JPH0675473B2 - Method for producing puffed feed for fish farming - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a puffed feed for fish culture, and more particularly to a method for producing a puffed feed for fish culture with extremely good taste.

[Conventional technology]

Conventionally, in eel feeds, eel feeds that use white fish meal as the main protein source and alpha starch as a binder have been popular, and clams have been used as taste enhancing substances.
Mussel, net, daphnia, thread earthworm, yeast,
Squid, Antarctic krill powder, etc. were provided. However, since these eel feeds need to be mixed with oil and fat at the time of feeding and well kneaded,
There are difficulties such as the feeding work is troublesome. Therefore, for the purpose of labor saving of feeding work and the like, instead of the above-mentioned kneaded feed, feeds in which feed ingredients are heated and pressurized by an extruder to be expanded and oils and fats are adsorbed are becoming popular. In the past, for feed for sweetfish, feed raw materials were pelletized by a pellet mill and then crumbled with a roll or the like and sieved to obtain a product, but since the apparent specific gravity is large and water contamination is likely to occur. There are drawbacks such as poor breeding performance of sweetfish, and in order to solve these difficulties, recently, feed raw materials that have been heated and pressed in an extruder to be puffed are crumbled and screened to obtain products. The expanded puffed feed for sweetfish is becoming popular.

However, since these puffed feeds for fish farming are extruded at high temperature and high pressure to be puffed, there are drawbacks such that the palatability substance may fly away or the effect may be weakened due to degeneration.

[Problems to be solved by the invention]

Conventionally, it has been known that powder of Antarctic krill is mixed as a feeding inducer in eel feeding feed used as a kneading feed (Japanese Patent Publication No. 53-38233), and this Antarctic krill powder is used and heated. When it is pressed and swelled into a puffed feed for fish farming, its effect as a feeding inducer is diminished. Therefore, in the present invention, in the production of a puffed feed for fish farming, which comprises heating and pressurizing a feed material to extrude and puff it, conventionally, it solves the drawbacks such as the palatability substance is scattered in the production process, It is intended to provide a method by which a puffed feed for fish farming which is not inferior in palatability even after a long time can be easily produced in a large amount.

In addition, a method for producing a seasoning using an extract aged after enzymatic decomposition of Antarctic krill has been known (Japanese Patent Laid-Open No. 57-8756), but it is completely impossible to add these extracts to a puffed feed for fish farming. unknown.

[Means for solving problems]

The present inventors have conducted various studies for the purpose of obtaining a feed having good palatability for fish in the production of puffed feed for fish farming, and as a result, adding an extract ripening Antarctic krill to a raw material for fish farming etc. It was found that the puffed feed for fish farming having a very good taste can be obtained by the above, and the present invention was completed.

That is, the present invention, when producing a puffed feed for fish farming by heating and pressurizing a feed raw material, in any step until a product is obtained, Antarctic krill extract obtained by enzymatically aging and digesting Antarctic krill. In a method for producing a puffed feed for fish farming, which is characterized in that it is added as a taste enhancing substance, the object is that even if it is puffed through a heating and pressurizing step, it has extremely excellent palatability and a small apparent specific gravity. Another object of the present invention is to provide a method for producing a puffed feed for fish farming, which is well digested and absorbed by the reared fish and has a good feeding rate and breeding performance.

In the present invention, the puffed feed for fish culture refers to a feed obtained by conditioning the feed material with water or steam, and then extruding it by heating and pressurizing it through a hole in a die, and feed obtained by crumbled these feeds with a roll or the like.

The Antarctic krill extract used in the present invention is usually industrially advantageously produced as follows. First, proteolytic enzymes are added to raw or frozen Antarctic krill to maintain the proper temperature to decompose the meat quality of the Antarctic krill, and then the shell portion and solids of the Antarctic krill are removed by filtration. Then, after adding about 10% of salt to the filtrate portion, it is aged at about 25 to 30 ° C. for about 10 to 30 days, and at the end of the aging, the protease is deactivated by heating, and the protease is deactivated. An Antarctic krill extract is obtained by concentrating as necessary.

Examples of puffed feed materials for fish farming other than the Antarctic krill extract used in the present invention include, for example, fish meal, soybean meal, feed yeast, fish soluble, rice bran oil meal, wheat germ, bread crumbs, corn gluten meal, starch or pregelatinized starch. , Flour, egg yolk, feed oil and vitamins, minerals and other raw materials,
These are appropriately selected and used in combination according to the growth degree 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 degree of growth of the fish species, but 0.1% or less does not lead to improvement of the palatability of the fish. Further, if added in an amount of 3% or more, the palatability will not be further improved and the cost will increase, so the range of 0.1 to 3% is desirable.

And, as a means for adding these Antarctic krill extract, it can be carried out by selecting any step until the product is obtained, for example, fish meal, wheat flour, may be carried out in a mixer for mixing other raw materials, also heating You may spray on 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 can be reduced as compared with the method of molding after mixing with other raw materials. In addition, when spraying Antarctic krill extract on the surface, it may be sprayed alone, but by spraying it with feed oil at the same time, it not only improves palatability but also reduces the powdering rate of puffed feed for fish farming. Can be made.

The puffed feed for fish farming according to the present invention is generally performed as follows. First, main ingredients such as fish meal and wheat flour are mixed with a certain amount of other auxiliary ingredients, an appropriate amount of Antarctic krill extract is added thereto, and after sufficiently mixed with a mixer or the like, kneaded by adding to an appropriate amount of water, Send this to a heating and pressure extruder,
Mold and dry to make swollen feed. Further, the dried product is crumbled with a roll or the like and sieved to obtain a crumbled puffed feed. When the raw materials are mixed or kneaded without forming the Antarctic krill extract, the molded or crumbled product is sprayed with an appropriate amount of the Antarctic krill extract as it is or mixed with feed oil or the like. Spray on the surface.

The puffed feed for fish farming produced by the method of the present invention is used for cultured fish such as carp, eel, sweetfish, masu, machi, and silver salmon.

(Effects of the Invention) According to the method of the present invention, puffed feed for fish farming with good palatability can be easily produced in large quantities. And since the Antarctic krill extract is obtained by enzymatically decomposing and aging the Antarctic krill, even if it is produced by heating and pressurizing and puffing, the obtained puffed feed for fish farming will have extremely excellent palatability. . Further, the puffed feed for fish farming obtained has an appropriate apparent specific gravity, and also has good digestive and absorption properties for fish, and has effects such as good feeding rate and breeding performance.

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

Example 1 Frozen Antarctic krill was crushed with a crusher, an equal amount of water was added, and a proteolytic enzyme was further added.
After stirring for an hour, Antarctic krill was enzymatically decomposed. Then, the enzyme-decomposed Antarctic krill was filtered through a cloth to remove the solid portion. 100g of salt was added to 1kg of the filtrate part, and 25 ℃
After aging for 20 days at 80 ° C, the enzyme was inactivated by heating at 80 ° C to obtain Antarctic krill extract.

Next, the raw materials shown in Table 1 were mixed well, water and steam were added to make the water content 30%, and the mixture was sent to a heating and pressure extruder (extruder) and kneaded well under high temperature and high pressure to obtain a 1.8 mm diameter After rapidly pushing out from the hole of the guy, about 2.
It was cut to a length of 5 mm. Then, 5% of feed oil was added to the dried product which was sent to a hot air dryer, and the Antarctic krill extract obtained as described above was sprayed at the ratio shown in Table 2 to puff the feed for fish culture A, B, C, D and E puffed feed for fish farming was obtained. A puffed feed for fish farming produced in the same manner as described above was used as a control feed except that a small amount of a blue dye was added to the raw materials shown in Table 1 to distinguish it from other samples and that Antarctic krill extract was not sprayed.

When the levitation rate of each feed when it was added to water was measured, there was no difference between the test feed and the control feed at a levitation rate of 98%.

Table 1 Composition of basic feed (%) Fish meal 66 Wheat flour 20 Potato starch 3 Soybean meal 3 Feed yeast 3 Vitamins / minerals 5 Next, five 200-liter circular water tanks were prepared, 100 eels having an average weight of 30 g were stored in each water tank, and they were kept under running aeration under running water. The breeding conditions were 28 ° C and the water exchange rate was once per hour.
As a feeding test, a control feed and one of the above test feeds were simultaneously administered to each aquarium, and after 30 minutes, the remaining feed was taken, the feed intake was calculated, and the palatability was compared by the feed intake ratio. The test was conducted twice for each of the 5 water tanks.

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.

Example 2 53 parts of fish meal, 21 parts of wheat flour, 7 parts of soybean meal, 4 parts of corn gluten meal, 7 parts of rice bran, 2 parts of wheat germ, 2 yeasts for feed
Part, feed oil 1 part, vitamins and minerals 2 parts by the same method as in Example 1 Antarctic krill extract 1
Parts were added and mixed well. Next, water and steam are added to these mixtures to adjust the humidity so that the water content becomes about 30%, and the mixture is fed into a heating and pressure extruder (extruder),
It was kneaded well under high temperature and high pressure, rapidly extruded from a 3.5 mm diameter die hole, and then cut into a length of about 6 mm by a rotary blade. Then, these were sent to a hot air drier and dried, and then crumbled with a roll and sampled with a sieve between 1.0 and 1.4 mm to obtain a puffed feed for sweetfish. When the feed for this sweetfish was administered to the sweetfish, it was confirmed that the sweetfish had a very good feeding and had a good palatability.

Claims (1)

[Claims] 1. An Antarctic krill extract obtained by enzymatically aging and digesting Antarctic krill in an arbitrary step until a product is obtained when producing a puffed feed for fish farming, which comprises heating and pressurizing a feed raw material. A method for producing a puffed feed for fish farming, which comprises adding it as a taste enhancing substance.