A compound feed for improving the crispness of tilapia muscle and a preparation method thereof

Abstract

The application discloses a compound feed for improving the crispness of tilapia muscle and a preparation method thereof, and belongs to the technical field of aquaculture feed.The compound feed for improving the crispness of tilapia muscle is composed of the following raw materials in percentage by weight: fish meal 5-8%, fermented rubber seed cake 15-25%, pea protein 8-12%, konjac glucomannan 2-4%, wheat middlings 20-28%, rice bran 10-15%, fish oil 1.5-2.5%, soybean lecithin 0.8-1.2%, calcium dihydrogen phosphate 0.8-1.2%, compound mineral premix 0.5-1.0%, compound vitamin premix 0.5-1.0%, L-hydroxyproline 0.3-0.5%, green tea extract 0.1-0.3%, and the balance is zeolite powder, and the sum of the percentage by weight of the raw materials is 100%. The compound feed can make the crispness of tilapia muscle reach the effect of the traditional "ordinary feed in the early stage + broad bean crispness feed in the later stage" mode and meet the quality demand of the market for crisp tilapia muscle through the synergistic effect of functional components such as konjac glucomannan, L-hydroxyproline and green tea extract in the formula and an innovative preparation process.

Description

Technical Field

[0001] This invention relates to the field of compound feed technology, specifically to a compound feed for improving the crispness of tilapia muscle and its preparation method. Background Technology

[0002] Tilapia is a high-quality fish recommended by the Food and Agriculture Organization of the United Nations for global aquaculture. It is characterized by its fast growth rate, strong adaptability, and tender flesh, and is hailed as one of the main sources of animal protein in the future. With the rapid development of tilapia farming, consumers have placed higher demands on the quality of tilapia meat. Among them, muscle crispness is one of the important indicators for measuring the quality of tilapia. Tilapia with excellent crispness, commonly known as crispy tilapia, has a chewy texture and unique flavor, and its market price is 30%-40% higher than that of ordinary tilapia, which has significant economic value.

[0003] Currently, the main way to improve the crispness of tilapia muscle is to adopt a phased feeding strategy of "ordinary feed in the early stage + broad bean crisping feed in the later stage". However, this method has a long crisping cycle, usually more than 65 days, low feed utilization rate, and high breeding cost. Existing tilapia compound feeds mostly focus on meeting growth requirements, lacking functional ingredients that specifically improve muscle crispness. Furthermore, the preparation process is relatively simple, often using a single drying and direct pelleting method, resulting in poor stability of feed nutrients, poor digestibility and absorption by tilapia, and difficulty in effectively improving muscle crispness. In addition, existing feed formulations often use large amounts of scarce protein sources such as soybean meal, which not only increases feed costs but also creates a resource dependency problem. Therefore, developing a compound feed with innovative formulation, reasonable preparation process, and the ability to effectively improve the crispness of tilapia muscle is of great practical significance. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a formulated feed for improving the crispness of tilapia muscle and its preparation method. Through innovative formula design and differentiated preparation process, it achieves rapid improvement in the crispness of tilapia muscle while reducing feed costs and increasing aquaculture efficiency.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A compound feed for improving the crispness of tilapia muscle, by weight percentage, consists of the following ingredients: fish meal 5-8%, fermented rubber seed cake 15-25%, pea protein 8-12%, konjac glucomannan 2-4%, wheat middlings 20-28%, rice bran 10-15%, fish oil 1.5-2.5%, soybean lecithin 0.8-1.2%, calcium dihydrogen phosphate 0.8-1.2%, compound mineral premix 0.5-1.0%, compound vitamin premix 0.5-1.0%, L-hydroxyproline 0.3-0.5%, green tea extract 0.1-0.3%, with the balance being zeolite powder, and the sum of the weight percentages of all ingredients is 100%.

[0006] Preferably, the raw materials for preparing fermented rubber seed cake include rubber seed cake, Aspergillus oryzae inoculant, and brown sugar, with a weight ratio of 100:2:5, a fermentation temperature of 30-32℃, and a fermentation time of 48-60h.

[0007] Preferably, the composite mineral premix, per 1 kg, consists of the following components: 2.3 g ferrous sulfate hexahydrate, 62 g magnesium sulfate heptahydrate, 0.15 g aluminum chloride hexahydrate, 1.2 g calcium iodate, 0.1 g copper chloride dihydrate, 0.8 g manganese sulfate monohydrate, 1 g cobalt chloride hexahydrate, 1 g zinc sulfate heptahydrate, and zeolite powder to make up to 1 kg.

[0008] Preferably, the compound vitamin premix, per 1 kg, consists of the following components: vitamin A 300 mg, vitamin D3 3 mg, vitamin E 30 g, vitamin K3 0.5 g, vitamin B1 1 g, vitamin B2 1 g, calcium pantothenate 0.2 g, niacin 3.5 g, biotin 3 mg, vitamin B6 165 mg, folic acid 40 mg, inositol 1.5 g, vitamin B12 0.02 g, and wheat bran to make up to 1 kg; Among them, fermented rubber seed cake, through Aspergillus oryzae fermentation treatment, can reduce anti-nutritional factors in rubber seed cake and improve protein digestibility; konjac glucomannan can enhance the toughness and elasticity of muscle fibers; L-hydroxyproline is a key precursor substance for collagen synthesis, which can promote the accumulation of muscle collagen and improve crispness; tea polyphenols in green tea extract have antioxidant effects, which can protect muscle cells and improve meat quality.

[0009] A method for preparing a compound feed to improve the crispness of tilapia muscle, as described above, includes the following steps: S1: Raw material pretreatment Fish meal, pea protein, konjac glucomannan, wheat bran, rice bran, and zeolite powder were separately fed into a grinder and ground. After grinding, all of them were passed through an 80-mesh sieve to obtain fine powder raw materials. Fermented rubber seed cake was ground and passed through a 60-mesh sieve to obtain fermented rubber seed cake powder. The pulverizer operates at a speed of 4500-5000 r / min and a pulverizing time of 3-5 min. S2: First Mixing The fine powder raw material obtained in step S1 and the fermented rubber seed cake powder are put into a double helix mixer. The mixing speed is 300-350 r / min and the mixing time is 15-20 min to obtain the primary mixture. S3: Functional component pretreatment Add L-hydroxyproline and green tea extract to 5 times their weight of warm water at a temperature of 40-45℃, stir and dissolve to obtain a functional ingredient solution. Pretreatment of functional components can improve their solubility and stability; S4: Second Mixing Add the compound mineral premix and compound vitamin premix to the primary mixture, stir and mix for 5-8 minutes, then slowly spray in the functional ingredient solution while stirring. The stirring speed is 200-250 r / min and the stirring time is 10-12 minutes to obtain the intermediate mixture. S5: Oil coating Fish oil and soybean lecithin are mixed evenly and heated to 50-55℃ to obtain coated oil. The coated oil is then sprayed evenly onto the surface of the intermediate mixture using a spraying method at a pressure of 0.3-0.5MPa. After spraying, the mixture is stirred for 8-10 minutes to obtain the final mixture. The material temperature during spraying should be controlled at 35-40℃ to prevent oil denaturation. Oil coating can reduce fish oil oxidation and improve feed palatability; S6: Conditioning and Granulation The final mixture is fed into a conditioner and saturated steam at 105-110℃ is introduced. The conditioning time is 6-8 minutes. After conditioning, it is fed into a pellet mill to granulate. The pellet size is 2-5 mm to obtain pellet feed. S7: Segmented Drying First, feed pellets are placed in a hot air dryer and dried at 80-85℃ for 30-40 minutes. Then, they are transferred to a low-temperature dryer and dried at 45-50℃ for 60-80 minutes until the feed moisture content is ≤8%. The air velocity of a hot air dryer is 1.2-1.5 m / s, and the air velocity of a low temperature dryer is 0.8-1.0 m / s. Segmented drying can avoid the destruction of nutrients caused by high temperatures, while ensuring that the feed moisture content meets the standards. S8: Post-curing treatment The dried pelleted feed is fed into a post-maturation equipment and matured for 25-30 minutes at 70-75℃ and 60-65% relative humidity. After maturation, it is naturally cooled to room temperature. The heating rate of the post-ripening equipment is 5℃ / min to avoid the destruction of feed nutrients caused by a sudden increase in temperature; Post-ripening treatment can further improve the digestibility and absorption rate of feed and enhance the stability of feed pellets; S9: Screening and Packaging The cooled pelleted feed is screened through a grading sieve to remove powder and unqualified pellets. After passing the inspection, it is vacuum-packed to obtain the finished compound feed. The grading sieve has sieve aperture sizes of 1.5mm and 5.5mm, which screen out qualified particles with a particle size of 2-5mm.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Significantly improves muscle crispness: Through the synergistic effect of functional ingredients such as konjac glucomannan, L-hydroxyproline, and green tea extract in the formula, combined with innovative preparation process, the muscle crispness of tilapia can reach the effect of the traditional "ordinary feed in the early stage + broad bean crisping feed in the later stage" method, meeting the market's quality demand for crispy tilapia. 2. Improve growth performance and reduce breeding costs: Fermented rubber seed cake in the formula replaces part of the scarce protein source. Combined with functional component pretreatment and oil coating processes, it improves nutrient absorption efficiency, which significantly increases the weight gain rate of tilapia and significantly reduces the feed conversion ratio. It is superior to commercially available ordinary feed and traditional crisping methods, thus reducing feed costs and breeding inputs. 3. Wide environmental adaptability: It is suitable for various environments such as intensive pond culture, high-density culture in land-based circular ponds, and low-temperature culture. Even under low-temperature conditions, its growth performance and muscle crispness are still better than ordinary feed, thus expanding its application scenarios. 4. High safety in aquaculture: The survival rate of tilapia after feeding is not significantly different from that of other groups, and will not have an adverse effect on the survival of tilapia, thus ensuring the stability of aquaculture benefits. Detailed Implementation

[0011] Example 1 In an intensive pond culture environment, with a water area of ​​5 mu (approximately 0.33 hectares), a water depth of 1.5 m, a water temperature of 25-28℃, a pH of 7.5-8.0, dissolved oxygen ≥5 mg / L, and natural light conditions; A compound feed for improving the crispness of tilapia muscle, by weight percentage, consists of the following ingredients: fish meal 6%, fermented rubber seed cake 20%, pea protein 10%, konjac glucomannan 3%, wheat middlings 25%, rice bran 12%, fish oil 2%, soybean lecithin 1%, calcium dihydrogen phosphate 1%, compound mineral premix 0.7%, compound vitamin premix 0.7%, L-hydroxyproline 0.4%, green tea extract 0.2%, with the balance being zeolite powder; The raw materials for preparing fermented rubber seed cake include rubber seed cake, Aspergillus oryzae inoculant, and brown sugar, with a weight ratio of 100:2:5. The fermentation temperature is 30-32℃, and the fermentation time is 48-60h. The compound mineral premix, per 1 kg, consists of the following components: 2.3 g ferrous sulfate hexahydrate, 62 g magnesium sulfate heptahydrate, 0.15 g aluminum chloride hexahydrate, 1.2 g calcium iodate, 0.1 g copper chloride dihydrate, 0.8 g manganese sulfate monohydrate, 1 g cobalt chloride hexahydrate, 1 g zinc sulfate heptahydrate, and zeolite powder to make up to 1 kg. The compound vitamin premix, per 1 kg, consists of the following components: Vitamin A 300 mg, Vitamin D3 3 mg, Vitamin E 30 g, Vitamin K3 0.5 g, Vitamin B1 1 g, Vitamin B2 1 g, Calcium pantothenate 0.2 g, Niacin 3.5 g, Biotin 3 mg, Vitamin B6 165 mg, Folic acid 40 mg, Inositol 1.5 g, Vitamin B12 0.02 g, and wheat bran to make up to 1 kg.

[0012] A method for preparing a compound feed to improve the crispness of tilapia muscle, as described above, includes the following steps: S1: Raw material pretreatment Fish meal, pea protein, konjac glucomannan, wheat bran, rice bran, and zeolite powder are put into a grinder and ground at 4800 r / min for 4 min, then passed through an 80 mesh sieve; fermented rubber seed cake is ground and then passed through a 60 mesh sieve. S2: First Mixing The above-mentioned fine powder raw materials and fermented rubber seed cake powder were put into a twin-screw mixer and mixed at 320 r / min for 18 min to obtain a primary mixture. S3: Functional component pretreatment Add L-hydroxyproline and green tea extract to 5 times their weight of warm water at 42°C, stir to dissolve, and obtain a functional ingredient solution; S4: Second Mixing Add the compound mineral premix and compound vitamin premix to the primary mixture, stir for 6 minutes, then slowly spray the functional ingredient solution, stir at 220 r / min for 11 minutes to obtain the intermediate mixture; S5: Oil coating Fish oil and soybean lecithin were mixed evenly and heated to 52°C. The mixture was sprayed onto the surface of the intermediate mixture at a pressure of 0.4 MPa. The material temperature was 38°C. After spraying, the mixture was stirred for 9 minutes to obtain the final mixture. S6: Conditioning and Granulation The final mixture is fed into a conditioner, 108℃ saturated steam is introduced, and the mixture is conditioned for 7 minutes. Then it is fed into a pellet mill to be granulated to a particle size of 3mm. S7: Segmented Drying First, dry at 82℃ and 1.3m / s wind speed for 35 minutes, then dry at 48℃ and 0.9m / s wind speed for 70 minutes, until the moisture content is ≤8%; S8: Post-curing treatment The product is fed into a post-curing equipment, heated to 72°C at a rate of 5°C / min, and cured for 28 minutes at a relative humidity of 62%. It is then allowed to cool naturally to room temperature. S9: Screening and Packaging The finished product is obtained by screening through 1.5mm and 5.5mm grading sieves and then vacuum packaging.

[0013] Example 2 In a high-density aquaculture environment in a land-based circular pond, the pond is 8m in diameter, 1.2m deep, with a water temperature of 28-31℃, pH of 7.8-8.2, dissolved oxygen ≥6mg / L, and continuous oxygenation for 24 hours with artificial lighting, i.e., 12 hours of light and 12 hours of darkness. A compound feed for improving the crispness of tilapia muscle, by weight percentage, consists of the following ingredients: 5% fish meal, 15% fermented rubber seed cake, 8% pea protein, 2% konjac glucomannan, 20% wheat middlings, 10% rice bran, 1.5% fish oil, 0.8% soybean lecithin, 0.8% calcium dihydrogen phosphate, 0.5% compound mineral premix, 0.5% compound vitamin premix, 0.3% L-hydroxyproline, 0.1% green tea extract, with the balance being zeolite powder; The raw materials for preparing fermented rubber seed cake include rubber seed cake, Aspergillus oryzae inoculant, and brown sugar, with a weight ratio of 100:2:5. The fermentation temperature is 30-32℃, and the fermentation time is 48-60h. The compound mineral premix, per 1 kg, consists of the following components: 2.3 g ferrous sulfate hexahydrate, 62 g magnesium sulfate heptahydrate, 0.15 g aluminum chloride hexahydrate, 1.2 g calcium iodate, 0.1 g copper chloride dihydrate, 0.8 g manganese sulfate monohydrate, 1 g cobalt chloride hexahydrate, 1 g zinc sulfate heptahydrate, and zeolite powder to make up to 1 kg. The compound vitamin premix, per 1 kg, consists of the following components: Vitamin A 300 mg, Vitamin D3 3 mg, Vitamin E 30 g, Vitamin K3 0.5 g, Vitamin B1 1 g, Vitamin B2 1 g, Calcium pantothenate 0.2 g, Niacin 3.5 g, Biotin 3 mg, Vitamin B6 165 mg, Folic acid 40 mg, Inositol 1.5 g, Vitamin B12 0.02 g, and wheat bran to make up to 1 kg.

[0014] A method for preparing a compound feed to improve the crispness of tilapia muscle, as described above, includes the following steps: S1: Raw material pretreatment Fish meal, pea protein, konjac glucomannan, wheat bran, rice bran, and zeolite powder were separately fed into a grinder and ground. After grinding, all of them were passed through an 80-mesh sieve to obtain fine powder raw materials. Fermented rubber seed cake was ground and passed through a 60-mesh sieve to obtain fermented rubber seed cake powder. The pulverizer has a pulverizing speed of 4500 r / min and a pulverizing time of 3 min; S2: First Mixing The fine powder raw material obtained in step S1 and the fermented rubber seed cake powder are put into a double helix mixer. The mixing speed is 300 r / min and the mixing time is 15 min to obtain the primary mixture. S3: Functional component pretreatment L-hydroxyproline and green tea extract were added to 5 times their weight of warm water at 40°C and stirred to dissolve, resulting in a functional ingredient solution. Pretreatment of functional components can improve their solubility and stability; S4: Second Mixing Add the compound mineral premix and compound vitamin premix to the primary mixture, stir and mix for 5 minutes, then slowly spray in the functional ingredient solution while stirring. The stirring speed is 200 r / min and the stirring time is 10 minutes to obtain the intermediate mixture. S5: Oil coating Fish oil and soybean lecithin were mixed evenly and heated to 50°C to obtain coated oil. The coated oil was then sprayed evenly onto the surface of the intermediate mixture using a spraying method at a pressure of 0.3 MPa. After spraying, the mixture was stirred for 8 minutes to obtain the final mixture. The material temperature during spraying should be controlled at 35℃ to prevent oil denaturation; Oil coating can reduce fish oil oxidation and improve feed palatability; S6: Conditioning and Granulation The final mixture is fed into a conditioner and 105°C saturated steam is introduced. The conditioning time is 6 minutes. After conditioning, it is fed into a pellet mill for pelleting. The pellet size is 2 mm to obtain pellet feed. S7: Segmented Drying The pelleted feed is first sent to a hot air dryer and dried at 80°C for 30 minutes, then transferred to a low temperature dryer and dried at 45°C for 60 minutes, until the feed moisture content is ≤8%. The air velocity of the hot air dryer is 1.2 m / s, and the air velocity of the low temperature dryer is 0.8 m / s; Segmented drying can avoid the destruction of nutrients caused by high temperatures, while ensuring that the feed moisture content meets the standards. S8: Post-curing treatment The dried pelleted feed is fed into a post-maturation equipment and matured for 25 minutes at 70°C and 60% relative humidity. After maturation, it is naturally cooled to room temperature. The heating rate of the post-ripening equipment is 5℃ / min to avoid the destruction of feed nutrients caused by a sudden increase in temperature; Post-ripening treatment can further improve the digestibility and absorption rate of feed and enhance the stability of feed pellets; S9: Screening and Packaging The cooled pelleted feed is screened through a grading sieve to remove powder and unqualified pellets. After passing the inspection, it is vacuum-packed to obtain the finished compound feed. The grading sieve has sieve aperture sizes of 1.5mm and 5.5mm, which screen out qualified particles with a particle size of 2-5mm.

[0015] Example 3 In a low-temperature aquaculture environment, intensive pond culture is carried out with a water temperature of 20-23℃, pH of 7.5-8.0, dissolved oxygen ≥5mg / L, and natural light. A compound feed for improving the crispness of tilapia muscle, by weight percentage, consists of the following ingredients: fish meal 8%, fermented rubber seed cake 25%, pea protein 12%, konjac glucomannan 4%, wheat middlings 28%, rice bran 15%, fish oil 2.5%, soybean lecithin 1.2%, calcium dihydrogen phosphate 1.2%, compound mineral premix 1.0%, compound vitamin premix 1.0%, L-hydroxyproline 0.5%, green tea extract 0.3%, with the balance being zeolite powder; The raw materials for preparing fermented rubber seed cake include rubber seed cake, Aspergillus oryzae inoculant, and brown sugar, with a weight ratio of 100:2:5. The fermentation temperature is 30-32℃, and the fermentation time is 48-60h. The compound mineral premix, per 1 kg, consists of the following components: 2.3 g ferrous sulfate hexahydrate, 62 g magnesium sulfate heptahydrate, 0.15 g aluminum chloride hexahydrate, 1.2 g calcium iodate, 0.1 g copper chloride dihydrate, 0.8 g manganese sulfate monohydrate, 1 g cobalt chloride hexahydrate, 1 g zinc sulfate heptahydrate, and zeolite powder to make up to 1 kg. The compound vitamin premix, per 1 kg, consists of the following components: Vitamin A 300 mg, Vitamin D3 3 mg, Vitamin E 30 g, Vitamin K3 0.5 g, Vitamin B1 1 g, Vitamin B2 1 g, Calcium pantothenate 0.2 g, Niacin 3.5 g, Biotin 3 mg, Vitamin B6 165 mg, Folic acid 40 mg, Inositol 1.5 g, Vitamin B12 0.02 g, and wheat bran to make up to 1 kg.

[0016] A method for preparing a compound feed to improve the crispness of tilapia muscle, as described above, includes the following steps: S1: Raw material pretreatment Fish meal, pea protein, konjac glucomannan, wheat bran, rice bran, and zeolite powder were separately fed into a grinder and ground. After grinding, all of them were passed through an 80-mesh sieve to obtain fine powder raw materials. Fermented rubber seed cake was ground and passed through a 60-mesh sieve to obtain fermented rubber seed cake powder. The pulverizer has a pulverizing speed of 5000 r / min and a pulverizing time of 5 min; S2: First Mixing The fine powder raw material obtained in step S1 and the fermented rubber seed cake powder are put into a double helix mixer. The mixing speed is 350 r / min and the mixing time is 20 min to obtain the primary mixture. S3: Functional component pretreatment L-hydroxyproline and green tea extract were added to 5 times their weight of warm water at 45°C and stirred to dissolve, resulting in a functional ingredient solution. Pretreatment of functional components can improve their solubility and stability; S4: Second Mixing Add the compound mineral premix and compound vitamin premix to the primary mixture, stir and mix for 8 minutes, then slowly spray in the functional ingredient solution while stirring. The stirring speed is 250 r / min and the stirring time is 12 minutes to obtain the intermediate mixture. S5: Oil coating Fish oil and soybean lecithin were mixed evenly and heated to 55°C to obtain coated oil. The coated oil was then sprayed evenly onto the surface of the intermediate mixture using a spraying method at a pressure of 0.5 MPa. After spraying, the mixture was stirred for 10 minutes to obtain the final mixture. The material temperature during spraying should be controlled at 40℃ to prevent oil denaturation; Oil coating can reduce fish oil oxidation and improve feed palatability; S6: Conditioning and Granulation The final mixture is fed into a conditioner and 110°C saturated steam is introduced. The conditioning time is 8 minutes. After conditioning, it is fed into a pellet mill for pelleting. The pellet size is 5 mm to obtain pellet feed. S7: Segmented Drying The pelleted feed is first sent to a hot air dryer and dried at 85°C for 40 minutes, then transferred to a low-temperature dryer and dried at 50°C for 80 minutes, until the feed moisture content is ≤8%. The air velocity of the hot air dryer is 1.5 m / s, and the air velocity of the low temperature dryer is 1.0 m / s; Segmented drying can avoid the destruction of nutrients caused by high temperatures, while ensuring that the feed moisture content meets the standards. S8: Post-curing treatment The dried pelleted feed is fed into a post-maturation equipment and matured for 30 minutes at 75°C and 65% relative humidity. After maturation, it is naturally cooled to room temperature. The heating rate of the post-ripening equipment is 5℃ / min to avoid the destruction of feed nutrients caused by a sudden increase in temperature; Post-ripening treatment can further improve the digestibility and absorption rate of feed and enhance the stability of feed pellets; S9: Screening and Packaging The cooled pelleted feed is screened through a grading sieve to remove powder and unqualified pellets. After passing the inspection, it is vacuum-packed to obtain the finished compound feed. The grading sieve has sieve aperture sizes of 1.5mm and 5.5mm, which screen out qualified particles with a particle size of 2-5mm.

[0017] Comparative Example 1 In an intensive pond culture environment, with a water area of ​​5 mu (approximately 0.33 hectares), a water depth of 1.5 m, a water temperature of 25-28℃, a pH of 7.5-8.0, dissolved oxygen ≥5 mg / L, and natural light conditions; Commercially available ordinary tilapia compound feed does not contain the functional ingredients unique to this invention, such as fermented rubber seed cake, konjac glucomannan, L-hydroxyproline, and green tea extract. Commercially available feed is prepared using conventional methods such as simple drying and direct pelleting, without the innovative steps of this invention, such as functional component pretreatment, oil coating, segmented drying, and post-maturation.

[0018] Comparative Example 2 In a high-density aquaculture environment in a land-based circular pond (8m in diameter, 1.2m deep, water temperature 28-31℃, pH 7.8-8.2, dissolved oxygen ≥6mg / L), with 24-hour continuous aeration and artificial lighting (12h light / 12h darkness): A compound feed for improving the crispness of tilapia muscle, by weight percentage, consists of the following ingredients: 5% fish meal, 15% fermented rubber seed cake, 8% pea protein, 2% konjac glucomannan, 20% wheat middlings, 10% rice bran, 1.5% fish oil, 0.8% soybean lecithin, 0.8% calcium dihydrogen phosphate, 0.5% compound mineral premix, 0.5% compound vitamin premix, 0.3% L-hydroxyproline, 0.1% green tea extract, with the balance being zeolite powder; The raw materials for preparing fermented rubber seed cake include rubber seed cake, Aspergillus oryzae inoculant, and brown sugar, with a weight ratio of 100:2:5. The fermentation temperature is 30-32℃, and the fermentation time is 48-60h. The compound mineral premix, per 1 kg, consists of the following components: 2.3 g ferrous sulfate hexahydrate, 62 g magnesium sulfate heptahydrate, 0.15 g aluminum chloride hexahydrate, 1.2 g calcium iodate, 0.1 g copper chloride dihydrate, 0.8 g manganese sulfate monohydrate, 1 g cobalt chloride hexahydrate, 1 g zinc sulfate heptahydrate, and zeolite powder to make up to 1 kg. The compound vitamin premix, per 1 kg, consists of the following components: Vitamin A 300 mg, Vitamin D3 3 mg, Vitamin E 30 g, Vitamin K3 0.5 g, Vitamin B1 1 g, Vitamin B2 1 g, Calcium pantothenate 0.2 g, Niacin 3.5 g, Biotin 3 mg, Vitamin B6 165 mg, Folic acid 40 mg, Inositol 1.5 g, Vitamin B12 0.02 g, and wheat bran to make up to 1 kg.

[0019] A method for preparing a compound feed to improve the crispness of tilapia muscle, as described above, includes the following steps: S1: Raw material pretreatment Fish meal, pea protein, konjac glucomannan, wheat bran, rice bran, and zeolite powder were separately fed into a grinder and ground. After grinding, all of them were passed through an 80-mesh sieve to obtain fine powder raw materials. Fermented rubber seed cake was ground and passed through a 60-mesh sieve to obtain fermented rubber seed cake powder. The pulverizer has a pulverizing speed of 4500 r / min and a pulverizing time of 3 min; S2: First Mixing The fine powder raw material obtained in step S1 and the fermented rubber seed cake powder are put into a double helix mixer. The mixing speed is 320 r / min and the mixing time is 18 min to obtain the primary mixture. S3: Functional component pretreatment L-hydroxyproline and green tea extract were added to 5 times their weight of warm water at 42°C and stirred to dissolve, resulting in a functional ingredient solution. Pretreatment of functional components can improve their solubility and stability; S4: Second Mixing Add the compound mineral premix and compound vitamin premix to the primary mixture, stir and mix for 6 minutes, then slowly spray in the functional ingredient solution while stirring. The stirring speed is 220 r / min and the stirring time is 11 minutes to obtain the final mixture. S5: Conditioning and Granulation The final mixture is fed into a conditioner and 108°C saturated steam is introduced. The conditioning time is 7 minutes. After conditioning, it is fed into a pellet mill for pelleting. The pellet size is 3 mm to obtain pellet feed. S6: Segmented drying The pelleted feed is first sent to a hot air dryer and dried at 82℃ for 35 minutes, then transferred to a low temperature dryer and dried at 48℃ for 70 minutes, until the feed moisture content is ≤8%; The air velocity of the hot air dryer is 1.2 m / s, and the air velocity of the low temperature dryer is 0.8 m / s; Segmented drying can avoid the destruction of nutrients caused by high temperatures, while ensuring that the feed moisture content meets the standards. S7: Screening and Packaging The above-mentioned pelleted feed is screened through a grading sieve to remove powder and unqualified pellets. After passing the inspection, it is vacuum-packed to obtain the finished compound feed. The grading sieve has sieve aperture sizes of 1.5mm and 5.5mm, which screen out qualified particles with a particle size of 2-5mm.

[0020] Comparative Example 3 In an intensive pond culture environment, with a water area of ​​5 mu (approximately 0.33 hectares), a water depth of 1.5 m, a water temperature of 25-28℃, a pH of 7.5-8.0, dissolved oxygen ≥5 mg / L, and natural light conditions; The traditional combination of "ordinary feed in the early stage + broad bean crisping feed in the later stage" is adopted. The early stage is conventional tilapia growth feed, and the later stage is pure broad bean or broad bean crisping feed. It does not contain the fermented rubber seed cake, functional ingredients, etc. of this invention. The initial ordinary feed was prepared using conventional processes; the later broad bean crisping feed was simply crushed or fed directly.

[0021] Experimental Example 1. Experimental subjects: 600 Nile tilapia of uniform size, i.e., initial weight of about 180g and robust physique, were selected and randomly divided into 6 groups, with 3 replicates in each group and 30 fish in each replicate. 2. Aquaculture Management: The experimental period was 56 days. The fish were fed twice a day, once in the morning and once in the evening, with the amount of feed being 3-5% of their body weight, adjusted according to their feeding behavior. The water was changed regularly, with 1 / 3 of the water changed every week. Water quality indicators were monitored, and diseases were prevented and treated in a timely manner. 3. Detection indicators: After the experiment, the final body weight, weight gain rate, feed conversion ratio, muscle fragility, muscle collagen content, and survival rate of tilapia in each group were measured; among them, muscle fragility was measured using a texture analyzer with the following parameters: probe P / 50, test speed 1mm / s, and compression degree 50%. 4. The specific experimental procedure is as follows: 1) Preliminary preparation: Before the experiment, the aquaculture pond and the land-based circular pond were thoroughly cleaned and disinfected, and aerated tap water was injected. The pond intensive culture group used natural water that had been filtered and settled. Tilapia were temporarily kept in the holding pond for 2 weeks to adapt to the aquaculture environment, and a small amount of commercial feed was fed during this period. 2) Group release: After temporary holding, the tilapia were grouped according to the experimental design and released into culture containers in different culture environments. The initial total weight and number of fish in each group were recorded. 3) Feeding management: Feed according to the feed corresponding to each group, once at 07:00 and once at 18:00 every day. Check the feeding situation 1 hour after feeding, clean up the uneaten feed, and record the feeding amount. 4) Water quality monitoring: Monitor water temperature, pH, dissolved oxygen and other water quality indicators daily, and measure ammonia nitrogen, nitrite and other indicators weekly. Change water or turn on oxygenation equipment in a timely manner according to water quality conditions. 5) Disease prevention and control: Disinfect the breeding containers regularly, feed medicated feed (garlic extract medicated feed) once a month to prevent disease occurrence; if sick fish appear during the experiment, isolate and treat them in time, and record the disease occurrence. 6) Sample collection and testing: After the experiment, the tilapia in each group were fasted for 24 hours. The total weight of each group was weighed, and the weight gain rate and survival rate were calculated. Ten fish were randomly selected from each group, and back muscle samples were taken. The muscle fragility was measured using a texture analyzer, and the muscle collagen content was measured using spectrophotometry. The total amount of feed given to each group was recorded, and the feed conversion ratio was calculated. The experimental results are shown in the table below. The data in the table are the mean ± standard error. There are significant differences (P<0.05) between those with different letters in the same column heading.

[0022] The results of the above comparative experiments show that: 1. Growth performance: The weight gain rate of Examples 1 and 2 was significantly higher than that of Comparative Examples 1, 2 and 3 (P<0.05), and the feed conversion ratio was significantly lower than that of Comparative Examples 1, 2 and 3 (P<0.05). Due to the low temperature environment, the weight gain rate of Example 3 was lower than that of Examples 1 and 2, but still higher than that of Comparative Examples 1 and 2. This indicates that the feed of the present invention can improve the growth performance of tilapia in different breeding environments, and the effect is better in the high temperature environment of land-based circular ponds. 2. Muscle crispness and collagen content: The muscle crispness and collagen content of Examples 1 and 2 were not significantly different from those of Comparative Example 3 (P>0.05), but were significantly higher than those of Comparative Example 1 and Comparative Example 2 (P<0.05); The muscle crispness and collagen content of Example 3 were lower than those of Examples 1 and 2, but higher than those of Comparative Example 1 and Comparative Example 2, indicating that the feed of the present invention can achieve the crisping effect of traditional crisping methods, and that the oil coating and post-maturation steps in the preparation method play an important role in improving crispness; 3. Survival rate: There was no significant difference in survival rate among the components (P>0.05), indicating that the feed of the present invention will not have an adverse effect on the survival of tilapia and has high aquaculture safety; In summary, the compound feed and its preparation method of the present invention can effectively improve the muscle crispness of tilapia, improve growth performance, reduce feed conversion ratio, and are suitable for different aquaculture environments, thus having broad application prospects.

Claims

1. A formulated feed for improving the crispness of tilapia muscle, characterized in that, By weight percentage, it consists of the following raw materials: fish meal 5-8%, fermented rubber seed cake 15-25%, pea protein 8-12%, konjac glucomannan 2-4%, wheat middlings 20-28%, rice bran 10-15%, fish oil 1.5-2.5%, soybean lecithin 0.8-1.2%, calcium dihydrogen phosphate 0.8-1.2%, compound mineral premix 0.5-1.0%, compound vitamin premix 0.5-1.0%, L-hydroxyproline 0.3-0.5%, green tea extract 0.1-0.3%, and the balance is zeolite powder. The sum of the weight percentages of all raw materials is 100%.

2. The formulated feed for improving the crispness of tilapia muscle according to claim 1, characterized in that, The raw materials for preparing fermented rubber seed cake include rubber seed cake, Aspergillus oryzae inoculant, and brown sugar, with a weight ratio of 100:2:

5. The fermentation temperature is 30-32℃, and the fermentation time is 48-60h.

3. The formulated feed for improving the crispness of tilapia muscle according to claim 2, characterized in that, The compound mineral premix, per 1 kg, consists of the following components: 2.3 g ferrous sulfate hexahydrate, 62 g magnesium sulfate heptahydrate, 0.15 g aluminum chloride hexahydrate, 1.2 g calcium iodate, 0.1 g copper chloride dihydrate, 0.8 g manganese sulfate monohydrate, 1 g cobalt chloride hexahydrate, 1 g zinc sulfate heptahydrate, and zeolite powder to make up to 1 kg.

4. The formulated feed for improving the crispness of tilapia muscle according to claim 3, characterized in that, The compound vitamin premix, per 1 kg, consists of the following components: Vitamin A 300 mg, Vitamin D3 3 mg, Vitamin E 30 g, Vitamin K3 0.5 g, Vitamin B1 1 g, Vitamin B2 1 g, Calcium pantothenate 0.2 g, Niacin 3.5 g, Biotin 3 mg, Vitamin B6 165 mg, Folic acid 40 mg, Inositol 1.5 g, Vitamin B12 0.02 g, and wheat bran to make up to 1 kg.

5. A method for preparing a compound feed to improve the crispness of tilapia muscle as described in claim 4, characterized in that, Includes the following steps: S1: Raw material pretreatment Fish meal, pea protein, konjac glucomannan, wheat bran, rice bran, and zeolite powder were separately fed into a grinder and ground. After grinding, all of them were passed through an 80-mesh sieve to obtain fine powder raw materials. Fermented rubber seed cake was ground and passed through a 60-mesh sieve to obtain fermented rubber seed cake powder. S2: First Mixing The fine powder raw material obtained in step S1 and the fermented rubber seed cake powder are put into a double helix mixer. The mixing speed is 300-350 r / min and the mixing time is 15-20 min to obtain the primary mixture. S3: Functional component pretreatment Add L-hydroxyproline and green tea extract to 5 times their weight of warm water at a temperature of 40-45℃, stir and dissolve to obtain a functional ingredient solution. S4: Second Mixing Add the compound mineral premix and compound vitamin premix to the primary mixture, stir and mix for 5-8 minutes, then slowly spray in the functional ingredient solution while stirring. The stirring speed is 200-250 r / min and the stirring time is 10-12 minutes to obtain the intermediate mixture. S5: Oil coating Fish oil and soybean lecithin are mixed evenly and heated to 50-55℃ to obtain coated oil. The coated oil is then sprayed evenly onto the surface of the intermediate mixture using a spraying method at a pressure of 0.3-0.5MPa. After spraying, the mixture is stirred for 8-10 minutes to obtain the final mixture. S6: Conditioning and Granulation The final mixture is fed into a conditioner and saturated steam at 105-110℃ is introduced. The conditioning time is 6-8 minutes. After conditioning, it is fed into a pellet mill to granulate. The pellet size is 2-5 mm to obtain pellet feed. S7: Segmented Drying First, feed pellets are placed in a hot air dryer and dried at 80-85℃ for 30-40 minutes. Then, they are transferred to a low-temperature dryer and dried at 45-50℃ for 60-80 minutes until the feed moisture content is ≤8%. S8: Post-curing treatment The dried pelleted feed is fed into a post-maturation equipment and matured for 25-30 minutes at 70-75℃ and 60-65% relative humidity. After maturation, it is naturally cooled to room temperature. S9: Screening and Packaging The cooled pelleted feed is screened through a grading sieve to remove powder and unqualified pellets. After passing the inspection, it is vacuum-packed to obtain the finished compound feed.

6. A method for preparing a compound feed to improve the crispness of tilapia muscle according to claim 5, characterized in that, In step S1, the grinding speed of the pulverizer is 4500-5000 r / min, and the grinding time is 3-5 min.

7. A formulated feed for improving the crispness of tilapia muscle according to claim 5, characterized in that, In step S5, the material temperature during spraying is controlled at 35-40℃ to prevent the oil from denaturing.

8. A formulated feed for improving the crispness of tilapia muscle according to claim 5, characterized in that, In step S7, the air velocity of the hot air dryer is 1.2-1.5 m / s, and the air velocity of the low temperature dryer is 0.8-1.0 m / s.

9. A formulated feed for improving the crispness of tilapia muscle according to claim 5, characterized in that, In step S8, the heating rate of the post-ripening equipment is 5℃ / min to avoid the destruction of feed nutrients due to a sudden temperature rise.

10. A formulated feed for improving the crispness of tilapia muscle according to claim 5, characterized in that, In step S9, the sieve aperture size of the grading sieve is 1.5mm and 5.5mm, and qualified particles with a particle size of 2-5mm are screened out.

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