阅读说明：本技术 一种石首鱼开口饵料强化试剂配方及强化方法 (Formula and strengthening method of rock-head fish initial feed strengthening reagent ) 是由 谭朋 徐冬冬 陈睿毅 王立改 于 2020-05-15 设计创作，主要内容包括：本发明公开了一种石首鱼开口饵料强化试剂配方及强化方法,属于海产动物苗种培育技术领域,该强化试剂的制备方法包括：以乳化型大豆分离蛋白和预糊化淀粉制备壁材；以鱼油、羟基化卵磷脂和生育酚制备芯材；然后在4-乙基-2-甲氧基苯酚和酸式磷酸铝钠存在的条件下,将壁材和芯材进行分级均质,得到水乳化型微胶囊试剂；上述微胶囊试剂还包括罗望子胶和α-淀粉酶形成的包衣层。上述方法能抑制试剂中脂质过氧化物含量增长,降低氧化脂肪对开口饵料的毒害作用,提升强化期轮虫/卤虫的密度,能将仔鱼开口率提高到93％以上,提高摄食率和鱼苗成活率。上述强化方法为：在开口饵料投喂前用包括上述方法制得的强化试剂的强化液进行强化操作。(The invention discloses a formula and a strengthening method of a chub initial feed strengthening reagent, belonging to the technical field of marine animal fry breeding, wherein the preparation method of the strengthening reagent comprises the following steps: preparing a wall material by using emulsified soybean protein isolate and pregelatinized starch; preparing a core material by using fish oil, hydroxylated lecithin and tocopherol; then, carrying out grading homogenization on the wall material and the core material in the presence of 4-ethyl-2-methoxyphenol and sodium aluminum acid phosphate to obtain a water-emulsified microcapsule reagent; the microcapsule reagent also comprises a coating layer formed by tamarind gum and alpha-amylase. The method can inhibit the increase of lipid peroxide content in the reagent, reduce the toxic action of oxidized fat on the initial feed, improve the density of rotifer/artemia in the strengthening period, improve the initial feeding rate of the fry to more than 93 percent, and improve the ingestion rate and the survival rate of the fry. The strengthening method comprises the following steps: before the feeding of the initial bait, the strengthening operation is carried out by using the strengthening liquid of the strengthening reagent prepared by the method.)

1. A preparation method of a chub initial feed strengthening reagent comprises the following steps:

preparing a wall material by using emulsified soybean protein isolate and pregelatinized starch; preparing a core material by using fish oil, hydroxylated lecithin and tocopherol; then, carrying out grading homogenization on the wall material and the core material in the presence of 4-ethyl-2-methoxyphenol and sodium aluminum acid phosphate to obtain a water-emulsified microcapsule reagent;

the microcapsule reagent also comprises a coating layer formed by tamarind gum and alpha-amylase, wherein the content of the alpha-amylase in the coating layer is 5-20 wt%.

2. The preparation method of the agent for enhancing the initial feed of the chub groupers as claimed in claim 1, wherein the agent comprises: the specific operation conditions of the grading homogenization are as follows: primary homogenization: the pressure is 40-60Mpa, and the time is 30-60 min; and (3) secondary homogenization: the rotation speed is 3500 plus 5000rpm, and the time is 15-30 min.

3. The preparation method of the agent for enhancing the initial feed of the chub groupers as claimed in claim 1, wherein the agent comprises: in the primary homogenizing operation environment, the intervention amount of the 4-ethyl-2-methoxyphenol and the sodium aluminum acid phosphate is 0.03-0.08 percent and 0.05-0.1 percent of the weight of the core material respectively.

4. The preparation method of the agent for enhancing the initial feed of the chub groupers as claimed in claim 1, wherein the agent comprises: in the secondary homogenizing operation environment, the addition amount of the coating layer is 10-35% of the weight of the wall material, the content of the tamarind gum is 45-60 wt%, and the balance is water.

5. The preparation method of the agent for enhancing the initial feed of the chub groupers as claimed in claim 1, wherein the agent comprises: the preparation temperature of the wall material is 35-45 ℃, and the mixing time is 30-60 min; the preparation stirring speed of the core material is 500-1000rpm, and the time is 30-60 min.

6. The preparation method of the agent for enhancing the initial feed of the chub groupers as claimed in claim 1, wherein the agent comprises: the weight ratio of the wall material to the core material is 3-5: 1; the content of emulsified soybean protein isolate in the wall material is 5-15 wt%, the content of pregelatinized starch is 15-40 wt%, and the balance is water; preferably, the weight ratio of the fish oil, the hydroxylated lecithin and the tocopherol in the core material is 2.5-7.5:1-2: 0.5.

7. A chunkard initial feed fortifying agent prepared by the preparation method of any one of claims 1 to 6.

8. A method of enhancing a starter feed for a chub fish, the starter feed comprising rotifers and artemia nauplii, comprising: performing strengthening operation by using strengthening liquid 6-12h before feeding the initial baits; the strengthening solution comprises a strengthening agent prepared by the preparation method of any one of claims 1 to 6.

9. The method for enhancing the initial feed of the brachypomus as claimed in claim 8, wherein the enhancing liquid comprises chlorella, enhancing reagent and seawater, and the concentration of the chlorella is 5 × 10⁷-7×10⁷cell/mL, and the addition amount of the enhancing reagent is 0.3-1g for every 50-150 ten thousand artemia/rotifer.

10. The method for enhancing the initial feed of the stone-headed fish according to claim 8, which is characterized in that: the initial density of the opening bait during strengthening is 100-300 Ind/mL; the water temperature of the strengthening operation is 25-27 ℃, the salinity is 29-33 per mill, and the concentration of dissolved oxygen in the environment is not lower than 7 ppm.

Technical Field

The invention belongs to the technical field of marine animal fry breeding, and particularly relates to a formula and a strengthening method of a reagent for strengthening initial feeding of a chub carp.

Background

Shimai (Drum) is a generic name for about 160 species of fish of the family Shimaidae (Sciaenidae) of the order Perciformes (Perciformes). The fish can be called as the fish with water, and can emit light at night, and the head is provided with stones like chessmen, so the fish is called as the stone-headed fish. The stone fish is generally benthic and carnivorous, most of the stone fish are distributed in warm sea or tropical coastal areas, and a few of the stone fish live in warm or fresh water areas.

The initial bait of the seawater fish in the larval stage can only use the tiny animal rotifer with the size of 200-. In the process of artificial breeding, the problem of low larval fish opening rate is always very serious, and meanwhile, the nutritive values of two animals are too low, so that a large number of larval fish die due to incapability of timely feeding or insufficient nutrition, and the survival rate of breeding is very low. Although rich in linolenic acid and linoleic acid, artemia and rotifers cannot synthesize n-3 series Highly Unsaturated Fatty Acids (HUFAs) by themselves, and the lipid content in vivo and the composition of the n-3 series highly unsaturated fatty acids are in positive correlation with the HUFA composition and content of the bait eaten by the artemia and rotifers. The n-3 series highly unsaturated fatty acid plays an important role in the growth, development and survival of seawater larvae and juvenile fish, and in particular, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are the most important n-3 HUFA. However, the essential fatty acids cannot be synthesized by the larvae and the juveniles, and can be ingested only from the bait.

Therefore, before feeding, rotifers are required to be subjected to nutrition enhancement to meet the nutritional elements required by fish larvae, so that the growth speed and survival rate of seawater larvae are improved, and the malformation incidence rate of larvae is reduced. At present, the bait strengthening agents aiming at strengthening are various, highly unsaturated fatty acid is emphasized to be increased, most strengthening agents are fish oil products, because the fish oil products are the only fat known to contain DHA in various grease, and the DHA in the fish oil products is originally derived from marine microalgae and is gradually transferred into fish bodies through a food chain. Most of the fish oil products are prepared into emulsions containing a plurality of unsaturated fatty acids and vitamins, but the emulsions are easy to oxidize during storage, the particle size of the emulsions is not easy to control, and a layer of oil film is easy to form on the water surface, so that the fish oil products not only can not play a role in enhancing nutrition, but also can influence the quality of rotifers and even can cause the rotifers to suffocate and die. Therefore, it becomes of research interest and economic value to provide and develop new starter fortification reagents and fortification methods.

Disclosure of Invention

The invention aims to provide a preparation method of a chukar initial feed enhancing reagent, which can inhibit the content of lipid peroxide in the reagent from increasing, reduce the toxic action of oxidized fat on initial feed, improve the density of rotifer/artemia in an enhancement period, further improve the initial feed rate of chukar/artemia from about 75% to more than 93%, and improve the feeding rate of the rotifer/artemia and the survival rate of the chukar.

The technical scheme adopted by the invention for realizing the purpose is as follows:

a preparation method of a chub initial feed strengthening reagent comprises the following steps: preparing a wall material by using emulsified soybean protein isolate and pregelatinized starch; preparing a core material by using fish oil, hydroxylated lecithin and tocopherol; then, under the condition that 4-ethyl-2-methoxyphenol and sodium aluminum phosphate exist, the wall material and the core material are graded and homogenized to obtain a water-emulsified microcapsule reagent;

the microcapsule reagent also comprises a coating layer formed by tamarind gum and alpha-amylase, wherein the content of the alpha-amylase in the coating layer is 5-20 wt%.

The water-emulsified microcapsule is formed by coating the core material substance incompatible with water by the wall material and the coating layer, so that the active substance in the core material can be protected from oxidative deterioration to prolong the effective storage period, the dispersibility of the active substance in a water environment can be enhanced, and the ingestion rate of rotifers/artemia is improved; the preparation method can also inhibit the increase of the content of lipid peroxide in the storage-period strengthening reagent, reduce the toxic action of oxidized fat on rotifer/artemia, improve the density of the rotifer/artemia during strengthening, improve the opening rate of the young chuatsi from about 75% to more than 93%, facilitate the improvement of the survival rate of the young chuatsi, and obviously increase the economic benefit.

For the purposes of the present invention, the specific operating conditions for the fractional homogenization are: primary homogenization: the pressure is 40-60Mpa, and the time is 30-60 min; and (3) secondary homogenization: the rotation speed is 3500 plus 5000rpm, and the time is 15-30 min.

Preferably, the amount of the 4-ethyl-2-methoxyphenol and the amount of the sodium aluminum acid phosphate added in the primary homogenizing environment are 0.03-0.08% and 0.05-0.1% of the weight of the core material, respectively. Under the combined action of mechanical energy and repulsion force between a wall material and a core material molecular chain, 4-ethyl-2-methoxyphenol and sodium aluminum acid phosphate existing in a homogeneous environment assist hydrophobic groups and hydrophilic groups in a system to be rearranged, the two groups can cooperate with lipid to form hydration, and the hydration molecules are mutually shared to reduce the oxidation degree of core material substances, inhibit the increase of lipid peroxide content in a storage period strengthening reagent, further reduce the toxic action of oxidized fat on rotifers/artemia, and improve the density of the rotifers/artemia during strengthening. Unexpectedly, the two methods can further improve the opening rate of the fry, specifically, the opening rate can be improved from about 75% to more than 93%, although the specific mechanism is yet to be verified, the survival rate of the fry can be obviously improved, and the economic benefit is favorably improved.

Preferably, in the secondary homogenizing operation environment, the addition amount of the coating layer is 10-35% of the weight of the wall material, wherein the content of tamarind gum is 45-60 wt%, and the balance is water.

More preferably, the pre-forming step of the coating layer is: mixing tamarind gum with water, forming gel at 70-90 deg.C, cooling to below 40 deg.C, adding alpha-amylase, and mixing. The alpha-amylase is beneficial to the digestion and absorption of starch by organisms, can improve the utilization rate of bait, and can supply energy to promote the growth of the organisms.

For the invention, the preparation temperature of the wall material is 35-45 ℃, and the mixing time is 30-60 min; the preparation stirring speed of the core material is 500-1000rpm, and the time is 30-60 min.

For the present invention, in the primary homogenizing operation, the weight ratio of the wall material to the core material is: 3-5: 1; the content of the emulsified soybean protein isolate in the wall material is 5-15 wt%, the content of the pregelatinized starch is 15-40 wt%, and the balance is water.

For the present invention, the weight ratio of fish oil, hydroxylated lecithin and tocopherol in the core material is 2.5-7.5:1-2: 0.5.

The invention also aims to provide the agent for enhancing the initial feed of the stone carp prepared by the preparation method. The particle size of the strengthening reagent is 20-300 mu m, and the strengthening reagent is suitable for feeding artemia/rotifer; through an accelerated storage test, the compound feed does not generate oil separation or layering phenomenon in a storage period of 360d, can be used for feeding artemia and rotifers for reinforcement, and is also suitable for being used as an additive of artificial compound feeds for fish, shrimps, shellfish and crabs.

In order to achieve the purposes of improving the initial feed rate of the larval carps of the stone carps and increasing the survival rate and the survival rate of the fries, the invention also provides a strengthening method of the initial feed of the stone carps, wherein the initial feed comprises rotifer and artemia nauplius, and comprises the following steps: performing strengthening operation by using strengthening liquid 6-12h before feeding the initial baits; the strengthening solution comprises the strengthening reagent prepared by the preparation method.

The enhancing liquid comprises chlorella, enhancing agent and seawater, wherein the concentration of the chlorella is 5 × 10⁷-7×10⁷cell/mL, and the addition amount of the enhancing reagent is 0.3-1g per 50-150 ten thousand artemia/rotifer.

For the invention, the initial density of the reinforcing initial bait is 100-300 Ind/mL; the water temperature of the strengthening operation is 25-27 ℃, the salinity is 29-33 per mill, and the dissolved oxygen concentration in the environment is not lower than 7 ppm.

The invention adopts the wall material and the coating layer to coat the core material substance incompatible with water to form the water-emulsified microcapsule reagent, thereby having the following beneficial effects: the preparation method of the strengthening reagent can enhance the dispersibility of the reagent in a water environment, inhibit the increase of the content of lipid peroxide in the strengthening reagent during the storage period, reduce the toxic action of oxidized fat on rotifers/artemia, and improve the density of the rotifers/artemia during the strengthening period; the prepared intensified reagent has the grain diameter of 20-300 mu m, does not generate oil separation or layering phenomenon in a storage period of 360d through an accelerated storage test, can be used for feeding artemia and rotifer for intensification, and is also suitable for being used as an additive of artificial compound feed for fish, shrimps, shellfish and crabs; the method for enhancing the initial feed by using the enhancing reagent can improve the initial feed rate of the larval carps of the chunkia groupers from about 75% to more than 93%, is beneficial to improving the ingestion rate and the survival rate of the larval carps, and obviously improves the economic benefit of farmers.

Therefore, the invention can inhibit the increase of the content of lipid peroxide in the reagent, reduce the toxic action of oxidized fat on the initial feed and improve the density of rotifer/artemia in the strengthening period; the formula of the chunkyu mouth-opening bait strengthening reagent and the strengthening method can improve the mouth-opening rate of the chunkyu fry and increase the survival rate and survival rate of the fry.

Drawings

FIG. 1 is a graph showing the change in lipid peroxide content during storage of different potentiating agents in test example 2;

FIG. 2 is the results of the density measurements of the different enhancing reagents of test example 2 after enhancing rotifers;

FIG. 3 is the measurement results of the pregnancy rate of different enhancing reagents after enhancing rotifers in test example 3;

FIG. 4 is a graph showing the effect of different potentiating agents on the activity of acetyl CoA carboxylase in Boehmeria malabaricus in Experimental example 3.

Detailed Description

The technical solution of the present invention is further described in detail below with reference to the following detailed description and the accompanying drawings:

the present invention and the conventional techniques in the embodiments are known to those skilled in the art and will not be described in detail herein.