RU2584442C1 - Method for production of dry-cured fish - Google Patents

Abstract

FIELD: food industry.

SUBSTANCE: prepared fish is salted, washed in salt solution, rinsed with water and maintained for draining excess water. Drying is carried out for 10-15 minutes at temperature of 18-33 °C and speed of heat carrier from 3 to 6 m/s. Main process is carried out at temperature of 18-33 °C and speed of heat carrier 2-3 m/s, including continuous initial phase duration from 3 to 8 hours and combined periods of equal duration, which number depends on required final moisture content of ready cured fish. Each combined period consists of drying phase and relaxation phase. Duration of relaxation phase is increased from first combined period to last combined period, and duration of drying phase is reduced from first to last combined period. During relaxation phase heating devices are switched off, heat carrier speed is decreased to 0.5-1.0 m/s and air fed into chamber with temperature lower by 3-10 °C and with relative humidity higher by 5-30 %.

EFFECT: invention allows to reduce power consumption, higher quality of products manufactured.

6 cl, 14 dwg, 4 ex

Description

The invention relates to the food industry and can be used in the manufacture of dried fish products.

A known method of drying using waves of various physical nature (Pat. RF No. 2464793, publ. 06/01/2011). According to the proposed method, the semi-finished fish are dried in natural and artificial conditions. Under natural conditions, at an air temperature of no higher than 30 ° C, a relative humidity of no more than 30% and an air velocity of 1-5 m / s. Under artificial conditions, they are dried in a preliminary convective-thermal drying chamber, in which the speed of the drying agent is no less than 20-30% higher than in the main convective-thermal drying chamber and, finally, dried in the main convective-thermal drying chamber. Moreover, in the process of natural and artificial drying, the semi-finished product is affected by acoustic waves in the range from 2 × 10 ¹ Hz to 5 × 10 ⁴ Hz with an intensity of at least 100 W / m ² at a distance of 1 m from the emitter, and in the process of artificial drying, it is additionally affected ultraviolet radiation, visible light radiation and infrared radiation. During periods of pauses of drying and disinfection with acoustic radiation, harmful insects and rodents are exposed to acoustic waves in the frequency range from 2 × 10 ¹ Hz to 5 × 10 ⁴ Hz with an intensity of at least 100 W / m ² at a distance of 1 m from the emitter.

The disadvantages of this method include:

- the technical complexity of the dehydration process;

- the use of a coolant with a relative air humidity of less than 30% can lead to overdrying of the surface layers of the fish and inhibition of the rate of dehydration;

- additional costs of electrical energy to ensure that the object is dehydrated by acoustic waves, ultraviolet radiation, visible light radiation and infrared radiation;

- the need to move the dehydration facility through the drying chambers;

- the inability to adapt the existing drying equipment to implement this method of dehydration.

A known method of cooking dried fish (US Pat. RF No. 2444198, publ. 10.03.2012), including butchering fish, ambassador, drying, according to the invention when cutting the fish skinned, and drying the fish is carried out in three stages at a speed of blowing air in the range from 0, 1 to 5.0 m / s, and in the first stage, the fish is dried at an air temperature of 0 ° C to 10 ° C and a relative humidity of 100% for 4-6 hours; in the second stage, dried with dry air with a temperature of from 0 ° C to 10 ° C, for 8-12 hours; at the third stage, drying is carried out with dry air with a temperature from 15 ° C to 30 ° C, until the moisture content in the finished product is not more than 45%.

However, at the first stage, air with a temperature of 0 ° C to 10 ° C and a relative humidity of 100% is used for 4-6 hours. Such thermophysical properties of air do not provide conditions for the evaporation of moisture from the surface of the fish. As you know, the first period of dehydration on the drying kinetics curve is characterized by a maximum speed, in this case, the dehydration rate will not reach maximum values, which leads to an increase in the duration of the whole process.

In the third stage, drying is carried out with dry air with a temperature of 15 ° C to 30 ° C. These conditions of the drying process lead to excessive dehydration of the surface layer and a slowdown in the evaporation of moisture from fish, which also contributes to an increase in the duration of dehydration and an increase in the cost of electric energy.

There is a method of preparing dried fish by salting, soaking, drying and drying, characterized in that, in order to reduce the duration of the process, drying is carried out to 55-60% moisture content in fish meat, and in the process of drying the surface of the product is moistened with water in an amount of 2- 5% of its mass every 3-5 hours (AS USSR No. 1219034, publ. 08.23.1986).

The disadvantages of this method include:

- the need for periodic wetting of the surface of the fish;

- the difficulty of ensuring uniform contact of the entire surface of the fish with water;

- the appearance of defects in appearance as a result of the presence of excess moisture on the surface of the fish;

- increase in the cost of electric energy for the evaporation of added water from the surface of the fish.

- the need for additional mechanization and automation of existing drying equipment to implement this method.

The problem that is solved by the invention is to develop a method free from the above disadvantages.

The technical result to which the claimed invention is directed is to improve the quality of products by reducing appearance defects, reducing the cost of electrical energy.

To achieve the technical result, the production of dried fish is carried out in the following way. Frozen fish is thawed in clean running or changing water with a temperature not exceeding 20 ° C or in air at a temperature not exceeding 20 ° C. The ratio of the mass of fish and water is at least 1: 2. Defrosting is completed when the temperature in the thickness of the body of the fish reaches from minus 2 to 0 ° C. Fish thawed in air is washed with clean running or often replaced water with a temperature of no higher than 15 ° C. Fish thawed in water are not washed. For drying use fish in a split and undivided form. After cutting, the fish is washed thoroughly with clean water at a temperature of no higher than 15 ° C and allowed to drain. The fish ambassador is carried out mixed without cooling or with cooling or acetyl methods until a predetermined mass of salt is achieved in the fish meat. The fish discharged from the salting tank is washed thoroughly in pure saline with a density of 1.14-1.16 g / cu. cm until complete removal of salt crystals and contaminants. Small fish salted in saline is rinsed with clean fresh water. For drying, the fish is strung on metal rods (ramrod) or laid out on sieves (nets). Rinse the fish with clean water before heading for drying. After rinsing with water before loading into the drying chamber, the fish is kept to drain excess water. After loading the fish into the drying chamber or oven, the dehydration process is set. Depending on the type of fish, dehydration occurs when the temperature of the coolant (air) is from 18 to 33 ° C, its relative humidity is from 30 to 60% and the speed is from 2 to 3 m / s. In the first 10-15 minutes, to intensify the drying process, the semi-finished product is dehydrated at the temperature of the main process (from 18 to 33 ° C) and the coolant velocity is from 3 to 6 m / s until the weight loss of the semi-finished product is from 3 to 4%. Further, during the process of drying, the velocity of the coolant is maintained from 2 to 3 m / s. During the drying and drying process, the drying agent is recycled in the drying chamber (furnace). The recycling process is as follows. The coolant that passed through the drying chamber, where heat was transferred to the dewatering object and absorbed part of the evaporated moisture, moves to the exit of the chamber. At the outlet of the chamber, part of the coolant is discharged into the atmosphere, and most of it is directed to the mixing chamber. In the mixing chamber, the waste coolant is mixed with part of the fresh air. Fresh air is supplied in an amount equal to that utilized in the atmosphere. Next, the mixed air is heated using tubular electric heaters and sent to the drying chamber. The amount of circulating coolant in the chamber should be 3 to 6 times higher than the amount of fresh air supplied for mixing.

The drying process according to the proposed method consists (Fig. 1) of a continuous initial phase T _n and combined periods T ₁ , T ₂ , ..., T _i . The number of combined periods depends on the required final moisture content of the dried products. The duration of the continuous initial phase τ _Tn is from 3 to 8 hours.

на кривой кинетики обезвоживания. Значения $${\omega }_{к2}^{с}$$

находят по формуле (Технология рыбы и рыбных продуктов: учебник для вузов / [Артюхова С.А. и др.]; под ред. А.М. Ершова. - [2-е изд.]. - М.: Колос, 2010. - 1064 с.):A reference point for starting the use of combined periods can be the second critical point K ₂ , which occurs on the kinetics curve of dehydration due to an increase in the binding energy of moisture with the material, which is expressed in a significant slowdown in the rate of dehydration. Critical points on the dehydration kinetics curve occur when the preferential removal of moisture with lower binding energy from the material ends and the removal of moisture with higher binding energy begins. The second critical point occurs in the zone of removal of microcapillary moisture from the fish. With dehydration, microcapillaries decrease in size (Technology of fish and fish products: a textbook for high schools / [Artyukhova S.A. et al.]; Edited by A.M. Ershov. - [2nd ed.]. - M. : Kolos, 2010. - 1064 p.), Therefore, increases the binding energy of water in microcapillaries. After the critical point K _2, moisture is removed more slowly. The second critical point K ₂ corresponds to moisture per dry matter $${\omega }_{\mathrm{to}2}^{\mathrm{from}}$$

on the kinetics curve of dehydration. Values $${\omega }_{\mathrm{to}2}^{\mathrm{from}}$$

are found by the formula (Technology of fish and fish products: a textbook for high schools / [Artyukhova S.A. et al.]; edited by A.M. Ershov. - [2nd ed.]. - M .: Kolos, 2010 . - 1064 s.):

- начальная влажность рыбы на сухое вещество, %.Where $${\omega }_0^c$$

- initial fish moisture on dry matter,%.

The duration of the continuous initial phase τ _Tn can be found from the experimental curve of the kinetics of dehydration by projecting the point K ₂ on the abscissa axis. The resulting value can be increased by up to 4 hours.

The required duration of the continuous initial phase τ _Tn , hours, calculated by the formula:

where τ ₂ is the duration of dehydration from the beginning of the process to the point K ₂ , hours;

K _rel is an empirical coefficient, the value of K _{rel is} chosen in the range from 0 to 4 hours. At the initial development of technological modes of drying, the maximum values of K _rel .

After the continuous initial phase T _{n, the} whole process is divided into equal intervals of duration - combined periods T ₁ , T ₂ , ..., T _i . T ₁ - the first period, T ₂ - the second period, T _i - the final period. The duration of the combined period T is from 2 to 6 hours. For small fish and fillets, the T value is from 2 to 4 hours, for large fish - from 4 to 6 hours. In turn, each combined period consists of a drying phase T _O1 , T _O2 , ..., T _Oi and a moisture relaxation phase T _R1 , T _R2 , ..., T _Ri . The duration of the relaxation phase of the first period T _{R1 is} taken from 5 to 10% of the duration of the combined period T. The duration of the relaxation phase of the final period T _{Ri is} taken from 20 to 40% of the duration of the combined period T. A gradual increase in the duration of the relaxation phase from T _R1 to T _{Ri is} carried out linearly addictions. A gradual increase in the relaxation phase and a decrease in the drying phase in the combined period are shown graphically in FIG. 1. A gradual increase in the relaxation phase over time of the drying process is associated with significant loss of moisture in the surface layer of the fish and a decrease in its moisture-conducting properties (Elements of the theory of “dashed” dehydration in the processes of cold smoking and drying of fish / Yu.T. Glazunov [et al.] / / Bulletin of MSTU: proceedings of the Murmansk State Technical University. - Murmansk, 2012. - T. 15, No. 1. - P. 15-20).

To restore the moisture-conducting properties of the surface layer as dehydration is required, more and more time is required, therefore, the duration of the relaxation phase increases. During relaxation, the heating elements are turned off, the velocity of the coolant in the installation is set from 0.5 to 1 m / s. Air of lower temperature (by 3 to 10 ° C less than in the drying chamber) and higher relative humidity than the heat carrier (by 5 to 30% more than in the drying chamber) is supplied to the drying chamber. For this purpose, workshop air is used. Provide a velocity of the coolant in the chamber from 0.5 to 1 m / s. The amount of circulating coolant in the chamber during relaxation should be 1.5-2.5 times higher than the amount of fresh air supplied for mixing. During relaxation, the temperature of the coolant circulating in the chamber gradually decreases by 3 to 8 ° C.

During the relaxation phase, it is necessary to provide conditions for the redistribution of moisture inside the dehydration facility. To do this, it is necessary to limit the transfer of moisture from the surface of the material to the environment of the drying chamber.

The speed of the drying agent affects the process of heat and mass transfer, therefore it is limited in order to provide conditions for the redistribution of moisture inside the dehydration object. The value of the speed of the drying agent 0.5-1.0 m / s is sufficient to ensure the necessary circulation of the coolant during relaxation and create an environment with a low temperature and high relative humidity. Moreover, this circulation speed will not have a significant effect on the dehydration of the object.

The proposed method of drying allows you to reduce the cost of electric energy in the production of dried fish by 15-20% without increasing the duration of the process in comparison with the continuous process of drying, i.e. the process of drying, in which breaks are not carried out for the redistribution of moisture in the thickness of fish meat. To improve the quality of products by reducing the effects of deformation in fish tissues as a result of relaxation. To increase the resource of smoke-drying plants due to a more rational use of the coolant, achieved through the circulation of the coolant. This method does not require significant technical changes in the traditional process.

The proposed method for the production of dried fish is illustrated by the drawings shown in FIG. 1-14.

In FIG. 1 shows the change in temperature of the coolant in the drying chamber when drying fish according to the proposed method, FIG. 2 presents the parameters of the drying phases and relaxation phases for example 1, FIG. 3 shows the kinetics of dehydration of the back of a blue whiting for the continuous and proposed methods, FIG. 4 - finished products obtained by the continuous method, FIG. 5 - finished products obtained by the proposed method, FIG. 6 - change in the temperature of the coolant in the drying chamber when the cod is dried (example 2), FIG. 7 - parameters of drying phases and relaxation phases of combined periods for example 2, FIG. 8 - curves of kinetics of dehydration of the cod by the continuous method and by the proposed method, FIG. 9 - parameters of drying phases and relaxation phases of combined periods for example 3, FIG. 10 - change in the temperature of the coolant in the drying chamber when the mackerel is dried (example 3), FIG. 11 - kinetics of dehydration of mackerel according to the continuous method and the proposed method, FIG. 12 shows the parameters of the phases of dehydration and relaxation phases of the combined modes T ₁ -T _{17 of} example 4, FIG. 13 - parameters of the phases of dehydration and relaxation of the combined modes T ₁₈ -T _{29 of} example 4, in FIG. 14 shows the dewatering curves of flounder-ruff for a continuous process and according to the proposed method.

EXAMPLE 1

Production of backless blue whiting back. Raw materials (frozen unfinished blue whiting) are subjected to general operations (preparation): thawing, washing, cutting into the back, washing and sorting, taste salted salting, rinsing, stringing fish on rods, draining, placing rods with fish in cages. Fish stands are loaded into the drying chamber. The initial moisture content of fish per dry matter is 400%, the specific surface of the fish (the ratio of the surface area of the fish to its mass) is 0.19 m ² / kg. The relaxation phase of the first combined period T _R1 = 10%. The relaxation phase of the final combined period T _R14 = 30%. Parameters of fresh air for mixing with waste coolant t _r.v. 15 to 16 ° C, relative humidity φ _r.v. from 39 to 44%.

Drying mode. Set the drying mode: coolant temperature t_P= 25 ° C, fluid velocity v_P= 4 m / s, drying time τ_P= 10 min, the amount of circulating coolant in the installation is 3 times the amount of fresh air supplied for mixing. Continuous Initial Phase T_n. Set parameters T_n: coolant temperature t_Tn= 25 ° C, fluid velocity v_Tn= 2.5 m / s, duration τ_Tn= 3 hours (τ₂= 2.9 hours, K_rel= 0.1), the amount of circulating coolant in the installation is 4 times the amount of fresh air supplied for mixing.

After completion of the initial phase T _n, the drying process is divided into combined periods T _i . For this example, the number of combined periods n _T = 14, the duration of each combined period of dehydration τ _T = 3 hours.

The first combined period is T ₁ .

Drying phase T _{O1 of the} first combined period T ₁ : coolant temperature t _TО1 = 25 ° C, coolant speed ν _TO1 = 2.5 m / s, duration τ _TО1 = 162 min (90% of the duration, the amount of circulating coolant in the installation is 4 times the amount of fresh air supplied to mix.

Relaxation Phase T_R1 first combined period T_one, T_R1= 10% of τ_T. During relaxation, the heating elements of the installation are turned off. Relaxation phase parameters T_R1: the temperature of the coolant at the beginning of relaxation is equal to the temperature of the coolant of the drying phase t_TR1start= 25 ° C, coolant temperature at the end of relaxation t_TR1con= 20.7 ° C, average coolant temperature of the relaxation phase t_TR1av= 22.9 ° C, the velocity of the coolant ν_TR1= 0.5 m / s, duration τ_TR1= 18 min (10% of the duration T_one), the amount of circulating coolant in the installation is 2 times the amount of fresh air supplied for mixing.

Next, the following combined T ₂ -T ₁₃ modes are performed _{, the} parameters of which differ only in the duration of the drying phases and relaxation phases and the temperature of the coolant in the chamber at the end of relaxation.

Parameters of the final combined dehydration period T ₁₄ .

Drying phase T _{O14 of the} combined period T ₁₄ : coolant temperature t _TO14 = 25 ° C, coolant velocity ν _TO14 = 2.5 m / s, duration τ _TO14 = 126 min (70% of the duration T ₁₄ ), amount of circulating coolant in the installation 4 times the amount of fresh air supplied for mixing.

Relaxation phase T _{R14 of the} combined period T ₁₄ , T _R14 = 30% of τ _t . During relaxation, the heating elements of the installation are turned off. The parameters of the relaxation phase T _R14 : the temperature of the coolant at the beginning of relaxation is equal to the temperature of the coolant of the drying phase t _{TR14 start} = 25 ° C, the temperature of the coolant at the end of relaxation t _TR14con = 18.6 ° C, the average temperature of the coolant t _TR14cp = 21.8 ° C , the velocity of the coolant ν _TR14 = 0.5 m / s, the duration τ _TR14 = 54 min (30% of the duration T ₁₄ ), the amount of circulating coolant in the installation is 2 times the amount of fresh air supplied for mixing.

In FIG. 2 shows the parameters of the phases of drying and relaxation of the combined modes T ₁ -T _{14 of} example 1.

In FIG. Figure 3 shows the kinetics of dehydration for blue whiting according to the proposed method and for the continuous process (without relaxation), which indicate a more even dehydration process according to the proposed method, which ultimately leads to a significant reduction in the phenomena of deformation in fish tissues and, as a result, an increase in the quality of the finished product product. The duration of the drying was 45 hours. The rate of dehydration of these processes was almost the same. However, for the drying process according to the proposed method, the total duration of the relaxation phases was 7.8 hours. At this time, tubular electric heaters were not supplied with power. The fans of the installation worked in an economical mode, providing a flow velocity in the chamber of 0.5 m / s. The costs of electric energy in this mode were 15% less than for a continuous process.

Products obtained using relaxation modes had a more attractive appearance (Fig. 5). The phenomena of deformation of fish tissues during drying were weakly expressed. Finished products obtained using combined periods and in a continuous process (without relaxation phases) are shown in FIG. 4 and FIG. 5. Thus, the proposed method for the production of dried fish makes it possible to save electric energy while saving the resources of the drying equipment and improving the quality (appearance) of the finished product.

EXAMPLE 2

Production of cod dried. The initial moisture content of fish per dry matter is 310%, the specific surface of the fish (the ratio of the surface area of the fish to its mass) is 0.20 m ² / kg. The relaxation phase of the first combined period T _R1 = 10%. The relaxation phase of the final combined period T _R14 = 20%. Parameters of fresh air for mixing with waste coolant t _r.v. 17.5 ° C, relative humidity φ _d.v. 51%

Drying mode. Set the drying mode: the temperature of the coolant t _p = 25 ° C, the velocity of the coolant ν _p = 5 m / s, the duration of drying τ _p = 12 min, the amount of circulating coolant in the installation is 3 times the amount of fresh air supplied for mixing.

Continuous initial phase T _n . Set the parameters T _n : coolant temperature t _Tn = 25 ° C, coolant speed ν _Tn = 2.6 m / s, duration τ _Tn = 6 hours (τ ₂ = 2.8 hours, K _rel = 0.2), the amount of circulating coolant in the installation is 4 times the amount of fresh air supplied for mixing.

After completion of the initial phase T _n, the drying process is divided into combined periods T _i . For this example, the number of combined periods n _T = 14, the duration of each combined period τ _T = 3 hours.

The change in temperature of the coolant in the drying chamber for example 2 is shown in FIG. 6. In FIG. 7 presents the parameters of the drying phases and relaxation phases of the combined periods T ₁ -T _{14 of} example 2.

In FIG. Figure 8 shows the curves of dehydration according to the proposed method and for a continuous process, which indicate a smooth dehydration process according to the proposed method, which ultimately leads to a significant reduction in the phenomena of deformation in fish tissues and, as a result, an increase in the quality of the finished product. The duration of drying to the desired final moisture content was 48 hours. The rate of dehydration of these processes was almost the same. However, for the drying process according to the proposed method, the total duration of the relaxation phases was 6.3 hours. At this time, tubular electric heaters were not supplied with power. The fans of the installation worked in an economical mode, providing a flow rate in the chamber of 0.7 m / s. The cost of electric energy in this mode was 14.6% less than for a continuous process.

EXAMPLE 3

Atlantic mackerel mackerel production. The initial moisture content of fish per dry matter is 169.5%, the specific surface of the fish (the ratio of the surface area of the fish to its mass) is 0.11 m ² / kg. The relaxation phase of the first combined period T _R1 = 10%. The relaxation phase of the final combined period T _R14 = 40%. Parameters of fresh air for mixing with waste coolant t _r.v. 16.8 ° C, relative humidity φ _d.v. 49.5%.

Drying mode. The drying mode is set: the temperature of the coolant t _p = 20 ° C, the velocity of the coolant ν _p = 5.5 m / s, the duration of drying τ _p = 13 min, the amount of circulating coolant in the installation is 3 times the amount of fresh air supplied for mixing.

Continuous Initial Phase T_n. Set parameters T_n: coolant temperature t_Tn= 20 ° C, the velocity of the coolant ν_Tn= 2.8 m / s, duration τ_Tn= 8 hours, the amount of circulating coolant in the installation is 4 times the amount of incoming fresh air for mixing.

After completion of the initial phase T _n, the drying process is divided into combined periods T _i . For this example, the number of combined periods n _T = 13, the duration of each combined period of dehydration τ _T = 3 hours.

In FIG. 9 shows the parameters of the drying phases and relaxation phases of the combined modes T ₁ -T ₁₃ for example 3.

In FIG. 10 shows the change in temperature of the coolant in the chamber during drying for example 3.

In FIG. 11 shows the kinetics of dehydration of mackerel according to the proposed method and for the continuous process, which indicate a significantly smooth dehydration process according to the proposed method, which ultimately leads to a significant reduction in the phenomena of deformation in fish tissues and, as a result, an increase in the quality of the finished product. The duration of drying to the desired final moisture content was 47 hours. The rate of dehydration of these processes was almost the same. For the drying process according to the proposed method, the total duration of the relaxation phases was 9.8 hours. At this time, tubular electric heaters were not supplied with power. The fans of the installation worked in an economical mode, providing a flow velocity in the chamber of 0.8 m / s. The cost of electric energy in this mode was 18.8% less than for a continuous process.

EXAMPLE 4

Production of flounder-ruff dried. The initial moisture content of fish per dry matter is 333.2%, the specific surface of the fish (the ratio of the surface area of the fish to its mass) is 0.13 m ² / kg. The relaxation phase of the first combined period T _R1 = 10%. The relaxation phase of the final combined period T _R29 = 20%. Parameters of fresh air for mixing with waste coolant t _r.v. 16.0 ° C, relative humidity φ _d.v. 30.0%.

Drying mode. Set the drying process mode: the temperature of the coolant t _p = 20 ° C, the velocity of the coolant ν _p = 4.8 m / s, the duration of drying τ _p = 15 min, the amount of circulating coolant in the installation is 3 times the amount of fresh air coming in for mixing .

Continuous initial phase T _n . The parameters T _{n are set} : the temperature of the coolant t _Tn = 20 ° C, the velocity of the coolant ν _Tn = 3.0 m / s, the duration τ _Tn = 6 hours (τ ₂ = 5 hours, K _rel = 1), the amount of circulating coolant in 4 times the amount of fresh air supplied for mixing.

After completion of the initial phase T _n, the dehydration process is divided into combined periods T. For this example, the number of combined periods n _T = 29, the duration of each combined period of dehydration τ _T = 4 hours.

In FIG. 12 and FIG. 13 shows the parameters of the phases of dehydration and relaxation of the combined modes T ₁ -T _{29 of} example 5. In FIG. 14 shows the kinetics of dewatering flounder-ruff kinetics in a continuous manner and proposed.

The proposed method for the production of dried fish allows to reduce the cost of electric energy in the production of dried fish by 15-20% without increasing the duration of the process in comparison with the continuous process of drying. To improve the quality of products by reducing the effects of deformation in fish tissues as a result of relaxation. To increase the resource of smoke-drying plants due to a more rational use of the coolant, achieved through the circulation of the coolant. This method does not require significant technical changes in the traditional process.

Claims (6)

1. A method of manufacturing dried fish, based on the use of heat carrier circulation in a drying chamber, characterized in that the prepared fish is salted, washed with saline, rinsed with water, kept to drain excess water, and dried for 10-15 minutes at a temperature equal to temperature the main process is 18-33 ° C, and the coolant speed is from 3 to 6 m / s, then, at a coolant speed of 2-3 m / s, the main process is carried out, including a continuous initial phase lasting from 3 to 8 hours and equal to the duration of the combined periods T _i , the number of which depends on the required final moisture content of the dried fish, each combined period T _i consists of a drying phase T _oi and a relaxation phase T _ri , while the duration of the relaxation phase is increased from the first combined period to the last combined period, and the duration of the drying phase is accordingly reduced from the first to the last combined period, during the relaxation phase the heating devices are turned off, the coolant speed is smart shayut to 0.5-1.0 m / s and is fed into the air chamber at a temperature below 3-10 ° C and a relative humidity of 5-30% higher. 2. The method according to p. 1, characterized in that the beginning of the combined period is the second critical point K ₂ , which corresponds to moisture on a dry matter

on the kinetics curve of dehydration and which is found by the formula:

Where

- initial fish moisture on dry matter,%. 3. The method according to p. 1, characterized in that the duration of one combined period is from 2 to 6 hours, for small fish it is 2-4 hours, for large fish - 4-6 hours. 4. The method according to p. 1, characterized in that the duration of the continuous initial phase of dehydration τ _{Tn is} calculated by the formula:

τ ₂ - the duration of dehydration from the beginning of the process to the point K ₂ , hours;
K _rel is an empirical coefficient, its value is selected in the range from 0 to 4 hours, at the initial development of technological dehydration modes, the maximum values of K _rel . 5. The method according to p. 1, characterized in that the duration of the relaxation phase of the first combined period is 5-10% of the duration of the combined period, and the duration of the final relaxation phase is 20-40% of the duration of the combined period, 6. The method according to p. 1, characterized in that during the drying and the main process recycle the coolant.

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