JPS61231973A - Method of treating fish - Google Patents

Abstract

PURPOSE:To separate and to collect easily fish bone, fish oil, and partially decomposed protein, by treating fish with a protein decomposing enzyme under a condition to cause thermal denaturation a bit. CONSTITUTION:Fishes are directly treated with a protein decomposing enzyme or internal organ parts and/or skin parts are removed and the fishes are treated with the enzyme at about 20-70 deg.C for about 5-2hr in such a way that a ratio of increase in soluble nitrogen in the whole nitrogen after the enzyme treatment is 3-50%, preferably 5-40%, especially preferably 5-30%. The fishes are made into a slurry state and at least one of fish bone, fish oil and partially decomposed protein is separated from the slurry by the use of a means such as filtration, centrifugal separation, etc.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for processing fish bodies, and more specifically, after treating fish bodies etc. with proteolytic enzymes, at least The present invention relates to a method for processing fish bodies characterized by separating IN.

[Prior art and problems to be solved by the invention] Conventionally, fish meal and fish oil have been produced from fish bodies and their processing residues, but this production method involves cutting, crushing, or grinding the raw materials as necessary. After pre-treatment, the liquid containing fish oil is steamed, and then the liquid containing fish oil is separated by squeezing, the resulting solid content is dried, and if necessary, crushed to obtain fishmeal. It consists of separating the fish oil and concentrating the remaining liquid to obtain a fish soluble. Therefore, since there is no step of separating fish bones in this production method, fishmeal containing a large amount of fish bone fragments can be obtained, and can be used as a protein feed or protein food material with high protein content. Moreover, since the manufacturing process includes heat treatment steps such as steaming, the protein is thermally denatured, and depending on the application, it is not necessarily satisfactory as a protein feed or protein food material.

In addition, so-called extracts have traditionally been produced as raw materials for seasonings by completely liquefying fish, shellfish, etc., in the presence of several times the amount of water, using autolysis and/or proteolytic enzymes for a long period of time. There is. When using fish bodies in this method, it is easy to separate the fish bones, but since the fish meat has been completely broken down to liquid extract, it is not possible to obtain fish protein in a form similar to that of fish meat.

[Means for solving problems]

The present inventors have investigated a method for processing fish bodies that can obtain fish protein in a form similar to fish meat or as a solid substance by processing it under conditions with little thermal denaturation, and that can also separate fish bones. When degrading enzymes are applied directly to the fish body, the fish meat surprisingly easily separates from the fish bones at an early stage, forming a slurry. From this slurry, fish bones, fish oil, and partially decomposed fish proteins can be extracted by filtration or centrifugation. The present inventors have discovered that they can be easily separated by the following means, and have completed the present invention.

That is, in the present invention, the fish body is treated as it is, or after removing the internal organs and/or the epidermis, using a proteolytic enzyme, and the rate of increase in soluble nitrogen after enzymatic treatment with respect to the total nitrogen in the raw material is: Ne -N.

-X 100 (where, in the formula, Nt is the weight percent of the total nitrogen in the raw material, He is the weight percent of soluble nitrogen in the product after enzyme treatment, and No is treated under the same conditions except that no enzyme is added. The weight percent of soluble nitrogen in the product after
This is a method for processing fish bodies, which is characterized by processing the fish bodies to form a slurry, and separating at least one of fish bones, fish oil, and partially decomposed fish proteins from this slurry.

Examples of fish bodies that can be used as raw materials for the present invention include those of highly caught fish such as herring, sardine, mackerel, saury, Japanese sardine, walleye, flounder, anchovies, and pilchard, as well as fish oil of good quality, fish bones, In order to obtain partially decomposed fish protein, it is preferable to use fish bodies of fish that are highly caught and have good freshness.

In the present invention, the fish body may be treated with a protease as it is, or the viscera and/or epidermis may be removed from the fish body and then treated with a protease.

Examples of the protease used in the present invention include acrosin, urokinase, urobevcin, elastase, enteropeptidase, catebusin, kallikrein,
Proteinases such as kininase 2, chymotrypsin, chymopapain, collagenase, streptokinase, subtilisin, thermolysine, trypsin, thrombin, papain, bankreatobeptidase, ficin, plasmin, renin, levutilase, rennin, etc.; e.g. arginine aminopeptidase, oxytosinase , aminopeptidases such as leucine aminopeptidase, angiotensinase, angiotensin converting enzyme, insulinase, carboxypeptidase such as arginine carboxypeptidase, kininase 1, thyroid peptidase, dipeptidase such as carnosinase, prolinase, etc. Peptidases; and other proteolytic enzymes and modified products thereof;
Depending on their mode of action, they can be divided into exopeptidases that act from the ends of polypeptide chains and endopeptidases that act internally, with endopeptidases being particularly preferred.

In the present invention, the raw material as described above is first treated with the proteolytic enzyme as described above, and the extent of the treatment is determined by the increase rate of soluble nitrogen after enzyme treatment with respect to the total nitrogen in the starting material: Ne -N.

-X 100 (where, Nt is the weight percent of the total nitrogen in the raw material, Ne is the weight percent of soluble nitrogen in the product after enzyme treatment, and No is treated under the same conditions except that no enzyme is added. The weight percent of soluble nitrogen in the product after
, preferably 5 to 40%, particularly preferably 5 to 30%, and the treatment with such an enzyme is carried out at a temperature of, for example, 20 to 70°C, preferably 30 to 60°C, for about 5 minutes to 2. The mixture may be mixed and stirred for a period of time, preferably 10 minutes to 1 hour. In addition, the amount of enzyme used in this case is usually 0.00 to 1.0% by weight based on the raw material to be treated. If the increase rate of soluble nitrogen is less than 3%, the peeling of fish meat from fish bones is insufficient, the separation of fish bones and fish proteins is not successful, and the separation of fish oil is also poor, and conversely, %, it is not preferable because the soluble fraction increases, leading to a decrease in the recovery rate of partially decomposed fish protein as a solid substance and deterioration in the separability of fish oil.

In this way, after the fish body is made into a slurry by treating it with a proteolytic enzyme, fish oil and
At least one of fish bones and partially degraded proteins is separated. These can be separated using various separation means such as filtration and centrifugation. As a specific example of such a separation method, for example, fish bones are separated and removed from an ill slurry by means such as filtration or centrifugal filtration, and then an aqueous phase containing fish oil and water-soluble components is separated by means such as centrifugation. and a solid portion consisting of fish protein partially decomposed with a proteolytic enzyme, and the liquid portion containing fish oil and water-soluble components is further separated by static separation, centrifugation, etc. (2) separating and removing fish bones from the slurry as described above, and then separating them into an aqueous phase containing partially decomposed fish proteins and water-soluble components and an oil phase consisting of fish oil; and further separating partially decomposed fish proteins from an aqueous phase, (3) a slurry consisting of a solid part containing fish bones and partially decomposed fish proteins, and an aqueous phase containing fish oil and water-soluble components. (4) A method in which the solid part is separated into a liquid part, and if necessary, after drying, the solid part is separated into fish bones and partially decomposed fish protein, and the liquid part is separated into an aqueous phase containing fish oil and water-soluble components. A method of separating an oil phase consisting of fish oil from a slurry, then separating fish bones, and degrading partially decomposed fish protein if necessary; (5) separating an oil phase consisting of fish oil from a slurry, and then A method of separating the solid part consisting of fish bones and partially decomposed fish protein and a liquid part consisting of an aqueous phase containing water-soluble components, and if necessary, separating the solid part into fish bones and partially decomposed fish protein, etc. Finally, the fish body can be fractionated into four parts: fish oil, fish bones, partially decomposed fish proteins, and an aqueous phase containing the remaining water-soluble components, and these can be obtained especially for purposes. A preferable separation method may be selected depending on the product to be obtained or its use.

In addition, in the method of the present invention, a physical process to break up the fish bones can be performed at any stage, thereby making it possible to separate and obtain partially decomposed fish protein containing a large amount of fish bone calcium. can.

〔Example〕

Example 1 0.3 g of proteolytic enzyme: Protease Amano A (manufactured by Ohno Pharmaceutical Co., Ltd.) was dissolved in a small amount of water and added to Ikg of sardines, and when the temperature was maintained at 50°C and stirred for 30 minutes, the fish meat gradually separated from the fish bones. peels off and the whole becomes slurry-like.

The rate of increase in soluble nitrogen in this slurry was measured by the following method. Take 10g of slurry, mix with 30ml of water, add 5ml of 10% trichloroacetic acid solution, and add 5ml of water.
ml, and filter through filter paper (Toyo Roshi Kabushiki 5A). After decomposing 10M1 of this filtrate with sulfuric acid using a conventional method, the amount of soluble nitrogen is measured using the Kelpool method and is defined as soluble nitrogen (Ne).
2 g of slurry is taken, decomposed with sulfuric acid, and treated in the same manner to convert it to total nitrogen (Nt). Furthermore, regarding enzyme-free raw materials 5
After keeping at 0° C. for 30 minutes, 10 g of the solution was taken, and 10 ml of the filtered filtrate was similarly added with a trichloroacetic acid solution, and 10 ml of the filtrate was decomposed with sulfuric acid to measure the amount of soluble nitrogen, which was defined as soluble nitrogen (No.). As a result of the above measurement, the soluble Ne -N of this slurry.

The rate of increase in nitrogen x 100 is 24.2%.
I got it.

Next, this slurry was heated and kept at 75°C for 15 minutes to inactivate the enzyme, and then the fish bones were removed using a basket-type centrifuge equipped with a 6-mesh stainless steel wire mesh. The slurry was centrifuged at 3000 r, p, m for 5 minutes to remove fish oil, aqueous phase (stick water),
The partially decomposed fish protein was separated into a precipitated part, and the liquid part was further fractionated into fish oil and aqueous phases using a separatory funnel.

The obtained fish bones were washed with water and dried, and the partially decomposed fish protein precipitate was also dried to form a powder.

In this way, 131 g of dried partially decomposed fish protein, 23 g of dried fish bones, and 149 g of fish oil were separated and obtained from Ikg of the raw material.

The analysis values and properties of each are shown in the table below.

As a reference example, analytical values of fishmeal and fish oil cleaved by a conventional method are shown.

Example 2 In Example 1, the enzyme amount was 0.2 g and the stirring time at 50°C was 20.
A slurry with an increase rate of 11% in soluble nitrogen was obtained by carrying out the same procedure as in Example 1 except that the time was changed to 11%.
In the same manner as above, 140 g of dried partially decomposed fish protein, 25 g of dried fish bones, and 147 g of fish oil were separated and obtained. The analysis values and properties of each are shown in the table below.

〔Effect of the invention〕

According to the method of the present invention, it is possible to separate and obtain partially decomposed fish protein that does not contain fish bones, and this protein is partially decomposed into a form that is easily digested and absorbed by humans and animals. Since it contains small amounts of active ingredients such as vitamins and phospholipids in the fish body without being altered by heat, it can be used as a high-quality protein source in raw or dried form, such as in feed, fodder, food, pet food, etc. suitable.

Furthermore, according to the method of the present invention, it is possible to separate and obtain high-quality fish bones with few other impurities from the fish body, and if necessary, this bone is subjected to simple treatment such as washing with water, then dried and crushed. It can be used in various feeds, fodder, foods, vet foods, etc. as a naturally derived high-quality calcium source. Furthermore,
According to the method of the present invention, it is possible to separate and obtain an aqueous solution containing water-soluble components. It can be used in feed, fodder, bed food, etc. in the form of 4-shrinked fish solubles, or in the form of adsorbed to fish meal, dried partially decomposed fish protein, other feeds, and feed ingredients. Furthermore, according to the method of the present invention, it is possible to separate and obtain high-quality fish oil that has not been denatured by heat, and since this oil contains trace amounts of useful components in fish oil without being denatured by heat, they cannot be denatured by heat. Not only can it be recovered in a non-condensed form, but it can also be used as high-quality edible fats and oils by subjecting it to ordinary purification, deodorization, hydrogenation, and other treatments.

Claims (1)

[Claims] The increase rate of soluble nitrogen after enzymatic treatment with respect to the total nitrogen in the raw material using a proteolytic enzyme for the fish body as it is or after removing the internal organs and/or the epidermal part: [(Ne-No) /Nt]×100 (however, in the formula, Nt
is the weight percent of the total nitrogen in the raw material, Ne is the weight percent of soluble nitrogen in the product after enzyme treatment, and No is the weight percent of soluble nitrogen in the product after treatment under the same conditions except that no enzyme is added. ) is 3 to 50% and made into a slurry.
A method for processing fish bodies, which comprises separating at least one of fish bones, fish oil, and partially decomposed fish proteins from this slurry.