RU2320180C1 - Method for preparing of hot smoked fish - Google Patents

Abstract

FIELD: fish processing industry.

SUBSTANCE: method involves three-staged fish processing: slightly drying fish with hot air, cooking-through fish with steam and smoking with smoke-air mixture during 30-110 min, with processes for slight drying and cooking of prepared fish being provided using overheated steam having temperature of 383-443 K and flow speed of 0.1-0.5 m/s during 25-45 min; performing smoking procedure using smoke having temperature of 373-403 K until temperature within fish trunk is 346-348 K; cooling ready fish with air, which is thereafter directed into smoke generator. Smoke is produced by burning mixture of sawdust and chips of bark-free beech, linden, alder, oak, nut-tree, and birch used in proportion of 20:20:25:15:10:10 and having moisture content below 20%.

EFFECT: improved quality of ready product, reduced material and power consumption.

1 dwg, 4 tbl, 2 ex

Description

The invention relates to the fish processing industry, and in particular to the technology of smoking fish, and can be used in the production of hot smoked fish.

The closest in its technical essence and the achieved effect is a method of cooking hot smoked fish (Nikitin BN Fundamentals of the theory of smoking fish / [Text] // B.N. Nikitin - M .: Light and food industry, 1982. - 244 s.), Including a three-stage fish treatment: drying fish with hot air at a temperature of 343 ... 363 K, boiling the fish with saturated steam at a temperature of 373 ... 443 K and smoking with a smoke-air mixture with a temperature of 373 ... 403 K for 40 ... 110 min.

The disadvantages of this method are:

- significant material and energy costs due to the preparation and use of three different in nature and purpose of the coolant (air, saturated steam and smoke mixture);

- low quality of finished products due to the complexity of the timely supply of different in nature and purpose of the coolant (steam, air and smoke) at each stage of thermal treatment of fish;

- the difficulty of maintaining the specified technological parameters at all stages of the cooking process of hot smoked fish.

An object of the invention is to reduce material and energy resources through the use of two types of coolant (superheated steam and smoke) instead of three types of coolant (steam, air and smoke), improving the quality of finished fish products by eliminating intermediate and auxiliary operations when feeding in the working chamber of different in nature and purpose coolants (steam, air and smoke) and the use of superheated steam to achieve a continuous and more uniform flow fish processing, improving the accuracy of controlling technological parameters due to the regulation of the thermal treatment regime at two stages of the cooking process of hot smoked fish instead of three.

The problem is achieved in that in the method of cooking hot-smoked fish, including three-stage processing of fish: drying the fish with hot air, boiling the fish with saturated steam and smoking the smoke-air mixture for 30 ... 110 min, the new is that the drying and boiling are pre-prepared fish are carried out with superheated steam with a temperature of 383 ... 443 K and a speed of 0.1 ... 0.5 m / s for 25 ... 45 minutes, smoking - with smoke smoke with a temperature of 373 ... 403 K until the temperature is reached in the center of the body of the fish is 346 ... 348 K, and the cooling of the finished p would be air, which is then sent to a smoke generator, and smoke is produced by burning a mixture of sawdust and shavings of beech, linden, alder, oak, hazel and birch without bark in a proportion of 20: 20: 25: 15: 10: 10 with a humidity of not higher twenty%.

Chilled or frozen fish is sent for hot smoking. For the production of hot smoked fish, halibut, flounder, sea bass, mackerel (fat content 4 ... 25%) are used, cod, haddock, pollock, pollock, blue whiting, saffron cod, freshwater burbot, etc. are used for fish reception. GOST 7631-85 for quantity accounting and quality control.

The method of cooking hot smoked fish is as follows. The method of cooking hot smoked fish includes the following technological operations: thawing, sorting, washing, cutting, washing, salting, rinsing, strapping (flashing or tattoos), drying, boiling, smoking, cooling, sorting, packaging in containers.

Large fish (families of sturgeon, cod, salmon) are thawed on racks in air at a temperature of 15 ... 20 ° С for 20 ... 30 h, other fish species are thawed in baths in water by immersion or irrigation at a temperature of not more than 15 ° C for 2 ... 6 hours, depending on the size of the fish. Moreover, defrosting by air is more preferable to obtain high-quality products. Thawed or chilled fish are washed with water at a temperature of no more than 15 ° C to remove mucus and other contaminants.

When processing medium-sized fish, thawing is combined with salting: in this case, frozen fish is placed in a saturated solution of sodium chloride with a temperature of 20 ... 24 ° C.

Before being sent for cutting or salting, fish are sorted by size and quality, separating non-standard samples. This allows us to produce products of uniform quality. Fish are sent to the ambassador of the same mass or length [Golubev V.N., Kutana O.I. Handbook of a fish and seafood processing technologist. - St. Petersburg: GIORD, 2003. - 408 p.].

Smoked fish is smoked in its whole form, large fish are cut in various ways in accordance with the requirements of the standard. Whitefish, asp, and muksun are preliminarily cleaned of scales, sturgeon, stellate sturgeon, spike and sea bass are smoked without a head, catfish in the form of pieces 0.25 ... 0.30 m long. Fish longer than 0.40 m long (pike perch, cod, whitefish, sturgeon, etc.) are cut into pieces. Pieces weighing more than 0.8 kg are cut along the spine.

Then, the washed fish is washed to remove residual entrails, blood, and other contaminants.

Then the fish is salted to a salt content in muscle tissue of 1.8 ... 2.0% dry salt or in saline (acetyl saline). In a dry way, evenly pouring 7-15% of the mass of fish in rows of table salt, salt the fish of the sturgeon, salmon, cod, halibut families. The fish is rolled in salt, the salt is poured into the gills and the abdominal cavity and laid in rows in the bathtubs. Large fish are rubbed with salt from the outside, from the side of the abdominal cavity and incisions, placed in the baths with their backs down and sprinkled with salt. Salt consumption - 7 ... 15% of the mass of fish. The duration of dry salting is 1 ... 12 hours for unrefined fish of medium and large sizes, moreover, fish from the cod family are kept in the ambassador for 3 ... 5 hours, and sturgeons are kept for 6 ... 12 hours. The remaining fish species are salted with an aceous saline in saturated sodium chloride solution (density 1.18 ... 1.20 kg / m ³ ) with the ratio of fish and solution 1: 2 from 10 minutes to 6 hours, depending on the type, size of fish and the method of its cutting. Losses during salting do not exceed 2 ... 4% of the mass of raw fish. After salting, the fish is washed with fresh water and transferred to the harness.

With mixed salting, an unbalanced fish-salt-brine system is formed, in which the diffusion transfer of sodium chloride from brine to fish tissue and the osmotic transfer of water from fish tissue to brine occur. Unidirectional movement continues until the system goes into an equilibrium state, characterized by a constant concentration of salt in the brine and in the muscle tissue of the fish.

In the brine-fish system, only insignificant transfer of sodium chloride into tissues and water from tissues is provided, since a quick dilution of the solution occurs. This subsequently leads to the fact that the mass of salted fish can not only increase and reach the initial mass, but also exceed it. During salting, ripening of fish products takes place, which is a whole complex of complex transformations that make up the fish. The ripening period can be divided into 3 stages.

The first stage (pre-maturation) takes place under the influence of muscle tissue peptidohydrolases. This period is characterized by a small accumulation of all non-protein fractions.

The second stage (maturation) is characterized by actively proceeding proteolysis under the total influence of muscle tissue enzymes.

The third stage is the formation of the main signs of ripened fish - taste and aroma. The appearance of taste and aroma, that is, the formation of qualitatively new signs of fish.

Mixed salted salted large oily fish with scales (bream). To do this, pour the fish in rows with dry salt, and then fill it with saline, as in wet salting. Throughout the salting maintain a temperature not exceeding 15 ° C. Salt consumption - 7 ... 15% of the mass of fish. Fish from the cod family are kept in the salting for 3 ... 5 hours, and sturgeons - 6 ... 12 hours. The remaining fish species are salted in saline with a density of 1.18 ... 1.20 kg / m ³ at a ratio of fish to solution 1: 2 for 2 ... 6 hours, depending on the size of the fish and the method of its cutting.

The salted fish is rinsed with fresh water and then tied to avoid falling when tacked onto the ramrod and slats or laid out on carrier grids of trolleys.

Large fish (pike perch, common carp, kutum, selected bream, etc.) are tied with a key or without a key, smaller fish is stitched, small fish is strung on a ramrod. Cod, haddock, sea bass and catfish are tied without dowels. Bream, mullet, roach, herring and other smaller fish are stitched unbroken. Small fish are strung on a ramrod through the mouth and gill slit or through the eyes. Stellate sturgeon and sturgeon are tied with twine through a loop with a strong knot, retreating 0.20 ... 0.25 m from the cut of the head.

Depending on the type of fish and its physico-chemical state, a certain temperature of superheated steam and smoke is maintained at different stages of the process. Technological parameters of hot smoking of some fish species are given in table 1.

Drying and boiling of previously prepared fish is carried out with superheated steam with a temperature of 383 ... 443 K and a speed of 0.1 ... 0.5 m / s for 25 ... 45 minutes. The purpose of drying is to remove surface moisture for better deposition of smoke components and the desired color formation. The purpose of boiling is the complete culinary readiness of the fish: muscle tissue is easily separated from the bones, the blood is completely clotted, the proteins are denatured, and the enzymes are inactivated. With an increase in the fat content of the fish, the temperature of the weld is lowered, otherwise a marriage will form: the tissues and skin of the fish burst. Weight loss during drying and boiling up to 20%.

Table 1 Technological parameters of hot smoking of some types of fish Fish Drying and boiling Smoking Total duration min T, K ν, m / s τ min T, K τ min Large cod 443 0.5 40 403 90 ... 100 130 ... 140 Sea bass 433 0.5 35 403 85 ... 90 120 ... 125 Bream, carp 423 0.4 thirty 373 55 ... 60 85 ... 90 Salaka 383 0.1 25 373 30 ... 40 55 ... 65 Tooth, crucian 393 0.2 thirty 383 30 ... 80 60 ... 110 Hake 403 0.2 thirty 393 35 ... 80 65 ... 110 Mackerel, mackerel 413 0.3 thirty 373 35 ... 55 65 ... 85 Stellate sturgeon 423 0.4 35 393 80 ... 100 115 ... 135

The use of superheated steam with a temperature below 383 K leads to a significant increase in the drying and boiling process. The use of superheated steam with a temperature above 443 K leads to burning of the surface layers of fish during drying and boiling. The use of superheated steam at a speed below 0.1 m / s leads to incomplete penetration due to insufficient heat input. The use of superheated steam at a speed above 0.5 m / s leads to overdrying of the surface layers of the fish and inadequate digestion of the central layers of the fish during drying and boiling. The range of the duration of drying and boiling 25 ... 45 min is determined not only by the technological parameters of the process, but by the thermophysical properties and chemical composition of the fish.

Then, smoking smoke is processed at a temperature of 3 73 ... 403 K until the temperature in the center of the body of the fish reaches 346 ... 348 K. The purpose of smoking is to saturate the boiled muscle tissue of the fish with smoke components to add smoked aroma and taste. At the same time, effective coloring of the fish surface in golden tones is carried out, which is facilitated by high process temperatures.

For hot smoking, fish smoke is used, which is obtained by burning a mixture of sawdust and shavings of beech, linden, alder, oak, hazel and birch (without bark) in a ratio of 20: 20: 25: 15: 10: 10 with a humidity of not higher than 20% .

table 2 Composition of smoke from the burning of certain tree species Indicators Beech Alder Linden Hazel Birch Oak Combustion temperature, K 300 ... 400 300 ... 400 300 ... 400 300 ... 400 300 ... 400 300 ... 400 Content (mg per 100 g of wood) phenol 248 ... 300 186 ... 195 232 ... 249 232 ... 249 232 ... 249 232 ... 249 formaldehyde 694 ... 1025 572 ... 874 1072 ... 1430 1072 ... 1430 1072 ... 1430 1072 ... 1430 furfural 634 ... 689 504 ... 655 694 ... 1027 694 ... 1027 694 ... 1027 694 ... 1027 aldehydes and diacetyl 3319 ... 3726 2449 ... 3096 3732 ... 5217 3732 ... 5217 3732 ... 5217 3732 ... 5217

Table 3 The composition of the smoke when burning a mixture of sawdust and shavings 20% beech, 20% linden, 25% alder, 15% oak, 10% hazel and 10% birch (without bark) Indicators A mixture of sawdust and shavings 20% beech, 20% linden, 25% alder, 15% oak, 10% hazel and 10% birch (without bark) with a moisture content of 20% The content of smoke smoke components, mg / m ³ : phenol 365 formaldehyde 201.6 furfural 144.5 aldehydes and diacetyl 90 resinous substances 1100 carbonyl compounds 134 organic acids 17 organic bases (amines) 7 polynuclear aromatic hydrocarbons: 3,4-benzpyrene 6.010 ² 1,12-benzperylene 3.2 · 10 ² 1,2,3,4-dibenzanthracene 12 · 10 ² ketones 0.003

The chemical composition of the smoke obtained from these trees is given in table 2 [E. Khan. Smoked, dried and dried fish [Text] / E.A. Khvan, A.V. Gudovich. - M .: Food industry, 1978. - 207 p.].

The chemical composition of the smoke obtained from a mixture of sawdust and shavings of 20% beech, 20% linden, 25% alder, 15% oak, 10% hazel and 10% birch (without bark) with a moisture content of 20% was calculated and determined by mathematical extrapolation. the data for which are given in table.3. The choice of the percentage of these types of wood is due to the following considerations. The trees of these species burn with a short flame, their smoke is very fragrant. It is not advisable to use trees of coniferous species alone as fuel, since the resinous substances contained in significant quantities give the fish an unpleasant bitter taste and a dark color. For smoking fish, firewood, wood chips, shavings and sawdust with a moisture content not exceeding 20% are used. At a smoke humidity of more than 50% (from raw wood), an unattractive gray product with a bitter and tarry aftertaste is obtained. With smoke humidity of 75 ... 80% moisture extraction from fish does not occur.

Sawdust smoke is much less concentrated than smoke obtained from firewood. If from 1 kg of sawdust with a moisture content of 18% you can get about 7 m ^{3 of} smoke, then from firewood, ceteris paribus - 5 ... 6 times more. The advantage of producing smoke from coarsely chopped wood is obvious, but the smoke from sawdust contains 1.19 mg / m ^{3 of} 3,4-benzpyrene, and the smoke from firewood contains significantly more - 47.9 mg / m ³ . If we take into account the different smoke output, the amount of 3,4-benzpyrene in the smoke from sawdust with a concentration equal to the concentration of smoke from firewood will be about 7.0 mg / m ³ .

The difference in the content of 3,4-pyrene-free is too great and it becomes clear the feasibility of obtaining smoke from sawdust. The moisture content of wood has a certain effect on the technological properties of smoke.

When substantiating the choice of moisture content of wood sawdust and shavings not higher than 20% and studying its effect on the process of smoke formation, the following considerations were guided. Firstly, water delays the beginning of the process of smoke formation, but this does not affect the total amount of smoke generated at sufficiently high temperatures. Secondly, water evaporated from sawdust partially displaces oxygen from the combustion zone, as a result, the temperature of the fire decreases and more smoke is formed. In addition, additional heat is required to evaporate water from sawdust, which also leads to a decrease in temperature in the smoke formation zone. Thirdly, a decrease in the pyrolysis temperature during the development of smoke is reflected in the chemical composition of the smoke and, as a consequence, on its sensory properties. Fourth, the increased moisture content in sawdust (over 25%) leads to a significant moistening of the smoke, to a decrease in its moisture capacity.

When studying the effect of fuel humidity on the dispersed composition of smoke, it was noted that the mass concentration of smoke at a given temperature decreases with increasing relative humidity of sawdust.

The air entering during the formation of smoke into the combustion zone is important, as it affects the chemical composition of the smoke to some extent. An increase in relative humidity leads to an increase in the number of phenolic compounds. The authors chose deciduous wood, since the smoke content of wood burning from deciduous wood was significantly higher than the smoke generated from coniferous wood. Volatile acids present in smoke and smoke preparations, play mainly an auxiliary role, but in combination with phenols and carbonyl compounds contribute to the creation of certain taste properties in the processed product.

Smoke generated in smoking chambers during smoking is a complex mixture of solid, liquid and gaseous products of incomplete combustion of wood. With incomplete combustion of wood, about 70 different chemicals are formed. The experimentally established proportion 20: 20: 25: 15: 10: 10 of a mixture of sawdust and shavings of beech, linden, alder, oak, hazel and birch (without bark) with a moisture content of not higher than 20% provides a rational ratio of a mixture of solid, liquid and gaseous products of incomplete wood combustion, i.e. smoke smoke components (see table 3).

Let us dwell in more detail on the mechanism of the effect of this ratio of smoke smoke components on fish. Of greatest importance in fish smoking are formaldehyde contained in smoke, higher aldehydes, ketones, formic and acetic acids, phenols, alcohols and resins. The saturation of smoke with these organic compounds depends on the completeness of oxidation of the main parts of wood - cellulose, lignin and hemicellulose, and therefore on the combustion temperature and the amount of air supplied.

After the deposition of smoke substances on the surface of the fish, the following phenomena occur:

- polymerization and drying of some smoke substances, accompanied by the formation of a golden brown film on the surface of the fish and the appearance of a characteristic smell of smoked meat;

- oxidation of some of the smoke substances, leading to the gradual fading of the golden brown film on the surface of the fish, especially after removing it from the smoke chamber;

- diffusion of part of the smoke substances of the smoke from the surface of the fish into its muscle tissue, as a result of which the fish acquires a characteristic smoked smack.

The use of smoke from a temperature below 373 K leads to a low intensity of smoking, and therefore, to a significant increase in the smoking process. The use of smoke from a temperature above 403 K leads to burning of the surface layers of fish. At the same time, from the action of high temperature, collagen septum and intermisium pass into glutin, which in a liquid state moves along septic paths to another place. The ability to bond collagen mass decreases. The meat of the fish relaxes and easily breaks down into septa into separate segments, and also separates from the skin.

Physico-chemical changes that occur during smoking are associated with heat exposure, the influence of curing substances and significant dehydration, as well as tissue saturation with components of the smoking environment [Mezenova O.Ya., Kim I.N., Bredikhin S.A. Smoked food production. - M .: Kolos, 2001. - 208 p.]. During smoking, some components of the smoking medium are deposited on the surface of the product, while others penetrate inside. In the process of diffusion, part of the components does not change its chemical nature, and part enters into various interactions with tissue substances. Acids contained in smoke acidify the product, reducing its pH to 5.7 ... 5.2.

Aldehydes in an amount of 90 mg / m ³ and ketones in an amount of 0.003 mg / m ³ (Table 3) of smoke smoke actively interact with the free amino groups of the polypeptides. Thus, formaldehyde, quantitatively predominant in the aldehyde group, ultimately forms mono- and dimethyl compounds: R-NHCH ₂ -OH or RH (CH ₂ -OH) ₂ . Interacting with two amino groups of two peptide chains, formaldehyde binds them with methylene bridges RH-CH ₂ -NH-R. Physically, this is expressed in the hardening of the fabric and, by the nature of the action, is similar to the tanning process. Phenols that react with amino acid residues and other functional groups of proteins also have a tanning effect on tissues.

Hot smoking is accompanied by protein denaturation and the release of hidden functional groups (sulfide, carboxyl, amine, hydroxy, etc.), which interact with the smoking components. As a result, irreversible dehydration, coagulation of part of the sarcoplasmic proteins and myofibrils of muscle tissues are observed, in connection with which the water-holding capacity of the tissue decreases, the product is better dehydrated and compacted.

Collagen undergoes the most severe changes during smoking. Fibrils of muscle tissue initially change their spatial packaging. At the same time, hydrogen bonds are destroyed and functional groups that react with smoke components are released. Under the action of aldehydes, ketones and phenols, transformations occur, called tanning. In this case, the collagen of the membranes and skin of fish plays a protective role, linking a number of active smoke substances and preventing their diffusion into the product.

At the same time, under the influence of high temperature, collagen molecules are dehydrated. At the end of smoking, their structure changes dramatically, as a result, the shell becomes thin, translucent, the skin of the fish dries up and easily separates from muscle tissue. The surface of the smoked product acquires a characteristic color from light golden to dark brown. The presence of phenolic compounds in an amount of 365 mg / m ³ (see table 3) causes a well-defined smoking aroma without any extraneous shades. In the case of combining the phenolic fraction with carbonyl compounds, a pronounced smoking aroma with spicy hues arises. The aroma of smoking with hints of burnt sugar is also very pronounced when phenols, carbonyl and non-carbonyl substances are combined into one composition.

Carbonyl compounds in an amount of 134 mg / m ³ (see Table 3) partially enhance the smoked flavor, but their main role in the smoking process is the formation of a characteristic color. The color formation mechanism seems to be a series of non-enzymatic reactions similar to the Maillard reactions, with the only difference being that the reaction products, dehydrogenated ether carbons arising in the process of smoke generation, are suitable for direct contact with the amino groups of the product proteins.

The carbonyl compounds that prevail in smoke and interact with the protein are formaldehyde, glyoxal, furfural, acetone, hydroxyacetone, diacetone, glycolaldehyde and methylglyoxal, the latter two being characterized as actively participating in the color formation reaction. It was also established that glyoxal and crotonic aldehyde, when interacting with solutions of amino acids, contribute to the appearance of intense color, dioxiacetone and acetaldehyde are moderately active, and formaldehyde and acetone do not participate in this reaction at all.

Coniferous and sanapalealdehydes were identified using a mass spectrometer. These chemicals react with the protein of the product, giving it an orange tint characteristic of smoked products. Color development of the product is associated with the growth of carbonyl groups that interact with the product protein.

Biochemical changes during smoking are associated with the action of sodium chloride, nitrites, tissue and microbiological enzymes, smoke components and process temperature.

As a result of denaturation, hidden functional groups of proteins are released, in particular OH groups with reducing properties. Under the influence of microorganisms, as well as reducing compounds from nitrites, added during the salting of meat of warm-blooded animals, nitrogen oxides are released, which, under the influence of high temperature with the participation of colored smoke substances, intensifies the color of the inner layers of meat.

Fats contained in muscle tissue, when smoked, actively sorb smoke components (carbonyls and especially phenols). The concentration of phenols in adipose tissue can reach 20 mg%. As a result of the antioxidant action of phenols in fats, oxidative reactions are inhibited, especially under the influence of pyrogallol homologs. The products of the interaction of phenols with fat radicals have a characteristic aftertaste, which introduces a specific shade into the aromatic sensations.

Smoking increases the fat's resistance to atmospheric oxygen, since smoke contains antioxidant substances.

The drying ability of the smoke depends on its temperature and the relative humidity of the air included in its composition, and does not depend on the chemical composition of the smoke. The higher the temperature of the smoke, the greater its moisture capacity and the more moisture is extracted from the fish.

During hot smoking, foods lose vitamins: up to 15 ... 20% of thiamine, riboflavin, niacin.

Color is considered the most important criterion for the correctness of the smoking process and is determined by the type of product, its structure and chemical composition. Increased fat content improves surface gloss; an increase in the salinity and freshness of the product, as well as a shift in the pH of the medium in the acidic and alkaline zones, intensify staining, and an increase in humidity, on the contrary, decreases. As the smoked products are stored, the color of the surface intensifies.

The shade of color depends on the type of wood used to produce smoke. Beech, maple, linden give golden yellow hues, acacia - lemon, oak, alder - yellowish brown, pear - reddish, etc. Smoke from coniferous wood stains products more intensively than smoke from hardwood. High humidity gives the product an undesirable gray tone. An increase in the oxygen concentration in the combustion zone contributes to a more intense staining of the products.

Smoke smoke aroma depends on the type of wood, the smoldering temperature, the type of smoke generator, the degree of dispersion and the chemical composition of the smoke. It is believed that the most aromatic components are contained in the gaseous phase of smoke. Smoke smoke aroma is provided by many organic substances, but phenol components, especially medium molecular weight ones, as well as carbonyl substances and lactones with a high boiling point (1,2-ciutopentadione, 2-butenolide, furfural, 2-cyclopentanone, 2-acetylfuran, their derivatives, etc.).

The following substances in the composition were found to be the basis of smoke smoke aroma: guaiacol, methyl guaiacol, pyrocatechol, syringol, vanillin, methylcyclopentadione.

The aroma and taste of the smoked product is the result of the combined effect of the smoke components, the product and the substances resulting from the reaction of the smoke components with each other and with the constituents of the product.

The mechanism of aroma and taste formation of smoked product is determined by the leading role of phenols (especially guaiacol, syringol and their derivatives). About 75% of phenolic substances, as they diffuse into the product, enter into various reactions with the protein and fat components of the product. In this case, the aromatic sensations largely depend on the consistency of the product, as well as on its chemical composition, in particular the ratio of lipids, proteins, moisture and salt in it.

The aroma and taste of smoked products is influenced by acid smoke components that add specific flavoring shades, as well as substances with active carbonyl groups (di- and polycarbonyl compounds, reductones, etc.) that interact with the protein components of the product.

A possible reaction path between glycolaldehyde and ethylamine to form brown compounds is shown in the drawing.

Of phenols, phenolaldehydes (coniferyl, synapaldehydes, and others) and polyphenols (pyrocatechol, hydroquinone, pyrogallol, and their derivatives) take the most active part. Staining is also enhanced as a result of caramelization of carbohydrates resulting from the breakdown of cellulose and hemicellulose.

The antioxidant effect is the result of a synergistic effect, primarily smoke phenols with at least one free OH group.

The inhibition of the oxidation process by phenols is due to the fact that the oxidation potential of the phenol molecule is lower than the oxidation potential of peroxide compounds that accumulate as a result of chain reactions of fat oxidation. The higher the molecular weight of phenols, the more OH groups they have, the stronger their antioxidant effect. So, guaiacol derivatives are better antioxidants than phenol, and syringol derivatives are better than guaiacol. The most effective antioxidants are derivatives of pyrogallol, pyrocatechol, hydroquinone and resorcinol. Of the phenolaldehydes and phenolic acids, vanillin, salicylic aldehyde, hydroxybenzoic acid possess antioxidant properties. The antioxidant effect is quantified by the peroxide and aldehyde numbers of fat.

The bactericidal effect is the result of the combined effect of the antiseptic components of smoke, dehydration, salting, lowering the pH (acidification), high temperature (with hot smoking). The bactericidal effect is manifested only on the surface of products. As the smoke components diffuse into the product, the microflora inhibition zone increases. The bactericidal effect depends on the parameters of the smoke, the chemical nature of the components of the smoke, the duration of smoking, the qualitative and quantitative characteristics of the contamination of the product. So, acids most effectively suppress spore-forming microflora, phenols - banal and conditionally pathogenic, neutral compounds and organic bases have a weak bactericidal effect, and carbohydrates, on the contrary, stimulate the growth of microorganisms.

V.A.Solinek managed to divide the smoke into three fractions and establish their correlation depending on the density of smoke and wood moisture (Table 4). He established an important relationship characterizing the effect of various fractions of smoke on the formation of taste and color of fish. According to him, for the formation on the surface of fish weighing 1 kg of tint, 0.46 g of resin is needed, and 0.14 g of condensate is needed to give the taste characteristic of smoked fish.

Table 4 Smoke smoke indicators depending on its density Indicators Smoke thick normal rare Temperature, K ... 375 373 375 Relative humidity, g / cm ³ ... 25.9 21.9 17.7 Weight, g / m ³ ... condensate resin ... 174.0 114.6 93.0 unburned particles ... 11.9 5,4 4.3 gaseous products ... 0.60 0.45 0.51 Smoke concentration, g / m ³ ... 948 950 951 1134.5 1070,4 1048.8

The main bactericidal components of smoke are high-boiling fractions of phenols and acids. So, with an increase in the alkyl side chains in the phenolic core, the bactericidal strength of the components increases: cresol-xylenol-propylguaiacol-ethylsyringol-hydroquinone-methylpyrocatechol-pyrogallol. One of the most effective antiseptics is formaldehyde and phenol. Of the acids, propionic and succinic acids are the most bactericidal, but due to the predominance of acetic acid in the smoke, the value of the latter will be leading.

Smoking selectively affects microorganisms, as a result of which lactic acid bacteria and gram-positive micrococci predominate in the residual microflora of smoked products. The death of microorganisms in the thickness of the product at the end of smoking (the residual bactericidal effect of smoking) is associated with the slow diffusion of bactericidal smoke components from the surface layers to the central ones. The bactericidal effect is quantified by the microbiological parameters of the finished product.

Antiproteolytic effect is expressed in the slowdown of autolytic processes in the product associated with the direct effect of the smoke components on its tissue enzymes. Smoke components, mainly phenolic and carbonyl, interact with product proteins and enzymes of a protein nature. As a result, proteins become less accessible to the activity of inactive enzymes.

Acids of the smoking medium, shifting the pH of the product into the acidic zone, contribute to the partial denaturation of enzymes, which makes them less active in the processes of tissue protein cleavage. As a result, proteolysis slows down or stops. Quantitatively, the antiproteolytic effect is determined by the content of various forms of non-protein nitrogen.

At the end of the process, the temperature of the inner layers of the muscle tissue of the fish, which is recorded by thermocouples near the spine, should be at least 346 ... 348 K. The mass loss during smoking is 25 ... 28% and when cooling is 3%. The consumption of firewood is 0.45 m ³ / h or 0.08 m ³ per 1 centner of raw.

After hot smoking, the fish is cooled with air to 8 ... 12 ° C, otherwise the surface of the fish will be excessively moistened in packed form, the juiciness of muscle tissue will deteriorate due to further boiling, favorable conditions will be created for the development of mold.

The exhaust air after cooling is heated to 35 ... 45 ° C. Then the heated air is sent to the smoke generator.

Ready fish is sorted by quality and size in accordance with the requirements of the standards, packaged in small consumer (cardboard boxes, plastic bags) or large (cardboard boxes, plastic inventory boxes, etc.) containers and packaged.

An example of the implementation of the method of cooking hot smoked cod. Cod is thawed on shelves in air at a temperature of 15 ... 20 ° C for 25 hours. Thawed cod is washed with water at a temperature of no more than 15 ° C to remove mucus and other contaminants. Before being sent for cutting or salting, fish are sorted by size and quality, separating non-standard samples.

Cod is cut in accordance with the requirements of the standard: the heads are separated. Fish longer than 0.40 m are cut into pieces. Pieces weighing more than 0.8 kg are cut along the spine. Then, the washed fish is washed to remove residual entrails, blood, and other contaminants.

Then the fish is salted to a salt content in muscle tissue of 1.8 ... 2.0% dry salt. The cod is rolled in salt, the salt is poured into the gills and the abdominal cavity and laid in rows in the bathtubs. Large fish are rubbed with salt from the outside, from the side of the abdominal cavity and incisions, placed in the baths with their backs down and sprinkled with salt. Salt consumption - 7 ... 15% of the mass of fish. The duration of dry salting is 3 ... 5 hours. After salting, the fish is washed with fresh water and transferred to the harness.

The salted cod is rinsed with fresh water and then tied without a key to avoid falling when tacked onto the ramrod and slats or laid out on carrier grids of trolleys.

The pre-prepared cod is dried and boiled by superheated steam at a temperature of 443 K and a speed of 0.5 m / s for 40 minutes. Weight loss during drying and boiling up to 20%.

The use of superheated steam with a temperature above 443 K leads to burning of the surface layers of fish during drying and boiling. The use of superheated steam at a speed below 0.1 m / s leads to incomplete penetration due to insufficient heat input. The use of superheated steam at a speed above 0.5 m / s leads to overdrying of the surface layers of fish and incomplete penetration of the central layers of fish during drying and boiling. The duration of drying and boiling for 40 minutes is determined not only by the technological parameters of the process, but also by the thermophysical properties and chemical composition of the fish.

Then, dried and boiled cod is treated with smoke at a temperature of 403 K until the temperature in the center of the fish body reaches 346 ... 348 K. When smoking cod, physico-chemical changes occur in it, a detailed description of which is given above.

The use of smoke at a temperature of 403 K is the optimal parameter for the smoking process. The use of smoke from a temperature above 403 K leads to burning of the surface layers of fish.

Hot smoking is accompanied by protein denaturation and the release of hidden functional groups (sulfide, carboxyl, amine, hydroxy, etc.), which interact with the smoking components. As a result, irreversible dehydration, coagulation of part of the sarcoplasmic proteins and myofibrils of muscle tissues are observed, in connection with which the water-holding capacity of the tissue decreases, the product is better dehydrated and compacted.

At the end of smoking, their structure changes dramatically, as a result, the shell becomes thin, translucent, the skin of the fish dries up and easily separates from muscle tissue. The surface of the smoked product acquires a characteristic color from light golden to dark brown.

For hot smoking, fish smoke is used, which is obtained by burning a mixture of sawdust and shavings of beech, linden, alder, oak, hazel and birch (without bark) in a ratio of 20: 20: 25: 15: 10: 10 with a humidity of not higher than 20% . At a higher moisture content of the wood mixture, an unattractive gray product with a bitter and tarry flavor is obtained.

At the end of the process, the temperature of the inner layers of the muscle tissue of the fish, which is recorded by thermocouples near the spine, should be at least 346 ... 348 K.

Then smoked cod is cooled with air to 8 ... 12 ° C, while the air is heated to 35 ... 45 ° C. Then the heated air is sent to the smoke generator.

Ready fish is sorted by quality and size in accordance with the requirements of the standards, packaged in plastic bags and packaged.

An example of the implementation of the method of preparation of hot smoked herring. Salaka is thawed in baths in water by immersion or irrigation at a temperature of no more than 15 ° C for 2 hours. Due to the fact that the salaka is small, it is thawed with salting: frozen fish is placed in saturated sodium chloride solution with a temperature of 20 ... 24 ° C until the salt content in muscle tissue reaches 1.8 ... 2.0%. Losses during salting do not exceed 2 ... 4% of the mass of raw fish. Then the herring is washed with water at a temperature of not more than 15 ° C to remove mucus and other contaminants. Before being sent for further processing, fish are sorted by size and quality, separating non-standard samples. This allows us to produce products of uniform quality. Fish are sent to the ambassador of the same mass or length.

Smoked salaka in its entirety: for this it is strung on a ramrod through the mouth and gill slit or through the eyes.

Drying and boiling of the previously prepared herring is carried out with superheated steam with a temperature of 383 K and a speed of 0.1 m / s for 25 minutes. The purpose of drying is to remove surface moisture for better deposition of smoke components and the desired color formation. The purpose of boiling is the complete culinary readiness of the fish: muscle tissue is easily separated from the bones, the blood is completely clotted, the proteins are denatured, and the enzymes are inactivated. With an increase in the fat content of the fish, the temperature of the weld is lowered, otherwise a marriage will form: the tissues and skin of the fish burst. Weight loss during drying and boiling up to 20%.

The use of superheated steam with a temperature below 383 K leads to a significant increase in the drying and boiling process. The use of superheated steam with a temperature above 443 K leads to burning of the surface layers of fish during drying and boiling. The use of superheated steam at a speed below 0.1 m / s leads to a significant increase in the drying process and boil-out due to insufficient heat input. The use of superheated steam at a speed above 0.5 m / s leads to overdrying of the surface layers of the fish and inadequate digestion of the central layers of the fish during drying and boiling. The range of drying and boiling for 25 minutes is determined not only by the technological parameters of the process, but also by the thermophysical properties and chemical composition of the fish.

Then, smoking smoke is processed at a temperature of 373 K until the temperature in the center of the fish body reaches 346 ... 348 K. The purpose of smoking is to saturate the boiled muscle tissue of the fish with smoke components to add smoked aroma and taste.

At the same time, effective coloring of the fish surface in golden tones is carried out, which is facilitated by high process temperatures. For hot smoking, fish smoke is used, which is obtained by burning a mixture of sawdust and shavings of beech, linden, alder, oak, hazel and birch (without bark) in a ratio of 20: 20: 25: 15: 10: 10 with a humidity of not higher than 20% . At a smoke humidity of more than 50% (from raw wood), an unattractive gray product with a bitter and tarry aftertaste is obtained.

The use of smoke from a temperature below 373 K leads to a low intensity of smoking, and therefore, to a significant increase in the smoking process. The use of smoke from a temperature above 403 K leads to burning of the surface layers of fish.

When smoking herring, physico-chemical changes occur in it, a detailed description of which is given above.

At the end of the process, the temperature of the inner layers of the muscle tissue of the fish, which is recorded by thermocouples near the spine, should be at least 346 ... 348 K. The mass loss during smoking is 25 ... 28% and when cooling is 3%. The consumption of firewood is 0.45 m ³ / h or 0.08 m ³ per 1 centner of raw fish.

After hot smoking, the herring is cooled with air to 8 ... 12 ° C, otherwise the surface of the fish will be excessively moistened in packed form, the juiciness of the muscle tissue will deteriorate due to further boiling, favorable conditions will be created for the development of mold.

The exhaust air after cooling is heated to 35 ... 45 ° C. Then the heated air is sent to the smoke generator.

Ready fish is sorted by quality and size in accordance with the requirements of the standards, packaged in small consumer containers (cardboard boxes, plastic bags) and packaged.

The proposed method of cooking hot smoked fish has the following advantages:

- reduction of material and energy resources through the use of two types of coolant (superheated steam and smoke) instead of three types of coolant (air, saturated steam and smoke mixture);

- improving the quality of finished fish products by eliminating intermediate and auxiliary operations when supplying heat transfer media of different nature and purpose (steam, air and smoke) to the working chamber and using superheated steam to achieve continuous and more uniform processing of fish, as well as the use of rational temperature modes;

- increase plant productivity by reducing the duration of auxiliary operations.

Claims (1)

A method of preparing hot smoked fish, including three-stage processing of fish: drying the fish with hot air, boiling the fish with saturated steam and smoking with a smoke-air mixture for 30 ÷ 110 min, characterized in that the drying and boiling of the previously prepared fish is carried out with superheated steam with a temperature of 383 ÷ 443 K and a speed of 0.1 ÷ 0.5 m / s for 25 ÷ 45 minutes, smoking smoke with a temperature of 373 ÷ 403 K until the temperature in the center of the body of the fish reaches 346 ÷ 348 K, and cooling the finished fish with air, which is then sent in smoke an herator, and smoke is produced by burning a mixture of sawdust and shavings of beech, linden, alder, oak, hazel and birch without bark in a ratio of 20: 20: 25: 15: 10: 10 with a humidity of not more than 20%.

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