DK158192B - PROCEDURE FOR THE PREPARATION OF FISH ENSILAGE - Google Patents

Description

1 DK 158192 B

The present invention relates to a method for preparing fish silage which is transferred in liquid form, also termed liquid fish protein.

By "fish silage", in the following description with claim 5, is meant a liquid fish product made from whole fish or parts of fish liquefied by the action of naturally occurring enzymes in the fish in the presence of an additive capable. to initiate or accelerate the transfer in liquid form. The enzymes break down the fish proteins into less soluble units, and the 10 acid helps to increase their activity while preventing bacterial degradation. Until now, fish silage has been prepared by vigorously stirring minced fish with organic or mineral acids.

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However, minced fish that is semi-solid becomes even more viscous upon addition of the acid, and therefore heavy equipment is required to stir and liquefy such a mass. After a while, the fish is liquefied and the liquefied 5 mixture is stored in tanks for later distribution. In this technique, powerful machinery is necessary not only to pump the float fish silage stock, but also to sufficiently comminute and stir the fish in order to reduce the duration of the agitation and transfer in liquid form.

10 It has now been found that the problems associated with handling ring and mixing of minced fish can be mitigated by using a relatively simple technique.

The present invention aims to remove a) the necessity of chopping, b) the transport of solid minced fish, c) mixing of a solid mass after the addition of acid, and d) the requirement for heavy equipment.

Thus, the present invention provides a process for preparing fish silage from fish in solid form and an additive which is added in sufficient quantity to initiate and accelerate the transfer of fish into liquid form, which is an organic or inorganic acid, a salt of a such acid, enzymes or mixtures thereof, characterized in that non-solid fish of dimensions up to 15 x 38 cm are mixed with finished fish silage in a wall ratio in the range of 10: 1 to 1; 10 and that the solid fish material is transferred to liquid form in the presence of the fish silage at a temperature of at least 20 ° C.

U.S. Patent No. 3,924,005 discloses a process for producing liquid fish protein in which a slurry 30 of a finely divided fish material is proteolytically processed to dissolve the protein. The enzymes may be naturally occurring in the fish (in viscera) or, if these are insufficient, commercially available enzymes may be added. What is carried out in accordance with the present invention is that the fish material which is not comminuted with already formed fish silage made of the same enzymes is treated. US Patent No. 3DO 3,880 relates to treatment of pressurized water from the fishing industry. This pressurized water is treated with a product obtained from finely divided fish viscera, obtained from certain useful products. Finely divided fish waste can also be added. 3 are used

DK 158192 B

that is, a finely divided fish material, thereby causing the above-mentioned problems with the viscosity associated with agitation and pumping. There is no indication in this patent of how to make a liquid product from solid fish without the use of a comminution process, nor is the use of an accelerator to liquefy the fish material described.

According to U.S. Patent No. 4,016,295, a proteinaceous material is subjected to an acid-forming fermentation followed by autolysis or proteolysis by added enzymes. In this patent, a distinction is made between the situation in which autolysis occurs and the case in which proteolytic enzymes are added. It is not proposed to add enzymes to materials already containing such to accelerate the process. When bacteria are added to the enzymes, instead of enzymes to the enzymes, this is done for another purpose. According to the present invention, an accelerator which may be an enzyme or an acid is added to a material already containing an enzyme to accelerate the reaction catalyzed by the latter enzyme. According to U.S. Patent No. 4,016,295, bacteria are added to a material containing enzymes to promote a different reaction and not to accelerate the one that is already in progress.

According to U.S. Patent No. 3,041,174, an oily animal material, e.g. fish and / or fish waste / into a pulp, which is then enzymatically treated by a substrate 25 of a fermented dead lactic acid bacterial culture containing proteolytic enzymes. Thus, according to this patent, finely divided fish material is used and therefore the aforementioned difficulties in stirring and pumping are obtained.

According to the present invention, the mixture can be carried out in a tank using ordinary mechanical blending agents. Since heavy equipment is not needed, the open method according to the invention is relatively flexible with regard to the choice of mixers. Examples of mixers may include turbine mixers, vane mixers, propeller mixers, tumble mixers and centrifugal impeller mixers. You prefer a chopper pump which mixes.

One of the major advantages of the method of the invention is that small and medium sized fish, e.g. up to 15 cm by 38 cm, no need to. chopped or finely divided before mixing. Under the particular mixing conditions, these are automatically comminuted and liquefied without becoming cumbersome viscose, and

DK 158192 B

4 for unnecessary strain on the mixers or pumping equipment.

If, on the other hand, relatively large fish e.g. for small sharks to be liquefied, it may be desirable to chop such fish to an appropriate size, preferably as indicated above for small and medium sized fish to facilitate operation. As will be known to those skilled in the art, it is not necessary to use whole fish to perform the method of the invention. Fish waste, fish feed and other discarded from the fishing industry that has been chopped or otherwise broken down can be used as feed for the mixing step.

10 Additives capable of initiating and accelerating transfer in liquid form can be selected from organic acids, mineral acids, salts thereof, some particular enzymes, e.g. papain and mixtures of these. Acids, especially organic acids, are preferred, and these may be lower monocarboxylic acids, such as formic acid and propionic acid. Formic acid, however, is the most preferred. The additive can be added to the fish either before the mixing step, e.g. for example, the preliminary chopping or comminuting step will occur if such a step is performed or during the mixing step.

The ratio of additive to fish supplied to the mixture 20 at the time of mixing in the tank is suitably between 0.5 and 30% by weight, preferably between 0.1 and 5% by weight. Within these ranges, the optimum concentrations will of course depend on the type of fish being liquefied, e.g. the water and oil content of these and the like and the amount of pre-formed liquid fish silage in the mixture.

The ratio of pre-formed liquid fish silage to the fish mass is preferably between 2: 1 and 1: 3 parts by weight. When starting the operation, it will be necessary to obtain the first supply of fish silage. Bites can be obtained by stirring minced fish with warm water together with any common additive,. preferably those which provide the necessary acidic environment to provide a ρθ value of 4 or less to protect against bacterial degradation. When all the fish is liquefied, at least part of the mixture is pumped for storage.

Using a portion of the liquefied fish as a substrate, a first batch of fish and additive is liquefied by the method of the invention under constant and rapid agitation.

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Another charge of fish can also be liquefied, and this can then be split, one part being retained for further addition of fish and the other part being stored. After five or six such operations, the silage produced is of substantially the same nutritional value as the fish used, and continuous operation in this way can be performed indefinitely.

Bone silage produced at the start-up stage is still a valuable feed and can be used as a pig feed, adjusting the feeding for excess water present.

The rate at which the fish is liquefied depends on the type of feedstock, the freshness of the material and the temperature of the process. It has been found that oily fish is liquefied faster than the waste from white fish, and fresh fish is liquefied much easier than old fish. Therefore, it is desirable to subject the fish to liquid 15 immediately upon receipt of the raw material.

The process of liquefaction is also temperature dependent. Temperatures of at least 20 ° C are used and temperatures between 20 and 40 ° C are preferred. At higher temperatures, the enzymes responsible for transfer to liquid form have been found to be inactivated. The invention is further explained with reference to the drawing:

Apparatus.

A mixing tank 1 is equipped with a chopper pump 2 capable of recycling to the tank 1 via a one-way valve 3 or pump to the stored A and B via discharge pipe 4 and supply pipe 5 and 6 respectively for feeding fish and supplying fish. aqueous formic acid. The discharge line 4 is connected to the storage tanks A and B via one-way valves 8, 9. A pipe 12 is connected to each of the storage tanks A and B to remove liquid fish silage via one-way valves 10 and 11. The pump 12 is further connected with the mixing tank 1 via the one-way valve 15 and back to the storage tanks A and B for recycling via the one-way valves 14 and 8 and 14 and 9.

Procedure.

1. 0.5 tonnes of fish are fed at a constant rate together with 3,5 gallons of formic acid (3.5% by weight of 85% formic acid) via the feed pipes 5 and 6 to a mixing tank 1 containing 0.5 tonnes of hot water: (J 0 to 40 ° C).

Claims (5)

A process for preparing fish silage from solid fish and an additive which is added in sufficient quantity to initiate and accelerate the fish's transfer to liquid form, which is an organic or inorganic acid, a salt of such an acid, enzymes or mixtures thereof, characterized in that unpainted fish on solid fom with dimensions up to 15 x 38 cm are mixed with finished fish silage in a weight ratio in the range of 10: 1 to 1:10 and that the solid fish material is transferred to liquid in the presence of the fish silage at a temperature of at least 20 ° C. Process according to claim 1, characterized in that the additive is a low monocarboxylic acid; such as formic acid. 2. Stirring and circulating the mixture in the tank 1 is started by closing the valve 7 and opening the valve 3, and the circulation is continued for 1 hour. Process according to claim 1, characterized in that the amount of additive in the mixture is between 0.5 and 30% by weight of the amount of fish. 3. Then, half of the liquid in the mixing tank 1 to 5 is pumped into storage tank A by closing valves 3 and 9 and opening valves 7 and 8. Liquid pumped to storage tank A is continuously recycled by opening valves 8, 10, 13 and 14. close valve 15 and start pump 12. Method according to claim 1, characterized in that the ratio of finished liquid fish silage to fish supplied is between 2: 1 and 1: 3. . In DK 158192 B 4. Circulation and stirring in the mixing tank 1 is continued by closing the valve 7 and opening the valve 3. At the same time, an additional 0.5 tonnes of fish and 3.5 gallons of formic acid are added as before to the mixing tank 1 via the conduit 5, and the mixing is continued for another 1 / 2 hours. Then add another 1 ton of fish and 7 gallons of formic acid as before to the mixing tank 1, and stirring and circulation 15 are continued. 5. Repeat operations 3 and 4 for continuous production of fish silage. Process according to any one of the preceding claims, characterized in that at least part of the obtained liquid fish silage is removed for storage that an additional amount of solid fish material together with the necessary amount of additive 5 is added to the remaining part of the obtained fish silage or to the entire derived amount of recycled fish silage obtained, and that these operations are repeated to obtain continuous operation.