technical Field

[0001] The invention belongs to the field of aquatic feed and relates to a method for preparing enzymatically hydrolyzed anchovy whole fish paste for feeding. Background Art

[0002] As an important marine economic fish, anchovies are rich in protein and polyunsaturated fatty acids, making them an important raw material in aquatic feed. Traditional anchovy processing methods, such as making fish meal or fish paste, usually include high-temperature drying or cooking steps, which not only lead to the denaturation and loss of nutrients such as protein and lipids, but also may produce harmful substances such as gizzard erosive factor and benzopyrene.

[0003] In aquatic feed, anchovy paste is a high-quality protein source, and its nutritional value and feeding effect are widely recognized. However, fish paste products in the prior art have some defects, especially in the process of storage and use, the easy stratification phenomenon becomes its main problem. After the fish paste is left to stand for a period of time, due to the density difference of different components, the oil and water phases often separate, resulting in the accumulation of oil in the upper layer and the poor nutrition of the lower water phase, which not only affects the uniformity and nutritional value of the feed, but also brings inconvenience to the processing and use of the feed.

[0004] In addition, in the process of processing, traditional fish paste products are often concentrated and defatted to reduce the water and oil content for easy storage and transportation, but this will lead to the loss of beneficial volatile attractants in the fish paste, such as trimethylamine oxide, thereby reducing the attractant effect of the fish paste. Therefore, the development of an enzymatic anchovy paste for feeding that can solve the problem of easy stratification and retain the nutrients of the whole fish is of great significance for improving the quality and effect of aquatic feed. Summary of the invention

[0005] In view of this, the object of the present invention is to provide a method for preparing enzymatically hydrolyzed anchovy whole fish paste for feeding which is not easy to stratify when stored at room temperature. The method effectively avoids the stratification of the fish paste during storage through a specific enzymatic hydrolysis process and an emulsification preservation treatment, while retaining all the nutrients in the anchovy, including fish oil and volatile attractant substances, thereby providing a high-quality raw material with high nutritional value, easy to store and use for aquatic feed.

[0006] The inventor has continuously innovated and reformed through long-term exploration and attempts, as well as multiple experiments and efforts, to solve the above technical problems. The technical solution provided by the present invention is to provide a method for preparing enzymatically hydrolyzed anchovy paste for feed, comprising the following steps in sequence:

[0007] S1, directly preparing low-temperature surimi using frozen anchovy plates as the only raw material;

[0008] S2, moving the low-temperature fish paste into a fermentation container, uniformly heating it to the fermentation temperature for compound enzyme fermentation; during the fermentation process, an emulsification pump is used to perform a first cycle of emulsification to obtain enzymatic fish paste;

[0009] S3, the enzymatically hydrolyzed fish paste is sterilized at high temperature to obtain sterile fish paste;

[0010] S4, lowering the temperature of the sterile fish paste to medium temperature, adding a preservative and an emulsifier, and using an emulsifying pump to perform a second cycle of emulsification and homogenization to obtain a sterile homogenized fish paste;

[0011] S5. After the aseptic homogenized fish paste is cooled to room temperature, it is sieved to obtain the enzymatic anchovy paste product for feed.

[0012] Furthermore, the anchovy frozen plate is an anchovy frozen plate for feeding.

[0013] The core technical function of the method for preparing enzymatic anchovy paste for feed of the present invention is to realize the efficient conversion and nutrition preservation of anchovy frozen plate raw materials through a series of finely controlled steps. First, the fish paste is prepared under low temperature conditions. This step reduces the damage to heat-sensitive nutrients in the raw materials and ensures the integrity of the nutritional components; water is not added in this step, which saves the subsequent concentration process. Secondly, by carrying out compound enzyme fermentation at a controlled temperature and combining the cyclic emulsification of the emulsification pump, the uniformity and thoroughness of the enzymatic hydrolysis process are promoted, so that the macromolecular proteins and fats in the fish paste are effectively converted into polypeptides and fatty acids that are more easily absorbed by animals. Finally, through high-temperature sterilization and subsequent medium-temperature emulsification treatment, not only the microbial safety of the product is ensured, but also the stability and homogeneity of the product are enhanced, thereby improving the quality and application value of the final product.

[0014] The overall technical concept of the present invention is to provide an innovative method for preparing enzymatic anchovy paste for feed, aiming to extract and retain the nutrients in anchovies to the maximum extent through mild physical treatment and precise enzymatic hydrolysis process, while ensuring the stability of the product and extending the shelf life. This concept is reflected in several key aspects: first, the selection of anchovy frozen plate as the single raw material ensures the purity and consistency of the product; second, the efficient conversion of protein and fat in the raw material is achieved through controlled low temperature and fermentation conditions; third, through two emulsification treatments, not only the stability of the product is enhanced, but also its application performance in feed is improved; finally, through high temperature sterilization and the addition of appropriate preservatives and emulsifiers, the safety and long-term preservation of the product are ensured. The implementation of this technical concept makes the prepared enzymatic anchovy paste for feed have significant advantages in nutritional value, processing performance and market application.

[0015] The beneficial effects of the present invention are:

[0016] (1) Due to the low temperature and precisely controlled enzymatic hydrolysis conditions, the product retains rich nutrients, such as high-quality protein and fatty acids, which are essential for improving the nutritional value of feed. (2) Through cyclic emulsification and the addition of appropriate emulsifiers and preservatives, the product has good stability and homogeneity, which not only helps to improve the processing and use efficiency of feed, but also helps to ensure the quality of feed during storage and use. (3) The high-temperature sterilization step effectively controls microbial contamination and ensures the hygiene and safety of the product. (4) The implementation of this method helps to improve the utilization efficiency of anchovy raw materials, reduce resource waste, and meet the requirements of sustainable development and environmental protection. (5) Except for a short enzyme inactivation time, the entire process does not involve excessive high-temperature processing and does not require concentration treatment. It is not easy to produce fish meal and other harmful substances such as gizzard erosive factors and benzopyrene produced by high-temperature processing, and effectively preserves trimethylamine and other volatile substances that have a strong appeal to animals. (6) After directed enzymatic hydrolysis by the complex enzyme, functional peptides or amino acids with flavor, appetite and growth promotion properties are produced. The acid-soluble protein content is high and the taste is not bitter or numbing. At the same time, it has the nutritional components of whole anchovies, is not easily stratified and oxidized, and is suitable for storage at room temperature. It is a functional raw material for appetite and growth promotion in animal feeds such as aquatic products, livestock and poultry.

[0017] On the basis of the above technical solution, the present invention can also be improved as follows:

[0018] Furthermore, in step S2, the rotation speed of the emulsification pump is 1200 to 2000 rpm.

[0019] Preferably, the rotation speed of the emulsifying pump is 1500-1800 rpm.

[0020] Preferably, the rotation speed of the emulsification pump is 1500 rpm.

[0021] Compared with the prior art, the beneficial effects of adopting the above further technical solution are:

[0022] By setting the speed of the emulsification pump in step S2 to 1200-2000 rpm, preferably 1500-1800 rpm, and particularly preferably 1500 rpm, it is ensured that the first cycle of emulsification operation in the complex enzyme fermentation process can efficiently decompose the protein and fat in the fish paste into smaller particles, thereby significantly improving the emulsification effect and the uniformity of the fish paste. Such a speed range helps to prevent mechanical damage caused by excessive emulsification, prevent the emulsification pump from being overloaded, and avoid the stratification and precipitation problems caused by insufficient emulsification, ensuring that the final product has better stability and a longer shelf life, while improving the bioavailability of nutrients, providing important technical support for the preparation of high-quality enzymatic anchovy paste for feed.

[0023] On the basis of the above technical solution, the present invention can also be improved as follows:

[0024] Furthermore, in step S4, the rotation speed of the emulsification pump is 1500 to 2500 rpm.

[0025] Preferably, the rotation speed of the emulsification pump is 2000-2200 rpm.

[0026] Preferably, the rotation speed of the emulsification pump is 2000 rpm.

[0027] Furthermore, the duration of the second cycle of emulsification and homogenization is 0.5 to 1.5 hours.

[0028] Preferably, the duration of the second cycle of emulsification and homogenization is 0.5 to 1 hour.

[0029] Compared with the prior art, the beneficial effects of adopting the above further technical solution are:

[0030] The efficient emulsification and homogenization of sterile fish paste after adding preservatives and emulsifiers was achieved. This sophisticated control strategy ensures that the preservatives and emulsifiers can be evenly distributed in the fish paste, forming a highly uniform and stable emulsion, thereby significantly improving the stability and homogeneity of the product, effectively preventing the stratification and precipitation of the product during storage, and extending the shelf life of the product. At the same time, the optimization of this emulsification parameter also helps to keep the nutrients in the fish paste from being destroyed to the greatest extent, ensuring that the final product has excellent nutritional quality and application performance, and providing important technical support for the production of high-quality enzymatic anchovy paste for feed.

[0031] On the basis of the above technical solution, the present invention can also be improved as follows:

[0032] Furthermore, the components of the emulsifier include 70% to 80% maltodextrin and 20% to 30% modified starch by weight.

[0033] Preferably, the modified starch comprises hydroxypropyl distarch phosphate or xanthan gum.

[0034] Furthermore, the added amount of the emulsifier is 0.3% to 0.6% of the weight of the sterile fish paste.

[0035] Compared with the prior art, the beneficial effects of adopting the above further technical solution are:

[0036] The fish paste emulsion is efficiently stabilized. The high content of maltodextrin helps to provide the viscosity and adhesion required by the emulsification system, ensuring the uniform distribution of the emulsion, while the addition of modified starch further enhances the stability of the emulsion and prevents the emulsion from separating during storage. This emulsifier combination not only optimizes the emulsification and homogenization effect of the fish paste, but also helps to maintain the physical stability of the product during long-term storage, preventing oil from floating and water from separating, thereby significantly improving the overall quality of the enzymatic anchovy paste product for feed, extending its shelf life at room temperature, and ensuring the wide applicability and economic value of the product in the feed industry.

[0037] On the basis of the above technical solution, the present invention can also be improved as follows:

[0038] Furthermore, the components of the preservative include, by weight percentage, 65% to 75% edible crude salt, 20% to 30% citric acid, 1% to 3% ethoxyquinoline, and 1% to 3% calcium propionate.

[0039] Furthermore, the added amount of the preservative is 8% to 10% of the weight of the sterile fish paste.

[0040] Compared with the prior art, the beneficial effects of adopting the above further technical solution are:

[0041] The high-efficiency preservation of enzymatic anchovy paste for feed has been achieved. The high proportion of edible crude salt helps to reduce water activity and inhibit the growth of microorganisms; citric acid not only reduces the pH value and enhances the antiseptic effect, but also helps stabilize vitamins and maintain the fresh taste of fish paste; ethoxyquin, as an effective antioxidant, can prevent oil oxidation and maintain product quality; the addition of calcium propionate further inhibits the growth of mold. In addition, the amount of preservative added is controlled at 8% to 10% of the weight of sterile homogenized fish paste, which can ensure the preservation effect without adversely affecting the nutritional value and sensory quality of the fish paste, thereby extending the shelf life of the product while ensuring food safety, improving the stability of the product during storage and transportation, and enhancing its market competitiveness.

[0042] On the basis of the above technical solution, the present invention can also be improved as follows:

[0043] Furthermore, the complex enzyme comprises neutral protease and lipase, and the neutral protease comprises papain and bromelain.

[0044] Preferably, the enzymatic activity of the papain is 2 million units (U / g); and the added amount is 0.06-0.1% of the weight of the surimi.

[0045] Preferably, the enzymatic activity of the bromelain is 500,000 units (U / g); and the added amount is 0.06-0.1% of the weight of the surimi.

[0046] Preferably, the lipase has an enzymatic activity of 100,000 units (U / g); and the added amount is 0.08-0.1% of the weight of the surimi.

[0047] Compared with the prior art, the beneficial effects of adopting the above further technical solution are:

[0048] The invention realizes efficient and directional enzymatic hydrolysis of anchovy surimi. The high activity of papain and bromelain ensures the rapid and thorough hydrolysis of the protein in the surimi under mild conditions, generating peptides and amino acids that are easy to digest and absorb, thereby improving the nutritional value and appetizing property of the surimi. The addition of lipase further promotes the hydrolysis of fat, releases energy-rich fatty acids, and enhances the energy density of the feed. The addition amount of these enzymes is precisely controlled, which not only ensures the efficiency of enzymatic hydrolysis, but also avoids unnecessary costs caused by excessive use, and finally realizes a feed enzymatic hydrolyzed anchovy surimi product that is rich in nutrients, easy to digest and absorb, and has good flavor. In addition, by precisely controlling the addition amount and activity of the enzymes, the method also helps to avoid bitterness and other undesirable flavors that may be produced by excessive hydrolysis, ensuring the palatability of the product and the feeding effect of the animal.

[0049] On the basis of the above technical solution, the present invention can also be improved as follows:

[0050] Preferably, the low temperature is 0-4°C, the fermentation temperature is 55±2°C, the medium temperature is 50-70°C, and the high temperature is 100-121°C.

[0051] Preferably, the enzymatically hydrolyzed anchovy paste product for feed is stored in a cool, dark and sealed condition for 1 to 90 days.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] The enzymatic anchovy paste for feed prepared by the method of the present invention is not easy to be stratified when stored at room temperature, and the enzymatic anchovy paste product for feed finally obtained can be stably stored for 1 to 90 days under a sealed condition in a cool and dark place without being easy to deteriorate. In contrast, some fish paste products have oily layer precipitation after standing for 24 hours. Through the method of the present invention, the synergistic effect of the complex enzyme, the precisely controlled emulsification process, and the addition of suitable preservatives and emulsifiers are utilized to significantly improve the physical stability of the fish paste, effectively prevent oil-water stratification and the loss of nutrients, thereby extending the shelf life of the product and enhancing its practicality and market competitiveness in the feed industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a picture of the actual storage state of enzymatically hydrolyzed anchovy paste for feed.

[0055] Figure 2This is a physical picture of the state of the enzymatically hydrolyzed anchovy paste sample for feed. DETAILED DESCRIPTION

[0056] The following describes the invention in conjunction with specific embodiments.

[0057] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention.

[0058] In the present invention, unless otherwise specified, all equipment and raw materials can be purchased from the market or are commonly used in the industry. The methods in the following embodiments, unless otherwise specified, are conventional methods in the art.

[0059] Example 1

[0060] The preparation method of enzymatically hydrolyzed anchovy paste for feed described in this embodiment comprises the following specific steps:

[0061] (1) The frozen anchovy plate is directly put into a grinder for crushing without thawing or adding water to obtain low-temperature surimi, wherein the temperature of the low-temperature surimi does not exceed 4°C.

[0062] (2) The low-temperature fish paste is pumped into a stainless steel enzymatic hydrolysis tank, stirred with a paddle and the tank is heated to a material temperature of 55°C.

[0063] (3) Adding a composite enzyme to the enzymolysis tank for enzymolysis, wherein the amount of papain (enzyme activity of 2 million U / g) and bromelain (enzyme activity of 500,000 U / g) added is 0.08% of the weight of the fish paste, and the amount of lipase (enzyme activity of 100,000 U / g) added is 0.1% of the weight of the fish paste, and the fish paste temperature is maintained at 55°C ± 2°C; at the same time, the emulsification pump is turned on for the first cycle of emulsification, and the speed of the emulsification pump is 1500 rpm. After enzymolysis and emulsification for 120 minutes, the enzymolysis fish paste is prepared.

[0064] (4) After the enzymatic hydrolysis is completed, the enzymatically hydrolyzed fish paste is heated to 100° C. and maintained for 15 minutes to inactivate the enzyme and sterilize to obtain a sterile homogenous fish paste.

[0065] (5) Cool the sterile homogenized fish paste naturally or with water to any temperature between 50 and 70°C, preferably 50, 55, 60, 65, or 70°C, and in this embodiment, 60°C. Then, add the preservative and emulsifier, and turn on the emulsifier pump to perform the second cycle of emulsification and homogenization. The speed of the emulsifier pump is 2000 rpm. The cycle of emulsification and homogenization starts from the addition of the preservative and emulsifier and ends when the preservative is cooled to room temperature. The components and their weight ratios in the preservative are: 65% edible crude salt, 30% citric acid, 2% ethoxyquinoline, and 3% calcium propionate; the amount of the preservative added is 8% of the weight of the sterile homogenized fish paste. The components and their weight ratios in the emulsifier are: 70% maltodextrin and 30% hydroxypropyl distarch phosphate; the amount of the emulsifier added is 0.4% of the weight of the sterile homogenized fish paste.

[0066] (6) The fish paste is cooled to room temperature and then pumped out, and after passing through a vibrating screen, the enzymatic hydrolyzed anchovy paste for feed is obtained, and the enzymatic hydrolyzed anchovy paste is packed into barrels, sealed, and stored in a cool, dark place for later use.

[0067] A series of nutrient content tests were conducted on the enzymatically hydrolyzed anchovy paste for feed obtained in the above examples, as shown in the following Tables 1 to 4.

[0068] Table 1 Nutrient composition index of enzymatic anchovy paste for feeding

[0069] index Numeric index Numeric index Numeric Moisture 75.0％ calcium 0.4％ Coarse ash 7.9％ Crude protein 12.5％ Total Phosphorus 1.1％ Crude fat 2.3％ Acid soluble protein 85.1％ Salt 6.0％ VBN 95.6mg / Kg

[0070] Note: Acid-soluble proteins generally refer to small peptides and amino acids with a molecular weight of 10,000 Daltons.

[0071] In the above Table 1, the moisture content was detected according to GB / T 6435-2014 Determination of moisture and other volatile substances in feed; the crude protein content was detected according to GB / T 6432-2018 Determination of crude protein in feed; the crude fat content was detected according to GB / T 6433-2006 Determination of crude fat in feed; the crude ash content was detected according to GB / T 6438-2007 Determination of crude ash in feed; the calcium content was detected according to GB / T 6436-2018 Determination of calcium in feed; the total phosphorus content was detected according to GB / T6437-2018 Determination of total phosphorus in feed by spectrophotometry; the salt content was detected according to GB / T 6439-2007 Determination of chloride in feed; and the VBN content was detected according to GB / T32141-2015 Determination of volatile basic nitrogen in feed.

[0072] As shown in Table 1, through the precise "enzymatic hydrolysis + secondary emulsification" process, a high degree of conversion of anchovy protein was achieved, and acid-soluble protein rich in low molecular weight peptides was generated, and its content accounted for 85.1% of the total protein. The cleverness of this process is that it uses directional enzymatic hydrolysis and synchronous emulsification technology to convert the macromolecular protein in anchovy into small peptides and amino acids that are easier to digest and absorb by animals, thereby improving the nutritional value and bioavailability of the feed. At the same time, the low level of volatile basic nitrogen (VBN) content (only 95.6 mg / Kg) shows that despite the enzymatic hydrolysis, the protein in the fish paste is not completely decomposed into free amino acids, which means that the acid-soluble protein is still mainly peptides. Such a treatment not only retains the nutritional value of fish protein to the maximum extent, but also avoids the loss and waste of nutrients caused by excessive hydrolysis, ensuring the efficiency and economy of the feed. Therefore, this method not only improves the nutritional value of the product, but also helps to improve the production performance of farmed animals, and has significant technical advantages and economic value.

[0073] Table 2 Amino acid index of enzymatic anchovy paste for feeding (wet basis)

[0074]

[0075]

[0076] In Table 2 above, the amino acid test adopts "GB / T 18246-2019 Determination of Amino Acids in Feed". The amino acid level in anchovy paste is one of the key indicators to measure its quality, because amino acids are the basic units of protein and are essential for animal life activities such as growth and development, tissue repair, and maintenance of immune function. As shown in Table 2, the total essential amino acids in anchovy paste accounted for 5.01% of the wet basis, indicating that it contains sufficient essential amino acids. These amino acids cannot be synthesized by the animal itself and must be ingested through diet, so they are essential for ensuring the nutritional needs of animals. At the same time, the sum of 17 amino acids accounted for 11.02% of the wet basis, reflecting the richness of total amino acids in anchovy paste, and the sum of 17 amino acids accounted for 88.16% of crude protein, which further highlighted the high quality and high nutritional value of protein in anchovy paste. These high levels of amino acid content not only help to improve the nutritional value of anchovy paste, but also make it have high application value in the feed industry, which can effectively promote the production performance of farmed animals and improve the conversion efficiency and economy of feed. Therefore, the amino acid level in anchovy paste is directly related to its quality and efficacy as a feed ingredient.

[0077] By analyzing the amino acid indexes shown in Table 3, we can conclude that the anchovy paste of this example is a high-quality protein source, especially because it provides a high proportion of essential amino acids and conditionally essential amino acids. This is essential for formulating a balanced feed diet, which can improve the production performance and health level of animals. In addition, the high content and balance of amino acids also indicate that anchovy paste has a high application value in the feed industry.

[0078] Table 3 Fatty acid index of enzymatic anchovy paste for feeding (ratio in crude fat)

[0079]

[0080] In the above Table 3, the detection of fatty acids adopts "GB / T 21514-2008 Determination of fatty acids in feed".

[0081] Fatty acids are the main components of fat and are essential for animal growth, life maintenance, energy storage, and cell structure. They are divided into saturated fatty acids and unsaturated fatty acids, among which the ω-3 and ω-6 series of unsaturated fatty acids are particularly important for animal health.

[0082] Table 3 lists the types of fatty acids detected in anchovy paste and their proportions in the total fatty acids.

[0083] in:

[0084] Saturated fatty acids (SFA): such as lauric acid (C12:0), myristic acid (C14:0), palmitic acid (C16:0) and stearic acid (C18:0). Saturated fatty acids are usually solid at room temperature and play a certain role in maintaining the structure and function of cell membranes.

[0085] Monounsaturated fatty acids (MUFA): such as palmitoleic acid (C16:1) and oleic acid (C18:1n9c). Monounsaturated fatty acids can lower LDL (bad cholesterol) levels in the blood while increasing HDL (good cholesterol) levels.

[0086] Polyunsaturated fatty acids (PUFA): such as linoleic acid (C18:2n6c), α-linolenic acid (C18:3n3), arachidonic acid (C20:4n6), EPA (C20:5n3), DHA (C22:6n3), etc. These are essential fatty acids that animals cannot synthesize on their own and must be ingested through diet. They are essential for brain development, vision protection, cardiovascular health, etc.

[0087] Special fatty acids: such as erucic acid (C22:1n9) and nervonic acid (C24:1). These fatty acids play a role in certain specific physiological functions.

[0088] Omega-3 fatty acids: Such as alpha-linolenic acid (C18:3n3), EPA, and DHA. Omega-3 fatty acids are important for reducing inflammation, promoting brain development, and maintaining cardiovascular health.

[0089] Omega-6 fatty acids: Such as linoleic acid and arachidonic acid. Omega-6 fatty acids are important for regulating the immune system and maintaining skin health, but excess amounts may cause inflammation.

[0090] DHA+EPA: These two are important components of ω-3 fatty acids and are generally considered to be particularly beneficial to the health of animals. The content of DHA+EPA is above 28%, which is a typical characteristic of marine fish nutrition.

[0091] By analyzing these fatty acid indicators, we can evaluate the nutritional value and potential health benefits of anchovy paste. The high content of omega-3 fatty acids, especially the presence of EPA and DHA, indicates that anchovy paste is a high-nutritional feed ingredient that can be used as a source of omega-3 fatty acids to help improve the meat quality and nutritional value of farmed animals. At the same time, the balance of saturated fatty acids and monounsaturated fatty acids is also important to ensure the overall nutritional value of the feed.

[0092] Table 4 Biogenic amine index of enzymatic anchovy paste for feeding (wet basis)

[0093] Biogenic amine index Value mg / kg Biogenic amine index Value mg / kg Tryptamine 124.55 histamine 74.36 Putrescine 15.55 Tyramine 15.40 Cadaverine 83.29 Spermidine 34.97 Spermine 7.67 .

[0094] In the above Table 4, the detection of biogenic amines adopts "GB / T 23884-2021 Determination of biogenic amines in animal-derived feeds by high performance liquid chromatography". As shown in Table 4, the indicators of various biogenic amines are low, indicating that the enzymatic hydrolysis process is rapid and accurate, does not produce much corrupt substances, and has little negative impact on the health of farmed animals.

[0095] The anchovies used in this embodiment are of poor quality for feeding. If anchovies of higher quality are selected, the above test index test results will better reflect the technical advantages.

[0096] The enzymatically hydrolyzed anchovy paste for feed prepared in this embodiment has functional peptides or amino acids such as flavor, appetite and growth promotion, a high acid-soluble protein content and no bitterness or numbness, and at the same time has the nutritional components of a whole anchovy, is not easy to stratify and oxidize, and is suitable for storage at room temperature. It is a functional raw material for appetite and growth promotion in animal feeds such as aquatic products, livestock and poultry.

[0097] After observation, the enzymatic anchovy paste for feed prepared in this embodiment Figure 1The fish paste was stored in the packaging bag shown, and no stratification was found on the 83rd day. No stratification was observed during the 83-day storage period, indicating that the fish paste product has excellent stability through specific enzymatic hydrolysis and emulsification treatment, which is essential to ensure that the feed product maintains its quality during storage and transportation. Long-term storage also proves the effectiveness of preservatives. The proper addition and selection of preservatives play a key role in extending the shelf life of fish paste and maintaining its freshness. Long-term storage without stratification also proves the effectiveness of emulsifiers. Emulsifiers reduce the interfacial tension of different components in fish paste (such as oil and water) and promote the formation of a uniform emulsion, thereby effectively preventing stratification and precipitation.

[0098] Take a small amount of enzymatic anchovy paste for feeding and observe it in a beaker. Figure 2 The uniform and fine texture observed in the sampling reflects the excellent emulsification effect during the preparation process, which enables the oil phase and water phase in the fish paste to be fully mixed to form a stable emulsion, which helps to improve the digestibility and nutritional value of the feed. Fine and uniform texture is usually associated with good taste and high digestibility, which has a positive effect on improving the appetite and growth performance of animals.

[0099] This stability and uniformity indicate that the enzymatically hydrolyzed anchovy paste is suitable as a feed raw material and can be widely used in aquaculture and livestock and poultry breeding. This embodiment reduces stratification and corruption, reduces product loss, improves the utilization efficiency of feed raw materials, and thus improves economic benefits.

[0100] Example 2

[0101] The difference between this embodiment and embodiment 1 is that:

[0102] The added amount of papain and bromelain was 0.06% of the weight of the surimi, and the added amount of lipase was 0.08% of the weight of the surimi.

[0103] The rest of the technical conditions are the same.

[0104] The nutritional indexes of the enzymatically hydrolyzed anchovy paste for feed prepared in this example are shown in Table 5.

[0105] Table 5 Nutrient composition index of enzymatic anchovy paste for feeding

[0106] index Numeric index Numeric index Numeric Moisture 75.0％ calcium 0.5％ Coarse ash 7.8％ Crude protein 12.2％ Total Phosphorus 1.2％ Crude fat 2.2％ Acid soluble protein 65.2％ Salt 6.1％ VBN 86.2mg / kg .

[0107] From the analysis of Table 5, it can be seen that in Example 2, compared with Example 1, the addition amount of papain and bromelain was reduced from 0.08% to 0.06% of the weight of the surimi, and the addition amount of lipase was reduced from 0.1% to 0.08% of the weight of the surimi, resulting in a significant decrease in the acid-soluble protein content to 65.2%, which is much lower than 85.1% of Example 1, and the content of peptides below 10,000 Daltons is low. This shows that the amount of enzyme added directly affects the efficiency and degree of enzymolysis, and thus affects the content of acid-soluble protein and the release of peptides.

[0108] In addition, although Example 2 used the same emulsifier combination and emulsification process as Example 1, oil separation occurred after standing for 24 hours. The main reason is that the degree of enzymatic hydrolysis is not enough, resulting in insufficient emulsification and dispersion of fat and protein, resulting in stratification during the standing process. The emulsification process involves forming a uniformly dispersed mixture of two liquids that are usually immiscible (such as water and oil), and the emulsifier helps to stabilize the mixture. In this example, the emulsifier may not have fully played its role because the peptides and fatty acids produced by enzymatic hydrolysis were not fully dispersed, resulting in oil-water stratification.

[0109] Therefore, this result emphasizes the importance of the amount of enzyme added during the enzymatic hydrolysis process on the quality of the final product, as well as the necessity to maintain a proper emulsification effect during the preparation process, as enzymatic hydrolysis is closely linked to emulsification.

[0110] Example 3

[0111] The difference between this embodiment and embodiment 1 is that:

[0112] The speed of the emulsification pump during the first cycle of emulsification is 1800 rpm, and the speed of the emulsification pump during the second cycle of emulsification and homogenization is 2500 rpm; the amount of the preservative added is 10% of the weight of the fish paste, and the emulsifier contains the following components in weight parts: 80% of maltodextrin and 20% of hydroxypropyl distarch phosphate; the amount of the emulsifier added is 0.6% of the weight of the fish paste.

[0113] The rest of the technical conditions are the same.

[0114] The nutritional indexes of the enzymatically hydrolyzed anchovy paste for feed prepared in this example are shown in Table 6.

[0115] Table 6 Nutrient composition index of enzymatic anchovy paste for feeding

[0116] index Numeric index Numeric index Numeric Moisture 75.4％ calcium 0.5％ Coarse ash 8.1％ Crude protein 12.2％ Total Phosphorus 1.1％ Crude fat 2.3％ Acid soluble protein 86.2％ Salt 6.0％ VBN 98.7mg / kg .

[0117] The main differences between this embodiment and embodiment 1 are the rotation speed of the emulsifying pump, the addition amount of the preservative and emulsifier, and the ratio of the emulsifier components. The results show that these changes have a significant impact on the stability of the final product.

[0118] Increase of the speed of the emulsification pump: In this embodiment, the speed of the emulsification pump is increased to 1800 rpm during the first cycle of emulsification, and increased to 2500 rpm during the second cycle of emulsification and homogenization. Compared with 1500 rpm and 2000 rpm in Example 1, theoretically, a higher speed helps to disperse the fat and protein in the fish paste more finely, thereby improving the uniformity and stability of the emulsion. However, despite the increase in speed, this embodiment showed a slight stratification phenomenon after standing for 24 hours, which shows that simply increasing the speed of the emulsification pump is not enough to completely overcome the decrease in stability caused by other changes.

[0119] Increase in the amount of preservative added: The amount of preservative added in this embodiment is increased from 8% in Example 1 to 10%. The increase in preservative can improve the antioxidant capacity and antiseptic properties of the product, and help extend the shelf life of the fish paste. However, excessive addition of preservative may affect the physical properties of the fish paste, such as viscosity and surface tension, and thus affect the stability of the emulsion.

[0120] Changes in emulsifier components: In this example, the composition ratio of the emulsifier has changed, the proportion of maltodextrin has increased from 70% to 80%, and the proportion of hydroxypropyl distarch phosphate has decreased from 30% to 20%. This change affects the hydrophilic-lipophilic balance (HLB) value of the emulsifier, and thus affects its emulsifying ability. The addition of maltodextrin may increase the viscosity of the system and enhance the stabilizing effect of the emulsifier, but it may also increase the viscosity of the system, resulting in poor fluidity, thereby affecting the uniformity of the emulsion.

[0121] Increase in the amount of emulsifier added: The amount of emulsifier added in this example is increased from 0.4% in Example 1 to 0.6%. The increase in the amount of emulsifier can enhance its adsorption on the oil-water interface, form a more stable emulsion film, and help improve the stability of the emulsion. However, excessive use of emulsifier may also cause the emulsion to be too viscous, affecting the sensory properties and application performance of the emulsion.

[0122] Although the stability of the product was enhanced by increasing the speed of the emulsifying pump and the amount of preservative and emulsifier added in this example, due to the interaction of various factors, the final product still showed a slight stratification phenomenon after standing for 24 hours. This shows that in the actual production process, it is necessary to comprehensively consider various factors and optimize the process parameters to ensure the stability and quality of the product.

[0123] In the description of the present invention, it should be understood that "-" and "~" represent the range between two values, and the range includes the endpoints. For example: "AB" represents a range greater than or equal to A and less than or equal to B. "A~B" represents a range greater than or equal to A and less than or equal to B.

[0124] In the description of the present invention, the term "and / or" herein is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent three situations: A exists alone, A and B exist at the same time, and B exists alone.

[0125] In the description of the invention, the numerical values ​​of time, temperature, ratio, mass, etc. involved may be based on actual measurements, standard parameters of equipment, simplified rounding results, or within an acceptable error range, ensuring the practicability and repeatability of the invention.

[0126] In the description of the present invention, the term "about" or "approximately" is used to express the approximate value of a numerical value or range, allowing a certain error to ensure the flexibility and practicality of the description while remaining within an acceptable error range, with the maximum error range not exceeding 10% of the corresponding numerical value or numerical range.

[0127] The above are only preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as limiting the present invention, and the protection scope of the present invention should be based on the scope defined by the claims. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing enzymatically hydrolyzed anchovy paste for feeding, characterized in that: The following steps are included: S1, directly preparing low-temperature surimi using frozen anchovy plates as the only raw material; S2, moving the low-temperature fish paste into a fermentation container, uniformly heating it to the fermentation temperature for compound enzyme fermentation; during the fermentation process, an emulsification pump is used to perform a first cycle of emulsification to obtain enzymatic fish paste; S3, the enzymatically hydrolyzed fish paste is sterilized at high temperature to obtain sterile fish paste; S4, lowering the temperature of the sterile fish paste to medium temperature, adding a preservative and an emulsifier, and using an emulsifying pump to perform a second cycle of emulsification and homogenization to obtain a sterile homogenized fish paste; S5. After the aseptic homogenized fish paste is cooled to room temperature, it is sieved to obtain the enzymatic anchovy paste product for feed.

2. The method for preparing enzymatically hydrolyzed anchovy paste for feed according to claim 1, characterized in that: In step S2, the rotation speed of the emulsification pump is 1200-2000 rpm.

3. The method for preparing enzymatically hydrolyzed anchovy paste for feed according to claim 1, characterized in that: In step S4, the rotation speed of the emulsification pump is 1500-2500 rpm.

4. The method for preparing enzymatically hydrolyzed anchovy paste for feed according to any one of claims 1 to 3, characterized in that: The components of the emulsifier include 70% to 80% maltodextrin and 20% to 30% modified starch by weight percentage.

5. The method for preparing enzymatically hydrolyzed anchovy paste for feed according to claim 4, characterized in that: The added amount of the emulsifier is 0.3% to 0.6% of the weight of the sterile fish paste.

6. The method for preparing enzymatically hydrolyzed anchovy paste for feed according to claim 4, characterized in that: The components of the preservative include, by weight percentage, 65% to 75% edible crude salt, 20% to 30% citric acid, 1% to 3% ethoxyquinoline, and 1% to 3% calcium propionate.

7. The method for preparing enzymatically hydrolyzed anchovy paste for feed according to claim 6, characterized in that: The added amount of the preservative is 8% to 10% of the weight of the sterile fish paste.

8. The method for preparing enzymatically hydrolyzed anchovy paste for feed according to claim 1, characterized in that: The complex enzyme comprises neutral protease and lipase, and the neutral protease comprises papain and bromelain.

9. The method for preparing enzymatically hydrolyzed anchovy paste for feed according to claim 1, characterized in that: The low temperature is 0-4°C, the fermentation temperature is 55±2°C, the medium temperature is 50-70°C, and the high temperature is 100-121°C.

10. The method for preparing enzymatically hydrolyzed anchovy paste for feed according to claim 1, characterized in that: The enzymatic anchovy paste product for feed can be stored in a cool, dark and sealed place for 1 to 90 days.

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