JPH06169703A - Granular feed composed mainly of fish and shellfish protein and its production - Google Patents

Abstract

PURPOSE:To obtain the subject feed exhibiting little dissolution of water-soluble nutrients, having excellent growth and survival rates and suitable for larva or juvenile fish such as yellowtail in high efficiency by treating a feed raw material composed mainly of fish or shellfish proteins under specific condition. CONSTITUTION:A feed raw material composed mainly of fish or shellfish proteins is melted in an extruder in the presence of water under high temperature and pressure to form a molten material containing the water in a uniformly dispersed liquid state. The molten material is immediately ejected through a die to a zone maintained to atmospheric pressure or below to effect the explosive evaporation of the water contained in the material. The molten feed raw material is solidified to obtain the objective feed having particle diameter of <1,400mum.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a particulate feed used for producing fish seedlings and a method for producing the same, more specifically, excellent growth and survival, and little elution of water-soluble nutrients when added to water. The present invention relates to a particulate feed containing seafood protein as a main component, which is suitable for use as a feed for larval and juvenile stages, such as yellowtail, red sea bream, flounder, striped horse mackerel, and sweetfish, and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, Japan's cultivated fisheries have become increasingly important. Accordingly, the development of seedling production has been remarkable, and it has become possible with various fish species. Conventionally, biological feeds such as rotifer and artemia have been used as feeds for seed production, but it has been found that this alone causes large mortality due to lack of nutrition. In order to solve this, research and development of particulate feed for seeds and seedlings has been conducted in universities and companies, and by using it in combination with biological feed, seed and seedling production technology has been improved.

By the way, conventional particulate feed is manufactured by a freeze-drying method or a fluidized bed granulation method. The former manufacturing process requires a great deal of labor such as kneading, freeze-drying, crushing, and classification, and since a freeze-dryer is used, it is very expensive. In the latter case, it is difficult to mix fats and oils into the powder due to the property that the powder is combined with the powder by stirring the powder in the fluidized bed granulator and diffusing the binder from the nozzle to combine the powder. . Moreover, the manufacturing cost is considerably high.

Extruders are also used in the production of powdered foods and the like. For example, a main raw material consisting of meat of fish and shellfish and / or its by-products is treated with an auxiliary extruder such as starch and vegetable protein at a temperature of 80 ° C. to 300 ° C. and then crushed. Although it is a characteristic method for producing a powdered food (Japanese Patent Publication No. 4-59870), a crushing step after extrusion molding is essential. Further, using a continuous heating extruder equipped with two screws, which rotate while meshing with each other, fish meat or a mixture of fish meat and its auxiliary raw material, under the condition that the cylinder temperature is 200 to 270 ° C. This is a method for producing a fish meat soboro that is originally processed (JP-A-4-104775), but the target product is a soboro-like product in which the target product is defibrated to an appropriate particle size.

[0005]

Under such a technical background, the present inventor has solved the problem of the elution of nutrients, that is, the problem of wetting of particles when the particulate feed is put into water, the problem that it takes time to manufacture, etc. In order to improve it, it is conceivable to manufacture it without going through a crushing process, and when the raw water with a high moisture content and oil content is subjected to the extruder dark cooking process, the pressure inside the extruder fluctuates and the object to be treated continuously. Focusing on the problem that it is not ejected, it is ejected intermittently, and sometimes it explodes and flashes, and research is done from various viewpoints. Finally, this phenomenon is positively utilized and the extruder method is powdered. Therefore, we succeeded in producing spherical particles having a controlled arbitrary particle size from raw materials containing fish and shellfish proteins as a main component. That is, the present invention is
A particulate feed that can be suitably used as a feed for larval and juvenile stages such as yellowtail, red sea bream, flounder, striped horse mackerel, and sweetfish. It has excellent growth and survival, and has little elution of water-soluble nutrients when added to water. An object is to provide a particulate feed containing proteinaceous protein as a main component. Further, the present invention provides
Granulate granular feed or particulate feed using an extruder to save labor, reduce costs, improve digestion and absorption, reduce component elution, etc. to improve the growth and survival rate of larvae and ensure a stable supply of seedlings. The purpose is to contribute to the realization of.

[0006]

[Means for Solving the Problems] The particulate feed for seeds and seedlings has a particle size from a particulate form using a plurality of nutritional components as a mixture and has an arbitrary particle size according to the fish species, the growth stage, etc. The floating time when added should be long to a certain extent, and the elution of water-soluble nutrients should be small. In order to obtain particles satisfying these conditions, especially in the case of fine particles, the particle surface must be smooth and dense. When the particle size is adjusted by crushing after extrusion molding or freeze-drying, neither smooth particles nor dense particles can be obtained. In the present invention, the product is completed by supplying the raw material to the extruder, kneading, pressurizing, heating, granulating and semi-drying, and then secondary drying. The starch contained in the wheat flour, which is an auxiliary material that is mixed with seafood proteins in the extruder, is melted, and the starch and the protein are mixed together. The main component is a seafood protein that has a smooth particle surface and is composed of particles with at least one spout formed by explosive evaporation of water inside, which is hard to settle and is difficult to elute water-soluble substances. Able to produce particulate feed In the present invention, it is possible to save labor, reduce time, and reduce production cost by producing particulate feed using an extruder. That is, a large amount of particulate feed can be produced in a short time as long as an arbitrary blended raw material, oil and fat, water and the like are supplied to the extruder.

In the present invention, the seafood protein as the main raw material may be from any seafood that can be used as a feed raw material, and such seafood can be used in a raw state or processed and dried in a small crushed state. As the raw material, for example, soft flour, strong flour, gluten, starch, flour powder, fish oil, soybean lecithin and the like can be optionally added. The selection, combination, blending ratio, etc. of each of these auxiliary raw material components are arbitrary, but since the water content of the raw material composition is related to the particle size of the product, it is necessary to adjust the water content of the raw material composition. In addition, each of these auxiliary materials serves as a water content adjusting agent, a reinforcing agent, or a binder, and imparts an appropriate particle size, density, surface condition, hardness, color tone, and flavor to the product particles, and the type and mixing ratio of the auxiliary ingredients. It is preferable that the combination can give particles rich in variety. Whether or not such subcomponents are used, powdery or liquid additives such as vitamins, minerals, flavors, swelling agents, thickeners, coloring agents and the like can be appropriately used separately. The mixing of these additives and the raw material composition may be performed in advance, or may be performed in an apparatus.

In the present invention, the raw material is composed of these seafood proteins or a mixture of the seafood proteins and auxiliary raw materials and / or various additives, and the raw material composition having a controlled water content is heated in an extruder under high temperature and high pressure. After melting,
The particles are ejected from the die into a zone maintained at atmospheric pressure or lower pressure to obtain almost spherical particles containing fish protein as a main component. By transferring the raw material by an extruder, the temperature and pressure are gradually increased, and the temperature of the raw material becomes the highest before the die part. Here, the raw material is in a molten state, water contained in the raw material is also kept in a liquid state, and is uniformly dispersed in the molten raw material. Because of such a state, it is possible to explosively introduce from the die portion into the zone maintained at atmospheric pressure or lower pressure. During this discharge, the temperature of the water is much higher than its boiling point, and the water that is still in a liquid state due to the pressure is immediately vaporized to vapor when it comes out from the discharge port, that is, the die hole, under atmospheric pressure or lower pressure. Escape from. Instantly converting water to steam in this manner instantaneously cools the raw materials as a result of the water and the raw materials releasing sensible heat for vaporizing the water. In addition, water escapes from the raw material as steam, leaving behind a jet outlet where the water inside the raw material collects and evaporates, so that the water continues to evaporate and the moisture content of the raw material particles is reduced.

In the present invention, single-screw and twin-screw extruders can be used. Extruder consists of feeder, barrel, screw, die,
It consists of five heaters (or cooling parts) and their characteristics are determined by the number and shape of the screws and their mutual positional relationship (in the case of multiple screws). One screw is uniaxial type and two screws are biaxial type.Mass transfer is only due to friction between barrel and substance in uniaxial type, but in biaxial type they rotate by meshing with each other. The pushing action and sliding action of the screw are also added. For this reason, the production capacity of the uniaxial type is also affected by the water content, oil content, pressure, etc. of the raw material, but the biaxial type is free within a certain range and is not affected by the water content, etc., and enables stable operation. Therefore, it is preferable to use a twin-screw type extruder in the present invention, since a twin-screw type can be favorably used even for a raw material with a high oil content such as a marine product raw material. However, even if a uniaxial type extruder is used, it can be satisfactorily processed if the raw material water content is appropriate. Twin screw extruders suitable for the present invention are commercially available and are well known to those skilled in the art. The temperature and pressure of the raw material are increased to almost the temperature and pressure before the die part by propelling the raw material along the barrel of the extruder by the mechanical force of the feed part for introducing the raw material and the screw. It includes a pressure restrictor that is either a fixed or variable orifice such as a high compression section and a variable die. The compressed material is then rapidly expanded into a zone maintained at atmospheric pressure or lower, where particulates are collected,
Alternatively, the particles are classified and further conveyed to a secondary drying device for adjusting the water content. Since the obtained particles have a low water content, it can be classified by a simple operation of passing through the sieve plate and not passing it by ejecting it so that it hits the sieve plate standing at a certain position from the discharge port. is there.

As described above, in the method of the present invention, the raw material containing water is advanced in the elongated cylinder, and gradually increasing pressure is applied to the advancing raw material, and the temperature of the raw material is gradually increased so that the raw material has the highest pressure in the cylinder. It is characterized in that the raw material is cooled by suddenly discharging it from the region to the low temperature and low pressure region to instantaneously vaporize the water in the raw material. That is, the raw material is supplied into the feed barrel of the extruder by the feeder, and sequentially transferred forward by the screw in the barrel. At that time, the mechanical pressure is increased and applied to the raw material so that this pressure value is always larger than the vapor pressure of the water in the raw material so that the water is kept in a liquid state. As a result, when the temperature of the raw material becomes higher than the boiling point of water, the sufficient compression action increased in the apparatus is added to the raw material. The screw is rotated at a relatively high speed to heat the raw material and the water contained therein. When the rotation speed of the screw is relatively large, not only the raw material can be heated quickly, but also the raw material can be sufficiently stirred while passing through the inside of the apparatus.

Further, the total heat transfer coefficient in the apparatus can be increased as compared with the case where water is evaporated in the material while the material is always passing through the apparatus, so as to be evaporated.
Furthermore, if the water content of the raw material is kept in the liquid state during the temperature rising process,
It is possible to sufficiently prevent the initial phenomenon in which the raw material is overheated on the barrel wall, the screw surface, or the shaft surface. By keeping the water content of the raw material in a liquid state in this way, the efficiency is improved in various aspects, and as a result, the residence time of the raw material at the maximum temperature immediately before the die part becomes an extremely short time that can hardly be measured, and the charring There is no problem. Like ordinary extruder docking, if moisture is constantly evaporated from the raw material as it progresses through the equipment, the raw material will be constantly heated, and the raw material will stay at a high temperature for a long time, causing problems such as burning. Occur.

In the present invention, the maximum temperature in front of the discharge die is 300 ° C. or lower, preferably in the range of 230 ° C. to 270 ° C., which is set in the barrel heater. However, since the residence time is short, the fish protein in the raw material is short. The heat-coagulation of sucrose is successful, non-sticking, and a savory particulate feed with a food-attracting effect while retaining the flavor of seafood proteins is obtained.

[0013]

EXAMPLES The present invention will now be described with reference to examples. Example 1 8 parts by weight of fish oil, 4.5 parts by weight of lecithin and 38.5 parts by weight of water were supplied to a commercially available twin-screw extruder with respect to 100 parts by weight of the blended raw materials shown in Table 1, and screw rotation 1
50 rpm, barrel heater set temperature 150 ℃,
The temperature was gradually increased to 200 ° C. and the treatment was performed at a preset temperature of the heater of the tip barrel of 250 ° C. Pressure at the tip is 1 kg / cm
It was ² . It was discharged from the die section under normal pressure. The temperature of the particles immediately after discharge from the extruder was 150 ° C. The particles that fell were collected in a sky tank, and the particle size distribution was examined after drying. As a result, as shown in Table 2, particles having a substantially spherical shape with a particle diameter of 1400 μm or more accounting for about 50% were obtained.

Example 2 A fine particle feed obtained by removing particles larger than 1400 μ from the particulate feed produced in Example 1 was used with 10 mm size and 1
Breeding experiments were performed on 5 mm size mojaco. A comparison was made between the biological feed alone group, the commercially available feed group, and the fine particle (hereinafter, referred to as “the feed of the present invention”) group of the extruder feed produced in Example 1. The results are shown in Tables 3 and 4. Although the survival rate is lower than that of the biological group, 40% in the test group of the compound feed is clear as compared with the commercial product, but it can be evaluated as a good result. it can. As described above, from the results of the 15 mm size mojaco test, the feed of the present invention showed the same growth in body weight as the commercial feed, and the survival rate was slightly inferior to that of the biological feed group. The value was considerably higher than that.

Example 3 To evaluate the particulate feed obtained in Example 1, POV,
Vitamin C and vitamin E were analyzed and the results are shown in Table 5.
Shown in. As a result, there was almost no deterioration of fats and oils, and the inactivation of vitamins was also slight. This proves that the loss of the active ingredient is small because the treatment with the extruder is carried out in a short time.

Example 4 As shown in FIG. 1, the surface structure of the particulate feed obtained in Example 1 was observed with an electron microscope at a magnification of 1,500.
As shown in FIG. 2, the fine particle feed produced by the freeze-drying method was also observed for comparison. As a result, the extruder-produced particulate feed has a smoother surface than the freeze-dried particulate feed. Although both feed particles have traces of water evaporation, it is observed that the particles of the feed of the present invention have a smooth and dense particle surface as compared with the freeze-dried fine particle feed.

[0017]

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to produce a particulate feed which can be used for fish seedling production by using an extruder. The particles of the feed are covered with a binder (starch) and a mixture of proteins in a smoother surface than those of the conventional production feed, and even in the feeding test with Mojaco, the growth is similar to that of the conventional feeding based on biological feed, It showed survival. Therefore, the particulate feed of the present invention can be effectively used not only as mojaco but also as feed for many other larvae.

[Brief description of drawings]

FIG. 1 shows a scanning electron micrograph (15,000 times) of particles of a particulate feed produced by an extruder method.

FIG. 2 shows a scanning electron micrograph (15,000 times) of particles of fine-grained feed produced by the freeze-drying method.

Claims (3)

[Claims] 1. A seafood comprising a particle having a smoother particle surface than a particle produced by a freeze-drying method and having at least one spout formed by explosive evaporation of water inside. Particulate feed containing protein as a main component. 2. The particulate feed according to claim 1, wherein the particle size is smaller than 1400 μm. 3. A feed material mainly comprising seafood proteins is melted under high temperature and high pressure in an extruder in the presence of water to form a melt in which coexisting water is uniformly dispersed in a liquid state, and immediately. A seafood protein characterized by discharging the melt from a die into a zone maintained at atmospheric pressure or at a pressure lower than that to explode coexisting water explosively and coagulate the melted feed raw material. A method for producing a particulate feed containing as a main component.