RU2061385C1 - Method of food meal preparing - Google Patents

Abstract

FIELD: food industry. SUBSTANCE: coarsed or ungrounded raw made of an aqueous organisms is dried up to the residual moisture 7-9%, cooled to 20-30 C, ground up to the content 40% (not less) of total grist fractions of diameter below 3 mm, moistened to 9-13 degrees and stirred. Then heat treatment of mass is carried out at stirring up to humidity 3.5-9% at 90-110 C followed by pressing under pressure 250-400 kg/cm.sq at simultaneous granulation. EFFECT: improved method of preparing.

Description

 The invention relates to the fishing industry.

 A known extraction method for producing feed flour (V.I. Zaitsev, I.V. Kizevetter and others. "Technology of fish products", p. 515, M. 1965) by drying the raw material, preparing it for extraction, extracting fat with a solvent, distillation of the solvent from miscella and meal, refining of fat, drying, grinding and cooling of flour.

 Significant disadvantages of the method are: the complexity of production, the use of a flammable, explosive, toxic solvent (gasoline, dichloroethane, etc.), environmental pollution, high consumption of steam, electricity, metal consumption, the need and complexity of solvent recovery and refining of fat, the inability to use the method on floating fish stocks, the deterioration of working conditions, safety and industrial hygiene, etc. Therefore, the method is not widespread in industry.

In Russia there is only one extraction workshop for the production of feed sprat from sprats in the city of Astrakhan. A known method of producing feed flour by direct drying ("Collection of technological instructions for processing fish", t.2, S. 271-280, M. VNIRO, 1980), which consists in the fact that the raw materials are dried under a small vacuum or atmospheric pressure , with stirring and a temperature of 80-90 ^o C to a residual moisture content in the dryer of 7-10%, then the dryer is pressed on a hydraulic press.

 The main disadvantages: in direct drying plants it is impossible to process fatty raw materials, they are used only in the processing of lean raw materials; direct drying technology does not provide the product with the required frequency (degreasing), the flour is produced in the form of large briquettes and does not comply with GOST in terms of fineness of grinding, frequency of action, low productivity, high cost of manual labor, metal consumption, etc.

 In recent decades, direct-drying plants have been dismantled everywhere and replaced with press-drying plants.

 There is a known press-drying method for the production of fodder flour with and without the use of prepress broths (Instructions for the preparation of fodder fish meal. "Collection of technological instructions for processing fish", t. 2, p. 271-280. M. VNIRO, 1980. In .M. Chupakhin "Equipment for fish processing enterprises, pp. 265-309, M. Pishchepromizdat, 1964).

 The press-drying method using prepress broths consists in boiling the raw materials in a varilnik, squeezing the fat-containing broths, drying the dense protein mass (pulp), cooling and grinding the finished feed flour.

 Prepress broths are clarified on vibrating screens or horizontal centrifuges, evaporating up to 50% of the content of dense substances in vacuum-evaporation plants. One stripped off broth is added to the pulp before drying. The flour is cooled and finely ground.

 The main disadvantages of the method: the complexity and cumbersome production, the need for a large production area, the need to purchase, install the necessary additional equipment (vibrating screens, horizontal centrifuges, mud and grease separators, vacuum evaporation plants, etc.).

 In addition, as the practice of operating modern and foreign press-drying plants equipped with one-, two- and three-stage vacuum-evaporation plants has shown, they do not give the necessary effect when working on salty raw materials, and they also differ in energy intensity and complexity of process control (see. Report on research "Improving processing methods, expanding the range and improving the quality of fish products", pp. 9-10, M. Smolenskaya, 14 VNITITsentr, 1988).

 Moreover, during operation, these devices have to be periodically stopped for the purpose of cleaning, which is a very time-consuming and inefficient process.

 Therefore, in practice, we do not have enterprises working with the full use of prepress broths, and the production of fodder flour with partial use of broths is very insignificant.

 Over the past decades and at present, more than 80% of the total production of fodder flour is produced by the domestic industry by the press-drying method, without the use of prepress broths.

 This method was adopted by us as a prototype.

The production of feed flour by a press-drying method without the use of broths consists in the fact that the raw materials are "boiled" in varilnik with hot and dead steam for 10-20 minutes to a temperature of 85-100 ^o C. From varilnik boiled fish mass is fed into a press to squeeze prepress broths and separation of the fish mass into fatty (broths) and dense part (pulp). The residual moisture content in the pulp, after pressing, should be no more than 55%
In accordance with the requirements of the current GOST, the finished feed flour should have a moisture content of not more than 12%. Therefore, the pulp is subjected to drying in the dryers during which the moisture of the pulp is reduced from 50-55 to 10-12%
With proper conduct of the drying process of the beet pulp, its temperature during progress in the dryer varies from 80 to 90 ^o C, and at the outlet of the dryer is 60-80 ^o C. The fineness of the flour grinding is provided by the current GOST. Therefore, the pulp after drying (dried) is subjected to grinding. The finished flour is cooled and calibrated (see V.P. Zaitsev, I.V. Kizevetter and others. "Technology of fish products", p. 507, M. 1965. "Collection of technological instructions for processing fish", v.2, S. 271-277, M. VNIRO, 1980).

 In some enterprises, broths are not immediately thrown out (after being squeezed out in a press) into the sewer, but first on a vibrating screen to isolate and dispose of dense particles. The broths clarified (on a vibrating screen and a horizontal centrifuge) are degreased on mud and grease separators, after which they are lowered into the sea or sewage system.

 Despite the widest distribution of this method in domestic industry, it is obsolete, unpromising and the problem of replacing it with a more advanced method for the fishing industry is very relevant.

The most significant disadvantages of the method (prototype) are as follows:
1. Fat-and-flour enterprises are sources of intense and dangerous environmental pollution. For example, fat-and-flour enterprises only in the Far East annually dump about 500,000 tons of prepress broths into the sea, which, when reacted with various elements of sea water, form compounds toxic to fish and marine animals. Compared with fresh, seawater self-cleaning is much slower (less absorption capacity).

 Behind floating fat-and-flour bases, muddy-white plumes of waste from the production of fodder flour stretch for kilometers.

 In conditions when the threat of an environmental crisis looms over a person, the further operation of press-drying plants is immoral.

 In 1992, at the Finland Palace in Helsinki, ministers of 12 states and a representative of the European Society signed the New Baltic Sea Basin Environmental Convention.

 The accompanying documents indicate 150 enterprises and associations that are sources of pollution ("hot spots"). The main pollutants are recorded including ours.

 At the same time, Danish Minister for the Environment, P. Miller, emphasized: "The main thing today is to make a breakthrough in solving the technological problems of the struggle for environmental protection." The solution to the technological problem of creating an environmentally friendly production of fodder flour is consonant with this call and is very important for maintaining the purity and productivity of the waters of the oceans.

 2. The existing method does not ensure the achievement of the required purity of feed flour.

The purity of the product is determined mainly by the degree of removal of fat from it. In accordance with GOST 13893-68; and 2116-71; 2116-82, the residual fat content in feed fish meal should not exceed 10%. However, in practice, most fish meal, for decades, is produced in excess of the specified indicator. The technology (prototype) adopted by the fishing industry does not provide the required degreasing of the produced fish meal for the following reasons:
a) using a "short-term (10-20 min) boiling" of raw materials in a varion tank at relatively low temperatures (85-100 ^o C) it is not possible to completely destroy the structure of fat-containing cells of fish raw materials and "digest" the bulk of the fat from it;
b) not all of the broth is squeezed out of the boiled fish mass in the press, but only 45-50% of it (see VNIRO Instructions above).

 Therefore, 50-55% of the broth, as well as the fat contained in it, remains in the pulp after pressing. During the subsequent drying of the pulp and the removal of moisture, the fat remaining in the undamaged cells and not squeezed from the pulp broth remains in the finished feed flour.

 Therefore, not only in the processing of fatty, but also medium-fat raw materials, the fat content in the resulting feed flour, as a rule, exceeds the standard. Flour contaminated with fat is unstable during storage and transportation. It is rapidly oxidized, self-heating and even self-igniting. The quality of the flour decreases sharply, and with spontaneous combustion, the flour becomes completely unusable. Flour with a high content of oxidized fat is unsuitable for feeding to fur animals, etc. In the process of fat oxidation of flour in the holds of transport vessels, fatal concentrations of carbon monoxide and carbon dioxide also accumulate. There were also accidents with maintenance personnel, with a fatal outcome (for example, on the m / v “Kuloy”).

 Therefore, without developing a more advanced technology for the degreasing of fishmeal, progress in this sector of the fishing industry is conceivable.

 3. The adopted method (prototype) adopted by the fishing industry does not provide high yields of fishmeal, because it is characterized by large losses of acute deficiency protein, fat and other substances in the production process.

 We have already noted that only the fishing industry of the Far East producing fodder flour annually dumps into the sea about half a million tons of prepress broths containing at least 20 thousand tons of pure protein, as well as a large amount of fish oil.

 Due to the huge losses of animal protein, fish processing enterprises receive very low yields of scarce feed flour.

 This implies the high cost of production of fishmeal and the difficulty in satisfying these products from agriculture and fur farming.

 On average, the yield of fodder fishmeal at the enterprises of the Far East is 16-17% (of the raw material directed to processing). Those. in the production of feed flour, the biological resources of the World Ocean, already undermined by the fishery, are used extremely irrationally, irresponsibly. Russia demonstrates the malicious wastefulness of the resources of the oceans.

 Therefore, the acute problem of today is the development of resource-saving, waste-free technology for obtaining fodder fish meal.

 4. The existing method of production does not provide high quality produced fodder flour. The most important (main) indicator determining the quality of feed meal is the content of animal protein in it.

 The protein content of protein in feed meal should be at least 48% (see GOST 2116-82). However, this industry sometimes does not reach this low indicator due to large losses of protein with outgoing broths (up to 30-40%). It should be emphasized that with prepress broths the most valuable, easily digestible group (fraction) of water-soluble proteins - albumin - is dumped into the sea. And in the bagasse, after squeezing the broths, less valuable proteins of globulins and others remain (salt-soluble, acid-soluble, etc.).

 Therefore, after drying the pulp, the finished feed meal is of poor quality, not only because of the low protein content, but also because of the depletion of the protein remaining in the product with the most valuable fraction of albumin.

 In addition, water-soluble vitamins, fat-soluble vitamins A and D, etc. are irretrievably lost with broths.

 5. Inefficiency and inconsistency of the results of technological operations of drying pulp and grinding of finished feed flour.

We noted above that pulp after squeezing the broth contains 50-55% moisture. Ready flour, in accordance with GOST, should have a moisture content of not more than 12%
Therefore, in the prototype, the pulp is dried (to remove excess moisture) to a residual moisture content of 10-12%
However, with the removal (evaporation) of moisture, the fat content in the dried material increases and at a moisture content of 10-12%, the fat content in the flour increases (compared to pulp) by 1.5-2.0 times.

 Therefore, achieving the production of flour with a standard moisture content, we increase its contamination with fat, and sometimes we produce a product that does not meet the requirements of the same standard, but with a fat content (not higher than 10%). What kind of additional operations for the degreasing of the finished flour, the existing method does not provide.

 The pulp drying process itself is associated with high consumption of steam and electricity.

 A similar situation occurs when grinding flour. Flour by grinding fineness must comply with current GOST.

 However, during the grinding process, the total surface of the flour particles sharply increases, which facilitates the intensive occurrence of oxidation processes in fat films on a wide-branched grinding surface.

 The oxidation of fat is accompanied by the process of self-heating and self-ignition of flour and an intensive decrease in its quality. The product becomes unstable during storage and transportation.

 The problem solved by the invention, the creation of an environmentally friendly, resource-saving, waste-free method for producing fodder flour from fish and non-fish fishing objects; ensuring high yields, quality and purity of the product.

The invention consists in the following: coarsely ground or unmilled raw materials are dried to a residual moisture content of 7-9%, cooled to 20-30 ^o C and ground to a flour; while the degree of grinding should be such that the combination of all fractions with a diameter of up to 3 mm should be at least 40% of the total grinding volume; the grinding is moistened up to 9-13%, mixed for conditioning by humidity, and then subjected to heat treatment with blank steam while stirring, bringing the material temperature to 90-100 ^o C, and humidity to 3.5-9.0% and then pressed under a pressure of 250- 400 kg / cm ² with simultaneous granulation of the product.

 The need for this sequence in the first three technological operations is as follows. Without resorting to overcooking, a deeper destruction of the cellular structure of the raw material (without the formation of broths) can be achieved by mechanically grinding it. However, raw fish contains up to 20% animal protein (crude protein) and up to 70% moisture. Thanks to this, raw has high plastic properties.

 It is not possible to achieve deep destruction of the structure of fat-containing cells, highly plastic protein bodies, because in the process of grinding, the material will lump, aggregate, and its cellular structure will only be deformed, but not destroyed.

 Therefore, in the recommended technical solution, the first technological operation is not cooking, but drying of the feedstock.

 As a result of drying, a double effect is achieved: firstly, due to the removal of moisture, the plasticity of the raw material is reduced, and secondly, in the process of drying a raw material having high humidity (up to 70%), thermal destruction of cell-impermeable cell membranes of the material occurs under the influence of heat, steam moisture) and the mechanical effects of the mixer.

But at the outlet of the dryer, the temperature of the material is 70-80 ^o C. In order to reduce this plasticity factor, the dryer must be cooled. In the second process operation, the temperature of the dried is reduced to 20-30 ^o C.

 Thanks to the implementation of the first two operations, the raw material acquires a new set of properties (attributes): fragility, reduced ductility, partial destruction of cells, etc.

The emergence of a new set of properties makes it possible to successfully carry out the third technological operation by mechanical destruction of the cell structure by grinding raw materials in a mill or disintegrator. The destruction effect is also enhanced by a combination of thermal and mechanical methods of opening the cellular structure of the material. Raw materials are usually dried in steam and drum dryers equipped with steam shirts and mechanical stirrers. It is possible to supply deaf steam to the agitator rotor. During the advancement in the dryer, the temperature of the fish mass ranges from 80 to 100 ^o C. The residual humidity is 7-9%. The cooling of the dried fish is carried out in cooling drums, in which the cold sea water is fed into the stump space.

 By the fineness of grinding, one can judge the degree of opening of the cellular structure of raw materials. The fineness of grinding (particle diameter of the crushed drying) is determined by the sieve method, and the number of opened cells by the method of instant agitation of the grinding with ether (according to Rzhekhin).

 In crushed dried, the combination of fractions with a particle diameter of not more than 3 mm should be at least 40% of the total volume (weight) of grinding.

 External and internal properties of objects obtained by the existing method (prototype) and a new technical solution have significant differences.

 External differences: in the prototype, the mass emerging from the varion mass has a semi-fluid flowing consistency. The volume of boiled fish mass exceeds the weight of the feedstock by 1.5-2.0 times. In the claimed technical solution, finely ground dried outwardly looks like finished feed flour: relatively homogeneous mass, solid, crumbly, low moisture content, semi-finished product is half as much as the original raw material, etc.

 The internal properties of objects are also significantly different.

In the prototype, the mass after cooking consists of two phases, liquid and solid. Therefore, the valuable ingredients of the feedstock (proteins, fats, vitamins, etc.) are found both in the liquid (broth) and solid (pulp) phases. For the production of feed flour in the prototype use a dense part of the boiled mass, which contains only part of the nutrients found in the feedstock. Broths have the properties of liquids, and the dense part has the properties of ointment-like protein substances (high humidity, ductility, etc.). The temperature leaving the mass variculum is 80-90 ^o C. In the claimed technical solution, the chilled and finely ground drying is like a concentrate of all useful (nutritious) ingredients contained in the feedstock (fish, etc.).

That is, all protein, macro- and microelements; vitamins and other biologically active substances are completely and without loss transferred to the composition of the finely ground dried, from which it is supposed, after degreasing, to obtain complete fodder using non-waste technology. Shredded dried has a low temperature (20-30 ^o C), low humidity (7-9%) and low ductility.

 By specially set experiments it was proved that by grinding pre-dried and cooled krill and maurolikus on an electric mill it is possible to destroy the cellular structure of their tissue by 70-80%.

 That is, thanks to the new technology of destruction of the cellular structure of raw materials, the primary effect is obtained in the claimed technical solution. A deep destruction of fat-containing cells was achieved, the formation of broths was prevented, the foundations of a waste-free resource-saving production method were laid. All the useful ingredients of the raw materials are transferred to the crushed dryer without loss. However, a full meal should be as free as possible from fat.

 It is still not possible to achieve almost quantitative squeezing of dried fat from dried cell membranes, which is impervious to it, by pressing, since the film released from the destroyed fat cells is held on its widely branched (external and internal) surfaces by force and molecular by the field.

 Therefore, moisture-heat treatment of crushed dried is introduced.

 For this, the semi-finished feed meal in a special apparatus is treated with heat and moisture with continuous stirring.

 The purpose of this operation is to cause certain physicochemical changes in the structure of the particles, leading to a weakening of the cohesion of fat with the surfaces of each particle and to create optimal structural and mechanical properties for the effective removal of fat during pressing of the material.

Moisture and heat treatment consists of two stages. The first stage: moistening up to 9-13% and quick heating of dried up to 40-60 ^o C (steam injection).

 The process proceeds with stirring for 8-10 minutes. At the end of the steam-water injection, the mass is stirred for another 5-7 minutes.

 The first stage is a kind of conditioning of the crushed dried milk in terms of humidity and provides a uniform course of changes in the properties of the material in the second stage.

The second stage is the processing of the moistened material with heat (dead steam) supplied to the stump space of the apparatus, in a layer defined by height and mixed with a mechanical stirrer to bring its moisture to optimal values when pressing (humidity 3.5–9%), temperature (90-110 ^o С ) The time of moisture-heat treatment is 60-90 minutes.

 The processing of finely ground dried water and heat takes place in special apparatuses and in specific conditions related to the design of the process, the nature of heating through the walls of the steam jacket, mixing of the material under mechanical influences of the mixer, with the peculiarities of drying occurring at a relatively high height (200-400 mm) and the phenomena of "self-steaming."

 The essence of moisture-heat treatment and the main physico-chemical changes occurring during this technological operation.

 Dried and finely ground dried is a dispersed system consisting of two parts: a gel hydrophilic, protein part and a liquid hydrophilic part-fat, located on the widely developed inner and outer surface of a part of the crushed material.

 The properties of crushed fish dried are close to the properties of protein substances, which make up a large proportion of the gel part. These properties include the ability of particles to stick together when moistened, absorb moisture, swell, connect to each other during mechanical processing (stirring with a stirrer) into large particles, aggregates in which primary particles cannot be distinguished, etc.

With a slight addition of water to the crushed dryer, the gel part of it swells, causing a number of significant changes:
a) a change in the ductility of the gel part;
b) aggregation of particles with each other;
c) chemical and biochemical changes in the dryer.

 During swelling, the microscopically homogeneous state of fat is disrupted and it is released in the form of small, and then larger droplets. The more water is added, the greater the release of fat to known limits, which is explained by the following phenomenon. Fat can be released due to selective wetting of the external and internal surfaces of the particles with water and due to the squeezing of fat by swelling forces from the channels (cavities) in which it is located, both of which are very closely related. In other words, when water is added, water molecules are bound by the force molecular field with the release of the corresponding sections from the fat molecules located on them. The more water is added, the greater part of the molecular force field is occupied by water; the less frequently it remains occupied with fat; the greater the number of fat molecules that remain outside the action of a force molecular field; the lower (weaker) the fat becomes bound by the dryer.

 When water spreads on the outer surface of each particle, in addition to hydration of the surface micelles, water is simultaneously absorbed - volumetric swelling of particles, in which water penetrates into its thickness and moistens its entire widely developed inner surface, displacing fat, both on the outer and the the inner surface of the particles.

 Therefore, as a result of moistening the crushed dried, the surface layers are always enriched with its fat. In addition, as a result of wetting, a part of the dried glue sticks together (aggregation), which leads to a decrease in the free surface, because at the points of contact and bonding of the particles, the surface is bonded, which ensures the displacement of fat from this part of the surface.

 Therefore, due to the moistening (up to 9–13%) of the crushed dried fruit, fat is displaced from the external and internal surfaces and the bond of fat with each particle of the processed material is weakened.

 However, a humidified dryer cannot yet be pressed, as it has high ductility and at low pressures it will crawl out of the press without separating fat.

 In the second stage of moisture-heat treatment, as a result of heating (dead steam), drying and mechanical action of the agitators, the aggregates formed in the first stage are disaggregated (decomposed), while the particles are densified. The internal structure of the individual parts included in the units is also changing.

 A rupture of some of those valuable dried cells that have been preserved during grinding occurs.

 The rupture of cells during moisture-heat treatment occurs under the mechanical influence of mixers, due to a decrease in the strength of cell membranes under the influence of water and heat. Water acts most strongly, as with greater moisture, cell rupture increases. Significant compaction of particles in the second stage occurs due to a) a decrease in humidity; b) thermal denaturation of protein substances; c) some separation of fat with its release on the surface of the particles. There is a change in the primary structure of dried with the formation of the secondary structure of the material (enlargement of particles, cell breakdown, compaction of particles, reduction of plasticity, etc.).

Upon reaching a moisture content of 3.5-9% and a temperature of 90-110 ^o C, we achieve the desired, optimal plasticity of the material. The pressing of a material with optimal ductility and the necessary structural and mechanical properties is carried out at high pressures (200-400 kg / cm ² ), which provides deep fat extraction (83-97%).

At a temperature of 90-110 ^o With there is a sharp decrease in the viscosity of fat and its surface tension, which also facilitates the extraction of the latter. The bonding of fat by the force molecular field of the particle surfaces during moisture-heat treatment is reduced, firstly, due to the weakening of intermolecular forces when heated and, secondly, due to a decrease in the surface of the particles when they are enlarged.

 Without performing the necessary technological operations, it is not possible to almost quantitatively squeeze out fat and obtain high yields of flour enriched with protein and biologically active substances.

 Moisture, temperature and structure of the prepared material are three factors that determine the depth of compression of fat by pressing. Deviation from the optimum humidity in the direction of increase (more than 9%) causes the material to creep out of the press, while drying the material (below 3.5%), it is difficult to deeply squeeze out fat and obtain dense briquettes of flour. The optimum humidity should be lower than the humidity at which creep of material from the press is observed, and at that at which friable briquettes of flour are obtained (the material is not pressed).

In our case, with an increase in the temperature of the pressed material above 110 ^o С and a decrease in humidity below 3.5%, the friability of the briquettes of flour increases, the conditions for squeezing the fat deteriorate, the yield of fat decreases and the quality of the flour deteriorates (increase in the fat content in the flour, deep denaturation of protein substances) . With an increase in the humidity of the pressed material above 9% and a decrease in temperature below 90 ^o C, there is a creep of material from the press, a decrease in the pressure of squeezing. As a result, the yields of flour and fat are reduced and the fat content in the finished product is increased.

 The last, final technological operation of the recommended method is the process of removing fish oil from the object.

 In our technological solution, the degreasing of the material occurs not at the beginning of the production cycle, but at the last, final stage of it in the pressing process.

 Nevertheless, the technological operations preceding pressing are aimed at creating optimal conditions for deep degreasing of the product. The drying, cooling, and grinding operations of the raw materials cause the destruction of the bulk of the fat-containing cells, the fat boundness of the fat is reduced by the force molecular field, and the optimal plastic and structural mechanical properties of the material being pressed are ensured.

 Compliance with the specified sequence when performing technological operations allows us to achieve not only basic, but also secondary goals, i.e. get an additional or side effect.

 For example, in the prototype, the pulp is very watered, because contains 50-55% moisture. Therefore, to obtain a standard moisture content of 10-12% flour, in a well-known solution, an energy-intensive and contradictory operation for drying pulp was introduced.

 In the claimed technical solution, in the second stage of the heat-heat treatment, the humidity decreases from 13 to 3.5–9%, and after the fat is squeezed out, the moisture content in the flour is 7–12%, i.e. is within the requirements of the current GOST.

 That is, along with the creation of optimal properties of the material for deep pressing of fat, we simultaneously, in the process of moisture and heat treatment, achieve the standard moisture content of the flour and the operation for drying the pulp (material) with the new technical solution becomes unnecessary.

 Due to the achievement of an additional effect from the pressing of the material (at high pressure), it became possible, in a new technical solution, to exclude the second contradictory operation from the production cycle: grinding dried pulp from beet pulp.

 The sole purpose of this operation, in the prototype, is to obtain feed flour, according to the fineness of grinding, corresponding to the requirements of GOST. However, when pulp is crushed, the external and internal surfaces of the product particles sharply increase. This leads to an increase in its oxidation lability. During storage and transportation, fat is on a wide-branched surface of the product, it is easily and quickly oxidized. In the process of oxidation, a huge amount of heat is generated and the flour undergoes self-heating and even self-ignition. These processes systematically take place in the work of fat-containing enterprises.

 At the same time, the quality of flour decreases rapidly, and when ignited, the flour becomes completely unusable.

 In order to make the feed flour more stable during storage and to keep its high quality to the consumer, at advanced foreign enterprises, the feed flour obtained by the press-drying method is granulated. Those. flour is not produced in bulk, but in the form of granules.

 During the granulation process, a dense, poorly permeable film for oxygen of air is formed on the surface of each granule, which makes the product more stable during storage. Moreover, the bulk weight of the granules exceeds that of conventional flour (in bulk) by 1.3-1.4 times. The increase in bulk weight allows more efficient use of cargo holds and reduce the cost of transporting flour. In addition, granulation of flour ensures the creation of safety conditions necessary for the operating personnel (see the description of the prototype). At the whirlpool “Soviet Russia” in the years 60-70, whale feed meal was partially produced in granular form. For granulation of flour, imported Matador press granulators were purchased and installed. However, the release of all flour in granular form was not ensured due to the lack of a free production site and the lack of press granulators.

 In the new technological solution, for the implementation of the above problem, additional production facilities and equipment are not needed. For this, a granulation unit is mounted on the screw press and the process of degreasing the flour proceeds in parallel with its granulation.

 The domestic industry also produces special granulation presses G-24, which have the following advantages: the production of strictly calibrated granules of a given shape and size; creating a uniform flour structure; the design of the screw shaft and granulation unit provide an additional increase in pressure in the press, which has a positive effect on the degree of extraction of fat and increase the productivity of the press.

 Thus, when implementing a new technical solution, there is no need for a technical operation for grinding fodder flour and ensures its release in granular form without additional equipment and occupation of additional production area.

EXAMPLE 1
Pollock, containing 7% fat and 70% moisture, in an amount of 2 kg was coarsely ground and dried. In the drying process, the temperature of the raw material changed from 80 to 90 ^o C. At the outlet of the dryer, the raw had a humidity of 9% and a temperature of 80 ^o C.

The dryer was cooled to 30 ^o C and sent for grinding to an electric mill (20 minutes). An average sample weighing 200 g was taken from the grinding. Using a sieve with a hole diameter of 3 mm, grinding fractions with a diameter of less than 3 mm (pass through a sieve) were separated from the sample, the total weight of these fractions was 100 g (or 50% of the total grinding weight).

 By instantly shaking up a sample of the material with ether (according to Rzhekhin) it was established that as a result of drying, cooling and grinding, 83% of fat-containing raw material cells were opened.

The grinding, with stirring, was moistened and warmed up using a steam-water spray (8 minutes), and then another 5 minutes. mixed for even distribution of moisture in the material (conditioning by humidity). The grinding after wetting had a temperature of 60 ^{° C.} and a humidity of 13%. Next, the material was heat treated with blank steam (heating through a steam jacket) with stirring in a layer 25 cm high for 60 minutes.

After heat treatment (before pressing), the moisture content in the material decreased to 9% and the temperature increased to 90 ^o C.

The semi-finished product was pressed under a pressure of 250 kg / cm ² . As a result of pressing, a high yield (400 g or 20%) of high-quality whole feed meal (protein content of 70% fat, 6% humidity, 10%) was achieved.

 The fat yield was 116 g. Or 83% of its initial content in raw materials.

EXAMPLE 2
Pollock, containing 7% fat and 70% moisture, in an amount of 2 kg was coarsely ground and dried. In the drying process, the temperature of the raw material changed from 85 to 90 ^o C, and at the outlet of the dryer was 60 ^o C. The dried sack contained 7% moisture.

The dryer was cooled to 20 ^{° C.} and subjected to grinding in an electric mill for 20 minutes. Using the sieve method, it was found that the total grinding weight with a particle diameter of less than 3 mm was 55% of the total grinding weight.

The number of opened cells (according to Rzhekhin) was 85%
The grinding was humidified with a steam-water spray and conditioned by humidity. At the same time, the grinding humidity increased to 9% and the temperature to 50 ^o C. Then the material was subjected to heat treatment in a layer with a height of 20 cm, for 20 minutes, with continuous stirring. Before pressing, the material contained 3.5% moisture, and its temperature reached 110 ^o C.

The fat was squeezed out at a pressure of 400 kg / cm ² . As a result of pressing, a high yield (440 g or 22%) of high-quality feed meal (protein content of 74% fat, 7%) was achieved. The fat yield was 110 g or 80%
EXAMPLE 3
2 kg of unmilled mavrolikus were sent for drying (fat content 14.8, moisture 67%). In the drying process, the temperature of the raw material ranged from 82 to 89 ^o C, and at the exit from the drying was 60 ^o C. Drying time 85 minutes. Dried contained 7% moisture. The dryer was cooled to 20 ^o C and subjected to grinding in an electric mill for 20 minutes. An average sample was taken from grinding.

 By the sieve method, it was found that the weight of grinding fractions with a particle diameter of less than 3 mm (passage through a sieve) amounted to 60% of the grinding weight; by instantly agitating the sample with ether (according to Rzhekhin), it was found that as a result of drying, cooling and grinding, 70% of the fat-containing cells were destroyed.

The grinding was heated and moistened with stirring with the help of a steam-water spray and conditioned by humidity. The grinding humidity reached 9% and a temperature of 60 ^o C. Then the material was subjected to heat treatment for 90 minutes (layer height 30 cm). Before pressing, the moisture content of the material was 3.5% and a temperature of 90 ^o C.

The pressing proceeded under a pressure of 250 kg / cm ² . As a result of these operations, a high yield of high-quality flour was achieved (420 g or 21%). Whole feed meal contained 72% protein. The fat yield was 257 g or 87%. The fat content in the flour was low (9%); The product met the requirements of GOST.

EXAMPLE 4
Krill, containing 2.2% fat and 71% moisture, in an amount of 2 kg was sent for drying.

In the drying process, the temperature of the raw material decreased from 80 to 90 ^o C. At the outlet of the dryer krill dried had a temperature of 75 ^o C and contained 8% moisture.

The dryer was cooled to 25 ^o C and subjected to grinding in an electric mill. As a result of grinding, the combination of grinding fractions with particles less than 3 mm amounted to 59% of the total grinding mass, and the number of opened cells reached 85%. The grinding was subjected to steam-water spray and conditioning by humidity. As a result, the grinding humidity reached 10% and the temperature rose to 55 ^o C.

 Wet and heated grinding was heat treated for 70 minutes with blank steam in a layer 25 cm high.

Before pressing, the semi-finished product had a temperature of 100 ^o C and contained 5% moisture. Pressing was carried out under a pressure of 220 kg / cm ² .

As a result of pressing, 430 g of feed flour was obtained. Those. her yield was high 21.5%
The flour was characterized by a high protein content of 70%
In addition, 30.8 g of fat (70%) was obtained. The fat content in the finished product was 4%
Thus, TINRO has developed a new, progressive, resource-saving technology that allows complex and waste-free processing of all types of raw materials of water origin to produce high-quality whole feed meal and fish oil.

 As a result of research conducted in laboratory and semi-production conditions, it was found that the proposed method is devoid of all the above disadvantages inherent in the prototype.

 When working with the new technology, environmental pollution is prevented, and the highest yield is achieved.

 For example, the yield of flour from Mavrolikus is 20-25% instead of 10-14% when using the press-drying method.

 That is, thanks to the new technology, the production of flour from this type of raw material increases in comparison with the prototype 1.5-2.0 times, and the consumption of raw materials per ton of flour decreases, respectively, from 7.14-10.0 (prototype) to 4, 54-5.0 tons.

 When processing traditional types of raw materials (waste from cutting, krill, etc.) due to the exclusion of losses of water-soluble proteins, the yield of flour according to the developed technology increases to 22% instead of 16-17% (prototype).

 The introduction of the developed technology will allow only at the enterprises of the fishing industry of the Far East to additionally produce about 50,000 tons per year of high-quality feed flour, without additional consumption of raw materials.

 Along with fodder flour, fish oil will be produced, the yield of which reaches 87-95% of its initial content in raw materials, instead of 15-20% currently obtained by industry. Due to the preservation of the most valuable water-soluble proteins, the protein content in the feed meal rises from 45-60 to 70 or more, and ensuring deep raw skimming reduces the lipid content in the finished feed meal to 7-10%. There is the possibility of releasing the feed meal in granular form, increasing stability feed flour, improved safety conditions and industrial hygiene at fat-flour enterprises.

 The technological scheme of the proposed method is simple, consists of only five basic technological operations. For the installation of the installation does not require large production areas. Almost all equipment for the new line can be manufactured in domestic factories. Production lines can be performed in both ship and onshore versions.

 The research results were heard and approved by the Scientific Council of TINRO, the Technical Council of the VRPO "Dalryba", a conference of specialists of the domestic fishing industry.

Claims (1)

A method of producing fodder flour, comprising heat treatment, pressing, drying and grinding of raw materials from aquatic organisms, characterized in that the drying of coarsely ground or unmilled raw materials is carried out to a residual moisture content of 7-9%, then it is cooled to 20-30 ^o C, ground to no less than 40% of the total grinding of fractions with a diameter of up to 3 mm, moisten up to 9-13% and mix, and heat treatment of the mass is carried out with stirring to a moisture content of 3.5-9% at 90-110 ^o C, after which they are pressed under pressure 250 -400 kg / cm ² with simultaneous granules tion.