JPH0746962B2 - How to treat fish - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for treating a fish body, and more specifically, after subjecting a fish body or the like to self-digestion to a range of characteristics, a fish bone, a fish oil, or a partially decomposed fish protein The present invention relates to a method for treating a fish body, which comprises separating at least one species.

[Problems to be Solved by Prior Art and Invention]

Conventionally, fish meal and fish oil are produced from fish bodies and their processing residues, but this production method involves steaming after pretreatment such as cutting, crushing or grinding the raw materials as needed, and then squeezing to a liquid containing fish oil. The solid content obtained by separating the product is dried, and if necessary, crushed to obtain fish meal,
On the other hand, it consists of separating fish oil from a liquid containing fish oil and concentrating the remaining liquid to obtain a fish soluble. Therefore, since there is no step of separating fish bones in such a production method, a fish meal containing a large amount of fish bone debris is obtained, and a protein feed or a protein food material having a high protein content is produced. In addition, since the production process includes a heat treatment process such as steaming, the protein is heat-denatured, and it is not always satisfactory as a protein feed or a protein food material depending on the application.

Further, conventionally, fish, shellfish, etc. have been used as seasoning raw materials in the presence of several times the amount of water, and autolyzed or / and decomposed for a long time using a proteolytic enzyme to be completely liquefied to produce a so-called extract. There is. In this method, when fish bodies are used, the separation of fish bones is easy, but since fish meat is completely decomposed into a liquid extract, fish protein cannot be obtained in a form close to that of fish meat.

[Means for solving problems]

The present inventors have studied a method for treating a fish body that can be treated under conditions with less heat denaturation to obtain fish protein in a form close to fish meat or as a solid matter, and can also separate fish bones. When self-digesting so that the rate of increase in soluble nitrogen after autodigestion with respect to total nitrogen falls within a specific range, fish meat is easily peeled off from fish bones to form a slurry, and from this slurry, fish bones, fish oil, partial The inventors have found that the decomposed fish protein can be easily separated by means such as filtration or centrifugation, and completed the present invention.

That is, according to the present invention, the increase rate of soluble nitrogen after self-digestion with respect to the total nitrogen in the raw material by self-digestion after the fish body is removed or the visceral portion and / or the epidermal portion is removed: (However, in the formula, Nt is the weight% of total nitrogen in the raw material, Ne is the weight% of soluble nitrogen in the product after self-digestion, and No is the weight% of soluble nitrogen in the raw material.) The method for treating a fish body is characterized in that it is self-digested so as to have a concentration of 0.1% to form a slurry, and at least one of fish bone, fish oil and partially decomposed fish protein is separated from the slurry.

Examples of fish bodies that can be used as the raw material of the present invention include herring, sardine, mackerel, saury, urumei sardines, walleye pollock, flounder, anchovy, pilchard, and other fish species with high catchability, good quality fish oil, fish bones, Also, in order to obtain the partially decomposed fish protein, it is preferable to use a fish body of a multi-catch fish having good freshness.

In the present invention, the fish body may be self-digested as it is, or may be self-digested after removing the visceral portion and / or the epidermis portion from the fish body.

In the present invention, the above-mentioned raw material is first self-digested, and the degree of self-digestion is determined by the rate of increase in soluble nitrogen after self-digestion with respect to the total nitrogen in the starting material: (However, in the formula, Nt is the weight% of total nitrogen in the raw material, Ne is the weight% of soluble nitrogen in the product after self-digestion, and No is the weight% of soluble nitrogen in the raw material.) %, Preferably 10
It may be self-digested to -40%, particularly preferably 10-30%, and such auto-digestion is carried out under the conditions of, for example, 30-60 ° C, preferably 40-60 ° C, for about 20 minutes to 2 hours, preferably 30%. The mixing may be carried out for 1 minute to 1 hour while mixing and stirring. When the rate of increase of the soluble nitrogen is less than 10%, the peeling of the fish meat from the fish bone is insufficient, and the fish bone and the fish protein and the separation thereof do not go well,
Further, the separability of fish oil is also poor, and conversely, when it exceeds 50%, the recovery rate of partially decomposed fish protein as a solid matter is deteriorated due to an increase in soluble fraction and the separability of fish oil is deteriorated, which is not preferable.

In this way, after the fish body is slurried by self-digestion, at least one of fish oil, fish bone, and partially degraded protein is separated from the slurry. These can be separated using various separation means such as filtration and centrifugation. As a specific example of such a separation method, for example, (1) a fish-bone is separated and removed from the slurry by a means such as filtration or centrifugal filtration, and thereafter, a fish oil and a water-soluble component are contained by a means such as centrifugation. A liquid portion consisting of an aqueous phase and a solid portion consisting of partially decomposed fish protein are separated, and the liquid portion is further separated by static separation, centrifugation, or other means containing water containing fish oil and a water-soluble component. (2) The fish bones are separated and removed from the slurry as described above, and then separated into an aqueous phase containing partially decomposed fish protein and water-soluble components and an oil phase consisting of fish oil. , A method for further separating partially degraded fish protein from the aqueous phase,
(3) Separation of a solid portion containing fish bones and partially decomposed fish protein from a slurry, and a liquid portion consisting of an aqueous phase containing fish oil and a water-soluble component, and if necessary, after drying the solid portion, the fish A method of separating the bone and partially decomposed fish protein, and separating the liquid part into fish oil and an aqueous phase containing a water-soluble component, (4) separating the oil phase consisting of fish oil from the slurry, and then the fish bone And (5) a method of decomposing partially decomposed fish protein if necessary, (5) separating an oil phase consisting of fish oil from the slurry, and thereafter,
A method of separating into a solid part consisting of fish bones and partially decomposed fish protein and a liquid part consisting of an aqueous phase containing a water-soluble component, and if necessary, separating the solid part into fish bones and partially decomposed fish protein, etc. Finally, the fish body can be finally fractionated into four sections of fish oil, fish bones, partially decomposed fish protein and an aqueous phase containing the remaining water-soluble components, and these can be obtained. The preferred separation method may be selected in relation to the obtained product or its use.

Further, in the method of the present invention, a physical treatment for finely dividing the fish bone can be performed at any stage, whereby a partially decomposed fish protein containing a large amount of fish bone calcium can be separated and obtained. Alternatively, it may be heat-treated at, for example, 70 to 80 ° C. in order to lose its enzymatic activity at the stage of the slurry-like substance after self-digestion.

〔Example〕

Example 1 When 1 kg of sardine was kept at a temperature of 50 ° C. and stirred for 40 minutes,
Gradually the fish meat peels from the fish bones and the whole becomes a slurry.

The rate of increase of soluble nitrogen in this slurry was measured by the following method. Take 10 g of slurry and mix with 30 ml of water,
Add 5 ml of a% trichloroacetic acid solution, make up to 50 ml with water, and filter with filter paper (Toyo Roshi: No. 5A). 10 ml of this filtrate is decomposed with sulfuric acid by a conventional method, and the soluble nitrogen content is measured by the Kjeldahl method to obtain soluble nitrogen (Ne). Also, 2 g of a slurry-like substance is taken and treated in the same manner after sulfuric acid decomposition to obtain total nitrogen (Nt). Further, 10 g of the raw material is taken, 10 ml of the filtrate obtained by adding trichloroacetic acid solution in the same manner and filtering is decomposed with sulfuric acid, and the amount of soluble nitrogen is measured to obtain soluble nitrogen (No). As a result of the above measurement, the rate of increase of soluble nitrogen in this slurry was: Was 16.0%.

Next, this slurry-like material is heated and kept at 75 ° C for 15 minutes to lose the enzyme activity, and then the fish bones are removed with a basket type centrifuge equipped with a 6-mesh stainless steel wire net to remove the fish bones. The resulting slurry was centrifuged at 3000 rpm for 5 minutes to separate into fish oil, an aqueous phase (stick water) and a partially decomposed fish protein precipitate portion, and the liquid portion was further fractionated into a fish oil and an aqueous phase with a separating funnel.

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

In this way, 1 kg of raw material is dried from partially decomposed fish protein 1
15g, dried fish bones 28g and fish oil 135g were separated and obtained.

The analysis values and properties are shown in the table below. As reference examples, the analytical values of fish meal and fish oil prepared by a usual method are shown.

[Effects of the Invention] According to the method of the present invention, a partially decomposed fish protein containing no fish bones can be separated and obtained, which is partially decomposed into a form that is easily digested and absorbed by humans and animals. In addition, since trace amounts of active ingredients such as vitamins and phospholipids in fish are contained without being altered by heat, they may be used as a source of high quality protein as they are or in a dried form, for example, feed, feed or food, pet food. It is suitable for applications such as
In addition, according to the method of the present invention, it is possible to separate and obtain a high-quality fish bone containing few other contaminants from a fish body, which is dried and crushed after a simple treatment such as washing if necessary. Thus, it can be used in various feeds, feeds, foods, pet foods, etc. as a naturally-occurring high-quality calcium source. Furthermore,
According to the method of the present invention, it is possible to separate and obtain an aqueous solution containing a water-soluble component, which contains a low-molecular-weight protein with good digestion and absorption properties and a water-soluble fish body component with high nutritional value. It can be used in feed, feed, pet food, etc. in the form of concentrated fish solubles or in the form of being adsorbed on fish meal, dried products of 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 good-quality fish oil that has not been heat-denatured. Since this substance contains trace amounts of useful components in fish oil without being altered by heat, they are thermally altered. Not only can it be recovered in a non-formable form, but it can also be used as an edible oil and fat of good quality by subjecting it to ordinary purification deodorization, hydrogenation and the like.

Claims (1)

[Claims] 1. A fish body as it is, or a visceral part or /
And, after removing the epidermis part, the rate of increase of soluble nitrogen after autolysis with respect to total nitrogen in the raw material by autolysis: (However, in the formula, Nt is the weight% of total nitrogen in the raw material, Ne is the weight% of soluble nitrogen in the product after self-digestion, and No is the weight% of soluble nitrogen in the raw material.) %, At least one of fish bones, fish oil, and partially decomposed fish protein is separated from the slurry, and the method for treating fish bodies is characterized.