JPS62294042A - Production of expanded feed for pisciculture - Google Patents

Abstract

PURPOSE:To easily obtain the titled feed keeping remarkably excellent palatability after thermal expansion treatment, low specific gravity and high digestive and absorptive efficiency in breeding fish, by aging an enzymatic decomposition product of antarctic krill and adding the obtained extract as an appetite- promoting substance to a feed. CONSTITUTION:Antarctic krill is subjected to enzymatic decomposition and aged to obtain an antarctic krill extract. The extract is added as an appetite- promoting substance in the production of expanded feed for pisciculture by thermally expanding a feed raw material. The addition of the extract is preferably carried out, for the further improvement in the appetite of fish, by spraying the extract to the surface of a feed formed by the thermal expansion of a feed raw material.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for producing a puffed feed for fish farming, and more particularly to a method for producing a puffed feed for fish farming that is extremely palatable. It is.

[Conventional technology]

Traditionally, eel feeds that use white fin schmeal as the main protein source and alpha starch as a binder have been widely used, and the palatability-enhancing substances include clams, mussels, iris, sea worms, threadworms, yeast, squid, Antarctic krill powder was provided. However, these feeds for eel farming have drawbacks such as the cumbersome feeding process because it is necessary to add oil, fat and water and mix thoroughly before feeding. Therefore, for the purpose of saving labor in feeding work, instead of the above-mentioned paste feed, feed in which feed raw materials are heated and pressurized in an extruder to swell and absorb fats and oils is becoming popular. Also, conventionally,
In feed for sweetfish, the raw material for sweetfish was turned into pellets using a pellet mill, turned into crumples using rolls, etc., and then sieved to produce the product. However, in order to solve these problems,
Recently, puffed feed for sweetfish has become popular, which is made by heating and pressurizing feed raw materials in an extruder to make them into crumbles, which are then sieved to produce a product.

However, these puffed feeds for fish farming are extruded and expanded at high temperatures and pressures, so they have drawbacks such as palatable substances being blown away or denaturing, making them less effective.

[Problem that the invention seeks to solve]

Conventionally, it has been known that powdered Antarctic krill is mixed as a feeding inducer in eel feed, which is used as paste feed. If it is pressed and expanded to make a puffed feed for fish farming, its effectiveness as a feeding inducer will be diminished. Therefore, the present invention solves the conventional drawbacks such as the dissipation of palatability substances during the production process in the production of puffed feed for fish farming, which involves heating and pressurizing feed raw materials to extrude and puff them. To provide a method for easily producing a large amount of puffed feed for fish farming that does not deteriorate in palatability even after aging.

In addition, there is already a known method for producing seasonings using extracts obtained by enzymatically decomposing Antarctic krill and then ripening it.
JP-A No. 57-8756), it is completely unknown to add these extracts to puffed fish feed.

[Means to solve the problem]

The present inventors have conducted various studies with the aim of obtaining a feed with good palatability for fish in the production of puffed feed for fish farming. As a result, the inventors have discovered that an extract obtained by aging Antarctic krill can be added to raw materials for fish feed, etc. The present invention was completed based on the discovery that it is possible to obtain a puffed feed for fish farming with extremely good palatability.

That is, the present invention involves the use of Antarctic krill extract obtained by enzymatically decomposing and ripening Antarctic krill in any step up to obtaining the product when producing a puffed feed for fish farming made by heating and pressurizing feed ingredients to expand them. This is a method for producing a puffed feed for fish farming, which is characterized by adding a palatability-enhancing substance, and its purpose is to maintain extremely high palatability even when puffed through a heating and pressurizing process, and to maintain an apparent specific gravity. To provide a method for producing a puffed feed for fish farming, which has a small amount of water, is easily digested and absorbed by the fish, and has a good feeding rate and breeding performance.

In the present invention, the term "expanded feed for fish farming" refers to feed obtained by conditioning feed materials with water or steam, heating and pressurizing them, and extruding them through the holes of a die to expand them, and feed obtained by crumple-forming these feeds using rolls or the like.

The Antarctic krill extract used in the present invention is usually advantageously produced industrially as follows. First, a proteolytic enzyme is added to raw or frozen Antarctic krill, the temperature is maintained to decompose the flesh of the Antarctic krill, and then the shells and solids of the Antarctic krill are filtered out. After adding about 10% of salt to the filtrate, about 25 to 30%
It is aged for about 10 to 30 days at 10°C, and when the aging is finished, it is heated to inactivate proteolytic enzymes and autolytic enzymes, and concentrated if necessary to obtain Antarctic krill extract.

Examples of the puffed feed raw materials for fish farming other than the above-mentioned Antarctic krill extract used in the present invention include fish meal, soybean meal, feed yeast, fish solubles, rice bran oil cake, wheat germ, bread crumbs, corn gluten meal, starch, or pregelatinized starch. , flour, egg yolk, feed oil, vitamins, minerals, and other raw materials, which are appropriately selected and used in combination depending on the growth level of the target fish species.

Next, in the present invention, the amount of Antarctic krill extract added to the puffed feed for fish farming varies depending on the fish species and the growth rate of the fish species, but if it is less than 0.1%, it will not improve the palatability of the fish. Moreover, addition of 3% or more does not further improve palatability and increases costs, so a range of 0.1 to 3% is desirable.

The means for adding these Antarctic krill extracts can be carried out by selecting any process up to obtaining the product. For example, it may be carried out in a mixer that mixes fishmeal, flour, and other raw materials, or it may be carried out by heating. It may also be sprayed onto the surface after pressure extrusion molding. In particular, the method of spraying on the surface is preferable because it further improves the palatability of fish, and the addition ratio is smaller than that of the method of mixing with other raw materials and then molding. When spraying, it may be sprayed alone, but by spraying simultaneously with feed oil, it is possible not only to further improve palatability but also to reduce the powderization rate of the puffed fish feed.

The puffed feed for fish farming according to the invention is usually made like a batter. First, a certain amount of other auxiliary materials are mixed with the main raw materials such as fishmeal, wheat flour, etc., an appropriate amount of Antarctic krill extract is added to this, and after thorough mixing with a mixer, an appropriate amount of water is added and kneaded. This is fed into a heating and pressure extruder, etc.
It is molded and dried to make puffed feed. Furthermore, the dried material is turned into crumples using a roll or the like, and then sieved to obtain a crumple-shaped puffed feed. In addition, for products that are molded without adding Antarctic krill extract during the mixing or kneading of raw materials, an appropriate amount of Antarctic krill extract may be sprayed directly onto the molded product or crumple product, or mixed with feed oil, etc. Spray onto the surface.

The puffed feed for fish farming produced by the method of the present invention is used for farmed fish such as carp, eel, sweetfish, trout, yellowtail, and coho salmon.

(Effects of the Invention) According to the method of the present invention, a puffed fish feed with good palatability can be easily produced in large quantities. And because Antarctic krill extract is obtained by enzymatically decomposing and maturing Antarctic krill, even if it is produced by heating and pressurizing and puffing, the resulting puffed feed for fish farming is extremely palatable. .

In addition, the obtained puffed feed for fish farming has an appropriate apparent specific gravity, is easily digested and absorbed by fish, and has the effect of improving the feed intake rate and breeding performance.

(Example) Next, specific examples of the present invention will be described with examples. The examples do not limit the invention in any way.

Example 1 Frozen Antarctic krill was crushed in a crusher, then an equal amount of water was added, a protease was further added, and the mixture was heated at 50°C in a constant temperature bath.
The mixture was stirred for 3 hours to enzymatically decompose Antarctic krill. Next, the enzymatically decomposed Antarctic krill was filtered through a cloth to remove the solid portion.

Add 100g of salt to 1kg of filtrate and heat at 25°C for 20 minutes.
After aging for one day, the enzymes were deactivated by heating at 80°C to obtain an Antarctic krill extract.

Next, the raw materials shown in Table 1 were thoroughly mixed, water and steam were added to make the moisture content 30%, and the mixture was sent to a heating and pressure extruder (extruder) and kneaded well under high temperature and pressure.
After rapidly extruding through the hole of the N-diameter die, the material was cut into a length of about 2.5 mm using a rotating blade. Then, these were sent to a hot air dryer and dried, to which 5% feed oil was added, and the Antarctic krill extract obtained as above was sprayed at the proportions shown in Table 2 to make puffed feed for fish farming A, B, C
, D and E were obtained. In addition, the control feed was a puffed feed for fish farming produced in the same manner as above, except that a small amount of blue pigment was added to the raw materials shown in Table 1 so that it could be distinguished from other samples, and Antarctic krill extract was not sprayed.

When the flotation rate of each feed was measured when added to water, the flotation rate was 98% for each feed, and there was no difference between the test feed and the control feed.

Table 1 Composition of basic feed (%) Fishmeal 66 Wheat flour 20 Potato starch 3 Soybean meal 3 Feed yeast 3 Vitamins and minerals 5 Table 2 (%) Next, prepare five 2001 capacity circular aquariums, with an average weight of 30g.
100 eels were housed in each tank and reared under running water with ventilation. The rearing conditions were 28°C and the water exchange rate was once every hour. As a feeding test, a control feed and one of the above test feeds were simultaneously administered to each aquarium, and 30 minutes later, the remaining feed was taken up, the amount of food consumed was determined, and the palatability was compared based on the ratio of the amount of food consumed. The test was conducted twice in each of the 5 aquariums.

The results are shown in Table 3, and it can be seen that the puffed feed for fish farming obtained by the method of the present invention has good palatability.

Table 3 Example 2 53 parts of fish meal, 21 parts of wheat flour, 7 parts of soybean oil cake, 4 parts of corn gluten meal, 7 parts of rice W, 2 parts of wheat germ, 2 parts of feed yeast, 1 part of feed oil, 2 parts of vitamins and minerals 1 part of Antarctic krill extract obtained in the same manner as in Example 1 was added to the mixture and mixed well. Next, water and steam are added to the mixture to adjust the moisture content to approximately 30%, and the mixture is sent to a heating and pressurizing extruder (extruder), where it is thoroughly kneaded under high temperature and high pressure, and the mixture is made into a 3.5 mm diameter After rapidly extruding from the hole of the die, it was cut into a length of about 6 fins using a rotating blade. Then, these are sent to a hot air dryer, dried, turned into crumples with rolls, and passed through a sieve of 1.0 to 1.4 m.
Puffed feed for sweetfish was obtained by collecting between m. When this feed for sweetfish was administered to sweetfish, the feeding of the sweetfish was extremely good, and good palatability was confirmed.

Claims (1)

[Claims] When producing expanded feed for fish farming, which is made by heating and pressurizing feed ingredients to expand them, Antarctic krill extract obtained by enzymatically decomposing and aging Antarctic krill is added as a palatability enhancer in any step up to obtaining the product. A method for producing a puffed feed for fish farming, characterized by: