Feed for improving muscle quality of onigiri and method for preparing the same

Abstract

This invention belongs to the field of formulated feed technology for marine fish, specifically relating to a feed for improving the muscle quality of *Hexagrammos oysterfish* and its preparation method. The feed for improving the muscle quality of *Hexagrammos oysterfish* is made from the following raw materials in the indicated weight percentages: 93.5%–96.5% basic ingredients, 1% compound vitamins, 1% compound mineral salts, and 1.5%–4.5% formulated feed composition, with the sum of the weight percentages of all raw materials being 100%. The formulated feed composition consists of yeast β-glucan, chitosan oligosaccharide, and coated sodium butyrate, with the mass ratio of yeast β-glucan, chitosan oligosaccharide, and coated sodium butyrate being 1–3:1–3:1–2. This invention not only effectively reduces fat deposition in the body of *Hexagrammos oysterfish*, improving its muscle elasticity and chewiness, but also significantly improves the textural properties of the fish meat, thereby enhancing the overall muscle quality of *Hexagrammos oysterfish* and meeting consumer preferences.

Description

Technical Field

[0001] This invention belongs to the field of formulated feed technology for marine fish, specifically relating to a feed for improving the muscle quality of Hexagrammos otakii and its preparation method. Background Technology

[0002] The large-scaled rockfish, also known as the European rockfish or commonly called yellow croaker, is a nearshore, cold-water, bottom-dwelling fish. This species is renowned for its tender flesh and delicious flavor, and is one of the prized marine economic fish species unique to northern regions. It is widely used in aquaculture, recreational fishing, and cage aquaculture.

[0003] The diversification of aquaculture methods has led to significant differences in the muscle quality of fish raised under different methods. Muscle texture is a key indicator for sensory evaluation, directly influencing consumers' judgment of the quality of Hexagrammos oysterfish meat. Generally, consumers prefer fish meat that is elastic and chewy. Currently, there are few feed varieties on the market specifically designed to improve the muscle quality of Hexagrammos oysterfish. The common strategy is to increase the lipid level in feed to conserve protein, aiming to promote fish growth and protect the aquatic environment. However, excessive fat in feed can easily lead to excessive fat deposition in the fish, decreased stress resistance, and even nutritional fatty liver. Compared to wild-caught species, farmed fish are of lower quality, with lower lean meat percentage, lower crude protein content in the muscle, lower essential amino acid ratios, and higher body fat content. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a feed for improving the muscle quality of Hexagrammos oysterfish and its preparation method. This invention utilizes yeast β-glucan, chitosan oligosaccharide, and coated sodium butyrate to prepare a compound feed composition for Hexagrammos oysterfish. The compound feed for Hexagrammos oysterfish is prepared using this feed composition, basic ingredients, compound vitamins, and compound mineral salts as raw materials. This invention's feed for improving the muscle quality of Hexagrammos oysterfish, through the addition of the compound feed composition of yeast β-glucan, chitosan oligosaccharide, and coated sodium butyrate, not only effectively reduces fat deposition in the Hexagrammos oysterfish, improving its muscle elasticity and chewiness, but also significantly improves the textural properties of the fish meat, thereby enhancing the overall muscle quality of Hexagrammos oysterfish and meeting consumer preferences.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: The first objective of this invention is to provide a feed for improving the muscle quality of Hexagrammos otakii, which is made from the following raw materials in the following weight percentages: 93.5% to 96.5% basic ingredients, 1% compound vitamins, 1% compound mineral salts, and 1.5% to 4.5% compound feed composition, wherein the sum of the weight percentages of each raw material is 100%.

[0006] The compound feed composition consists of yeast β-glucan, chitosan oligosaccharide, and coated sodium butyrate.

[0007] The mass ratio of yeast β-glucan, chitosan oligosaccharide and coated sodium butyrate is 1~3:1~3:1~2.

[0008] Preferably, the mass ratio of yeast β-glucan, chitosan oligosaccharide and coated sodium butyrate is 1:1:1.

[0009] Preferably, the basic ingredients consist of the following raw materials in the following mass percentages: 40%~42% fish meal, 29.5%~30.5% soybean meal, 16% casein, 4.5%~5.5% fish oil, 1.5%~5% flour and 0.5%~1.5% corn starch, with the sum of the mass percentages of each raw material being 100%.

[0010] Preferably, the compound vitamins include the following ingredients: VA, VE, VD3, VK3, VB1, VB2, VB6, VB12, niacin, VC, calcium pantothenate, folic acid, and inositol.

[0011] Preferably, the ratio of VA, VE, VD3, VK3, VB1, VB2, VB6, VB12, niacin, VC, calcium pantothenate, folic acid and inositol is 7000 IU: 50 mg: 2000 IU: 10 mg: 20 mg: 20 mg: 30 mg: 0.1 mg: 80 mg: 100 mg: 50 mg: 6 mg: 80 mg.

[0012] Preferably, the composite mineral salt comprises the following raw materials: MgSO4·7H2O, FeSO4·7H2O, NaCl, ZnSO4·7H2O, MnSO4·4H2O, CuSO4·5H2O, CoCl2·6H2O, and KI.

[0013] Preferably, the mass ratio of MgSO4·7H2O, FeSO4·7H2O, NaCl, ZnSO4·7H2O, MnSO4·4H2O, CuSO4·5H2O, CoCl2·6H2O and KI is 5782:1000:3000:150:50.3:15:1.2:1.5.

[0014] The second objective of this invention is to provide a method for preparing the above-mentioned feed for improving the muscle quality of Hexagrammos otakii, comprising the following steps: The basic ingredients, compound vitamins, compound mineral salts, and compound feed composition are pulverized and mixed to obtain a mixed powder.

[0015] After conditioning, the mixed powder is extruded, granulated, dried, and cooled to obtain feed that improves the muscle quality of Hexagrammos otakii.

[0016] Preferably, the basic ingredients, compound vitamins, compound mineral salts and compound feed composition are pulverized and passed through a 40-mesh sieve to ensure uniform particle size and ensure the uniformity of raw materials. At the same time, it improves the granulation and extrusion process, thereby increasing processing efficiency and granulation quality.

[0017] Preferably, the temperature for the conditioning process is 90℃~100℃ to maintain the integrity of the nutrients.

[0018] Preferably, the particle size of the granulation is required to be 2.0mm~2.5mm.

[0019] Preferably, the extrusion granulation conditions are: extrusion at 4MPa~5MPa.

[0020] The preferred feed for improving the muscle quality of Ōtaki Hexagrammos has a moisture content of less than 10%.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention provides a feed for improving the muscle quality of *Hexagrammos otakii* (a type of rockfish). The feed is made from the following raw materials in the indicated weight percentages: 93.5%–96.5% basic ingredients, 1% compound vitamins, 1% compound mineral salts, and 1.5%–4.5% a compound feed composition, with the sum of the weight percentages of all raw materials being 100%. The compound feed composition consists of yeast β-glucan, chitosan oligosaccharide, and coated sodium butyrate. The weight ratio of yeast β-glucan, chitosan oligosaccharide, and coated sodium butyrate is 1–3:1–3:1–2. This invention, through the addition of the compound feed composition of yeast β-glucan, chitosan oligosaccharide, and coated sodium butyrate, not only effectively reduces fat deposition in the body of *Hexagrammos otakii*, improving its muscle elasticity and chewiness, but also significantly improves the textural properties of the fish meat, thereby enhancing the overall muscle quality of *Hexagrammos otakii* and meeting consumer preferences.

[0022] 2. In the feed for improving the muscle quality of Hexagrammos otakii provided by this invention, yeast β-glucan can activate digestive enzymes and promote growth. Simultaneously, yeast β-glucan can be fermented by intestinal flora to produce short-chain fatty acids, which help reduce lipid production and have a positive impact on the body's growth.

[0023] Chitosan oligosaccharides further improve muscle quality by maintaining the functional integrity of cells and tissues. Simultaneously, they regulate fatty acid metabolism, reduce lipid accumulation, and allow energy to be used more efficiently for growth.

[0024] Sodium butyrate can regulate fatty acid metabolism, reduce fat accumulation in the body of the rockfish, and thus promote the release of more energy for the growth of the rockfish.

[0025] A compound feed composition that combines yeast β-glucan, chitosan oligosaccharide, and coated sodium butyrate to improve the muscle quality of Hexagrammos oysterfish not only works synergistically at the fatty acid metabolism level to effectively reduce body fat accumulation, but also ensures that energy can serve the growth and development of Hexagrammos oysterfish more efficiently, thereby comprehensively improving the muscle quality and growth performance of Hexagrammos oysterfish.

[0026] In addition, yeast β-glucan has more β-1,6-glycosidic bonds than β-glucan from other sources, and has stronger biological activity. It can regulate the intestinal flora structure, promote the growth of beneficial bacteria, and inhibit harmful bacteria, thereby accelerating the growth of Hexagrammos otakii.

[0027] Chitosan oligosaccharides can increase the activity of beneficial bacteria in the gut, reduce pathogen invasion, promote gut health, improve the absorption and utilization efficiency of nutrients, and thus promote the growth of rockfish. At the same time, chitosan oligosaccharides can also maintain gut environment stability and enhance gut barrier function by improving the composition of gut microbiota.

[0028] Coated sodium butyrate is a bioactive substance produced using coating technology. This coating not only effectively masks the unpleasant odor of sodium butyrate itself but also enables its slow release into the digestive tract of Hexagrammos oysterfish, allowing sodium butyrate to exert its biological effects for a longer period. In maintaining intestinal health, sodium butyrate optimizes the intestinal flora structure, promoting the growth of beneficial bacteria and inhibiting harmful bacteria, thus maintaining a stable intestinal environment.

[0029] By combining yeast β-glucan, chitosan oligosaccharide, and sodium butyrate, a bioactive network is formed that collectively activates digestive enzymes, promotes the growth of beneficial bacteria, and inhibits harmful bacteria, thereby enhancing intestinal health and improving the absorption and utilization efficiency of nutrients. At the same time, by regulating the balance of the intestinal microecology, the barrier function of the intestine is further strengthened.

[0030] 3. The feed for improving the muscle quality of Hexagrammos oysterfish provided by this invention can also meet the nutritional needs of juvenile Hexagrammos oysterfish. The fish meal, soybean meal and casein in the basic ingredients contain a variety of essential amino acids for Hexagrammos oysterfish. These components can significantly improve the protein quality of the feed for improving the muscle quality of Hexagrammos oysterfish, thereby improving the muscle quality of Hexagrammos oysterfish. Attached Figure Description

[0031] Figure 1 This is a diagram of the feed prepared in Example 1 of the present invention to improve the muscle quality of Hexagrammos otakii. Detailed Implementation

[0032] The technical solution of the present invention will be clearly and completely described below with reference to the data in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0033] It should be noted that the technical terms used in this invention are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of this invention. Unless otherwise specified, all raw materials, reagents, instruments and equipment used in the following embodiments of this invention can be purchased on the market or prepared by existing methods.

[0034] Currently, formulated feeds for rockfish often neglect targeted improvements in muscle quality, focusing only on increasing growth rate and feed conversion ratio. This results in a decline in muscle quality and reduced consumer satisfaction.

[0035] To address these technical deficiencies, this invention provides a feed for improving the muscle quality of *Hexagrammos otakii*, made from the following raw materials by weight percentage: 93.5%–96.5% basic ingredients, 1% compound vitamins, 1% compound mineral salts, and 1.5%–4.5% compound feed composition, the sum of the weight percentages of each raw material being 100%; the compound feed composition consists of yeast β-glucan, chitosan oligosaccharide, and coated sodium butyrate; the weight ratio of yeast β-glucan, chitosan oligosaccharide, and coated sodium butyrate is 1–3:1–3:1–2.

[0036] In this invention, yeast β-glucan and chitosan oligosaccharides not only improve the intestinal environment by optimizing the gut microbiota structure, but also directly participate in the metabolic regulation of fatty acids, effectively reducing lipid accumulation in Hexagrammos oysterfish. Meanwhile, coated sodium butyrate, with its unique sustained-release properties, continuously releases its biological activity in the intestine, further enhancing the absorption efficiency of nutrients and providing a solid guarantee for intestinal health. These three substances work together to form a powerful bioactive network, significantly improving the muscle quality of Hexagrammos oysterfish.

[0037] The technical solution of the present invention will be further explained and illustrated below with examples, as detailed below: Example 1 A method for preparing feed to improve the muscle quality of Hexagrammos oysterfish includes the following steps: S1. Weigh out yeast β-glucan, chitosan oligosaccharide and sodium butyrate according to the mass percentages of 0.5%, 0.5% and 0.5% respectively, and mix them to obtain a compound feed composition.

[0038] S2. Weigh out the following ingredients according to their mass percentages: fish meal (42%), soybean meal (30.5%), casein (16%), fish oil (5%), flour (2%), corn starch (1%), compound vitamins (1%), compound mineral salts (1%), and a compound feed composition (1.5%). Grind the weighed materials through a 40-mesh sieve and mix them to obtain a mixed powder. The compound vitamins consist of: VA 6500 IU, VE 50 mg, VD3 2500 IU, VK 35 mg, VB1 20 mg, VB2 20 mg, VB6 25 mg, VB12 0.05 mg, niacin 50 mg, VC 100 mg, calcium pantothenate 80 mg, folic acid 6 mg, and inositol 80 mg. The compound mineral salts consist of: MgSO4·7H2O 5782 mg, FeSO4·7H2O... It consists of 1000mg of NaCl, 3000mg of NaCl, 150mg of ZnSO4·7H2O, 50.3mg of MnSO4·4H2O, 15mg of CuSO4·5H2O, 1.2mg of CoCl2·6H2O, and 1.5mg of KI.

[0039] S3. The mixed powder is fed into a rotating feeder and steam-conditioned at 90℃. Then, it is extruded into 2.0mm diameter pellets using a twin-screw extruder under 4.5MPa pressure. The pellets are then dried in a dryer at 55℃ with a moisture content below 10%, yielding feed that improves the muscle quality of *Hexagrammos otakii*. Figure 1 As shown.

[0040] The feed for improving the muscle quality of Hexagrammos otakii has a crude protein content of 47.21% and a crude fat content of 12.48%.

[0041] Example 2 A method for preparing feed to improve the muscle quality of Hexagrammos oysterfish includes the following steps: S1. Weigh out yeast β-glucan, chitosan oligosaccharide and sodium butyrate according to the mass percentages of 1%, 1%, and 1%, respectively, and mix them to obtain a compound feed composition.

[0042] S2. Weigh out the following ingredients according to their mass percentages: fish meal (41%), soybean meal (30%), casein (16%), fish oil (5%), flour (2%), corn starch (1%), compound vitamins (1%), compound mineral salts (1%), and a compound feed composition (3%). Grind the weighed materials through a 40-mesh sieve and mix them to obtain a mixed powder. The compound vitamins consist of: VA 6500 IU, VE 50 mg, VD3 2500 IU, VK 35 mg, VB1 20 mg, VB2 20 mg, VB6 25 mg, VB12 0.05 mg, niacin 50 mg, VC 100 mg, calcium pantothenate 80 mg, folic acid 6 mg, and inositol 80 mg. The compound mineral salts consist of: MgSO4·7H2O 5782 mg, FeSO4·7H2O... It consists of 1000mg of NaCl, 3000mg of NaCl, 150mg of ZnSO4·7H2O, 50.3mg of MnSO4·4H2O, 15mg of CuSO4·5H2O, 1.2mg of CoCl2·6H2O, and 1.5mg of KI.

[0043] S3. The mixed powder is loaded into a rotating feeder and steam-conditioned at 95°C. Then, it is extruded into 2.5mm diameter pellets using a twin-screw extruder under 4MPa pressure. The pellets are then dried in a dryer at 60°C with a moisture content below 10%, resulting in feed that improves the muscle quality of the large-scaled rockfish.

[0044] The feed for improving the muscle quality of Hexagrammos otakii has a crude protein content of 47.12% and a crude fat content of 12.50%.

[0045] Example 3 A method for preparing feed to improve the muscle quality of Hexagrammos oysterfish includes the following steps: S1. Weigh out yeast β-glucan, chitosan oligosaccharide and sodium butyrate according to the mass percentages of 1.5%, 1.5% and 1.5% respectively, and mix them to obtain a compound feed composition.

[0046] S2. Weigh out the following ingredients according to their mass percentages: fish meal (40%), soybean meal (29.5%), casein (16%), fish oil (5%), flour (2%), corn starch (1%), compound vitamins (1%), compound mineral salts (1%), and a compound feed composition (4.5%). Grind the weighed materials through a 40-mesh sieve and mix them to obtain a mixed powder. The compound vitamins consist of: VA 6500 IU, VE 50 mg, VD3 2500 IU, VK 35 mg, VB1 20 mg, VB2 20 mg, VB6 25 mg, VB12 0.05 mg, niacin 50 mg, VC 100 mg, calcium pantothenate 80 mg, folic acid 6 mg, and inositol 80 mg. The compound mineral salts consist of: MgSO4·7H2O 5782 mg, FeSO4·7H2O... It consists of 1000mg of NaCl, 3000mg of NaCl, 150mg of ZnSO4·7H2O, 50.3mg of MnSO4·4H2O, 15mg of CuSO4·5H2O, 1.2mg of CoCl2·6H2O, and 1.5mg of KI.

[0047] S3. The mixed powder is loaded into a rotating feeder and steam-conditioned at 100°C. Then, it is extruded into 2.5mm diameter pellets using a twin-screw extruder under 5MPa pressure. The pellets are then dried in a dryer at 60°C until the moisture content is below 10%, resulting in feed that improves the muscle quality of the large-scaled rockfish.

[0048] The feed for improving the muscle quality of Hexagrammos otakii has a crude protein content of 47.01% and a crude fat content of 12.53%.

[0049] Example 4 A method for preparing feed to improve the muscle quality of Hexagrammos oysterfish includes the following steps: S1. Weigh out yeast β-glucan, chitosan oligosaccharide and coated sodium butyrate according to the mass percentages of 1.5%, 1.5% and 1% respectively, and mix them to obtain a compound feed composition.

[0050] S2. Weigh out the following ingredients according to their mass percentages: fish meal (40%), soybean meal (29.5%), casein (16%), fish oil (5%), flour (2%), corn starch (1%), compound vitamins (1%), compound mineral salts (1%), and a compound feed composition (4.5%). Grind the weighed materials through a 40-mesh sieve and mix them to obtain a mixed powder. The compound vitamins consist of: VA 6500 IU, VE 50 mg, VD3 2500 IU, VK 35 mg, VB1 20 mg, VB2 20 mg, VB6 25 mg, VB12 0.05 mg, niacin 50 mg, VC 100 mg, calcium pantothenate 80 mg, folic acid 6 mg, and inositol 80 mg. The compound mineral salts consist of: MgSO4·7H2O 5782 mg, FeSO4·7H2O... It consists of 1000mg of NaCl, 3000mg of NaCl, 150mg of ZnSO4·7H2O, 50.3mg of MnSO4·4H2O, 15mg of CuSO4·5H2O, 1.2mg of CoCl2·6H2O, and 1.5mg of KI.

[0051] S3. The mixed powder is loaded into a rotating feeder and steam-conditioned at 100°C. Then, it is extruded into 2.5mm diameter pellets using a twin-screw extruder under 5MPa pressure. The pellets are then dried in a dryer at 60°C until the moisture content is below 10%, resulting in feed that improves the muscle quality of the large-scaled rockfish.

[0052] Comparative Example 1 A method for preparing a formulated feed for rockfish (Hexagrammos octopus) includes the following steps: S1. Weigh out fish meal, soybean meal, casein, fish oil, flour, corn starch, compound vitamins, and compound mineral salts according to the following mass percentages: 41% fish meal, 30% soybean meal, 16% casein, 5% fish oil, 5% flour, 1% corn starch, 1% compound vitamins, and 1% compound mineral salts. Grind the weighed materials through a 40-mesh sieve and then mix them to obtain a mixed powder. The compound vitamins consist of VA 6500 IU, VE 50 mg, VD3 2500 IU, VK3 5 mg, VB1 20 mg, VB2 20 mg, VB6 25 mg, VB1 20.05 mg, niacin 50 mg, VC 100 mg, calcium pantothenate 80 mg, folic acid 6 mg, and inositol 80 mg. The compound mineral salts consist of MgSO4·7H2O 5782 mg, FeSO4·7H2O 1000 mg, NaCl 3000 mg, and ZnSO4·7H2O. It consists of 150mg of MnSO4·4H2O, 50.3mg of CuSO4·5H2O, 15mg of CoCl2·6H2O, 1.2mg of KI, and 1.5mg of KI.

[0053] S2. The mixed powder is loaded into a rotating feeder and steam-conditioned at 90°C. Then, it is extruded into pellets with a diameter of 2.0 mm using a twin-screw extruder at a pressure of 4.5 MPa. The pellets are then dried in a dryer at a temperature controlled at 55°C until the moisture content is reduced to 10%, yielding the formulated feed for Hexagrammos otakii.

[0054] The crude protein content of the compound feed for rockfish is 47.02%, and the crude fat content is 12.51%.

[0055] The following examples use the feeds for improving the muscle quality of *Hexagrammos oysteri* prepared in Examples 1-3 and the formulated feed for *Hexagrammos oysteri* prepared in Comparative Example 1 as examples. These feeds were then used to feed juvenile *Hexagrammos oysteri* and the results were studied. Application method: Using the feeds for improving the muscle quality of Hexagrammos otakii prepared in Examples 1 to 3 of the present invention, and the formulated feed for Hexagrammos otakii prepared in Comparative Example 1, juvenile Hexagrammos otakii were subjected to an indoor culture experiment for 8 weeks. After disinfection, juvenile Hexagrammos oysters were placed in a temporary cement pond measuring 4.0m×6.0m×2.0m for 14 days to acclimate them to the aquaculture environment. After fasting for 24 hours, 360 juvenile Hexagrammos oysters from the same batch, with an individual weight of 30.00±0.16g and a body length of 15.00±0.28cm, were randomly selected and divided into 4 groups, with 3 replicates in each group and 30 experimental fish in each replicate. The juvenile Hexagrammos oysters were loaded into cylindrical net cages with a diameter of 1m and a height of 1.2m and placed in the same aquaculture pond in the factory-style aquaculture workshop for flow-through culture.

[0056] The differences in growth and muscle texture of juvenile Hexagrammos otakii prepared in Examples 1-3 and the formulated feed for Hexagrammos otakii prepared in Comparative Example 1 were detected.

[0057] Test method: Growth of juvenile Hexagrammos ogakii: Weight gain rate (%) = 100 × (final weight - initial weight) / initial weight.

[0058] Specific growth rate (%) = 100 × (ln final body weight – ln initial body weight) / 56.

[0059] Condition (%) = 100 × sampled fish weight / sampled fish body length 3 .

[0060] Muscle texture: Dorsal muscle of *Hexagrammos oysteri* was collected, and the hardness, elasticity, and chewiness of the muscle were measured using a texture analyzer with a 6mm cylindrical probe. Three parallel muscle samples were taken from each fish for measurement. The texture analyzer was purchased from Perten, Sweden, model TVT6700.

[0061] The test results are shown in Tables 1 and 2.

[0062] Table 1 shows the effects of the feeds prepared in Examples 1-3 to improve the muscle quality of *Hexagrammos octopus* and the formulated feed prepared in Comparative Example 1 on the growth of juvenile *Hexagrammos octopus*. Note: The data in the table are average ± standard error.

[0063] Table 1 shows that the weight gain rate, specific growth rate, and condition factor of juvenile Hexagrammos otakii fed with the diets prepared in Examples 1-3 to improve muscle quality were all higher than those fed with the formulated diet prepared in Comparative Example 1. Furthermore, the weight gain rate and specific growth rate showed a trend of first increasing and then decreasing. The diets prepared in Examples 1 and 2 to improve muscle quality were significantly different from the formulated diet prepared in Comparative Example 1. P <0.05). Regarding condition factor, the juvenile *Hexagrammos oysterfish* fed the diets prepared in Examples 1 and 3 to improve muscle quality showed significantly higher results than those fed the formulated diet prepared in Comparative Example 1. P <0.05). Therefore, the feed for improving the muscle quality of Hexagrammos oysterfish provided by the present invention can improve the growth performance of juvenile Hexagrammos oysterfish.

[0064] Table 2 shows the effects of the feeds prepared in Examples 1-3 to improve the muscle quality of *Hexagrammos octopus* and the formulated feed prepared in Comparative Example 1 on the muscle texture properties of *Hexagrammos octopus*. Note: The data in the table are average ± standard error.

[0065] Table 2 shows that, compared to the formulated feed for Hexagrammos oysterfish prepared in Comparative Example 1, the muscle hardness, elasticity, and chewiness of Hexagrammos oysterfish fed with the feeds prepared in Examples 1-3 for improving muscle quality showed an increasing trend. Among them, the muscle hardness, elasticity, and chewiness of Hexagrammos oysterfish fed with the feeds prepared in Examples 2 and 3 for improving muscle quality were significantly higher than those in Comparative Example 1. P<0.05 Therefore, the feed for improving the muscle quality of Ōtaki Hexagrammos provided by this invention can improve the textural properties of the muscle of juvenile Ōtaki Hexagrammos.

[0066] It should be noted that when numerical ranges are involved in this invention, it should be understood that both endpoints of each numerical range, as well as any value between the two endpoints, can be selected. Since the steps and methods used are the same as in the embodiments, preferred embodiments are described here to avoid redundancy. Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this invention.

[0067] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A feed for improving the muscle quality of *Hexagrammos otakii*, characterized in that, The feed for improving the muscle quality of Hexagrammos otakii is made from the following ingredients by weight percentage: 93.5%~96.5% basic ingredients, 1% compound vitamins, 1% compound mineral salts, and 1.5%~4.5% compound feed composition, with the sum of the weight percentages of each ingredient being 100%. The compound feed composition consists of yeast β-glucan, chitosan oligosaccharide and coated sodium butyrate; The mass ratio of yeast β-glucan, chitosan oligosaccharide and coated sodium butyrate is 1~3:1~3:1~2.

2. The feed for improving the muscle quality of *Hexagrammos otakii* according to claim 1, characterized in that, The mass ratio of yeast β-glucan, chitosan oligosaccharide, and coated sodium butyrate is 1:1:

1.

3. The feed for improving the muscle quality of *Hexagrammos otakii* according to claim 1, characterized in that, The basic ingredients consist of the following raw materials in the following mass percentages: fish meal 40%~42%, soybean meal 29.5%~30.5%, casein 16%, fish oil 4.5%~5.5%, flour 1.5%~5%, and corn starch 0.5%~1.5%, with the sum of the mass percentages of each raw material being 100%.

4. The feed for improving the muscle quality of Hexagrammos otakii according to claim 1, characterized in that, The multivitamin contains the following ingredients: VA, VE, VD3, VK3, VB1, VB2, VB6, VB12, niacin, VC, calcium pantothenate, folic acid, and inositol.

5. The feed for improving the muscle quality of Hexagrammos otakii according to claim 1, characterized in that, The composite mineral salt comprises the following raw materials: MgSO4·7H2O, FeSO4·7H2O, NaCl, ZnSO4·7H2O, MnSO4·4H2O, CuSO4·5H2O, CoCl2·6H2O, and KI.

6. A method for preparing a feed for improving the muscle quality of *Hexagrammos otakii* as described in any one of claims 1 to 5, characterized in that, Includes the following steps: The basic ingredients, compound vitamins, compound mineral salts and compound feed composition are pulverized and mixed to obtain a mixed powder. After conditioning, the mixed powder is extruded, granulated, dried, and cooled to obtain feed that improves the muscle quality of Hexagrammos otakii.

7. The method for preparing feed for improving the muscle quality of Hexagrammos otakii according to claim 6, characterized in that, The basic ingredients, compound vitamins, compound mineral salts, and compound feed composition are pulverized and passed through a 40-mesh sieve.

8. The method for preparing feed for improving the muscle quality of Hexagrammos otakii according to claim 6, characterized in that, The modulation process is performed at a temperature of 90℃~100℃.

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