Mandarin fish feed for improving muscle fat content of mandarin fish and application of mandarin fish feed

Abstract

The invention discloses mandarin fish feed capable of increasing the muscle fat content of mandarin fish and application of the mandarin fish feed. The mandarin fish feed capable of improving the muscle fat content of mandarin fish comprises a basic mandarin fish feed, and a mixture of 2-hydroxyisobutyric acid and S-adenosylmethionine is added; wherein the 2-hydroxyisobutyric acid accounts for 0.2-0.6% of the mass fraction of the basic mandarin fish feed; the mass fraction of the S-adenosylmethionine in the basic mandarin fish feed is 0.4-0.9%. According to the mandarin fish feed, a commercially available basic mandarin fish feed is used as a base material, a mixture of 2-hydroxyisobutyric acid and S-adenosylmethionine is added, and after all the raw materials are matched according to a certain proportion, the 2-hydroxyisobutyric acid and the S-adenosylmethionine are subjected to synergistic interaction, fat synthesis related genes are up-regulated, meanwhile, fat decomposition related genes are inhibited, and the content of fat in the mandarin fish feed is increased. The accumulation of fat in muscles is promoted.

Description

Technical Field

[0001] The invention relates to the technical field of aquaculture, and in particular to a mandarin fish feed capable of increasing the fat content of mandarin fish muscles and an application thereof. Background Art

[0002] With continuous breakthroughs in mandarin fish feed domestication and formulation technologies, the feed-based mandarin fish farming model has gradually emerged. However, the existing mandarin fish feed nutritional system largely follows the formula system for largemouth bass, resulting in a significant difference in muscle quality between feed-based mandarin fish and bait-based mandarin fish. Mandarin fish muscle fat content is a key factor affecting its meat quality, and the difference in muscle quality between feed-based mandarin fish and bait-based mandarin fish is primarily reflected in muscle fat content. Currently, feed-based mandarin fish often lack the "fatness" of mandarin fish due to low muscle fat content, resulting in a 10% to 15% price difference between feed-based mandarin fish and bait-based mandarin fish.

[0003] Patent application publication number CN113812545A discloses a nutritional method for regulating the fatty acid composition of large yellow croaker muscle under high-fat feeding. This method, which belongs to the field of aquatic nutritional feed, involves adding 0.5% phytosterols to the large yellow croaker high-fat feed. This method significantly reduces the SFA content in the muscle fatty acid composition and increases the ratio of n-6 PUFA to n-3 PUFA to a certain extent, thereby improving the nutritional value of the fish. Patent application publication number CN109156386B discloses a nutritional method for regulating fat deposition in the muscles of redfin pufferfish. This method increases or decreases the fat content in the muscles of farmed redfin pufferfish by adding a certain amount of astaxanthin to the feed and controlling the methionine content.

[0004] my country's mandarin fish farming has long relied primarily on live bait fish, and research into technologies for regulating mandarin fish muscle quality under feed-based conditions is lacking. Currently, fish meal in mandarin fish feed generally accounts for over 50% of the feed's dry weight, and all fish meal contains at least 2% methionine. While this content exceeds the methionine content specified in patent CN 109156386 B, under these conditions, the fat content in mandarin fish muscle from grow-out feed remains far lower than that of high-quality mandarin fish. Therefore, developing a mandarin fish feed that increases the fat content in mandarin fish muscle and its application method are urgent technical challenges. Summary of the Invention

[0005] In response to the above-mentioned shortcomings of the prior art, one of the objectives of the present invention is to provide a mandarin fish feed that increases the muscle fat content of mandarin fish. The feed is added with a certain amount of a mixture of 2-hydroxyisobutyric acid and S-adenosylmethionine to increase the muscle fat content of mandarin fish during growth, thereby improving the muscle quality of the mandarin fish fed as feed.

[0006] The present invention also aims to provide an application of a mandarin fish feed, wherein the mandarin fish feed containing the mixture of 2-hydroxyisobutyric acid and S-adenosylmethionine is fed to the mandarin fish to promote the accumulation of fat in the muscles of the mandarin fish.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] In a first aspect, the present invention provides a mandarin fish feed for increasing the muscle fat content of mandarin fish, comprising a basic mandarin fish feed and a mixture of 2-hydroxyisobutyric acid and S-adenosylmethionine added thereto; wherein the mass fraction of 2-hydroxyisobutyric acid in the basic mandarin fish feed is 0.2-0.6%; the mass fraction of S-adenosylmethionine in the basic mandarin fish feed is 0.4-0.9%.

[0009] The mandarin fish feed uses commercially available basic mandarin fish feed as a base material, and is added with a mixture of 2-hydroxyisobutyric acid and S-adenosylmethionine. After the raw materials are mixed in a certain proportion, the 2-hydroxyisobutyric acid and S-adenosylmethionine synergistically enhance the effect, increase the regulation of fat synthesis-related genes, and inhibit the fat decomposition-related genes, thereby promoting the accumulation of fat in muscles.

[0010] Furthermore, the mixture also includes microcrystalline cellulose.

[0011] Furthermore, the mass fraction of the mixture in the basic mandarin fish feed is 2-3%; every 100g of the mixture is composed of the following components: 10-20g of 2-hydroxyisobutyric acid, 20-30g of S-adenosylmethionine, and the remaining components are microcrystalline cellulose.

[0012] Furthermore, the mass fraction of the mixture in the basic mandarin fish feed is 2.5%; every 100g of the mixture is composed of the following components: 15g of 2-hydroxyisobutyric acid, 25g of S-adenosylmethionine, and the remaining components are microcrystalline cellulose.

[0013] In a second aspect, the present invention provides an application of a mandarin fish feed, characterized in that the mandarin fish feed for increasing the muscle fat content of the mandarin fish as described above is used to feed the mandarin fish, thereby promoting the expression of fat synthesis genes in the mandarin fish and inhibiting the expression of fat decomposition genes in the mandarin fish, thereby increasing the muscle fat content of the mandarin fish.

[0014] Furthermore, the fat synthesis gene includes at least one of sterol regulatory element binding protein SREBP1, fatty acid synthase FAS and acetyl-CoA carboxylase ACC1.

[0015] Furthermore, the lipolytic gene includes carnitine palmitoyltransferase CPT1.

[0016] Furthermore, the mandarin fish is fed with the mandarin fish feed that increases the muscle fat content of the mandarin fish, and the feeding time is not less than 8 weeks.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The mandarin fish feed of the present invention is added with a mixture of 2-hydroxyisobutyric acid and S-adenosylmethionine, which plays a synergistic role in promoting muscle fat deposition and inhibiting fat decomposition, thereby promoting the directional deposition of fat in the muscle.

[0019] (2) After the additive of the present invention is applied to mandarin fish feed, it can effectively increase the muscle fat of mandarin fish cultured on feed (an average increase of 30% to 40%) and improve the muscle quality of mandarin fish cultured on feed.

[0020] (3) Both 2-hydroxyisobutyric acid and S-adenosylmethionine used in the present invention are endogenous metabolites with strong targeting and high safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention and its features and advantages will become more apparent upon reading the detailed description of non-limiting embodiments made with reference to the following accompanying drawings.

[0022] Figure 1 The crude fat content of the mandarin fish muscle of Examples 1 to 3 of the present invention and Comparative Examples 1 to 3.

[0023] Figure 2 It is the relative expression level of muscle fat metabolism related genes in Examples 1 to 3 of the present invention and Comparative Examples 1 to 3. DETAILED DESCRIPTION

[0024] The following further illustrates the structure of the present invention with reference to the accompanying drawings and specific embodiments, but does not limit the present invention. The actions, steps, and other procedures in the devices and methods described in the claims, specifications, and drawings may be performed in any order unless otherwise specified, and as long as the output of a preceding process is not used in a subsequent process.

[0025] The raw materials and additive components involved in the following embodiments and examples are all commercially available. The detection instruments and detection reagents involved in the following effect examples are all commercially available, and the detection methods used are the prior art that can be retrieved.

[0026] The invention provides a mandarin fish feed for improving muscle fat content of mandarin fish. The feed comprises a basic mandarin fish feed and a mixture of 2-hydroxyisobutyric acid and S-adenosylmethionine added thereto; wherein the mass fraction of 2-hydroxyisobutyric acid in the basic mandarin fish feed is 0.2-0.6%; and the mass fraction of S-adenosylmethionine in the basic mandarin fish feed is 0.4-0.9%.

[0027] As a preferred example, the mixture further includes microcrystalline cellulose. The microcrystalline cellulose is a filler additive with no nutritional value and is used to dilute the compounded 2-hydroxyisobutyric acid and S-adenosylmethionine. It should be noted that other common feed diluents can also be used as fillers.

[0028] As a more preferred example, the mass fraction of the mixture in the basic mandarin fish feed is 2-3%; every 100 g of the mixture is composed of the following components: 10-20 g of 2-hydroxyisobutyric acid, 20-30 g of S-adenosylmethionine, and the remaining components are microcrystalline cellulose.

[0029] In order to obtain a higher muscle fat content in mandarin fish, the mixture accounts for 2.5% of the mass fraction of the basic mandarin fish feed; each 100g of the mixture consists of the following components: 15g of 2-hydroxyisobutyric acid, 25g of S-adenosylmethionine, and the remaining components are microcrystalline cellulose.

[0030] 2-Hydroxyisobutyric acid is an intermediate product in the metabolism of the amino acid valine, which is essential for fish. It can promote the expression of genes related to fat synthesis, inhibit the expression of genes related to fat breakdown, and promote muscle fat deposition. At the same time, it can also activate the insulin signaling pathway, indirectly promoting fat synthesis.

[0031] S-adenosylmethionine is an intermediate product in the metabolism of the amino acid methionine, which is essential for fish. It is an important methyl donor and can regulate the expression of genes related to fat synthesis and breakdown through methylation. Furthermore, S-adenosylmethionine can activate the mTOR signaling pathway, indirectly regulating fat metabolism.

[0032] The 2-hydroxyisobutyric acid and S-adenosylmethionine in the present invention can synergistically promote muscle fat synthesis and fat decomposition. At the same time, they can also synergistically activate the insulin signaling pathway and regulate fat metabolism by affecting mTOR.

[0033] The technical solutions of the present invention and the technical effects achieved are described in detail below with reference to specific embodiments and comparative examples.

[0034] Example 1

[0035] The formula of mandarin fish feed commonly used in the market was used as the basic formula (see Table 1 for the formula composition), and compound additives were added. The compound additives accounted for 2.5% of the total weight of the mandarin fish basic feed.

[0036] The composite additive comprises: 10 g of 2-hydroxyisobutyric acid, 20 g of S-adenosylmethionine and 70 g of microcrystalline cellulose, which are fully mixed in a step-by-step mixing manner.

[0037] Table 1 Basic feed formula and crude composition (% dry matter) used in the experimental diet

[0038] Components content Steamed fish meal 55 Fermented soybean meal 10 corn gluten meal 5 Blood cell powder 4 squid paste 2 Yeast hydrolysate 1 Vitamin premix 1 Mineral premix 1 lecithin oil 2 soybean oil 6 α-starch 8 microcrystalline cellulose 5

[0039] Example 2

[0040] The formula of mandarin fish feed commonly used in the market was used as the basic formula (see Table 1), and compound additives were added. The compound additives accounted for 2.5% of the total weight of the mandarin fish basic feed.

[0041] The composite additive comprises 15 g of 2-hydroxyisobutyric acid, 25 g of S-adenosylmethionine and 60 g of microcrystalline cellulose, which are fully mixed in a step-by-step mixing manner.

[0042] Example 3

[0043] The formula of mandarin fish feed commonly used in the market was used as the basic formula (see Table 1), and compound additives were added. The compound additives accounted for 2.5% of the total weight of the mandarin fish basic feed.

[0044] The composite additive comprises 20 g of 2-hydroxyisobutyric acid, 30 g of S-adenosylmethionine and 50 g of microcrystalline cellulose, which are fully mixed in a step-by-step mixing manner.

[0045] Comparative Example 1

[0046] The formula of mandarin fish feed commonly used in the market was used as the basic formula (see Table 1), and 2% microcrystalline cellulose was added.

[0047] Comparative Example 2

[0048] The formula of mandarin fish feed commonly used in the market was used as the basic formula (see Table 1), and a single additive was added. The additive accounted for 2.5% of the total weight of the mandarin fish basic feed.

[0049] The additive comprises: 15 g of 2-hydroxyisobutyric acid and 85 g of microcrystalline cellulose, which are fully mixed in a step-by-step mixing manner.

[0050] Comparative Example 3

[0051] The formula of mandarin fish feed commonly used in the market was used as the basic formula (see Table 1), and a single additive was added. The additive accounted for 2.5% of the total weight of the mandarin fish basic feed.

[0052] The additive comprises: 25 g of S-adenosylmethionine and 75 g of microcrystalline cellulose, which are fully mixed in a step-by-step mixing manner.

[0053] The six formulated feeds of Examples 1-3 and Comparative Examples 1-3 were prepared as described above. Juvenile mandarin fish (Siniperca chuatsi) with an initial body weight of 30.15 ± 0.97 g were used in an 8-week culture experiment using the aforementioned feeds. Three replicates were set up for each treatment, and the fish were fed twice daily (at 7:30 AM and 5:00 PM) at full capacity. Natural light was used for the experiment, and water conditions during the experiment were as follows: 28°C, pH 7.5-8.0, dissolved oxygen >6 mg / L, total ammonia nitrogen <0.5 mg / L, and nitrite <0.1 mg / L.

[0054] After the experiment, the weight and number of fish in each bucket were recorded to characterize changes in growth performance and survival rate. Muscles were isolated and measured for crude fat content using Soxhlet extraction, and the expression of genes related to muscle fat metabolism was determined using fluorescence quantitative analysis. Additionally, subdorsal fin muscle (2 cm × 1 cm × 1 cm) was sampled for texture analysis using a texture analyzer (TPA) (TA.ZM-Plus, Dexin Technology (Kunming) Co., Ltd., China). Testing conditions were as follows: a 25 mm × 25 mm flat-bottom cylindrical probe, a compression ratio of 35%, a test speed of 1 mm / s, a post-test speed of 1 mm / s, and a dwell time of 1 second. Shear force testing conditions were as follows: a compression distance of 25 mm, a test speed of 2 mm / s, a post-test speed of 2 mm / s, and a dwell time of 1 second.

[0055] 1. Growth performance and survival rate

[0056] Table 2 details the effects of additives on the growth performance and survival rate of mandarin fish. The experimental results show that the addition of the composite additive not only did not affect the growth performance of mandarin fish, but also that the groups containing the additives described herein (Examples 1-3) exhibited higher growth performance than the control group (Comparative Example 1) and the groups containing only one additive (Comparative Examples 2 and 3). There were no significant differences in survival rate among the groups.

[0057] Table 2 Effects of additives on growth performance and survival rate of mandarin fish

[0058] index Initial body weight (g) Final body weight (g) Survival rate (%) Comparative Example 1 30.15±0.97 <![CDATA[204.15±1.97 b ]]> 98.89±1.11 Comparative Example 2 30.15±0.97 <![CDATA[206.07±1.63 ab ]]> 100±0.00 Comparative Example 3 30.15±0.97 <![CDATA[207.14±2.11 ab ]]> 100±0.00 Example 1 30.15±0.97 <![CDATA[212.34±1.59 a ]]> 100±0.00 Example 2 30.15±0.97 <![CDATA[215.28±2.03 a ]]> 100±0.00 Example 3 30.15±0.97 <![CDATA[214.53±1.37 a ]]> 100±0.00

[0059] Note: Different superscript letters indicate significant differences (P < 0.05)

[0060] 2. Analysis of muscle fat content and texture index

[0061] The experimental results show that Figure 1The crude fat content of mandarin fish in the groups treated with the additives of the present invention (Examples 1-3) was significantly higher than that in the control group (Comparative Example 1) and the groups treated with the single additives (Comparative Examples 2 and 3). The fat content in the single additive group was significantly higher than that in the control group (Comparative Example 1). Furthermore, as shown in Table 3, the hardness, toughness, and shear force of mandarin fish muscle in the groups treated with the additives of the present invention (Examples 1-3) were significantly lower than those in the control group (Comparative Example 1) and significantly lower than those in the single additive groups (Comparative Examples 2 and 3). The adhesiveness of mandarin fish muscle exhibited the opposite trend.

[0062] Table 3 Effects of additives on muscle fat content and texture of mandarin fish

[0063] index Hardness (gf) Adhesion (g.sec) Viscosity and toughness (gf) Shear force (g.sec) Comparative Example 1 <![CDATA[756.23±5.97 a ]]> <![CDATA[-6.65±0.03 c ]]> 0.41±0.01 <![CDATA[1062.15±10.24 a ]]> Comparative Example 2 <![CDATA[710.19±3.37 ab ]]> <![CDATA[-7.02±0.02 b ]]> 0.35±0.01 <![CDATA[956.12±7.92 ab ]]> Comparative Example 3 <![CDATA[713.25±2.11 ab ]]> <![CDATA[-6.98±0.05 b ]]> 0.36±0.02 <![CDATA[960.25±8.13 ab ]]> Example 1 <![CDATA[670.29±1.59 b ]]> <![CDATA[-7.72±0.02 a ]]> 0.27±0.01 <![CDATA[910.23±10.23 b ]]> Example 2 <![CDATA[674.28±2.15 b ]]> <![CDATA[-7.59±0.05 a ]]> 0.26±0.02 <![CDATA[905.73±9.73 b ]]> Example 3 <![CDATA[675.53±1.61 b ]]> <![CDATA[-7.77±0.04 a ]]> 0.26±0.01 <![CDATA[902.13±8.78 b ]]>

[0064] Note: Different superscript letters indicate significant differences (P < 0.05)

[0065] 3. Expression of genes related to muscle fat metabolism

[0066] Effects of additives on the expression of genes related to fat metabolism in mandarin fish muscle Figure 2 . The results showed that the expression levels of AKT1, a key downstream kinase of the insulin signaling pathway, and its downstream rapamycin target protein mTOR, as upstream of the genes regulating fat synthesis, in the muscles of mandarin fish in the additive groups (Examples 1 to 3) of the present invention were significantly higher than those in the control group (Comparative Example 1) and the single addition groups (Comparative Example 2 and Comparative Example 3), and their expression levels in the single addition group were significantly higher than those in the control group (Comparative Example 1). Similarly, the expression levels of fat synthesis-related genes (sterol regulatory element binding protein SREBP1, fatty acid synthase FAS, and acetyl-CoA carboxylase ACC1) in the muscles of mandarin fish in the additive groups (Examples 1 to 3) of the present invention were significantly higher than those in the control group (Comparative Example 1) and the single addition groups (Comparative Example 2 and Comparative Example 3), and their expression levels in the single addition group were significantly higher than those in the control group (Comparative Example 1). However, the expression level of carnitine palmitoyltransferase CPT1, a key gene for fatty acid oxidation, in the muscle of mandarin fish in the additive groups of the present invention (Examples 1 to 3) was significantly lower than that in the control group (Comparative Example 1) and the single addition groups (Comparative Example 2 and Comparative Example 3), and its expression level in the single addition group was significantly lower than that in the control group (Comparative Example 1).

[0067] These results suggest that the addition of 2-hydroxyisobutyrate and S-adenosylmethionine can regulate the AKT1 / mTOR pathway, promoting lipogenesis and inhibiting lipolysis, thereby promoting muscle fat accumulation in mandarin fish. Furthermore, 2-hydroxyisobutyrate and S-adenosylmethionine have a synergistic effect in promoting muscle fat accumulation in mandarin fish.

[0068] Those skilled in the art should understand that they can implement variations by combining the prior art with the above embodiments, which will not be described in detail here. Such variations do not affect the essence of the present invention and will not be described in detail here.

[0069] The above describes the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the above-mentioned specific embodiments, and the devices and structures that are not described in detail should be understood to be implemented in a common manner in the art; any technician familiar with the art can use the above-mentioned disclosed methods and technical contents to make many possible changes and modifications to the technical solutions of the present invention without departing from the scope of the technical solutions of the present invention, or modify them into equivalent embodiments of equivalent changes, which does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention that do not depart from the content of the technical solutions of the present invention are still within the scope of protection of the technical solutions of the present invention.

Claims

1. A mandarin fish feed for increasing muscle fat content of mandarin fish, comprising a basic mandarin fish feed, characterized in that: adding a mixture of 2-hydroxyisobutyric acid and S-adenosylmethionine; The mass fraction of 2-hydroxyisobutyric acid in the basic mandarin fish feed is 0.2-0.6%; the mass fraction of S-adenosylmethionine in the basic mandarin fish feed is 0.4-0.9%.

2. A mandarin fish feed for increasing muscle fat content of mandarin fish according to claim 1, characterized in that: The mixture also includes microcrystalline cellulose.

3. A mandarin fish feed for increasing muscle fat content of mandarin fish according to claim 2, characterized in that: The mass fraction of the mixture in the basic mandarin fish feed is 2-3%; every 100g of the mixture is composed of the following components: 10-20g of 2-hydroxyisobutyric acid, 20-30g of S-adenosylmethionine, and the remaining component is microcrystalline cellulose.

4. A mandarin fish feed for increasing muscle fat content of mandarin fish according to claim 3, characterized in that: The mass fraction of the mixture in the basic mandarin fish feed is 2.5%; every 100g of the mixture is composed of the following components: 15g of 2-hydroxyisobutyric acid, 25g of S-adenosylmethionine, and the remaining component is microcrystalline cellulose.

5. An application of mandarin fish feed, characterized in that: Feeding mandarin fish with the mandarin fish feed for increasing the muscle fat content of mandarin fish as claimed in any one of claims 1 to 4 promotes the expression of mandarin fish fat synthesis genes and inhibits the expression of mandarin fish fat decomposition genes, thereby increasing the muscle fat content of mandarin fish.

6. The use of a mandarin fish feed according to claim 5, characterized in that: The fat synthesis gene includes at least one of sterol regulatory element binding protein SREBP1, fatty acid synthase FAS and acetyl-CoA carboxylase ACC1.

7. The use of a mandarin fish feed according to claim 5, characterized in that: The lipolytic genes include carnitine palmitoyltransferase CPT1.

8. The use of a mandarin fish feed according to claim 5, characterized in that: The mandarin fish is fed with the mandarin fish feed for increasing muscle fat content of mandarin fish according to any one of claims 1 to 4, and the feeding time is not less than 8 weeks.

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