JP2002536983A - Method for producing a nutritional composition - Google Patents

Abstract

(57) Abstract: A method for producing a nutritional composition, feed or feed, comprising emulsifying a mixture containing raw fish, and then heating and / or drying the emulsion.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a method for producing a feed containing fish as a main component and a feed produced by the method. The aquaculture industry, sometimes referred to as the fish farming industry, is a rapidly developing industry that is increasing the demand for fish feed, or feed. At present, the main components of fish feed are marine proteins (in the form of fishmeal) and marine oils (in the form of fish oil).

[0002] The term "bait" is generally used in the art to describe products that meet the daily nutritional needs of the organism being fed (ie, farmed fish), and thus Contains all essential nutrients. By comparison, the term "feed" is used to refer to one component of a complete feed, such as protein or fish oil, or to a component that contains the necessary proteins and oils but lacks the proper vitamin content. . As used herein, the term "nutritional composition" is a term that encompasses both complete feed and feed.

[0003] In the aquaculture industry, particularly in the culture of salmon and catfish, feed pellets are used as bait. These pellets are usually made from fish meal and fish oil, resulting in a more efficient use of raw materials. Thus, for example, 10 kg of swordfish, which is used directly as food for cod, produces about 2 kg of cod,
This is equivalent to about 0.7 kg of cod fillet. If you want to be replaced
If kg are processed to produce fishmeal and fish oil and used as feed for farmed salmon, the yield will be approximately 4.6 kg salmon or 2.8 kg salmon fillets. Furthermore, the energy yield is significantly higher; cod fillets correspond to about 3 MJ, whereas salmon fillets correspond to about 28 MJ.

[0004] Fish meal and fish oil are produced by cooking raw ingredients (fish), and the cook is squeezed and separated into three fractions: water; fish oil; protein. The protein fraction is the dry solid residue of the cooking and squeezing steps, about 70% protein, 10% fat and 10% water, and is ground to produce fish meal. The oil fraction can be used directly for animal / fish feed production or may be purified and used for human consumption.

[0005] Although it is called fish oil, the more precise term is probably lipid and both terms are used below. In the manufacture of bait pellets, fish oil, optionally with vegetable oil, is sprayed onto pellets formed from fish meal, optionally with vegetable carbohydrates. In this way, pellets having a lipid content of up to about 35% by weight can be produced. Ideally, the lipid content should be high to maximize the growth of fish farms such as salmon. However, at warm temperatures, such as those experienced in summer, there is significant lipid leakage from the bait pellets. That is, from a 500 kg bag, there may be as much as 30-50 kg of lipid leakage. Since the spilled oil is not consumed by the fish, this not only wastes the fish oil, but also becomes a dirty, difficult-to-treat “feed”, and automatic feeding systems (this device relies on pneumatic feeding. Often). In addition, oil spreads on the surface of water and is not environmentally preferable.

[0006] Further processing of the raw material (fish) to separate it into fishmeal and fish oil, and then combining them to produce bait pellets, involves significant energy and equipment use. An alternative method of fish feed production is described in NO 903175 (Hamre). In this method, raw materials, such as whole fish, fish heads, fish guts, are crushed, mixed with whole wheat flour, pelletized and cooked in a microwave oven, floating in water and 10-30% moisture Pellets that are content are produced. Microwave cooking coagulates the protein and prevents the pellets from coalescing. However, the problem of lipid leakage has not been solved, and if the pellets are not used in time, the water content is undesirably high. In storage-stable fish pellets, the water content is preferably less than 10% by weight.

[0007] The inventors have found that emulsifying the raw material mixture before heating and / or drying, for example to a mayonnaise-like consistency, allows improved baits and feeds to be produced, especially in the form of pellets. In this way, there is no problem of lipid leakage, the lipid content can be increased, and a storage-stable pellet having a low water content can be produced.

[0008] Accordingly, the present invention, in one aspect, provides a method for producing a nutritional composition, comprising emulsifying a material, including raw fish, and heating and / or drying the resulting emulsion. And preferably heating the emulsion to coagulate the protein therein. In the method of the present invention, the raw fish used may be a whole fish, or a fish part, specifically a viscera, a head, a tail, etc., for example, as a waste material when removing fish or making cuts. There may be. As raw fish, it is not recommended to use fish of the same species as those intended as organisms consuming the nutritional composition.

[0009] In addition to raw fish, other substances in the material to be emulsified, specifically fish meal, fish silage (
silage, hydrolyzed fish), vegetable carbohydrates (eg, whole wheat flour, corn flour, etc.), fish oil, vegetable oils, coloring agents, vitamins, minerals, drugs (eg, antibiotics, growth promoters, etc.), plant proteins, especially stored Proteins, especially gluten, may be included.

[0010] These additional substances, such as vitamins and minerals, can contribute to providing a balanced diet to the organisms receiving the nutritional composition. That is, lipid /
The protein balance can be adjusted. Specifically, if the raw fish used has low lipids, fish oil or vegetable oil can be used to increase the lipid content. Additives can be used, such as coloring agents, so that the meat part of the farmed fish closely resembles that of wild fish. This is especially desirable for farmed salmon. Alternatively, such as when using antibiotics, such additives may contribute to promote or protect the health of the organism being fed. However, the use of plant storage proteins, especially gluten, is particularly preferred because it significantly and surprisingly improves the texture, physical strength, and lipid retention capacity of the product.

[0011] The product according to the method of the invention, thus containing such additive substances, comprises:
In one preferred embodiment, it is a complete diet, especially a diet in pellet form, or a diet or feed in granular form (eg in powder, granular or fine powder form). The material to be emulsified and heated must have a protein content high enough to solidify when heated. Typically, the protein content will be 30-60% by weight on a dry weight basis, and will specifically be 35-55%, preferably 38-45%, most preferably about 40%. Up to 100% of this may be fish protein, preferably at least 50% may be derived from raw fish. However, up to 50% by weight of the protein may be vegetable protein, preferably gluten.
Gluten is particularly preferably 0-40% of the total protein weight, e.g.
It may contribute 40%, more preferably 5-30%, for example 10-30% or 15-25%, most preferably 10-20%. It is preferred to use the gluten itself, that is, rather than in the carbohydrate-containing flour.

[0012] The high protein content of the emulsified material also helps to enhance emulsion formation by contributing as an emulsifier. In addition, this effect can be optionally enhanced by the use of at least one specific emulsifier. The mixture that is emulsified and preferably coagulates will preferably have a lipid content of 15-55% by weight, more preferably 20-40%, on a dry weight basis. This may be obtained entirely from raw fish. However, typically up to 25% of the total lipids may be derived from added vegetable or fish oils. Suitable vegetable and fish oils include oils from cod, capsicum, herring, sprat sardines, blue whiting, cuttlefish, Norway pout, soybeans, seed oil rape, spice seeds, sunflower, safflower, etc. Is mentioned.

In general, vitamins, colorants, drugs and minerals form only a small part of the mixture that emulsifies and solidifies, for example up to 10% by weight, based on dry solids. The appropriate amount can be readily calculated from the appropriate dose and feed consumption rate of the organism being fed. Carbohydrates, in particular digestible plant starch, such as wheat starch, will constitute up to 20% by weight, preferably 5-15% by weight, based on the dry weight of the emulsified and cooked mixture.

The water content of the mixture to be emulsified and cooked generally ranges from 40 to 75% by weight, for example
It may be 55-75% or 60-70%, but most preferably 45-60%. If, after cooking and drying, the feed is stored before use, the moisture content is preferably 0.5
It may be reduced to ~ 70%, particularly preferably 2-10%, most preferably 3-8%.

In the method of the present invention, the mixture to be emulsified is obtained by grinding raw fish, such as whole herring, splatter sardine, mackerel, or cape shamo, into flour, chopped (sliced), or chopped, In addition, they are prepared by mixing with special substances, such as, for example, wheat starch, a mixture of vitamins, gluten (eg, from wheat and / or corn), and coloring agent (eg, astaxanthin or canthaxanthin for salmon diet). Is preferred. This crude mixture is then used, for example, by Simo Mi from Simo Industries A / S in Denmark.
It is emulsified using a micro cutter such as crocutter MC250 / 115 PFVB175SS.

In the Simo Microcutter, the mixture is fed through a die plate with 4 mm and 2.5 mm openings at a speed of up to 6 tons / hour and emulsified by rotating a knife plate. The resulting emulsion contains oil droplets having a maximum dimension (e.g., diameter) of about 1-50 [mu] m, and substantially larger solid particles, except for bone fragments that will typically be 200-500 [mu] m. That is, it does not include particles larger than 50 μm. Typically, the percentage of solid particles (other than bone fragments) larger than 5 μm, which can be seen by light microscopy (eg, by volume), is, for example, a factor At least 10, more usually at least 100 less. As mentioned above, the emulsion typically has a mayonnaise-like consistency. According to inspection by light microscopy, the emulsion appears to have all or substantially all of the components of the mixture as a continuous aqueous phase or a discontinuous oil phase. This is immediately distinguished from the pre-emulsified mixture produced by chopping and grinding. In the mixture before emulsification,
Solid particles from raw fish, particularly muscle fibers and large bone fragments, are a prominent feature, and lipid droplets are larger than in emulsions.

After emulsification, the mixture is partially vacuumed (eg,
0.1 to 0.9 bar). Floating bait is undesirable to saltwater fish farmers and thus prevents the production of floating bait. In addition, this reduces oxygen pressure (ie, oxygen concentration), thereby reducing oxidation of lipids in the composition. However, in catfish cultivation, floating bait is desirable, so degassing may be omitted or performed incompletely. The final feed has a density greater than 0.6 g / mL, preferably greater than 1 g / mL, more preferably 1.2 g / m
It is desirable to be larger than L.

In one embodiment of the invention, following emulsification and optional degassing, the emulsion is heated to solidify the protein and produce a lipid-retained matrix. This can be done in several ways, such as passing over a heated surface, passing through a hot air dryer, steam heating, heating by electromagnetic radiation, infrared heating, etc. May be done. However, microwave heating is preferred.

In the heating step, the heating temperature and time are at least set to coagulate the protein,
Should be sufficient to make the lipid-encapsulated substrate. It is not necessary that heating significantly reduce the water content of the mixture. In general, the mixture should reach a temperature in the range 50-100 ° C, preferably above 78 ° C. The required range of heating is easily determined in practice. That is, if the heating is too low, the pellets of the emulsion will be soft, easily deformed, and will stick together and coalesce. When heated sufficiently, such pellets are independent, transportable, and do not coalesce. Excessive heating is unproductive because it destroys the properties of the protein and reduces the nutritional value of the feed.

The heating step of coagulating the protein is preferably achieved using electromagnetic (eg, microwave) irradiation at a frequency in the range of 10-3000 MHz, preferably in the range of 900-950 MHz. Irradiation intensity is 0.025 per kg / hour of emulsion throughput
0.5 kW, especially 0.05-0.2 kW / kgh ^-1 , especially 0.075-0.15 kW / kg
Preferably it is in the range of h- ¹ . To use higher frequencies to enhance the ability to penetrate the emulsion, it is preferred to use a microwave frequency of 900-950 MHz, especially about 915 MHz.

The water content in the coagulation step is desirably as low as possible, and the subsequent processing steps, such as for example using hot air drying, for further drying until the desired final water content is achieved Is achieved in. Dry, storage-stable baits preferably have a final moisture content of less than 10% by weight. However, baits used without storage are acceptable up to a water content of 30%. Moisture content may usually be determined using an infrared moisture meter such as, for example, a Mettler Toledo HR73 halogen moisture meter.

Prior to the coagulation step, the emulsion is preferably extruded into sheets or ropes, more preferably 2 to 40 mm thick, particularly preferably 3 to 25 mm diameter ropes,
Or it is molded. The emulsion may, if desired, be formed into "pellets". However, it is generally preferred to cut such ropes into pellets after solidification. The size of such a pellet is, for example, 2 to 30 mm, preferably 3 to 20 mm.

If extruded or molded as a sheet, the coagulated emulsion
It may be ground into flakes, cut into small pieces, or transformed into particles of a desired size. Particularly preferably, the emulsion is shaped before coagulation, for example into sheets or ropes, coagulated and cut into pellets or small pieces or smaller sheets,
Dried on a perforated belt in a multi-sector hot air dryer and, if desired, crushed into flakes. Particularly preferably, the emulsion is extruded into a rope before coagulation, coagulated, cut into pellets and then dried on a perforated belt in a multi-sector hot air dryer. In one preferred embodiment, in the first sector of the multi-sector dryer, the air flow is passed through the belt from below to separate the pellets, while in the later sector, to increase the drying effect. , The air flow is passed through the belt from above. It is preferred that a further later sector is arranged to cool the dried pellets.

The dryer used in this embodiment of the apparatus of the present invention is advantageously a Lindauer from Lindau, Germany, for drying pelletized sewage sludge.
A multi-sector dryer, such as a dryer manufactured by Dornier GmbH. Where the product of the method of the present invention is feed, a wide range of dryers may be used, such as, for example, the multi-sector dryers, hot air drum dryers, flash dryers, and the like described above.

In another embodiment of the present invention, after emulsification and optional degassing, the emulsion is passed directly to drying means, and thus in the form of granules (eg powder, granules or meal) To form a nutritional composition. The drying means is optional, and may be, for example, a high-temperature drying means such as a disk drier, or a low-temperature drying means such as a vacuum drier, a spray drier or a flash drier. In a dry, storage-stable bait flour (meal), the final moisture content is preferably less than 10% by weight. However, for feeds or feeds used without storage, a water content of up to 30% is acceptable.

In one particularly preferred embodiment, the nutritional composition is substantially vegetable-carbohydrate or vegetable-oil-free, produced in relatively fine granules, for example pellets of size 2-5 mm, or especially in meals. The feed. The powdered or granular feed is then pelletized or extruded, for example, with binders and vegetable carbohydrates to add fish and / or vegetable oils and other substances mentioned above (eg, vitamins, drugs, colorants, etc.). For example, it may be used as a material for preparing pellets for feed by a conventional method. Fish and vegetable oils may be added to achieve the desired balance of fatty acid residues (eg, ω-3 and ω-6 acids) in the final product, human or animal (eg, mammals, fish , Reptiles, etc.) or food supplements.

After drying and cooling, the nutritional composition may be packaged for storage or transport, for example, in a waterproof plastic container such as a bag or drum. The nutritional composition produced using the method of the invention is novel and forms a further aspect of the invention. In this regard, the present invention provides a nutritional composition that can be produced by emulsifying and coagulating and / or drying a mixture containing raw fish.

In a further aspect, the present invention provides a nutritional composition comprising fish oil and fish protein, preferably coagulated fish protein, wherein the composition comprises:
It is substantially free of muscle fiber fragments exceeding 200 μm in length and is preferably a gluten-containing composition. The apparatus used in the method of the invention is also novel and forms a further aspect of the invention. In this regard, the present invention provides an apparatus for the production of a nutritional composition, wherein one embodiment of the apparatus comprises: a grinder arranged to produce a ground mixture of raw fish; An emulsifier arranged to convert the ground mixture into an emulsion, a heater arranged to coagulate the emulsion, and a dryer arranged to dry the coagulated emulsion.

[0029] Such a device also provides a mixer for mixing the raw fish mixture with other auxiliary ingredients, such as vitamins, oils, minerals, gluten, starch, etc., to reduce the gas content of the emulsion. Means for forming the emulsion into the desired shape and solidifying it with a heater, such as a spreader for producing sheets or an extruder for producing emulsion extrudates, and Includes a cutter for cutting the solidified emulsion into the desired shape, such as a pelletizer for pelletizing.

A further aspect of the device of the present invention is a grinder arranged to produce a ground mixture of raw fish, an emulsifier arranged to convert the ground mixture of raw fish into an emulsion, and an emulsion. And a drier arranged to dry the product.

[0031] Such a device is also preferably a mixer for mixing the ground raw fish mixture with other auxiliary ingredients such as vitamins, oils, minerals, gluten, starch, the gas content of the emulsion. Includes a deaerator to reduce

[0032]

【Example】

Aspects of the method, apparatus, and product of the present invention are further described by way of example with reference to the following non-limiting examples and accompanying figures. FIG. 1 shows an apparatus 1 for implementing the method according to the invention. Raw fish (eg:
The whole herring is transferred from the receiving hopper 2 to the grinder 4 by the screw feed 3. The ground fish is supplied from the grinder 4 to the screw mixer 6 by the screw feed 5. In the screw mixer 6, a mixture of carbohydrates (wheat starch), pigment, gluten and vitamins from the hopper 7 is mixed with the ground fish, and the resulting mixture is passed through a buffer mixer tank 8. The mixture that has entered the tank 8 is pumped by the
And emulsified there. The emulsion passes through a suction silo 11 and a vacuum tank 12 which are degassed at a pressure of 0.7 bar. The degassed emulsion is supplied to an extruder 14 by a pump 13,
Extrude a 12mm emulsion rope. The belt conveyor 15 transports the degassed emulsion ropes through three heating sectors of a microwave oven 16 operating at 915 MHz. Remove water vapor from oven and concentrate. The coagulated rope leaving the oven 16 is cut into pellets by a cutter 17 and the pellets are conveyed by a belt 18 to a dryer 19 having seven sectors. In the first three sectors of the dryer 19 hot air is passed upward through the perforated belt, and in the subsequent four sectors the perforated belt 2
Pass hot air downward through 0. In the last sector, cool air is dried between the pellets, followed by sieving, cooling and bagging the partially cooled pellets.

[0033]

Example 1 Formation of an Emulsion To make an emulsion for feeding to a microwave oven in the apparatus described in Figure 1, the following materials are used: 100 parts by weight of raw whole herring gluten 5. 13 parts by weight Wheat starch 4.30 parts by weight Vitamin mixture 0.08 parts by weight Colorant 0.02 parts by weight Micrographs of the raw fish and carbohydrate emulsion thus produced are shown in FIGS. As can be seen from this figure, the emulsion contains oil droplets between 1 and 50 μm in size. From FIG. 4 as a comparison, it can be seen that such an emulsion does not occur even when the raw fish is ground and shredded as in the Hamre method (described above).

The emulsion flow at 500 kg / hr is subjected to 75 kW microwave irradiation at 915 MHz, pelletized and dried to a moisture content of 7%. The resulting bait pellet shows little lipid leakage.

[0035]

Example 2 Lipid Leakage Test In order to prove the stability of fat in the product of the present invention, the following pressure test was performed. Samples of the milled bait pellets formed by the process of the present invention, and a sample of a well-mixed blend of fishmeal and fish oil were pressurized in a specially designed test apparatus. Each sample is composed of 400 g of material with a fat content of about 43% of the dry weight.

The following results were obtained.

[0037]

[Table 1]

This result indicates that the product of the invention has no detectable lipid leakage at pressures up to 17 bar, while the comparative mixture has, under the same conditions, more than 33% of the original fat content It clearly shows that much has been lost.

[Brief description of the drawings]

FIG. 1 is a schematic layout of an apparatus for performing the method of the present invention.

FIG. 2 is a micrograph of the emulsion used in the method of the present invention.

FIG. 3 is a micrograph of the emulsion used in the method of the present invention.

FIG. 4 is a photomicrograph of a mixture of raw, non-emulsified fish that has been ground and chopped.

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Claims (20)

[Claims] 1. A method for producing a nutritional composition, comprising emulsifying a material containing raw fish, and heating and / or drying the obtained emulsion. 2. The method of claim 1, wherein the emulsion is heated to coagulate proteins therein. 3. The method according to claim 2, wherein the coagulated emulsion is further dried.
The method described in the section. 4. The method according to claim 2, wherein the emulsion is heated by electromagnetic radiation, preferably by microwave radiation. 5. The method according to claim 1, wherein the emulsion is heated and dried by using a disk dryer. 6. The method according to claim 1, wherein the drying is performed using a belt drier, a spray drier, a flash drier or a vacuum drier. 7. A step of extruding the emulsion into a rope, optionally degassing the emulsion, heating the formed emulsion to coagulate the protein contained therein, drying the coagulated emulsion, and a dried emulsion. The method according to any one of claims 2 to 4, comprising a step of subdividing the powder into pellets. 8. The method according to claim 1, wherein said material to be emulsified includes raw fish and gluten.
A method according to any of claims 7 to 13. 9. A nutritional composition formed by emulsifying and coagulating and / or drying a mixture comprising raw fish. 10. A nutritional composition comprising fish oil and coagulated fish protein substantially free of muscle fiber fragments greater than 200 μm in length. 11. The method according to claim 9, further comprising a plant storage protein, preferably gluten.
Item 11. A feed or a nutritional composition according to any one of Items 10. 12. The feed or nutritional composition according to claim 9, wherein the lipid content is 15 to 55% by weight on a dry weight basis. 13. The feed or nutritional composition according to claim 9, wherein the water content after drying is 2 to 10%. 14. The method according to claim 9, wherein said mixture is subjected to incomplete vacuum after emulsification.
14. The feed or nutritional composition according to any of paragraph 13. 15. The feed or nutrient composition according to any of claims 9 to 14, wherein the final density exceeds 1 g / ml. 16. An apparatus for producing a nutritional composition, the apparatus comprising: a grinder arranged to produce a ground mixture of raw fish; and a grinder for converting the ground fish mixture to an emulsion. An apparatus comprising: an emulsifier arranged; a dryer arranged to dry the emulsion; and, optionally, a heater arranged to solidify the emulsion before drying. 17. Apparatus according to claim 16, wherein the heating step is performed by electromagnetic radiation, preferably by microwave radiation. 18. The apparatus according to claim 16, wherein the heating and drying steps are performed by a disk dryer or a hot air dryer. 19. The apparatus according to claim 16, wherein the drying step is performed using a hot air drier, a vacuum drier, a spray drier, or a flash drier. 20. The apparatus according to claim 16, wherein the emulsion is directly transferred to a disk dryer, hot air dryer, spray dryer, flash dryer or vacuum dryer.