A marine fish bait and its preparation process

Abstract

This application discloses a marine fish feed and its preparation process, relating to the field of aquaculture feed technology. It includes 73.2-82.8 parts by weight of protein components, 10.8-13.2 parts by weight of energy components, 4.5-5.6 parts by weight of fortifying components, 2.5-3.5 parts by weight of functional additives, and 33.5-40% by weight of a compound bacterial solution. The protein components include 28-32 parts by weight of red fish meal, 40-43 parts by weight of modified compound protein, 4-6 parts by weight of soybean protein concentrate, and 1.2-1.8 parts by weight of compound enzymatically hydrolyzed fish lysate. The modified compound protein is a biparental composite modified protein grafted with hydrophilic and hydrophobic monomers. This application achieves the effect of gentle dissolution of the feed in seawater through the combination of biparental composite modified protein and fortifying components, along with the synergistic effect of specific components, thereby improving nutrient utilization and digestibility, reducing fish meal dependence and aquaculture costs, and promoting fish growth.

Description

Technical Field

[0001] This application relates to the field of aquaculture feed technology, and in particular to a marine fish feed and its preparation process. Background Technology

[0002] Marine fish feed refers to specialized nutritional substances made from natural or synthetic raw materials through specific processes, based on the physiological characteristics, nutritional needs, and growth stages of marine fish. It is used to meet the feeding, growth, development, and reproduction needs of marine fish and is a core basic material for ensuring aquaculture efficiency and improving fish quality in the marine aquaculture industry.

[0003] In existing technologies, the composition of marine fish bait has formed a complex system mainly composed of core nutritional components, functional additives, and carrier raw materials. Specifically, it can be divided into the following categories: First, protein sources, which are the core nutritional components of the bait, mainly include animal and plant-derived proteins such as fishmeal, soy protein concentrate, and casein. Among them, fishmeal, due to its balanced amino acid composition, accounts for 40%-65% of the bait for valuable species such as grouper and deep-sea farmed fish. It is also combined with shrimp shell powder, krill powder, and frozen tubifex powder to enhance palatability and protein utilization. Second, energy supply components, mainly carbohydrates provided by grain raw materials such as flour and cassava flour. The feed consists of four main components: first, a combination of oils such as soybean oil and fish oil to supplement energy and essential fatty acids. Fish oil, rich in active ingredients such as DHA, is an essential component in both fry and adult fish feed; second, a vitamin and mineral system covering essential nutrients such as VA, VC, VE, calcium, phosphorus, and zinc, usually added as a compound additive. Some feeds use VC phosphate esters or other stabilizing forms to improve nutrient retention; and third, functional additives, including binders such as sodium carboxymethyl cellulose, antifungal agents such as calcium propionate, antioxidants such as butylated hydroxyanisole, and probiotics such as Bacillus subtilis, used to improve feed stability, extend shelf life, and regulate fish gut health.

[0004] However, existing marine fish feeds suffer from poor stability in water, especially in seawater, and difficulty in retaining nutrients, which are difficult to effectively solve. When using marine fish feeds with conventional binders, the high salinity of the seawater environment causes the feed to dissolve too quickly or settle too rapidly, resulting in nutrient loss, reduced feed utilization, and water pollution due to the decomposition of residual feed, thus increasing the risk of fish diseases. While adding excessive binders to reduce the dissolution rate of marine fish feeds can reduce palatability and affect the feeding enthusiasm of marine fish, improvements are needed. Summary of the Invention

[0005] In view of this, the first objective of this application is to provide a marine fish bait and its preparation process, so as to achieve gentle dissolution and improve nutrient utilization. The specific solution is as follows:

[0006] A marine fish feed comprises, by weight, 73.2-82.8 parts protein, 10.8-13.2 parts energy, 4.5-5.6 parts fortifying components, 2.5-3.5 parts functional additives, and 33.5-40% compound bacterial solution by weight; wherein:

[0007] The protein components include 28-32 parts of red fish meal, 40-43 parts of modified compound protein, 4-6 parts of soy protein concentrate, and 1.2-1.8 parts of compound enzymatically hydrolyzed fish lysate.

[0008] The modified composite protein is an amphiphilic composite modified protein grafted with hydrophilic and hydrophobic monomers.

[0009] Preferably, the preparation method of the amphiphilic composite modified protein includes step ① mixing the composite animal and plant protein with sodium sulfite and deionized water at a mass ratio of 40:0.5-0.55:9.5-10, stirring at a controlled temperature of 48-50℃ for 28-32 minutes, then freeze-drying under vacuum until the moisture content is below 8% and pulverizing to 80-120 mesh to obtain the activated protein; step ② mixing polyethylene glycol monomethyl ether with glycidyl octanoate and triethylamine at a mass ratio of 3:1.9-2.05:0.09-0.1, stirring at a controlled temperature of 68-70℃... After reacting at ℃ for 2-2.1 h, grafting mixture A is obtained; in step ③, the activating protein and grafting mixture A are mixed at a mass ratio of 10:1-1.1, and then an ammonium sulfate solution with a solid-liquid ratio of 1:5 is added. The mass ratio of ammonium sulfate to grafting mixture in the ammonium sulfate solution is controlled at 0.3:1-1.1, and the temperature is 65-67℃. The reaction is carried out under an inert gas atmosphere for 1.5-1.7 h to obtain grafting mixture B; in step ④, grafting mixture B is successively subjected to centrifugation, washing with anhydrous ethanol, and vacuum drying at 60℃ to obtain amphiphilic composite modified protein.

[0010] Preferably, the energy component comprises 3.5-4 parts of deep-sea fish oil, 2.8-3.2 parts of refined soybean oil, and 4.5-6 parts of modified corn starch; the modified corn starch is a temperature-sensitive modified starch cross-linked with N-isopropylacrylamide.

[0011] Preferably, the preparation method of the temperature-sensitive modified starch includes step ① mixing corn starch and deionized water at a mass ratio of 1:4-5, gelatinizing at a controlled temperature of 88-90℃ for 28-30 minutes, then cooling to 35-40℃ and adjusting the pH to 3.5-4 for acid hydrolysis to obtain activated starch; step ② mixing N-isopropylacrylamide and N,N'-methylenebisacrylamide at a mass ratio of 2:0.2-0.21, then adding an ethanol solution of azobisisobutyronitrile, controlling the azobisisobutyronitrile... In the ethanol solution of nitrile butadiene nitrile, the mass ratio of azobisisobutyronitrile to N,N'-methylenebisacrylamide is 0.1:0.2-0.21, and the mixture is refluxed at 68-70℃ for 1-1.2 h to obtain PNIPAM-thermosensitive polymer; in step ③, activated starch and PNIPAM-thermosensitive polymer are mixed with a mass ratio of 3:1-1.1, and the pH is adjusted to neutral with sodium hydroxide. The mixture is stirred at 53-55℃ for 45-48 min to obtain thermosensitive modified starch.

[0012] Preferably, the fortifying components include 1.3-1.7 parts of calcium dihydrogen phosphate, 0.3-0.5 parts of choline chloride, 1.5-1.8 parts of multilayer core-shell vitamin microcapsules, and 1.4-1.6 parts of zinc, iron, and selenium mineral premix; wherein the multilayer core-shell vitamin microcapsules are obtained by sequentially encapsulating compound vitamins from the inside out with sodium alginate, chitosan, and PLGA.

[0013] Preferably, the preparation method of the multilayer core-shell vitamin microcapsules includes step ① mixing vitamins, taurine, and gum arabic in a mass ratio of 1.4-1.5:0.5-0.52:1-1.1, and obtaining a core material suspension with a solid content of less than 40% after adding deionized water and stirring; step ② adding the core material suspension dropwise to an aqueous solution of sodium alginate and stirring, and adding calcium chloride, controlling the mass ratio of sodium alginate, calcium chloride, and vitamins to be 2:0.28-0.3:1.4-1. Step 5: Obtain sodium alginate inner layer microcapsules; Step ③: Transfer the sodium alginate inner layer microcapsules to an acetic acid solution of chitosan with a pH of 4.0-4.5, and control the mass ratio of chitosan to vitamins to be 1.5:1.4-1.5. After stirring, obtain the middle layer wall material capsules; Step ④: Add a dichloromethane solution of PLGA to the middle layer wall material capsules, and control the mass ratio of PLGA to vitamins to be 1:1.4-1.5. After ultrasonic treatment and spray drying, obtain multilayer core-shell type vitamin microcapsules.

[0014] Preferably, the particle size of the sodium alginate inner layer microcapsules is 5-10 μm; the ultrasonic treatment time is 15-18 min; the inlet air temperature of the spray drying is 78-80℃, and the outlet air temperature is 43-45℃.

[0015] Preferably, the functional additive includes 0.3-0.5 parts of betaine, 0.12-0.16 parts of coated methionine, 0.25-0.33 parts of coated lysine, 0.15-0.2 parts of taurine, and 1.8-2.2 parts of thermosensitive modified starch.

[0016] Preferably, the compound bacterial solution comprises compound bacteria, brown sugar, and deionized water in a mass ratio of 3.5-5:0.012-0.018:30-35; the compound bacteria are composed of Bacillus subtilis and Saccharomyces cerevisiae in a mass ratio of 2:1.

[0017] The second objective of this invention is to provide a process for preparing marine fish bait, for preparing the marine fish bait as described above, characterized by comprising the following steps:

[0018] Step 1: Mix the corresponding weight parts of protein components, energy components, fortifying components and functional additives to obtain a mixture;

[0019] Step 2: Add deionized water to the mixture to adjust the moisture content of the material to 18-20% and then condition it. Control the conditioning temperature to 85-90℃ and the pressure to 0.1-0.12MPa and condition for 2-3 minutes to obtain the conditioned material.

[0020] Step 3: Granulate the conditioning material to obtain bait pellets, mix the bait pellets with the compound bacterial liquid for fermentation, control the fermentation temperature at 35-37℃ for 48-50 hours, remove and dry to obtain finished marine fish bait with a moisture content of less than 10%.

[0021] As can be seen from the above solutions, this application provides a marine fish bait and its preparation process, which has the following beneficial effects:

[0022] 1. By combining the modified protein of both parents with the synergistic effect of specific components, the feed can be gently dissolved in seawater, improving nutrient utilization and digestibility, reducing fishmeal dependence and aquaculture costs, and promoting fish growth.

[0023] 2. By grafting hydrophilic and hydrophobic monomers onto the amphiphilic composite modified protein to form hydrogen bonds and hydrophobic interactions with starch hydroxyl groups and fatty acid chains of lipids, molecular bridges are constructed between components, thereby effectively avoiding the problem of loose and easily soluble traditional feeds; at the same time, the interpenetrating network structure of the temperature-sensitive modified starch allows for slow water absorption and expansion in the seawater environment without disintegration, thus achieving a gentle dissolution effect.

[0024] 3. Through the multi-layered core-shell type vitamin microcapsules, sodium alginate, chitosan, and PLGA form a gradient shell protection structure, thereby achieving the effects of oxygen barrier, high temperature resistance, and significantly improved stability in the alkaline environment of seawater. When it enters the acidic environment of the fish intestine, it plays a role in rapid degradation and release. In addition, the probiotics in the compound bacterial solution simultaneously promote the activity of intestinal digestive enzymes, thereby effectively improving the absorption efficiency of vitamins and proteins.

[0025] 4. By dynamically adjusting the network density of the thermosensitive modified starch according to the temperature of the seawater, the dissolution stability at different water temperatures can be effectively guaranteed; and the three-dimensional network structure of the modified amphiphilic composite protein will encapsulate the nutrients, which will reduce the loss of seawater and enhance the protein degradation properties by combining with the compound enzymatic hydrolysis of fish lysate. Detailed Implementation

[0026] The technical solutions described below in conjunction with the embodiments of this application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0027] It should be mentioned that, in the embodiments of this application, the compound animal and plant protein is a mixture of soybean meal and cottonseed meal in a mass ratio of 3:1.

[0028] The following will provide a detailed description of a marine fish bait and its preparation process according to this application.

[0029] A marine fish feed comprises 73.2-82.8 parts by weight of protein component, 10.8-13.2 parts by weight of energy component, 4.5-5.6 parts by weight of fortifying component, 2.5-3.5 parts by weight of functional additive, and 33.5-40% by weight of compound bacterial liquid.

[0030] The protein components include 28-32 parts of red fish meal, 40-43 parts of modified composite protein, 4-6 parts of soy protein concentrate, and 1.2-1.8 parts of complex enzymatically hydrolyzed fish lysate. Furthermore, the modified composite protein is an amphiphilic composite modified protein grafted with both hydrophilic and hydrophobic monomers.

[0031] To obtain the amphiphilic composite modified protein, the preparation method of the amphiphilic composite modified protein in the embodiments of this application includes step ① mixing the composite animal and plant protein with sodium sulfite and deionized water at a mass ratio of 40:0.5-0.55:9.5-10, stirring at a controlled temperature of 48-50℃ for 28-32 minutes, then freeze-drying under vacuum until the moisture content is below 8% and pulverizing to 80-120 mesh to obtain the activated protein; step ② mixing polyethylene glycol monomethyl ether with glycidyl octanoate and triethylamine at a mass ratio of 3:1.9-2.05:0.09-0.1, and stirring at a controlled temperature of 48-50℃ for 28-32 minutes, then freeze-drying under vacuum until the moisture content is below 8% and pulverizing to 80-120 mesh to obtain the activated protein; After reacting at 68-70℃ for 2-2.1h, grafting mixture A is obtained; in step ③, the activating protein and grafting mixture A are mixed at a mass ratio of 10:1-1.1, and then an ammonium sulfate solution with a solid-liquid ratio of 1:5 is added. The mass ratio of ammonium sulfate to grafting mixture in the ammonium sulfate solution is controlled at 0.3:1-1.1, and the temperature is 65-67℃. The reaction is carried out under an inert gas atmosphere for 1.5-1.7h to obtain grafting mixture B; in step ④, grafting mixture B is subjected to centrifugation, washing with anhydrous ethanol, and vacuum drying at 60℃ to obtain amphiphilic composite modified protein.

[0032] The energy components include 3.5-4 parts deep-sea fish oil, 2.8-3.2 parts refined soybean oil, and 4.5-6 parts modified corn starch. The modified corn starch is a temperature-sensitive modified starch cross-linked with N-isopropylacrylamide. The preparation method of the temperature-sensitive modified starch includes step ① mixing corn starch and deionized water at a mass ratio of 1:4-5, gelatinizing at a controlled temperature of 88-90℃ for 28-30 minutes, then cooling to 35-40℃ and adjusting the pH to 3.5-4 for acid hydrolysis to obtain activated starch; step ② mixing N-isopropylacrylamide and N,N'-methylenebisacrylamide at a mass ratio of 2:0.2-0.21, then adding an ethanol solution of azobisisobutyronitrile, controlling the azobisisobutyronitrile... The mass ratio of azobisisobutyronitrile to N,N'-methylenebisacrylamide in the ethanol solution is 0.1:0.2-0.21, and the reaction is carried out under reflux at 68-70℃ for 1-1.2h to obtain PNIPAM-thermosensitive polymer; in step ③, activated starch and PNIPAM-thermosensitive polymer are mixed with a mass ratio of 3:1-1.1, and the pH is adjusted to neutral with sodium hydroxide. The reaction is carried out at 53-55℃ with stirring for 45-48min to obtain thermosensitive modified starch.

[0033] The fortified components include 1.3-1.7 parts of calcium dihydrogen phosphate, 0.3-0.5 parts of choline chloride, 1.5-1.8 parts of multilayer core-shell vitamin microcapsules, and 1.4-1.6 parts of zinc, iron, and selenium mineral premix. The multilayer core-shell vitamin microcapsules are obtained by encapsulating the complex vitamins sequentially from the inside out with sodium alginate, chitosan, and PLGA.

[0034] The preparation method of multilayer core-shell vitamin microcapsules includes step ① mixing vitamins, taurine, and gum arabic in a mass ratio of 1.4-1.5:0.5-0.52:1-1.1, and obtaining a core material suspension with a solid content of less than 40% after adding deionized water and stirring; step ② adding the core material suspension dropwise to an aqueous solution of sodium alginate and stirring, and adding calcium chloride, controlling the mass ratio of sodium alginate, calcium chloride, and vitamins to be 2:0.28-0.3:1.4-1.5, to obtain sodium alginate inner layer microcapsules with a particle size of 5-10 μm; step Step ③: Transfer the sodium alginate inner layer microcapsules to an acetic acid solution of chitosan at pH 4.0-4.5, controlling the mass ratio of chitosan to vitamins to be 1.5:1.4-1.5. After stirring, the middle layer wall material capsules are obtained. Step ④: Add a dichloromethane solution of PLGA to the middle layer wall material capsules, controlling the mass ratio of PLGA to vitamins to be 1:1.4-1.5. After ultrasonic treatment for 15-18 minutes and spray drying with the inlet air temperature controlled at 78-80℃ and the outlet air temperature controlled at 43-45℃, multi-layer core-shell type vitamin microcapsules are obtained.

[0035] The functional additives include 0.3-0.5 parts of betaine, 0.12-0.16 parts of coated methionine, 0.25-0.33 parts of coated lysine, 0.15-0.2 parts of taurine, and 1.8-2.2 parts of thermosensitive modified starch. The compound bacterial solution comprises a compound of bacteria in a mass ratio of 3.5-5:0.012-0.018:30-35, brown sugar, and deionized water; the compound bacteria consist of Bacillus subtilis and Saccharomyces cerevisiae in a mass ratio of 2:1.

[0036] A process for preparing marine fish bait, used to prepare the marine fish bait as described above, characterized by comprising the following steps:

[0037] Step 1: Mix the corresponding weight parts of protein components, energy components, fortifying components and functional additives to obtain a mixture;

[0038] Step 2: Add deionized water to the mixture to adjust the moisture content of the material to 18-20% and then condition it. Control the conditioning temperature to 85-90℃ and the pressure to 0.1-0.12MPa and condition for 2-3 minutes to obtain the conditioned material.

[0039] Step 3: Granulate the conditioning material to obtain bait pellets, mix the bait pellets with the compound bacterial liquid for fermentation, control the fermentation temperature at 35-37℃ for 48-50 hours, remove and dry to obtain finished marine fish bait with a moisture content of less than 10%.

[0040] Example 1

[0041] A marine fish feed comprises 73.2 parts by weight of protein component, 10.8 parts by weight of energy component, 4.5 parts by weight of fortification component, 2.5 parts by weight of functional additive, and 33.5% by weight of compound bacterial liquid.

[0042] The protein components include 28 parts red fish meal, 40 parts modified composite protein, 4 parts soy protein concentrate, and 1.2 parts complex enzymatically hydrolyzed fish lysate. Furthermore, the modified composite protein is an amphiphilic composite modified protein grafted with both hydrophilic and hydrophobic monomers.

[0043] To obtain the amphiphilic composite modified protein, the preparation method of the amphiphilic composite modified protein in the embodiments of this application includes step ① mixing the composite animal and plant protein with sodium sulfite and deionized water at a mass ratio of 40:0.5:9.5, stirring at a controlled temperature of 48°C for 32 minutes, then freeze-drying under vacuum until the moisture content is below 8% and pulverizing to 80 mesh to obtain the activated protein; step ② mixing polyethylene glycol monomethyl ether with glycidyl octanoate and triethylamine at a mass ratio of 3:1.9:0.09, stirring at a controlled temperature of 6... After reacting at 8℃ for 2.1h, grafting mixture A is obtained; in step ③, the activating protein and grafting mixture A are mixed at a mass ratio of 10:1, and then an ammonium sulfate solution with a solid-liquid ratio of 1:5 is added. The mass ratio of ammonium sulfate to grafting mixture in the ammonium sulfate solution is controlled at 0.3:1, and the temperature is 65℃. The reaction is carried out under an inert gas atmosphere for 1.7h to obtain grafting mixture B; in step ④, grafting mixture B is subjected to centrifugation, washing with anhydrous ethanol, and vacuum drying at 60℃ to obtain amphiphilic composite modified protein.

[0044] The energy components include 3.5 parts deep-sea fish oil, 2.8 parts refined soybean oil, and 4.5 parts modified corn starch. The modified corn starch is a thermosensitive modified starch cross-linked with N-isopropylacrylamide. The preparation method of thermosensitive modified starch includes the following steps: Step ①: Mix corn starch and deionized water at a mass ratio of 1:4, gelatinize at 88℃ for 30 min, then cool to 35℃ and adjust the pH to 4 for acid hydrolysis to obtain activated starch; Step ②: Mix N-isopropylacrylamide and N,N'-methylenebisacrylamide at a mass ratio of 2:0.2, then add an ethanol solution of azobisisobutyronitrile, controlling the mass ratio of azobisisobutyronitrile to N,N'-methylenebisacrylamide in the ethanol solution to be 0.1:0.2, and reflux at 68℃ for 1.2 h to obtain PNIPAM-thermosensitive polymer; Step ③: Mix activated starch and PNIPAM-thermosensitive polymer at a mass ratio of 3:1, then adjust the pH to neutral with sodium hydroxide, and stir at 53℃ for 48 min to obtain thermosensitive modified starch.

[0045] The fortified components include 1.3 parts calcium dihydrogen phosphate, 0.3 parts choline chloride, 1.5 parts multilayer core-shell vitamin microcapsules, and 1.4 parts zinc, iron, and selenium mineral premix. The multilayer core-shell vitamin microcapsules are obtained by encapsulating the complex vitamins from the inside out with sodium alginate, chitosan, and PLGA sequentially.

[0046] The preparation method of multilayer core-shell vitamin microcapsules includes the following steps: Step ① Mixing vitamins, taurine, and gum arabic in a mass ratio of 1.4:0.5:1, and then adding deionized water and stirring to obtain a core material suspension with a solid content of less than 40%; Step ② Adding the core material suspension dropwise to an aqueous solution of sodium alginate and stirring, and adding calcium chloride, controlling the mass ratio of sodium alginate, calcium chloride, and vitamins to be 2:0.28:1.4 to obtain sodium alginate inner layer microcapsules; Step ③ Transferring the sodium alginate inner layer microcapsules to an acetic acid solution of chitosan at pH 4.0, controlling the mass ratio of chitosan to vitamins to be 1.5:1.4, and stirring to obtain a middle layer wall material capsule; Step ④ Adding a dichloromethane solution of PLGA to the middle layer wall material capsule, controlling the mass ratio of PLGA to vitamins to be 1:1.4, and then ultrasonically treating for 18 minutes and spray drying with an inlet air temperature of 78℃ and an outlet air temperature of 43℃ to obtain multilayer core-shell vitamin microcapsules.

[0047] The functional additives include 0.3 parts betaine, 0.12 parts coated methionine, 0.25 parts coated lysine, 0.15 parts taurine, and 1.8 parts thermosensitive modified starch. The compound bacterial solution includes a compound of bacteria in a mass ratio of 3.5:0.012:30, brown sugar, and deionized water. The compound bacteria consist of Bacillus subtilis and Saccharomyces cerevisiae in a mass ratio of 2:1.

[0048] A process for preparing marine fish bait, used to prepare the marine fish bait as described above, characterized by comprising the following steps:

[0049] Step 1: Mix the corresponding weight parts of protein components, energy components, fortifying components and functional additives to obtain a mixture;

[0050] Step 2: Add deionized water to the mixture to adjust the moisture content of the material to 18% and then condition it. Control the conditioning temperature to 85℃ and the pressure to 0.1MPa and condition for 3 minutes to obtain the conditioned material.

[0051] Step 3: Granulate the conditioning material to obtain bait pellets, mix the bait pellets with the compound bacterial liquid for fermentation, control the fermentation temperature at 35℃ for 50 hours, remove and dry to obtain finished marine fish bait with a moisture content of less than 10%.

[0052] Example 2

[0053] A marine fish feed comprises 78 parts by weight of protein component, 12 parts by weight of energy component, 5.05 parts by weight of fortifying component, 3 parts by weight of functional additive, and 37.5% by weight of compound bacterial liquid.

[0054] The protein components include 30 parts red fish meal, 41.5 parts modified composite protein, 5 parts soy protein concentrate, and 1.5 parts complex enzymatically hydrolyzed fish lysate. Furthermore, the modified composite protein is an amphiphilic composite modified protein grafted with both hydrophilic and hydrophobic monomers.

[0055] To obtain the amphiphilic composite modified protein, the preparation method of the amphiphilic composite modified protein in the embodiments of this application includes step ① mixing the composite animal and plant protein with sodium sulfite and deionized water at a mass ratio of 40:0.53:9.75, stirring at a controlled temperature of 49°C for 30 minutes, then freeze-drying under vacuum until the moisture content is below 8% and pulverizing to 100 mesh to obtain the activated protein; step ② mixing polyethylene glycol monomethyl ether with glycidyl octanoate and triethylamine at a mass ratio of 3:2:0.095, and stirring at a controlled temperature of 69°C. After reacting for 2.05 h, grafting mixture A was obtained; in step ③, the activating protein and grafting mixture A were mixed at a mass ratio of 10:1.05, and then an ammonium sulfate solution with a solid-liquid ratio of 1:5 was added. The mass ratio of ammonium sulfate to grafting mixture in the ammonium sulfate solution was controlled at 0.3:1.05, and the temperature was 66℃. The reaction was carried out under an inert gas atmosphere for 1.6 h to obtain grafting mixture B; in step ④, grafting mixture B was successively subjected to centrifugation, washing with anhydrous ethanol, and vacuum drying at 60℃ to obtain amphiphilic composite modified protein.

[0056] The energy components include 3.75 parts deep-sea fish oil, 6 parts refined soybean oil, and 5.25 parts modified corn starch. The modified corn starch is a thermosensitive modified starch cross-linked with N-isopropylacrylamide. The preparation method of thermosensitive modified starch includes the following steps: Step ①: Corn starch and deionized water are mixed at a mass ratio of 1:4.5, gelatinized at 89℃ for 29 min, cooled to 38℃ and pH adjusted to 3.7 for acid hydrolysis to obtain activated starch; Step ②: N-isopropylacrylamide and N,N'-methylenebisacrylamide are mixed at a mass ratio of 2:0.205, and an ethanol solution of azobisisobutyronitrile is added, controlling the mass ratio of azobisisobutyronitrile to N,N'-methylenebisacrylamide in the ethanol solution to be 0.1:0.205, and refluxed at 69℃ for 1.1 h to obtain PNIPAM-thermosensitive polymer; Step ③: Activated starch and PNIPAM-thermosensitive polymer are mixed at a mass ratio of 3:1.05, and the pH is adjusted to neutral with sodium hydroxide, and stirred at 54℃ for 46 min to obtain thermosensitive modified starch.

[0057] The fortified components include 1.5 parts calcium dihydrogen phosphate, 0.4 parts choline chloride, 1.65 parts multilayer core-shell vitamin microcapsules, and 1.5 parts zinc, iron, and selenium mineral premix. The multilayer core-shell vitamin microcapsules are obtained by encapsulating the complex vitamins from the inside out with sodium alginate, chitosan, and PLGA sequentially.

[0058] The preparation method of multilayer core-shell vitamin microcapsules includes the following steps: Step ① Mixing vitamins, taurine, and gum arabic in a mass ratio of 1.45:0.51:1.05, and after adding deionized water and stirring, a core material suspension with a solid content of less than 40% is obtained; Step ② Dropwise adding the core material suspension to an aqueous solution of sodium alginate and stirring, and adding calcium chloride, controlling the mass ratio of sodium alginate, calcium chloride, and vitamins to be 2:0.28:1.45, to obtain sodium alginate inner layer microcapsules; Step ③ ... The sodium alginate inner layer microcapsules were transferred to a chitosan acetic acid solution at pH 4.2, and the mass ratio of chitosan to vitamins was controlled at 1.5:1.45. After stirring, the middle layer wall material capsules were obtained. In step ④, a dichloromethane solution of PLGA was added to the middle layer wall material capsules, and the mass ratio of PLGA to vitamins was controlled at 1:1.45. After ultrasonic treatment for 16 minutes and spray drying with the inlet air temperature controlled at 79°C and the outlet air temperature controlled at 44°C, multi-layer core-shell type vitamin microcapsules were obtained.

[0059] The functional additives include 0.4 parts betaine, 0.14 parts coated methionine, 0.29 parts coated lysine, 0.175 parts taurine, and 2 parts thermosensitive modified starch. The compound bacterial solution includes a compound of bacteria in a mass ratio of 3.75:0.015:32.5, brown sugar, and deionized water. The compound bacteria consist of Bacillus subtilis and Saccharomyces cerevisiae in a mass ratio of 2:1.

[0060] A process for preparing marine fish bait, used to prepare the marine fish bait as described above, characterized by comprising the following steps:

[0061] Step 1: Mix the corresponding weight parts of protein components, energy components, fortifying components and functional additives to obtain a mixture;

[0062] Step 2: Add deionized water to the mixture to adjust the moisture content to 19% and then condition it. Control the conditioning temperature to 88℃ and the pressure to 0.11MPa and condition for 2.5 minutes to obtain the conditioned material.

[0063] Step 3: Granulate the conditioning material to obtain bait pellets, mix the bait pellets with the compound bacterial liquid for fermentation, control the fermentation temperature at 36℃ for 49 hours, remove and dry to obtain finished marine fish bait with a moisture content of less than 10%.

[0064] Example 3

[0065] A marine fish feed comprises 82.8 parts by weight of protein component, 13.2 parts by weight of energy component, 5.6 parts by weight of fortifying component, 3.5 parts by weight of functional additive, and 40% by weight of compound bacterial liquid.

[0066] The protein components include 32 parts red fish meal, 43 parts modified composite protein, 6 parts soy protein concentrate, and 1.8 parts complex enzymatically hydrolyzed fish lysate. Furthermore, the modified composite protein is an amphiphilic composite modified protein grafted with both hydrophilic and hydrophobic monomers.

[0067] To obtain the amphiphilic composite modified protein, the preparation method of the amphiphilic composite modified protein in the embodiments of this application includes step ① mixing the composite animal and plant protein with sodium sulfite and deionized water at a mass ratio of 40:0.55:10, stirring at a controlled temperature of 50°C for 28 minutes, then freeze-drying under vacuum until the moisture content is below 8% and pulverizing to 120 mesh to obtain the activated protein; step ② mixing polyethylene glycol monomethyl ether with glycidyl octanoate and triethylamine at a mass ratio of 3:2.05:0.1, stirring at a controlled temperature of 70°C for 28 minutes, then freeze-drying under vacuum until the moisture content is below 8% and pulverizing to 120 mesh to obtain the activated protein; After reacting at 0℃ for 2 hours, grafting mixture A is obtained; in step ③, the activating protein and grafting mixture A are mixed at a mass ratio of 10:1.1, and then an ammonium sulfate solution with a solid-liquid ratio of 1:5 is added. The mass ratio of ammonium sulfate to grafting mixture in the ammonium sulfate solution is controlled at 0.3:1.1, and the temperature is 67℃. The mixture is reacted for 1.5 hours in an inert gas atmosphere to obtain grafting mixture B; in step ④, grafting mixture B is subjected to centrifugation, washing with anhydrous ethanol, and vacuum drying at 60℃ to obtain amphiphilic composite modified protein.

[0068] The energy components consist of 4 parts deep-sea fish oil, 3.2 parts refined soybean oil, and 6 parts modified corn starch. The modified corn starch is a thermosensitive modified starch cross-linked with N-isopropylacrylamide. The preparation method of thermosensitive modified starch includes the following steps: Step ①: Mix corn starch and deionized water at a mass ratio of 1:5, gelatinize at 90℃ for 28 min, then cool to 40℃ and adjust the pH to 4 for acid hydrolysis to obtain activated starch; Step ②: Mix N-isopropylacrylamide and N,N'-methylenebisacrylamide at a mass ratio of 2:0.21, then add an ethanol solution of azobisisobutyronitrile, controlling the mass ratio of azobisisobutyronitrile to N,N'-methylenebisacrylamide in the ethanol solution to be 0.1:0.21, and reflux at 70℃ for 1 h to obtain PNIPAM-thermosensitive polymer; Step ③: Mix activated starch and PNIPAM-thermosensitive polymer at a mass ratio of 3:1.1, then adjust the pH to neutral with sodium hydroxide, and stir at 55℃ for 45 min to obtain thermosensitive modified starch.

[0069] The fortified components include 1.7 parts calcium dihydrogen phosphate, 0.5 parts choline chloride, 1.8 parts multilayer core-shell vitamin microcapsules, and 1.6 parts zinc, iron, and selenium mineral premix. The multilayer core-shell vitamin microcapsules are obtained by encapsulating the complex vitamins from the inside out with sodium alginate, chitosan, and PLGA sequentially.

[0070] The preparation method of multilayer core-shell vitamin microcapsules includes the following steps: Step ① Mixing vitamins, taurine, and gum arabic in a mass ratio of 1.5:0.52:1.1, and after adding deionized water and stirring, a core material suspension with a solid content of less than 40% is obtained; Step ② Adding the core material suspension dropwise to an aqueous solution of sodium alginate and stirring, and adding calcium chloride, controlling the mass ratio of sodium alginate, calcium chloride, and vitamins to be 2:0.3:1.5, to obtain sodium alginate inner layer microcapsules; Step ③ Transferring the sodium alginate inner layer microcapsules to an acetic acid solution of chitosan at pH 4.5, controlling the mass ratio of chitosan to vitamins to be 1.5:1.5, and stirring to obtain a middle layer wall material capsule; Step ④ Adding a dichloromethane solution of PLGA to the middle layer wall material capsule, controlling the mass ratio of PLGA to vitamins to be 1:1.5, and then ultrasonically treating for 18 minutes and spray drying with an inlet air temperature of 80℃ and an outlet air temperature of 45℃, to obtain multilayer core-shell vitamin microcapsules.

[0071] The functional additives include 0.5 parts betaine, 0.16 parts coated methionine, 0.33 parts coated lysine, 0.2 parts taurine, and 2.2 parts thermosensitive modified starch. The compound bacterial solution consists of a compound of bacteria in a mass ratio of 5:0.018:35, brown sugar, and deionized water. The compound bacteria are composed of Bacillus subtilis and Saccharomyces cerevisiae in a mass ratio of 2:1.

[0072] A process for preparing marine fish bait, used to prepare the marine fish bait as described above, characterized by comprising the following steps:

[0073] Step 1: Mix the corresponding weight parts of protein components, energy components, fortifying components and functional additives to obtain a mixture;

[0074] Step 2: Add deionized water to the mixture to adjust the moisture content of the material to 20% and then condition it. Control the conditioning temperature to 90℃ and the pressure to 0.12MPa and condition for 2 minutes to obtain the conditioned material.

[0075] Step 3: Granulate the conditioning material to obtain bait pellets, mix the bait pellets with the compound bacterial liquid for fermentation, control the fermentation temperature at 37℃ for 48 hours, remove and dry to obtain finished marine fish bait with a moisture content of less than 10%.

[0076] Comparative Example 1

[0077] The difference between Comparative Example 1 and Example 2 is that the biparental composite modified protein in Comparative Example 1 is replaced by a composite animal and plant protein.

[0078] Comparative Example 2

[0079] The difference between Comparative Example 2 and Example 2 is that the temperature-sensitive modified starch in Comparative Example 2 is replaced by corn starch.

[0080] Comparative Example 3

[0081] The difference between Comparative Example 3 and Example 2 is that the multilayer core-shell type vitamin microcapsules in Comparative Example 3 do not have sodium alginate and chitosan layers.

[0082] The following will conduct performance tests on Examples 1 to 3 and Comparative Examples 1 to 3. The performance test methods are as follows:

[0083] 1. Water stability test: The solubility rate was measured according to GB / T 23184-2008 "Determination of solubility in feed";

[0084] 2. Vitamin retention rate test: The vitamin retention rate was measured according to GB / T 14700-2002 "Determination of Vitamin C in Feed";

[0085] 3. Protein digestibility test: Protein digestibility was measured according to SC / T 1079-2004 "Determination of apparent digestibility of aquatic feed by in vitro method".

[0086] The performance test results are shown in Table 1 below.

[0087] Table 1 Performance Test Results

[0088]

[0089] As shown in Table 1 above, the solubility loss rate at 60 min in Examples 1 to 3 was all below 8.2%. This indicates that the amphiphilic composite modified protein constructs molecular bridges through hydrophilic and hydrophobic monomers, thereby tightly binding the protein, starch, and oil. Furthermore, the interpenetrating network structure of the thermosensitive modified starch exhibits slow expansion without disintegration in the seawater environment, thus synergistically achieving a significant reduction in solubility loss. In Comparative Example 1, the composite animal and plant proteins were loosely bound to other components, resulting in rapid dissolution after soaking and a large loss of residual bait. Comparative Example 2 used corn starch without a thermosensitive interpenetrating network structure, resulting in weak adhesion and an inability to effectively maintain particle morphology. Comparative Example 3 lacked sodium alginate and chitosan layers, leading to insufficient capsule structural strength, with the modified protein providing only stability.

[0090] Furthermore, the vitamin C retention rates in Examples 1 to 3 are relatively high. This indicates that the inner layer of the multilayered core-shell vitamin microcapsules, composed of sodium alginate, has a buffering effect against seawater erosion; the middle layer of chitosan has an oxygen-barrier and moisture-proof effect; and the outer layer of PLGA is stable in alkaline seawater. The three layers are interconnected and adhere, significantly reducing vitamin degradation and loss, while exhibiting rapid dissolution and release upon entering the fish's intestines. Additionally, the extended molecular chains of the amphiphilic modified protein ensure sufficient exposure of active sites, making it easily decomposed by digestive enzymes, resulting in high protein digestibility in Examples 1-3. In contrast, the complex protein in Comparative Example 1 has a compact molecular structure, fewer enzymatic sites, and the anti-nutritional factors in the plant protein are not effectively removed, leading to reduced digestibility. In Comparative Example 2, the corn starch hinders the contact between digestive enzymes and the protein, resulting in decreased protein digestibility.

[0091] In summary, this application provides a marine fish feed and its preparation process. This process utilizes amphiphilic composite modified protein to enhance component binding, combined with the synergistic effect of specific components, to achieve gentle dissolution in seawater, improving nutrient utilization and digestibility, reducing fishmeal dependence and aquaculture costs, and promoting fish growth. The marine fish feed uses hydrophilic and hydrophobic monomers grafted onto the amphiphilic composite modified protein to form hydrogen bonds and hydrophobic interactions with starch hydroxyl groups and fatty acid chains, respectively, constructing molecular bridges between components. This effectively avoids the problems of loose and easily soluble traditional feeds. Simultaneously, the interpenetrating network structure of the thermosensitive modified starch allows for slow water absorption and expansion in the seawater environment without disintegration, thus achieving a gentle dissolution effect. This marine fish feed contains multi-layered core-shell vitamin microcapsules with a gradient shell protection structure formed by sodium alginate, chitosan, and PLGA. This achieves oxygen barrier properties, high-temperature resistance, and significantly improved stability in the alkaline environment of seawater. Furthermore, it rapidly degrades and releases nutrients once it enters the acidic environment of the fish's intestines. Simultaneously, the probiotics in the compound bacterial solution promote the activity of intestinal digestive enzymes, effectively enhancing the absorption efficiency of vitamins and proteins. At the same time, the temperature-sensitive modified starch dynamically adjusts the network density according to seawater temperature, effectively ensuring dissolution stability at different water temperatures. The three-dimensional network structure of the modified amphiphilic composite protein encapsulates nutrients, reducing seawater erosion and enhancing protein degradation through enzymatic hydrolysis of fish lysate.

[0092] The terms “first,” “second,” “third,” “fourth,” etc., used in this application (if applicable) are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, or apparatus that includes a series of steps or units is not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, or apparatus.

[0093] It should be noted that the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0094] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A marine fish bait, characterized in that: It includes 73.2-82.8 parts by weight of protein components, 10.8-13.2 parts by weight of energy components, 4.5-5.6 parts by weight of fortification components, 2.5-3.5 parts by weight of functional additives, and 33.5-40% by weight of compound bacterial solution; wherein: The protein components include 28-32 parts of red fish meal, 40-43 parts of modified compound protein, 4-6 parts of soy protein concentrate, and 1.2-1.8 parts of compound enzymatically hydrolyzed fish lysate. The modified composite protein is an amphiphilic composite modified protein grafted with hydrophilic and hydrophobic monomers. The energy component includes 4.5-6 parts of modified corn starch, which is a temperature-sensitive modified starch cross-linked with N-isopropylacrylamide. The fortifying component includes 1.5-1.8 parts of multilayer core-shell vitamin microcapsules, which are obtained by encapsulating a complex vitamin from the inside out with sodium alginate, chitosan, and PLGA.

2. The marine fish bait according to claim 1, characterized in that: The preparation method of the amphiphilic composite modified protein includes step ① mixing the composite animal and plant protein with sodium sulfite and deionized water at a mass ratio of 40:0.5-0.55:9.5-10, stirring at a controlled temperature of 48-50℃ for 28-32 minutes, then freeze-drying under vacuum until the moisture content is below 8% and pulverizing to 80-120 mesh to obtain the activated protein; step ② mixing polyethylene glycol monomethyl ether with glycidyl octanoate and triethylamine at a mass ratio of 3:1.9-2.05:0.09-0.1, stirring at a controlled temperature of 68-70℃ and... After reacting for 2-2.1 h, grafting mixture A is obtained; in step ③, the activating protein and grafting mixture A are mixed at a mass ratio of 10:1-1.1, and then an ammonium sulfate solution with a solid-liquid ratio of 1:5 is added. The mass ratio of ammonium sulfate to grafting mixture in the ammonium sulfate solution is controlled at 0.3:1-1.1, and the temperature is 65-67℃. The reaction is carried out under an inert gas atmosphere for 1.5-1.7 h to obtain grafting mixture B; in step ④, grafting mixture B is subjected to centrifugation, washing with anhydrous ethanol, and vacuum drying at 60℃ to obtain amphiphilic composite modified protein.

3. The marine fish bait according to claim 1, characterized in that: The energy components also include 3.5-4 parts of deep-sea fish oil and 2.8-3.2 parts of refined soybean oil.

4. The marine fish bait according to claim 1, characterized in that: The method for preparing the temperature-sensitive modified starch includes step ① mixing corn starch and deionized water at a mass ratio of 1:4-5, gelatinizing at a controlled temperature of 88-90℃ for 28-30 minutes, then cooling to 35-40℃ and adjusting the pH to 3.5-4 for acid hydrolysis to obtain activated starch; step ② mixing N-isopropylacrylamide and N,N'-methylenebisacrylamide at a mass ratio of 2:0.2-0.21, then adding an ethanol solution of azobisisobutyronitrile, controlling the azobisisobutyronitrile... The mass ratio of azobisisobutyronitrile to N,N'-methylenebisacrylamide in the ethanol solution is 0.1:0.2-0.21, and the reaction is carried out under reflux at 68-70℃ for 1-1.2h to obtain PNIPAM-thermosensitive polymer; in step ③, activated starch and PNIPAM-thermosensitive polymer are mixed with a mass ratio of 3:1-1.1, and the pH is adjusted to neutral with sodium hydroxide. The reaction is carried out at 53-55℃ with stirring for 45-48min to obtain thermosensitive modified starch.

5. A marine fish bait according to claim 1, characterized in that: The reinforcing components also include 1.3-1.7 parts of calcium dihydrogen phosphate, 0.3-0.5 parts of choline chloride, and 1.4-1.6 parts of zinc, iron, and selenium mineral premix.

6. The marine fish bait according to claim 1, characterized in that: The preparation method of the multilayer core-shell vitamin microcapsules includes step ① mixing vitamins, taurine, and gum arabic in a mass ratio of 1.4-1.5:0.5-0.52:1-1.1, and obtaining a core material suspension with a solid content of less than 40% after adding deionized water and stirring; step ② adding the core material suspension dropwise to an aqueous solution of sodium alginate and stirring, and adding calcium chloride, controlling the mass ratio of sodium alginate, calcium chloride, and vitamins to be 2:0.28-0.3:1.4-1.

5. Step 3: Sodium alginate inner layer microcapsules are obtained; Step 4: Sodium alginate inner layer microcapsules are transferred to a chitosan acetic acid solution with pH 4.0-4.5, and the mass ratio of chitosan to vitamins is controlled at 1.5:1.4-1.

5. After stirring, the middle layer wall material capsules are obtained; Step 5: PLGA dichloromethane solution is added to the middle layer wall material capsules, and the mass ratio of PLGA to vitamins is controlled at 1:1.4-1.

5. After ultrasonic treatment and spray drying, multi-layer core-shell type vitamin microcapsules are obtained.

7. A marine fish bait according to claim 6, characterized in that: The particle size of the sodium alginate inner layer microcapsules is 5-10 μm; the ultrasonic treatment time is 15-18 min; the inlet air temperature of the spray drying is 78-80℃, and the outlet air temperature is 43-45℃.

8. A marine fish bait according to claim 1, characterized in that: The functional additives include 0.3-0.5 parts of betaine, 0.12-0.16 parts of coated methionine, 0.25-0.33 parts of coated lysine, 0.15-0.2 parts of taurine, and 1.8-2.2 parts of thermosensitive modified starch.

9. A marine fish bait according to claim 1, characterized in that: The compound bacterial solution comprises compound bacteria, brown sugar, and deionized water in a mass ratio of 3.5-5:0.012-0.018:30-35; the compound bacteria consists of Bacillus subtilis and Saccharomyces cerevisiae in a mass ratio of 2:

1.

10. A process for preparing marine fish bait, used to prepare a marine fish bait as described in any one of claims 1-9, characterized in that, Includes the following steps: Step 1: Mix the corresponding weight parts of protein components, energy components, fortifying components and functional additives to obtain a mixture; Step 2: Add deionized water to the mixture to adjust the moisture content of the material to 18-20% and then condition it. Control the conditioning temperature to 85-90℃ and the pressure to 0.1-0.12MPa and condition for 2-3 minutes to obtain the conditioned material. Step 3: Granulate the conditioning material to obtain bait pellets, mix the bait pellets with the compound bacterial liquid for fermentation, control the fermentation temperature at 35-37℃ for 48-50 hours, remove and dry to obtain finished marine fish bait with a moisture content of less than 10%.

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