JP2007104938A - Feed for culture of fish and shellfish, and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide feed for culture of fish and shellfish used as culturing feed for raising seeds and seedlings such as young shells or young fish so as to favorably and stably grow the young shells or fish, and solving the problem of environmental pollution. <P>SOLUTION: The feed for culture of fish and shellfish comprises biodegradable hybrid gel particles formed of wall material gel 3 comprising biodegradable polymer gel formed at the surface of a core material gel 2 comprising fish meat gel. The feed improves culturing effect through the fish meat gel, and feeding efficiency, and also avoids environmental pollution. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an aquaculture feed suitable for aquaculture of aquatic animals such as abalone, sea urchin, sea cucumber, and turban shell, that is, seafood, and particularly so-called seedlings such as juvenile shellfish and fry, and a method for producing the same. .

Aquatic animals, so-called seafood, currently occupy about 38% of edible animal protein in Japan.
However, recently, the yield has been declining, and along with this, the importance of the production of seedlings, that is, the cultivation of seafood to obtain high seeding efficiency, especially the cultivation of seedlings of seafood shellfish is increasing.
For example, various materials and production methods have been proposed including, for example, using a cultured leaf-like portion of a kombu as a food for aquaculture of seedlings such as abalone, sea urchin, turban shell, etc. .
However, taking the abalone larvae, for example, as currently practiced, slaughtering from eggs to larvae shows high efficiency, for example, close to 100%, but it leads to obtaining released seedlings from these larvae. The yield that can be grown up to the present shows a low value of about 5%, the growth rate is low, and the growth variation is large.

On the other hand, for example, in large and medium-sized fishnet fishing and bottom net fishing, fish that are not intended, such as unused fish that are not used for normal food use, or fish that are difficult to use due to problems with taste, odor, toxicity, etc. Are often discarded in the sea or on the beach.
In some cases, red tide is generated due to rot, killing algae and seaweeds that feed on fish and shellfish, and consequently inhibiting the growth of fish and shellfish, resulting in a decrease in harvest and catch.
JP 2004-135562 A

  The seafood aquaculture feed according to the present invention and the method for producing the same are used as the aquaculture feed for growing so-called seedlings such as abalone, sea urchin, and turban shell, such as juvenile shellfish, fry, and the like. The purpose is to be able to make it.

  The seafood aquaculture feed according to the present invention is a biodegradation composed of a core material gel made from a fish gel mainly composed of fish meat and a wall material gel made from a biodegradable polymer gel formed on the surface of the core material gel. It is characterized by consisting of sex hybrid gel particles.

The present invention is the above-described seafood aquaculture feed, wherein the fish gel is added with a nutrient or a drug in the core material gel.
The present invention is the above-described fishery culture feed, wherein the wall material gel is made of biodegradable polyurethane.
The present invention is the seafood aquaculture feed described above, wherein a large number of biodegradable hybrid gel particles according to claim 1 are held in an artificial seaweed feed.

  According to the method for producing a feed for seafood cultivation according to the present invention, 1% to 8% (weight), preferably 1% to 4% (weight) of salt is added to fish meat, and the sol prepared by crushing is heated and cooled. And a step of obtaining a fish meat gel, a step of granulating the fish gel containing the fish meat gel as a main component, and a step of attaching a biodegradable polymer gel to the fish gel particles obtained by the particle formation. After that, a wall material gel made of a biodegradable polymer gel is formed on the surface of the core material gel made of the fish meat gel particles, and a food for seafood aquaculture comprising biodegradable hybrid gel particles is obtained.

  The present invention is the above-described method for producing seafood aquaculture feed, which has a process for producing an artificial seaweed feed, and the biodegradable hybrid is added to the artificial seaweed feed during or after the production of the artificial seaweed feed. It is characterized by holding gel particles.

  The present invention is the above-described method for producing seafood aquaculture feed, wherein the artificial seaweed feed consists of aquaculture feed, and the artificial seaweed feed production process dissolves desalted seaweeds and adjusts the components, and then is required. And a step of spreading and hardening into a shape.

  In the above-described feed for seafood culture using the biodegradable hybrid gel particles according to the present invention, the fish meat gel of the core material serves as food for seafood such as abalone seedlings, and this fish meat gel will be described later. In addition, it was confirmed that the growth of seafood seedlings was promoted.

However, since the fish meat gel itself swells rapidly in water, when a water-soluble component or the like is added thereto, it is dispersed in water. Therefore, feeding fish gel directly into water cannot effectively feed fish and shellfish.
On the other hand, in the present invention, this fish gel is used as a core material gel, and a wall material is formed on the surface thereof, so that it is a hybrid gel capsule structure. The swelling of the fish meat gel can be controlled by selecting the deposition condition such as. That is, it is possible to prevent the water-soluble component in the fish meat gel from being dispersed in water, to have a required time lag from feeding to feeding, and to enable effective feeding. Is.
In addition, the wall material is provided in this way, but since this wall material is a biodegradable polymer gel, the entire capsule is biodegraded, and in particular, the wall material remains in the water indefinitely. The environmental pollution caused by is also avoided.

Furthermore, as described above, the fish and seafood feed according to the present invention has a configuration in which a large number of the above-described fish gel and biodegradable polymer gel hybrid gel particles are retained as artificial seaweed bait as a holder. In some cases, even if this hybrid gel particle has an ultrafine particle structure, it can be prevented from floating and dispersing in water or on water, so even seed and shellfish can be fed efficiently.
In this case, since the carrier for holding the hybrid gel particles is a food for seafood culture, the cultured seafood can eat the artificial seaweed bait together with the hybrid gel particles, so that it can be effectively fed. It is.

  In addition, according to the method for producing a food for seafood cultivation according to the present invention, natural seaweed can be used as the raw material, so that it is not necessary to procure a special raw material.

Embodiments of the fishery food and its production method according to the present invention will be described.
However, it goes without saying that the present invention is not limited to this embodiment.
FIG. 1 is a schematic cross-sectional view of one particle of a particulate fishery feed 1 according to the present invention.
As shown in FIG. 1, this seafood aquaculture feed 1 includes a core material gel 2 made of a gel mainly composed of fish meat, and a wall material gel 3 made of biodegradable polymer formed on the surface of the core material gel 2. Biodegradable hybrid gel particles, especially biodegradable hybrid capsules.
The particles 1 are spherical or amorphous particles, and are hybrid gel microcapsules having an average size, for example, an average particle size of 100 μm to 300 μm.
The fish gel of the core material gel 2 is formed by crosslinking of fish protein components.
Further, the biodegradable hybrid capsule is a biodegradable wall material gel 3 synthesized from a fish gel of the core material gel 2 and polyurethane, for example, or a synthetic biodegradable hybrid capsule of the biodegradable wall material gel 3 made of polyester, polyvinyl alcohol or the like. Can be configured.

FIG. 2 is a schematic plan view of a fish-cultured feed 11 according to the present invention in which a large number of the above-described granular fish-cultured feed 1 are collectively supported or held.
This seafood aquaculture feed 11 has a configuration in which a large number of the above-described particulate seafood aquaculture feed 1 are arranged on an artificial seaweed 12 as a carrier (holding body). In this case, the particulate seafood aquaculture feed 1 is formed by holding a large number of the seafood aquaculture feed 1 so as to face the surface of the artificial seaweed 2.

The seafood aquaculture bait and its manufacturing method according to the present invention will be described.
First, the fish meat gel of the core material gel 2 is demonstrated with the manufacturing method.
《Fish Meat Gel》
For the formation of fish meat gel, the sol is prepared by crushing using 1-8% by weight, preferably 1-4% by weight of salt, as the raw material. It can be obtained by heating and cooling of this, and can be formed by crosslinking of the fish protein component in this process. Here, the addition of 1 to 8% by weight of sodium chloride, more preferably the addition of 1 to 4% by weight is due to the fact that the gelation was favorably achieved by the addition of this amount.

Next, the formation of this fish meat gel will be described with reference to examples.
(Example 1 of fish meat gel)
In this example, unused fish Aigo was used as a raw material.
By the way, Aigo (Sigannus fuscens) is a fish close to butterflyfish and nizadai, and inhabits the warm waters south of Kanto. The dorsal fin has 13 to 14 thorns, and the tip of the fin is poisonous. Due to its poisonous nature, it is difficult to catch, and adult fish are omnivorous that prefer soft portions of seaweed, and are therefore subject to damage caused by firewood burning.

The preparation of the fish meat gel was performed by removing the head and internal organs of the raw fish, that is, in this example, Aigo, and dropping them into two pieces and washing them in cold water.
Next, using a stamp-type meat mining machine (hole diameter: 5 mm), a drop was obtained.

This lost body was exposed to Shimizu.
This fresh water bleaching was thoroughly washed by adding 5 times the amount of cold distilled water to the fish meat. This operation was repeated three times. After the bleaching, the bleached meat was filtered using a filter cloth to remove excess water, and dehydrated by a dehydrator. Then, the water content was adjusted to 80%, 3% NaCl was added to the sashimi, and crushed with a masher for 30 minutes to obtain a fish sol.
The fish sol was filled in a bag and ligated, and then heated at 30 ° C. to 90 ° C. at intervals of 10 ° C. for 20 minutes and 120 minutes in a warm bath. The gel after heating was immediately cooled in ice water and then returned to room temperature.
In this way, a fish meat gel was obtained.

(Example 2 of fish gel)
Also in this Example 2, the same raw material as in Example 1 described above was used, and a fish meat gel was obtained by the same method. In this Example 2, an alkaline was used instead of fresh water exposure to the fallen meat in Example 1. It was salt water bleached.
This alkaline salt water exposure was performed with 0.15% NaHCO ₃ + 0.1% NaCl for the first time and 0.3% NaCl for the second and third times.
In this way, a fish meat gel was obtained.

(Example 3 of fish gel)
In this Example 3, although it was based on the raw material and method similar to Example 1, in this case, it did not expose to a fallen body.
Thus, fish myofibrillar protein gel was obtained.

(Example 4 of fish gel)
In Example 4, a fish gel was prepared using gusset as a raw material. As the manufacturing method, the method of Example 1 or Example 2 can be adopted. In this case, the heat treatment is performed after heating for 1 hour at a temperature range of 50 ° C. to 90 ° C. at intervals of 10 ° C. The solution was quenched in ice water for 30 minutes.
By doing so, a fish meat gel was obtained.

  Next, an example of the biodegradable hybrid particle 1, that is, a biodegradable hybrid microcapsule using a fish meat gel and a synthetic polymer will be described together with a preparation method thereof, that is, a manufacturing method.

《Biodegradable hybrid microcapsule》
As the fish gel of the core material gel 2, the above-described fish gel, gusset and other fish gels can be used.
As a raw material for the biodegradable polymer of the wall material gel 3, biodegradable polyols, diisocyanates, and low-molecular polyhydric alcohols of food additives can be used. Moreover, a vitamin agent, a safe drug, etc. can be used as an additive to fish meat gel.
Although biodegradable hybrid microcapsule is illustrated, it is not limited to this example.

(Examples of biodegradable hybrid microcapsules)
A predetermined amount of polyol and diisocyanate, which are raw materials of polyurethane constituting the wall material, were weighed, and low-molecular polyhydric alcohol was added thereto at a constant molar ratio and diluted with a solvent.
Polyols are biodegradable oligopolyols such as polycaprolactone, polyester, and polyvinyl alcohol, diisocyanates are aliphatic isocyanates such as lysine derivative isocyanates, and low molecular weight polyhydric alcohols are recognized as food additives. Alcohol was used.
A finely powdered fish gel was added to this diluted solution and stirred for 24 hours at room temperature, and then the solvent was removed while continuing stirring to obtain biodegradable hybrid microcapsules. The thickness ratio between the core material gel and the wall material gel was adjusted by changing the weight ratio between the polyurethane raw material and the fish meat gel.
On the other hand, a hybrid gel microcapsule embedded with a vitamin preparation is obtained by adding a vitamin preparation dissolved in a solvent to a powdered fish gel, crushing until the solvent evaporates, and drying under reduced pressure. The powder was used as a capsule core, and biodegradable hybrid microcapsules were obtained by the same method as described above.

Next, characteristics of the biodegradable hybrid microcapsules thus obtained were evaluated.
(Characteristic evaluation):
Fourier transform infrared spectroscopy (FT-IR) spectrum measurement by ATR method (total reflection measurement method), differential thermogravimetric analysis (TGA), particle size distribution measurement by laser diffraction method and microscope method, vitamin drug by UV-visible spectrophotometry Based on water dissolution test.

In the FT-IR spectrum of the above-described biodegradable hybrid microcapsule, peaks derived from CH ₂ stretching vibration (nCH ₂ ) and C = O stretching vibration (nC = O) are observed near 2900 and 1730 cm ⁻¹ , respectively. Observed. These peaks were not confirmed in the fish gel, but only in biodegradable hybrid microcapsules and polyurethane samples.
In the TGA curves of fish gel, polyurethane and biodegradable hybrid microcapsules, the weight of the fish gel decreased gradually from room temperature to around 250 ° C. On the other hand, the weight of polyurethane did not decrease to around 250 ° C, but decreased rapidly from 250 to 470 ° C. The biodegradable hybrid microcapsules gradually decreased in weight from room temperature to around 250 ° C, and further remarkably decreased from 340 to 590 ° C. From the above, it was clarified that the surface of the fish meat gel in the biodegradable hybrid microcapsule was covered with a polyurethane film and encapsulated.

The particle size distribution was calculated by laser diffraction and microscopy. When the sample of fish meat gel was diffused in distilled water, which was a pretreatment for laser diffraction measurement, the sample swelled, and accurate measurement could not be performed. The average particle size of the fish gel sample determined by microscopy was about 60-100 μm.
The particle size distribution was measured for two types of capsule samples MC-PU1 and MC-PU2 having different ratios of polyurethane to the fish meat gel (urethane raw material / fish meat gel). The measurement results are shown in FIG. The average particle size of the encapsulated sample increased to 110 μm and 310 μm as the urethane raw material / fish meat gel ratio increased. This is thought to be due to the fact that a thicker polyurethane film was formed on the surface of the fish meat gel due to the increase in the amount of charged polyurethane and the aggregation of capsules during synthesis. The particle size and particle size distribution can be adjusted by the degree of pulverization of the fish meat gel.
Fine powdered fish gel swells easily with water and easily releases water-soluble additives, but in the encapsulated sample, the elution amount of the water-soluble additive is suppressed, and the maximum value is 30 to 90 minutes after the sample is charged. After that, it became almost constant.
Further, as the amount of polyurethane charged in the encapsulated sample increased, the elution rate and the elution amount gradually decreased. This is because as the amount of charged polyurethane increases, a thicker polyurethane film is formed, and the water-soluble embedding substance in the fish meat gel becomes difficult to elute.

  From these, it is possible to form particulate biodegradable hybrid microcapsules with a size of 100 μm to 300 μm, for example, depending on the target culture target, environment, etc. Further, the required water-soluble additive release or dissolution, that is, sustained release can be selected.

Next, the biodegradation of biodegradable hybrid gel hybrid microcapsules synthesized from fish meat gel and polyurethane was discussed.
First, a polyurethane thin film sample was prepared. The sample is prepared by weighing a predetermined amount of polyol and diisocyanate, which are raw materials of polyurethane used as a microcapsule wall material, adding a low-molecular polyhydric alcohol at a constant molar ratio, reacting the mixture, pouring the reaction mixture into a mold and heating. It was performed by curing (samples A and B). As a control sample, poly (oxytetramethylene glycol) -4,4′-diphenyl polycyclic methane diisocyanate-trimethylolpropane (sample C), which is a general-purpose polyurethane, was used. On the other hand, an enzymatic degradation test and a soil burying test were conducted.

Enzymatic degradation test:
In the enzymatic degradation test of polyurethane film, which is a microcapsule wall material, Candida cylindracealipase (manufactured by Wako Pure Chemical Industries, Ltd.) is used as the enzyme, and phosphate buffer (1/15 mol / l, pH = 7.0) is used as the buffer. The enzyme digestion solution was adjusted to enzyme / phosphate buffer = 1.5 mg / ml. This decomposition test was performed at about 37 ° C. During the decomposition test, the film was periodically taken out, washed with distilled water, dried under reduced pressure, and the weight was measured. Enzymatic degradation was evaluated by weight loss and swelling degree of the film.

Soil embedding test:
The soil burying test was conducted at a test site in the Kanto region where soil microorganisms were known. The burial period is 4 months from July to November. The biodegradability was evaluated by lactophenol cotton blue staining, stereomicroscopic observation, EDX-SEM observation, and FT-IR spectrum.

  FIG. 4 shows the weight loss of different polyurethanes in the enzymatic degradation test. In each sample, the weight loss increased with time, and the biodegradable polyol polyurethanes (A) and (B) showed a large weight loss, but the general-purpose polyurethane (C) showed no weight loss.

  Further, in the soil burying test, the biodegradable polyol-based polyurethane was observed to have a shape degradation, surface roughness, and whitening, and was significantly degraded. In general-purpose polyurethane (C), almost no change in shape and surface was observed. When the indicator cotton blue reacts with carbohydrates on the cell walls of microorganisms, the color changes to bright blue, and when a method for confirming the presence or absence of microorganisms is used, polyurethane based on biodegradable polyol is bright overall. It was stained blue and stained vividly, especially in the whitened areas and the voided areas. From this, it can be considered that the microbial activity is the most active microbial activity in the whitened portion and the pore portion, and that the pore is formed as a result.

  FIGS. 5 (a), (b), (c), and (d) show the initial surface of polyurethane (sample A) based on a biodegradable polyol based on a scanning electron microscope (SEM), the surface after 4 months of embedment, It is each SEM photograph of a cross section at 45 °. In this way, the polyurethane surface based on the biodegradable polyol had a smooth surface at first, but after 4 months of embedding, the surface of the sample was uneven and the shape was severely degraded. It was observed. From the change in the surface shape, it can be seen that the unevenness of the sample surface advances, and as a result of the connection of the uneven portions and the active microbial activity in the further uneven portions, voids are formed. Further, as can be seen from the cross section and the scanning electron micrograph of 45 ° obliquely, the vacancies progressed to the inside of the sample, and some of the vacancies penetrated the sample. This progression of vacancies inside the sample is thought to be due to microbial degradation.

In the surface analysis by analytical scanning electron microscope, Al, Fe, Ca, Cu, and Zn metal elements were found in the polyurethane based on biodegradable polyol. This is because, in the biodegradation process in the soil burying test, hydroperoxide generated in the degradation process is catalytically decomposed by metal ions such as Fe and Al, so that Fe, Considering that it is clear that metal elements such as Al and Ca are concentrated, metal ions promote oxidative degradation of the generated C = C double bond, and indirectly promote microbial degradation. It is thought that it is done.
A large difference is seen in the FT-IR spectrum before and after embedding polyurethane based on biodegradable polyol, and the carbonyl stretching vibration of 1721 cm ^-1 and 1160 cm ^-1 overlapped based on the urethane group and ester group before embedding CO stretching vibration of, after the decomposition peak intensity of CO stretching vibration of 1160 cm ^-1 is reduced, the carbonyl stretching vibration caused by the urethane groups found in 1700 cm ^-1 appeared as a peak.
This suggests that the influence of the carbonyl stretching vibration derived from the ester group is reduced. In other words, it can be seen that the ester group is mainly subjected to the decomposition action rather than the urethane group.
From the above, it was revealed from the enzymatic degradation test and soil embedding test that the polyurethane used for the preparation of the hybrid gel microcapsules has biodegradability.

The biodegradable hybrid microcapsules described above can enhance the feeding effect by being retained by artificial seaweed.
《Seafood aquaculture by holding artificial seaweed》
It is desirable that the artificial seaweed of the seafood aquaculture bait by holding this artificial seaweed is an artificial seaweed having a function as a target aquaculture bait.
Next, an example of fish and seafood cultured bait in which biodegradable hybrid microcapsules are held with respect to artificial seaweed will be described. However, the present invention is not limited to this example.

(Examples of seafood aquaculture bait with artificial seaweed retention)
In this example, a biodegradable hybrid microcapsule is embedded in a seaweed sheet (substrate) of artificial seaweed, and this is used as an aquaculture feed for abalone seedling production.
The artificial seaweed in this case used wakame, kombu, hijiki, akamoku, and anaoaosa as raw materials.
Here, wakame and kombu are processed by salting (boiled raw material and then salted), then frozen and stored at -25 ° C. Akamoku was frozen and stored at -25 ° C. Anaanaosa was salted and then frozen and stored at -25 ° C.

The above four kinds of seaweed, excluding the above-mentioned raw cypress, were exposed to half-day running water, desalted and then dried with hot air, and pulverized with a pulverizer (mesh 1 mm).
Next, this was mixed using a degassing crusher at a weight ratio of seaweed powder: sodium alginate: water = 4: 1: 15. The mixture was stretched into a thin plate (thickness 1 mm), immersed in a 5% calcium chloride aqueous solution for 3 hours to solidify, placed in a vinyl chloride bag, sealed, stored at 5 ° C., and successively fed. The control was mixed in a weight ratio of sodium alginate: water = 1: 3 so that the water content was the same as that of the seaweed feed, and the same treatment as the seaweed feed was performed.

Abalone seedlings, that is, juveniles were reared for about one month by using the seafood cultured bait with artificial seaweed produced in this way.
This breeding was performed by placing a mesh net with a side of about 0.5 mm on the bottom of a vinyl chloride cylinder having a diameter of 10 cm, and dropping filtered seawater from about 4-5 locations at a rate of about 50 cc / min. Forty individual abalone were bred per vinyl chloride tube. The sheet-like food prepared by the above method was given at 0.25 g / individual, the remaining food was removed the next day, and the food was freshly fed. The breeding water temperature was almost constant at 20 ° C.

Analysis of general components:
The water content was determined by weighing 10 g of the sample and weighing it at 105 ° C. The sample was ashed at 600 ° C. and then made a constant weight to obtain a crude ash content. The crude protein content was determined by multiplying the total nitrogen content by the Kjeldahl method and then multiplying by 6.25. Crude fat content was determined by the method of Folch et al.

Measurement of fatty acid composition:
30 mg of the crude fat extracted by the above method was precisely weighed and then boiled in 30 ml of methanol to which 3 to 5 drops of hydrochloric acid was added dropwise for 3 hours.
After cooling, hexane (Wako Special Grade) was added and shaken vigorously in a separatory funnel to obtain only the hexane layer.
After purifying this with silica gel (Kieselgel 60, 70-230 mesh manufactured by Merk & Co Ltd), the obtained methyl ester was analyzed with a gas chromatograph mass spectrometer (GC17A-MSQP5000, manufactured by Shimadzu Corporation, column is SUPELCOWAX-10) . The analytical conditions were that the injector and detector temperatures were both 250 ° C., and the column was maintained at an initial temperature of 200 ° C. for 14 minutes and then heated to 250 ° C. at 3 ° C./min. The split ratio was 25: 1.

Determination of protein constituent amino acids:
After precisely weighing 20 mg of the sample, 1 ml of 6N HCl was added and hydrolyzed at 110 ° C. for 22 hours. A part of this was diluted 10-fold with a sodium citrate buffer (pH 2.2), and free amino acids were measured using an amino acid automatic analyzer (ALC-1000 type, manufactured by Shimadzu Corp., and Na type column).

Measurement of physical properties:
The prepared abalone feed by holding artificial seaweed was subjected to a break test using a rheometer (NRM-2003J, manufactured by Fudo Kogyo Co., Ltd.). That is, a sample cut into a thickness of 0.5 mm and a width of 10 mm was measured with a plunger equipped with a safety razor blade and a sample stage ascending speed of 6 cm / min, and the load at the time of rupture was defined as the rupture stress (g). The average value for 6 measurements was shown in the results.

Measurement of solidification rate of sodium alginate sol:
A sodium alginate sol having a diameter of 27 mm and a length of 100 mm was immersed in a 5% calcium chloride aqueous solution, and the solidification distance was measured by cutting it round with time. At this time, four types of sodium alginate concentrations in the sodium alginate sol were prepared: 2.5%, 5.0%, 7.5, and 10.0%.

Considerations for seafood aquaculture with artificial seaweed retention:
As a result of examining the nutritional components of seaweed powder, it was found that the crude protein content assumed to be most necessary for the growth of juvenile shellfish is the largest in Anaanaosa, followed by wakame, in terms of solid matter. Furthermore, with regard to the crude fat content, wakame was the most popular, followed by kombu. Carbohydrate content was most abundant in akamoku.
Among the above five seaweeds, the relationship between crude fats is in the order of wakame>kombu> akamoku = anaaosa> hijiki, and the size of crude proteins is anaaaosa>wakame>hijiki>kombu> akamoku. In the size relationship, it was in the order of hijiki>akamoku>kombu> ana aosa> wakame

  In saturated acids, all seaweed powders contained the largest amount of C16: 0 (16 carbon atoms, 0 double bonds), and monoenoic acid did not show any dominant fatty acid. Polyenoic acid did not contain any seaweed C22: 5 n-3 (DPA) (22 carbon atoms, 5 double bonds, 3 positions where double bonds appear for the first time by the number of carbons counted from the end) . C20: 5 n-3 (EPA), which has been clarified as an essential fatty acid for marine fish, was found in all seaweed powders, but was high in wakame and kombu in both composition ratio and absolute amount. C22: 6 n-3 is also regarded as an essential fatty acid like EPA, but these were not found in cypress, seaweed and kombu. As mentioned above, since the big difference in the composition ratio by the kind of seaweed was not recognized, it was thought that there was no difference in the restriction | limiting amino acid and protein score of these seaweed powder.

  Further, as a result of examining the solidification rate of the sodium alginate sol for each of the above seaweeds, the solidification distance with respect to the immersion time was correlated at any sodium alginate concentration, which was shown by a straight line. In addition, the higher the sodium alginate concentration, the greater the slope of the regression line, suggesting that the calcium chloride solution permeates and coagulates faster. It was also found that a substrate with a thickness of 5 mm or less solidifies sufficiently when immersed for 24 hours. In the change in substrate physical properties, the rate of disintegration of hijiki was the highest, and that of Anosa was the smallest.

Moreover, about each said seaweed, the change of the shell length of abalone young shellfish, the change of a weight, the growth rate, and the weight increase rate was examined. As a result, the magnitude relationship of the growth rate of the shells was in the order of Anaaaosa>Wakame>Kombu>Hinoki>Control> Akamoku.
Further, in terms of the weight increase rate, it was in the order of kombu> anaaosa≈wakame >>hijiki> ≈control≈akamoku, and as a seaweed powder used as a substrate, it was revealed that anaaaosa, wakame and kombu are excellent.
In addition, the number of moribund individuals at the time of breeding was 1 control sample, 0 akamoku, 1 anaahosa, 1 hinoki, 2 wakame, and 3 kombu, and there was no significant difference due to the difference in food type.

  In addition, general components of abalone were examined. There was no significant difference in the composition ratio of the general ingredients due to the difference in feed. The wakame and kombu breeds tended to have a slightly higher crude fat content, which may be due to the high crude fat content of the feed.

From the above results,
-Anaaaosa, kombu and wakame were found to be suitable as seaweeds used as substrates.
-It was confirmed that the immersion time of the coagulating liquid (5% calcium chloride) of the substrate having a thickness of 5 mm or less is sufficient if it is 24 hours.

Furthermore, the effectiveness of the artificial seaweed, particularly the characteristics when used as an abalone feed, that is, the state of elution of the water-soluble component from the substrate and the oxidation of wakame lipid during the processing process were examined as follows.
Elution of water-soluble components from the substrate:
Wash salted seaweed in running water for 1 hour to remove salt, add 2% sodium bicarbonate (for food additives manufactured by Wako Pure Chemical Industries, Ltd.), dissolve with heat in alkali, and add 5% to the total weight. % Sodium alginate (Wako Pure Chemical Industries, first grade, Na-Arg) and 5% sodium glutamate were added, then immersed in a 5% calcium chloride aqueous solution for 3 hours to solidify, 3cm x 3cm x 1mm plate (Substrate). This was put in a 15 L container, 30 mL / min of seawater was changed, the substrate was taken out over time, and the amount of nitrogen in the substrate was calculated by the Kjeldahl method.

FIG. 6 shows changes in water-soluble components in the substrate during immersion in seawater. In this case, the amount of extract nitrogen in the paste before solidification of the substrate was taken as 100 and expressed as a relative value. As FIG. 6 shows, the efflux of water-soluble components from the substrate begins with the step of coagulating the seaweed paste in the calcium chloride solution (at this point, 85% of the original), and already immersed in seawater for 45 minutes. It was halved.
Although the speed decreased, elution continued after that, and after 4 hours, 20% of the original amount was dissolved, and after 16 hours, everything was eluted.
Thus, considering that it takes a long time for abalone larvae to feed and feed, it was confirmed that there was a great need for encapsulation of water-soluble components by hybrid gel.

Wakame lipid oxidation during processing:
Raw seaweed is heated at 80 ° C for 5 minutes, mixed with 15% sodium chloride, left for 48 hours, dehydrated with a centrifugal dehydrator, and further 10% sodium chloride with respect to the total weight. In addition, a part was vacuum freeze-dried, and the general components and fatty acid composition were measured. Table 1 shows changes in general components during the processing step, and Table 2 shows changes in fatty acid composition.

There was no change in general components, including the increase in salt-derived crude ash during the process, and there was no change in the fatty acid composition. Thereby, it turns out that the problem by the oxidative degradation of a lipid does not arise when using salted seaweed as an abalone feed.

Next, the influence on the abalone larvae, that is, the abalone seedlings, of the seafood aquaculture feed by artificial seaweed, in which hybrid microcapsules are held in the artificial seaweed described above, was examined.
《Effects of Abalone Feed on Abalone Juveniles by Holding Artificial Seaweeds》
Hybrid gel microcapsule-added diet and vitamin gel-encapsulated hybrid gel microcapsule-added diet were given to abalone juveniles, and their effects on growth and survival were examined.
In this case, a diet containing 100 μm to 200 μm hybrid gel microcapsules was given to abalone larvae, and the influence on growth and survival was examined.
And in this case, the bait | feed which embedded the hybrid gel capsule of 100 micrometers-200 micrometers by the above-mentioned method using the salted seaweed was prepared.
At this time, the addition amount of the hybrid gel microcapsule was changed to 3% and 7%.
Moreover, the thing which does not add a hybrid gel was used as a control.

  Abalone juveniles were raised for one month. Breeding was carried out by placing a mesh net with a side of about 0.5 mm on the bottom of a vinyl chloride cylinder having a diameter of 10 cm and dropping filtered seawater from about 4-5 locations at a rate of about 50 cc / min. Forty individual abalone were bred per vinyl chloride tube. The sheet-like food prepared by the above method was fed at 0.25 g / individual, and the remaining food was removed the next day and fed again.

General component analysis:
The water content was determined by weighing 10 g of the sample and weighing it at 105 ° C. The sample was ashed at 600 ° C. and then made a constant weight to obtain a crude ash content. The crude protein content was determined by multiplying the total nitrogen content by the Kjeldahl method and then multiplying by 6.25. Crude fat content was determined by the method of Folch et al.

Measurement of peroxide value, acid value, and fatty acid composition:
The measurement of the peroxide value and the acid value was performed by a conventional method. 30 mg of the crude fat extracted by the above method was precisely weighed and then boiled in 30 ml of methanol to which 3 to 5 drops of hydrochloric acid was added dropwise for 3 hours. After cooling, hexane (Wako Special Grade) was added and shaken vigorously in a separatory funnel to obtain only the hexane layer. After purifying this with silica gel (Kieselgel 60, 70-230 mesh manufactured by Merk & Co Ltd), the obtained methyl ester was analyzed with a gas chromatograph (GC17A manufactured by Shimadzu Corp., column is SUPERCO OMEGAWAX-250). The injector, column and detector temperatures were 250, 205 and 250 ° C, respectively. The split ratio was 25: 1.

Statistical analysis:
Comparison of average values was performed using the Scheffe test method.
7 and 8 show the total weight and shell length of abalone bred on a substrate supplemented with hybrid gel microcapsules.
Abalone gained was not observed in the abalone bred in the control, but increased in any of the animals fed with the hybrid gel-added substrate.
In addition, there was no significant difference in the weight-increasing effect between the feeds containing 3% and 7% of the hybrid gel. In terms of shell length, the abalone bred in the control was greater than at the start, but the increase was inferior to the substrate with the hybrid gel, and with the feed with 3% and 7% of the hybrid gel. There was no significant difference.

From the above results, it was revealed that the hybrid gel contributes to abalone weight increase and shell growth.
Moreover, as shown in Table 3, the daily feeding rate and the survival rate did not decrease due to the addition of the hybrid gel.

  Furthermore, as shown in Table 4, the component change of the abalone larvae by taking in the hybrid gel was not recognized.

Furthermore, we investigated the effects of artificial seaweed, which holds water-soluble vitamin-containing hybrid gel microcapsules on artificial seaweed, on abalone larvae.
《Effect of seafood aquaculture feed on abalone larvae by artificial seaweed retention》
In abalone seedling production, the cause of necrosis in the process leading to larvae of a size that can be released from larvae is unknown. In order to solve this problem, it is considered to feed water-soluble nutrients such as vitamins and medicines, but there was no such method and it was impossible until now. This was made possible by seafood aquaculture feed. Here, several vitamins were actually embedded in the hybrid gel microcapsules, which were fed to abalone, and the effects were investigated.

Artificial seaweed:
Wakame, which was produced by longline culture, salted and frozen at -25 ° C, was used.
Preparation of seafood aquaculture feed by artificial seaweed retention:
The salted processed seaweed was exposed to running water for half a day, and after desalting, an equal amount of tap water was added to this, and 3% sodium hydrogen carbonate was added to the total amount and dissolved by heating (seaweed paste).
Next, 10% sodium alginate was added thereto, and 1% and 5% of microgel capsules embedded with vitamin C, vitamin B ₁ and vitamin B ₁₂ were added, respectively. The microcapsule gel contains vitamin C, vitamin B ₁ and vitamin B ₁₂ at 8.1 × 10 ⁻⁶ (mol / g), respectively. The mixture was stretched into a thin plate (thickness 1 mm), immersed in a 5% calcium chloride aqueous solution for 3 hours to solidify, placed in a vinyl chloride bag, sealed, and sequentially fed. A predetermined amount of blank (not containing vitamins) microcapsule gel was added as a control.

Abalone juvenile rearing:
The animals were raised for about 1 month. Breeding was carried out by placing a mesh net with a side of about 0.5 mm on the bottom of a vinyl chloride cylinder having a diameter of 10 cm and dropping filtered seawater from about 4-5 locations at a rate of about 50 cc / min. Forty individual abalone were bred per vinyl chloride tube. As for the feed, 0.25 g / individual seafood aquaculture feed by artificial seaweed retention in sheet form prepared by the above-described method was given, and the remaining food was removed the next day and fed again.

The measurement results of the effects of vitamins on the total weight, shell length and obesity of abalone juveniles are shown in FIGS. 9, 10 and 11, respectively.
According to these measurement results, for example, when vitamin C is added at 5% addition, the total weight and the degree of obesity are improved.

  In the above-described example, the addition of vitamins is exemplified, but not limited to vitamins, various nutrients, drugs and the like can be easily added as needed.

  The shape, size, thickness, etc. of the artificial seaweed can be appropriately selected according to the feeding object and the situation. However, since the gelation reaction during the production is caused by, for example, sodium alginate encountering calcium ions, if the thickness is too thick, the penetration of the calcium ion solution becomes worse and it takes time to solidify. Therefore, practically, when it is used as abalone food, the thickness is preferably about 100 μm, for example, about seaweed.

As described above, the fish and shellfish culture feed according to the present invention is such that the fish muscle myofibrillar protein gel of the core material is used as a feed for fish and shellfish such as abalone seedlings. The growth of seafood seedlings can be promoted effectively.
Since this fish myofibril protein protein gel is used as a core material gel, the capsule structure of a synthetic hybrid gel with a wall material gel biodegradable polymer formed on the surface thereof is used. It is possible to control the extraction of water into the water, to give a required time lag from feeding to feeding, and to enable effective feeding.
In spite of providing the wall material in this way, the entire capsule is biodegraded, and in particular, environmental pollution due to the wall material remaining in the water indefinitely is avoided.

Furthermore, as described above, when the seafood culture feed according to the present invention is configured as a seafood aquaculture feed composition with artificial seaweed holding a hybrid gel particle artificial seaweed feed, the hybrid gel particles are composed of ultrafine particles. Even so, it is possible to avoid floating and dispersing in water or water, so even seed and seafood can be fed efficiently.
In this case, since the carrier for holding the hybrid gel particles is a food for seafood cultivation, the cultured seafood can eat the artificial seaweed food together with the hybrid gel particles, so that it can be effectively fed. It is.
Further, according to the method for producing fish and shellfish aquaculture feed according to the present invention, since the raw material can be natural seaweed, it is not necessary to procure a special raw material. Feed is one that has many practical advantages.

  In addition, it is needless to say that the food for seafood aquaculture according to the present invention is not limited to the above-described example, and the detailed configuration and structure can be changed according to the use situation and the like.

It is typical sectional drawing of one particle | grains of an example of the fishery culture feed by this invention. It is a typical top view of an example of the feed for seafood cultivation by the present invention. It is a particle size distribution of a hybrid gel microcapsule. It is a figure which shows the enzymatic decomposition of a polyurethane. It is a SEM photograph figure after 4-month soil embedding decomposition | disassembly of the polyurethane which uses a biodegradable polyol as a base material. It is a figure which shows the fluctuation | variation of the water-soluble component in the substrate during seawater immersion. It is a figure which shows the total weight change of the abalone reared with the substrate which added. It is a figure which shows the shell length change of the abalone reared with the substrate which added the hybrid gel microcapsule. It is a figure which shows the total weight change of the abalone young shellfish reared with the feed which added the vitamin containing hybrid gel microcapsule. It is a figure which shows the shell length change of the abalone young shellfish reared with the feed which added the vitamin inclusion hybrid gel microcapsule. It is a figure which shows the obesity degree of the abalone young shellfish reared with the feed which added the vitamin inclusion hybrid gel microcapsule.

Explanation of symbols

  1,11 ... Seafood feed for seafood culture, 2 ... Core material gel, 3 ... Wall material gel, 12 ... Artificial seaweed

Claims (7)

It is composed of biodegradable hybrid gel particles composed of a core material gel composed of a fish gel mainly composed of fish meat and a wall material gel made of a biodegradable polymer gel formed on the surface of the core material gel. Characteristic fish and seafood feed.   The feed for seafood cultivation according to claim 1, wherein a nutrient or drug is added to the fish meat gel.   The food for seafood cultivation according to claim 1, wherein the wall material gel is made of biodegradable polyurethane. A seafood aquaculture feed comprising a large number of biodegradable hybrid gel particles according to claim 1 held in an artificial seaweed feed. Adding 1% to 8% (by weight) of salt to fish meat, crushing the prepared sol to heat treatment and cooling to obtain a fish gel;
A particleizing step for forming a fish gel containing the fish gel as a main component;
And a step of depositing a biodegradable polymer gel on the fish gel particles obtained by the granulation, and a wall material gel made of the biodegradable polymer gel is formed on the surface of the core gel made of the fish meat gel particles. A method for producing a food for seafood culture comprising obtaining a food for seafood culture comprising hybrid gel particles. A process for producing artificial seaweed feed,
The method for producing a feed for seafood aquaculture according to claim 5, wherein the biodegradable hybrid gel particles are held in the artificial seaweed feed during or after the production process of the artificial seaweed feed. The artificial seaweed feed comprises an aquaculture feed, and the production process of the artificial seaweed feed has a step of dissolving and desalting the desalinated seaweed and then spreading and hardening to a required shape. 5. A method for producing a feed for seafood cultivation according to 5.