JP2010193872A - Method for treating fish stick water, and feed obtained by the method for treating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for separating a valuable nitrogen-containing material of fish stick water. <P>SOLUTION: The method for treating the fish stick water includes, in a production step of fish meal: steaming a bony part of a fish; then carrying out solid-liquid separation; centrifuging and recovering the resultant broth into three layers of fish oil, the stick water, and fine solid materials under high-temperature conditions; adding an aqueous solution of chitosan to a part or all of the stick water, or adding the aqueous solution of the chitosan to a part or all of solubles obtained by concentrating the stick water utilizing waste heat; separating precipitates; then carrying out a dehydration treatment; feeding solid materials to a drying step; filtering the treated liquid through a membrane; and drying the resultant filtration residue in the drying step. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is carried out using chitosan having the characteristics of polymer coagulation in order to separate the valuable nitrogen-containing material of stick water at the time of fish meal production, further separating the agglomerated solid containing chitosan, The present invention relates to a stick water treatment method in which a liquid other than the aggregated solid is subjected to membrane filtration to separate collagens.

  At present, in the manufacturing process of fish meal, stick water obtained by solid-liquid separation of fish-raised steamed food is concentrated in an evaporator using waste gas and further concentrated in an evaporator using steam. The sugar content of the stick water is concentrated from about 8 degrees to about 40 to 50 degrees, mixed as a soluble with the steamed solids after pressing, sent to a dryer in the drying process, and dried.

However, in this method, the protein in the stick water is subjected to strong heat denaturation in the concentration can, so that the digestion and absorption are changed. In addition, in order to concentrate the sugar content of stick water from 8 degrees to 40 to 50 degrees, it is necessary to evaporate 80% or more of the water contained in the stick water. Occupies 30% or more of the whole process for producing fish meal, and CO ₂ is also generated greatly. Moreover, the tube wall in the concentrating can is easily scaled, and unless the tube wall is periodically cleaned, the thermal efficiency is remarkably lowered. Cleaning the pipe wall is a daunting task in summer.

  Further, when the stick water is concentrated, a large amount of waste gas containing a large amount of evaporated water and an unpleasant odor is generated, the temperature is lowered by condensation by a condenser, and then the waste gas is burned in a deodorizing furnace. For this reason, large facilities are required in the collection blower which collects waste gas, and the deodorizing furnace for combustion.

  Further, the condensed water discharged from the condenser contains ammonia and other malodorous components, and the BOD value is as high as about 1500 ppm.

  Stick water is concentrated in a concentration can, mixed as a soluble solid with steamed solids after pressing, dried in a dryer to become fish meal, but the main component contained in stick water is a water-soluble protein that is easily soluble in water. There is a problem that when it is used as a feed for fish culture, it easily dissolves in water and causes water pollution.

  By the way, as is well known, chitosan is attracting attention as one of the few huge biomass remaining on the earth, and its utilization research has been rapidly progressing in recent years. One application of chitosan is the recovery and use of water soluble proteins in fish. However, when the stick water is aggregated with a chitosan solution and the chitosan aggregate is dried, the amount of the crude protein is considerably smaller than when only the same stick water is dried. This is considered to be because collagen proteins are contained in the supernatant after aggregation with chitosan. Therefore, the crude protein content of fish meal obtained by dehydrating agglomerated solids obtained by aggregating stick water with chitosan and mixing with steamed solids was achieved by the conventional method of concentrating stick water in a concentration can. Compared to fishmeal, it is inferior by the amount of collagen proteins.

  For the recovery of protein from stick water containing a large amount of water-soluble muscle plasma protein, a pH shift recovery method and a recovery method using a flocculant have been studied, and the nutritional value thereof has been evaluated. Patent Document 1 proposes a collagen recovery technique using ultrafiltration membranes after stick water is filtered through diatomaceous earth, and a treatment method for separating and recovering collagens and amino acids using stick water using membrane technology and ion exchange technology. Has been.

  On the other hand, as an example of using chitosan effectively, a research study comparing the breeding rate in the case where feed containing chitosan is fed to livestock or the like and in the case where commercially available feed for breeding is given has been made. Has proposed a production method for producing livestock feed by adding chitosan to food residues. However, there is no example of producing fish meal by aggregating fish stick water with chitosan and further treating the dehydrated solution by membrane filtration to recover collagen protein.

  JP 2007-166989 A   JP 2007-020482 A

  The objective of this invention is providing the improvement of said problem generate | occur | produced at the time of processing of stick water at the time of manufacture of fish meal, and effective utilization of chitosan.

  This invention is made | formed as a result of examining giving chitosan to the component obtained by processing while performing the process of stick water more efficiently using chitosan in view of the said subject.

  That is, the present invention includes a step of steaming fish rough, a step of solid-liquid separation and recovery of steamed solids and broth from the obtained steamed food, a fish oil and a stick under high temperature conditions in the fish meal manufacturing process A step of three-layer centrifugation into water and fine solids, a first drying step of drying the steamed solids and the fine solids, and a coagulation treatment step of adding a chitosan aqueous solution to a part or all of the stick water Separating the agglomerated solids produced in the agglomeration treatment step and the supernatant solution, a second drying step for drying the agglomerated solids, and membrane filtering the supernatant solution produced in the agglomeration treatment step. And a third drying step of drying the filtration residue containing the collagens.

  The present invention also includes a step of steaming fish rough, a step of solid-liquid separation and recovery of steamed solids and broth from the obtained steamed food, and fish oil and stick under high temperature conditions in the fish meal manufacturing process. A part of the soluble obtained by concentrating the stick water with a concentrating device, a step of three-layer centrifugation into water and fine solid, a first drying step of drying the steamed solid and the fine solid Or a flocculation treatment step in which an aqueous chitosan solution is added to the whole, a step of separating the flocculated solids and supernatant solution produced in the flocculation treatment step, a second drying step for drying the flocculated solids, and the flocculation treatment step And a third drying step of drying the filtration residue containing the collagen obtained by membrane filtration of the supernatant solution produced in 1) A.

  Further, the present invention uses the waste water generated from at least one of the step of steaming the fish rough and the first drying step in the concentrating device, the method for treating stick water as described above It is.

  Further, the present invention is characterized in that at least two of the first drying step, the second drying step, and the third drying step are the same step. It is a processing method.

  Moreover, this invention is a feed containing chitosan characterized by being obtained from the said aggregation solid substance.

According to the present invention, there is no need for a concentrating can that uses steam used in the conventional processing of stick water, and it is possible to reduce the heavy oil required for the concentrating can in the boiler, and to that extent CO _2. Can be reduced. In addition, the burden on the condenser for the treatment of the waste gas generated from the concentration can is reduced, and the amount of waste gas containing an odor with an irritating odor including ammonia and the like is reduced. Furthermore, the temperature rise of the cooling water for cooling the condenser is reduced, and the burden on the collection blower for collecting the waste gas and the deodorizing furnace for burning the waste gas can be reduced.

  In the present invention, the chitosan immunity enhancing function can be added to the fish meal by using chitosan as a stick water treatment. In chitosan, research results show that the value of the anti-hemagglutination-inhibiting antibody titer of the Newcastle disease vaccine was higher when added to the feed of chicks of egg-laying chickens than when it was not added. Immunity improves, and the morbidity and mortality during the breeding period of livestock and the like can be greatly reduced. Chitosan is a substance contained in shrimps, crabs, shellfish, etc., and is easily decomposed by microorganisms and intestinal bacteria and is very safe as a food. Furthermore, chitosan has the effect of delaying the growth of E. coli and Staphylococcus aureus and inhibiting the growth of mold. Therefore, the fish meal produced by the present invention can be expected to greatly improve the added value as a feed as compared with the conventional fish meal.

  When stick water is agglomerated with chitosan, agglomerated solids containing water-soluble proteins agglomerated with chitosan agglomerate and precipitate, but the supernatant solution also contains many proteins containing collagens. In the present invention, collagen protein obtained by membrane filtration is recovered and dried from a solution obtained by removing sticking water from agglomerated solids after agglomeration with chitosan, so that the crude protein amount of fish meal produced by the production method according to the present invention is also reduced. There is not much difference compared to that of fish meal using conventional concentrated cans.

  Furthermore, the BOD value of the final filtrate that has been membrane-filtered with stick water can be reduced, and the burden of water treatment can be reduced.

It is the flowchart which showed one preferable form for implementing this invention. It is the flowchart which showed another 1st preferable form for implementing this invention. It is the flowchart which showed another 2nd preferable form for implementing this invention.

  The present invention resides in a method of treating stick water produced during fish meal production. The processing method of this invention is demonstrated with reference to the flowchart of FIGS. 1-3.

  In FIG. 1, fish rough is crushed by a crusher and sent to a cooker which is a steaming process. In the steaming step, steaming is performed at a temperature of about 90 to 95 ° C. for about 30 minutes and heated to such an extent that the fish oil can be sufficiently separated.

  Solid-liquid separation into steamed solids and broth with press after cooker. The broth is centrifuged with a decanter to remove fine solids, and then heated and separated into stick water, fish oil and fine solids with a three-layer centrifuge. The fine solid is dried with a dryer together with the steamed solid after pressing, and becomes a fish meal through a meal cooler, a contaminant removal machine, a metal removal machine, a grinder, and a shifter.

  The stick water is concentrated in a concentration canister using the waste heat generated from the process of cooking the fish rough or the first drying process, that is, the heat of the waste gas generated from the cooker or dryer. In a concentration canister that uses waste gas, the boiling point is lowered by lowering the pressure of the surface of the stick water with a vacuum device to increase the concentration efficiency. By applying this stick water to the treatment method of the present invention, valuable nitrogen-containing substances are separated.

  The stick water is sequentially sent to the stick water tank. When an appropriate amount of stick water is stored, an appropriate amount of chitosan solution dissolved in advance is added and stirred and allowed to stand for aggregation precipitation. The chitosan amount is about 1% of the solid content of stick water.

  Next, a dehydration process is performed in the dehydration process D to separate the aggregated solid E and the dehydration liquid. The agglomerated solid is dried with a dryer A together with the steamed solid after pressing. The dehydration treatment liquid contains collagens that are not aggregated and precipitated with the chitosan solution, and is processed in the following ultrafiltration step G.

  In the ultrafiltration step G, the dehydration liquid is separated into a filtration residue H containing collagens and a filtrate. The filtration residue H containing collagens is dried with the dryer A together with the steamed solid matter after pressing, and the filtrate is treated in the next drainage step.

  In the practice of the present invention, the stick water after separation by a three-layer centrifuge is agglomerated with a chitosan solution in FIG. 1 without using a concentration canister utilizing waste gas. It can also be processed in the process.

  In FIG. 2, regarding the drying step A, the drying step F, and the drying step I, a fish meal containing a large amount of myofibrillar protein that is hardly soluble in water can be obtained from the drying step A. From the drying step F, a fish meal containing a large amount of muscle trait protein that is mainly soluble in water can be obtained. This fish meal contains most of the chitosan used in the flocculation process. From the drying step I, a fish meal mainly containing a large amount of collagen can be obtained. By combining the drying steps, it is possible to produce fish meal according to the purpose.

  In FIG. 3, it is possible to take out a part of stick water from the conventional fish meal process, and to manufacture only the fish meal containing chitosan in the processing process of the present invention. The filtrate after the ultrafiltration can be concentrated by returning to the concentrator using steam.

  Next, a specific embodiment of the present invention will be described with reference to FIG.

  40 tons of rough fish are crushed with a crusher and transported to a cooker. Heat in a sealed state at about 95 ° C. for about 30 minutes with a cooker. The steamed product is solid-liquid separated with a screw press. 26 tons of boiled juice and 14 tons of steamed solids are recovered. The recovered steamed solid is conveyed to the dryer A and dried at about 140 ° C. for about 2 hours. The production volume of fish meal is about 8 tons with a water content of 10% or less.

  The broth is centrifuged in a decanter, and the fine solid is conveyed to the dryer A. The broth excluding fine solids is heated to 90 ° C. or higher and separated into stick water, fish oil, and fine solids by a three-layer centrifuge. The fine solid is conveyed to the dryer A. About 22 tons of stick water and about 3.2 kl of fish oil are recovered. The stick water is concentrated in a concentration canister utilizing the heat of waste gas, and about 13 tons are recovered.

  In advance, 16 kl of acetic acid solution is dissolved in 3 tons of water, and 16 kg of chitosan powder is dissolved in an acetic acid aqueous solution while stirring little by little. The chitosan solution is mixed with the above-mentioned stick water and coagulated and separated. When the coagulation / separation is sufficiently advanced, dewatering is performed with a belt press dehydrator. The dehydrated solid is conveyed to the dryer A. The dehydration liquid is conveyed to the ultrafiltration step G.

  The filtration residue H containing collagens including high molecules and low molecules is separated with an ultrafiltration membrane (UF membrane, molecular weight cut off 3000) and transported to the dryer A. The filtrate is treated by wastewater treatment.

  As described above, according to the present invention, by introducing a coagulation process using chitosan, it is possible to obtain a feed containing exceptional nutrients that cannot be obtained by the conventional method, and the heavy oil in the concentration process can be obtained. Since the amount of consumption can be reduced, it can also contribute to reducing the load on the environment.

  It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that the present invention includes modifications and corrections that can be conceived by persons having ordinary knowledge in the technical field.

Claims (5)

In the fish meal manufacturing process,
The process of steaming fish rough,
A step of solid-liquid separation and recovery of steamed solids and broth from the resulting steamed food,
A step of centrifuging the broth into fish oil, stick water and fine solids under high temperature conditions;
A first drying step of drying the steamed solid and the fine solid;
A coagulation treatment step of adding a chitosan aqueous solution to a part or all of the stick water;
Separating the agglomerated solids produced in the agglomeration treatment step and the supernatant solution;
A second drying step of drying the agglomerated solid,
A method for treating stick water, comprising a third drying step of subjecting the supernatant solution produced in the aggregation treatment step to membrane filtration, and drying the obtained filtration residue containing collagens. In the fish meal manufacturing process,
The process of steaming fish rough,
A step of solid-liquid separation and recovery of steamed solids and broth from the resulting steamed food,
A step of centrifuging the broth into fish oil, stick water and fine solids under high temperature conditions;
A first drying step of drying the steamed solid and the fine solid;
A coagulation treatment step of adding a chitosan aqueous solution to a part or all of the soluble obtained by concentrating the stick water with a concentrator;
Separating the agglomerated solids produced in the agglomeration treatment step and the supernatant solution;
A second drying step of drying the agglomerated solid,
A method for treating stick water, comprising a third drying step of subjecting the supernatant solution produced in the aggregation treatment step to membrane filtration, and drying the obtained filtration residue containing collagens.   The method for treating stick water according to claim 2, wherein the concentrating device uses waste heat generated from at least one of the step of steaming the fish rough and the first drying step.   4. The method according to claim 1, wherein at least two of the first drying step, the second drying step, and the third drying step are the same step. 5. The processing method of the stick water as described.   A feed containing chitosan, which is obtained from the agglomerated solid according to claim 1 or 2.

Images