JPH0358700B2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method for producing feed for young and larval fish.

(Conventional technology) Conventionally, natural feeds such as rotifers and Artemia have been used as feed for young fish, but due to their high cost, artificially formulated feeds such as protein (tzein) and carrageenan have recently been used as an alternative. It is known that it is hardened using a binder. However, many of the feeds developed for young fish do not release sufficient nutrients due to the weak digestibility of young fish, or conversely, nutrients are released quickly enough to cause water pollution. It had the disadvantage of
In addition, microcapsules made of polymer membranes do not pollute water, but they have poor digestibility and nutrients are difficult to absorb.

There is also known a method called melt dispersion cooling method (spray solidification granulation method) in which particles as a core material are added to a heated melted wax. Although it was considered to use this method as a feed manufacturing method, it has not actually been used because the core material is susceptible to thermal denaturation.

(Problems to be Solved by the Invention) The present invention solves the problem that when using such conventional feed for young fish, for example, when an artificial compound feed is hardened with a binder, the nutrients cannot be sufficiently absorbed by the young fish due to the presence of the binder. This is also an attempt to solve the problem that if the binder is weakened, it will quickly dissolve in water and release nutrients.

(Means for Solving the Problems) In order to solve the problems of the conventional feed for young fish as described above, the present invention aims to solve the problems of the conventional feed for young fish as described above. The final coating 16 (to be described later) has a rich surface smoothness and has a shape that follows the particle surface layer.

In addition, the feed of the present invention undergoes very little thermal denaturation during its manufacturing process, so it is designed so that the nutritional value of the feed is not impaired.

(Function) When the product 17 of the above-mentioned waxes and final coating 16 is introduced into a pond for frying young fish, most of the microcapsules are eaten by the young fish during their feeding time, and the microcapsule product 17 is absorbed into the bodies of the young fish. The microcapsule product 17 is configured so that it starts dissolving and disintegrates within the body of the young fish within the time period during which it is taken in.

Therefore, the dry nutrients of the primary particles 3 are efficiently absorbed by the young fish, improving feeding efficiency and preventing water pollution as a result. In addition, during the manufacturing process, it undergoes almost no thermal denaturation, so nutrients are not lost during the feed manufacturing process.

(Description of Structure) The method for producing feed for young and larval fish of the present invention will be described below.

Formation of primary particles: As an example, a raw material for nutrients that will become the core material of feed particles is supplied to the spray dryer 2. In FIG. 1, 1 is a raw material supply pipe. By spray-drying the raw material in this manner, primary particles 3 are obtained.

Examples of substances and properties of the primary particles 3 will be described later.

Another method for forming the primary particles 3 is as shown in FIG. 1, where the feed raw material 4 is dried in a drier to obtain a lumpy feed material 4, and the feed material 4 is crushed by a crusher 5 to obtain the primary particles 3. It is also possible.

Formation of First Film of Waxes As shown in FIG. 2, waxes 6 are dissolved in an organic solvent 7 to prepare a waxes solution, and the solution is placed in a container 7v. The wax concentration is generally 0.1-40 wt/%. The primary particles 3 described above are immersed in this wax solution for 1 to 60 minutes as shown in FIG. Next, this primary particle 3 is vacuum dried (vacuum level 1~
30 Torr), the organic solvent 7 is removed from the solution containing waxes on the surface of the primary particles 3, and the first
A subsequent coating 9 is formed. Mononuclear particles with a waxy coating are thus formed. In addition, 1
The secondary particles 3 must, of course, be poorly soluble in the organic solvent 7 or must be surrounded by poorly soluble particles.

Since the organic solvent 7 escapes from the primary coating 9, the surface thereof exhibits rough and non-dense properties. Further, due to the presence of these primary coatings 9, the primary particles 3 stick to each other and form an agglomerate as shown in FIG.

Formation of semi-finished capsule: The agglomerated particles are disintegrated by a crusher 10 as shown in FIG. 3, to obtain a semi-finished capsule 11 having a mononuclear primary coating 9 as shown in FIG.

Note that it is preferable that the waxes have a crystalline structure so that they can be crushed.

Completion of microcapsule product: The semi-finished capsule 11 is supplied to the melting cooling chamber 13 together with air a or nitrogen gas. (Fig. 4) Then, the primary coating 9 of the semi-finished capsule 11 supplied to the melting and cooling chamber 13 is instantly melted in the melting zone 14 by hot air (h) with a melting point of +100°C or higher, as shown in Fig. 4. melted.

This molten primary film 9 is then cooled in a cooling zone 15 with cold air c at a temperature below the melting point, preferably below 10° C., and is re-solidified. In this way, a final coating 16 with a rich surface smoothness and a shape that follows the particle surface layer is formed. In this way, the microcapsule product 17 is manufactured continuously in a short period of time.

Waxes: The waxes referred to in the present invention are in the following range.

1 (Natural oils and fats and hydrogenated oils): Hydrogenated rapeseed oil, hydrogenated castor oil, hydrogenated beef tallow, palm oil 2 Waxes: Carnauba wax, white beeswax, paraffin wax, Montan wax, Ceresine wax, Candelilla wax, Selax wax, 3 Fatty acids: (c ₁₀ or more) Capric acid, undecanoic acid, lauric acid, tridecylic acid, myristic acid, palmitic acid, stearic acid, elaidic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, octadecenoic acid, vaccenic acid, erucic acid, brassic acid , cerotic acid, montanic acid, hexadecenoic acid, eicosenoic acid, pentadecyl acid, heptadecylic acid, heptacanoic acid melisic acid, lactic acid, linoleic acid, linoleic acid, undecylenic acid, cetoleic acid, arachidonic acid, octadecic acid, oleic acid, 4 alcohols Undecanol, lauryl alcohol, tridecyl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, elaidin alcohol, nonadecyl alcohol, eicosyl alcohol, seryl alcohol, pentadecyl alcohol, heptadecyl alcohol, mericyl alcohol, latucerol, undecyl alcohol, Linoleyl alcohol, oleic alcohol, linolenyl alcohol.

5 Fatty acid glycerin esters: caprin, myristicin, palmitin, laurin, stearin, elaidin, brassidine, linolein, linolenin, olein.

6 Other cholesterol and lecithin In other words, these refer to organic substances that dissolve when heated and solidify when cooled, either singly or in combination.

Further, it is desirable that the wax has a crystal structure that allows it to be separated without sticking even if it is crushed by the crusher 10.

Organic Solvent As the organic solvent, common solvents with a low boiling point such as ethanol, acetone, chloroform, carbon tetrachloride, benzene, n-hexane, etc. are used, but those that dissolve the primary particles 3 must of course be avoided.

Addition of Water Soluble and Attractant Substances By adding some water soluble substances to the waxes, the disintegration time of the final coating 16 can be controlled. Therefore, it is desirable to add a water-soluble attractant in accordance with the feeding time of the young fish and the time when the feed enters the body.

Furthermore, if skim milk powder or the like is used as an attractant for young fish, further improvement in feeding efficiency can be expected. Water-soluble substances that can be added include gelatin, gum arabic, sodium carboxymethyl cellulose (CMC), polyvinyl alcohol (PVA), cellulose acetate phthalate (CAP), and methyl methacrylic acid-methacrylic acid copolymer (trade name Eudragit L30D-55). etc.

Examples of substances and particle size of primary particles The substance or composition of the primary particles 3 is not particularly limited as long as it is used as general feed for young fish, and examples thereof are shown in Examples.

The particle size of these primary particles 3 is desirably about 50 to 300 microns in consideration of the swallowing ability of young fish.

Example (1) Example (1) shows the case where the method of the present invention is applied to feed for young fish.

As feed for young fish, the following composition is used.

Chicken egg yolk 24% (by weight) Clam extract 8% (〃) Bonito extract 5% (〃) Egg albumin 10% (〃) Squid liver oil 2% (〃) Krill extract oil 2% (〃) Vitamin E 1% (〃) ) 12% oleaginous yeast ( 〃) 8% vitamin mixture ( 〃) 6% mineral mixture (by weight) are dissolved in water to make an emulsion with a solid content of 40%.

This emulsion is spray-dried using a spray dryer to obtain powder consisting of primary particles of about 100 microns in diameter.

On the other hand, 20 g of wax consisting of 40% palmitic acid and 60% lauric acid was dissolved in 80 g of ethanol and kept at 40°C.

The granular material made of the primary particles 3 is immersed in the wax solution for 5 minutes.

Next, the primary particles are taken out of the wax solution and immediately vacuum dried. The degree of vacuum at this time is 20 Torr while a large amount of solvent remains.
When the amount of solvent is small, set it to 2Torr.
In this way, the primary coating 9 is formed, and the primary particles 3 stick together through the primary coating 9 to form an agglomerate shape.

Next, these agglomerated primary particles 3 are crushed by a crusher 10 to obtain an aggregate of semi-finished capsules 11.

Next, this assembly of semi-finished capsules 11 is supplied to a melting and cooling chamber 13, where the primary coating 9 is instantaneously melted in a melting zone 14 with hot air at a temperature of 200°C, and then into a cooling zone with cold air at a temperature of 10°C. A microcapsule product 17 having a final coating 16 is obtained by rapid solidification at 15 .

The microcapsule product obtained as described above was put into water and the amount of vitamin B ₂ eluted from the product was tested, and the curve shown in FIG. 5 was obtained. In FIG. 5, the horizontal axis shows the elapsed time after adding the microcapsule product, and the vertical axis shows the elution amount of vitamin _B2 .

In FIG. 5, the curve shows the test results without any wax coating.

Also, the curved line is white beeswax as wax type.
Microcapsule product 17 obtained by immersing primary particles 3 in a solution of 10 g dissolved in 90 g of chloroform
The results of the test are shown below.

Moreover, the curve shows the case where the composition of the primary particles 3 is solidified as it is with a binder and used as feed for young fish.

Further, the curve shows the case where a water-soluble substance is added to the wax shown in the curve. The method of adding this water-soluble substance is Eudragit L-30D-55.
A fine powder obtained by spray-drying is dispersed in a chloroform solution containing 5 g of the white beeswax dissolved therein.

(Effects of the Invention) In order to obtain semi-finished capsules 11 in the pre-process of the melting and cooling process, it is avoided to provide a particle shock. Therefore, the surface layer wax will not be deformed or damaged. Therefore, since the film is melted and cooled in its most normal state, a uniform final film 16 with excellent shape retention can be obtained.

Since the final coating 16 is momentarily melted in the melting and cooling chamber 13 and then rapidly solidified, a highly smooth coating can be easily and continuously formed along the particle surface layer. Furthermore, since the thermal melting is instantaneous, the nutritional value of the core substance is not impaired.

Since the agglomerated particles are vacuum-dried as a pre-process of the crushing process, the primary wax coating 9 is uniformly formed in large quantities without being subjected to shock.

The method of the present invention combines a series of steps of vacuum drying, crushing, and melting and cooling to obtain a final coating 16 that does not impair the nutritional value of feed and ensures time for the nutritional value to be released into water. It is.

[Brief explanation of drawings]

Figure 1: An explanatory diagram of the production process of primary particles 3 by the spray dryer 2, Figure 1: An explanatory diagram of the production process in which the dry lumpy raw material 4 becomes the primary particles 3 by the crusher 5, Figure 2: Waxes 6 2: An explanatory diagram of the formation process of the first coating 9 of primary particles. FIG. 2: An explanatory diagram of the agglomeration of the primary particles 3 by the primary coating 9. , Fig. 3: An explanatory diagram of the operation of the crusher 10, Fig. 3: An explanatory diagram of the semi-finished capsule 11, Fig. 4: Melting cooling chamber 1
3. FIG. 4: An explanatory diagram of the microcapsule product 17. FIG. 5: A graph showing the test results of the feed obtained by the method of the present invention. 1...Spray dryer supply pipe, 2...
...Spray dryer, 3...Primary particles, 4...
Raw materials, 5... Crusher, 6... Waxes,
7... Organic solvent, 7v... Container, 8... Vacuum drying chamber, 9... Primary coating, 10... Disintegrator, 11...
...Semi-finished product capsule, 12...Semi-finished product capsule storage tank, 13...Melting cooling chamber, 14...Melting zone,
15... Cooling zone, 16... Final coating, 17...
...Microcapsule products.

Claims (1)

[Scope of Claims] 1. Primary particles 3 of dry nutrients are immersed in a solution of waxes 6 dissolved in an organic solvent 7, taken out, vacuum dried, and the surface of each primary particle 3 has a rough and dense surface. At the same time, the primary particles 3 are agglomerated through the primary coating 9, and the agglomerated primary particles 3 are then separated one by one. Semi-finished capsules of mononuclear particles broken into pieces 11
Next, the semi-finished capsule 11 made of the primary particles 3 is supplied to the melting and cooling chamber 13, and the primary coating 9 of the primary particles 3 is melted in the melting zone 14 of the melting and cooling chamber 13. Similarly, cooling zone 1
In step 5, the molten primary coating 9 is rapidly cooled and solidified to form the final coating 16 into the microcapsule product 1.
7. A method for producing feed for young fish comprising microcapsule particles.