RU2348159C1 - Method of manufacturing dried celery roots - Google Patents

Abstract

FIELD: food products.

SUBSTANCE: method includes washing, inspection, alkaline cleaning, skinning and washing off alkaline, advanced cleaning, cutting, drying and inspection. Drying is performed in three stages. At the first stage cut celery roots are treated in dense layer by coolant flow at the temperature of 328 K and speed of 2.0 m/s during 15 minutes. At the second stage - at the temperature of 338 K and speed of 1.3 m/s during 45 minutes. At the third stage - at the temperature of 348 K and speed of 0.4 m/s during 25 minutes. Celery roots are mixed under drying process during 3 seconds. At the first stage - every 3 minutes, at the second stage - every 3 minutes, at the third stage - every 5 minutes.

EFFECT: quality improvement of finished product and improvement of thermal effectiveness of drying process.

1 dwg, 1 tbl

Description

The invention relates to a vegetable drying and food concentrate industry, namely the production of dried celery roots, and can be used for the production of spices and seasonings.

There is a known method for the production of dried celery roots, which involves washing in cam or drum machines (water to product ratio 3: 1), inspection (manually rotten roots with black spots and other defects are manually removed, the roots are cleaned of side roots), alkaline cleaning ( caustic soda solution with a concentration of 3 ... 6% at a temperature of 80 ... 85 ° C for 5 min), peeling and alkali washing in a washing and cleaning machine, manual tertiary treatment, cutting or on columns (shavings) with a section of 3 × 5 mm, lengthe less than 5 mm, or cubes with sides measuring 5 ... 9 mm or a plate is not more than 4 mm in thickness, length and width of 9 ... 12 mm), drying and inspection. Celery roots are dried on five-belt conveyor dryers. The product enters the dryer, is laid out with the help of a stacker and moves along the conveyor belt, pouring from one belt to another. The initial drying temperature is 48 ... 50 ° C, the temperature in the middle sections of the dryer is 52 ... 55 ° C, at the final stage the temperature is 45 ... 40 ° C. Drying time 3.50 ... 4.13 hours. Humidity of the final product no more than 14% (in agreement with the consumer - with a mass fraction of moisture not more than 8%) [Handbook of the technologist of food-concentrate and vegetable-drying production / V.N. Gulyaev, N.V. Dremin, 3.A. Katz et al .; Ed. V.N. Gulyaev. - M .: Light and food industry, 1984. - 488 p., S. 330-332].

The disadvantages of this method is the significant energy consumption and low quality of the finished product and the duration of the drying process.

An object of the invention is to improve the quality of the finished product and increase the thermal efficiency of the drying process through the use of stepwise drying modes of celery roots in a dense layer using fluidization for mixing, reducing energy consumption to obtain the finished product, and intensifying the drying process.

The problem is achieved in that in the proposed method for the production of dried celery roots, including washing, inspection, alkaline cleaning, peeling and alkali washing, post-treatment, cutting, drying and inspection, the new is that drying is carried out in three time stages: the first stage, the chopped celery roots are treated in a dense layer with an air coolant stream with a temperature of 328 K and a speed of 2.0 m / s for 15 minutes; at the second stage - with a coolant air flow with a temperature of 338 K and a speed of 1.3 m / s for 45 minutes; at the third stage - with a flow of air coolant with a temperature of 348 K and a speed of 0.4 m / s for 25 minutes; throughout the entire drying process, celery roots are mixed in a fluidized bed for 3 s, and in the first stage, every 3 min; on the second - after 4 minutes; in the third - after 5 minutes.

The technical result consists in increasing the thermal efficiency and intensification of the drying process, improving the quality of the finished product through the use of stepwise drying modes of celery roots in a dense layer using fluidization for mixing, in reducing the energy consumption for obtaining the finished product.

- время, с; в - термограмма процесса сушки кореньев сельдерея Т_с=ƒ(τ), где Т_с - температура кореньев сельдерея.The drawing shows the kinetic dependences of the drying process of celery root cubes with rational operating parameters: a - diagram of the change in speed v and temperature T of the coolant over time, b - drying curve W = f (τ) and drying speed curve dW / dτ = f (W) celery root, where W is the moisture content of celery root,%,

- time, s; c - thermogram of the drying process of celery roots T _c = ƒ (τ), where T _c - temperature of celery roots.

Fresh celery roots were used as an object of study. The edged root crop of celery, which is being processed, must meet the technical specifications of OKP 97 3223 PCT RSFSR 749-88 in quality and meet the following requirements:

in appearance: the root crops are fresh, whole, healthy, unpolluted, the root crops are not deciduous, unkempt, the lower roots are cut to a length of not more than 50 mm from the root crop; with petioles of leaves no more than 20 mm;

by the size of root crops by the largest transverse diameter, mm, not less than 30;

the content of root crops with minor damage by pests, in% by weight, not more than 5;

slightly wilted, damaged by pests and diseases - 5 (damage by rodents is not allowed);

root crops of less than the established size: root crops from 20 to 30 mm - 10%; with healed cracks - 5%; with incorrectly cut leaves and roots - 10%;

by the presence of land adhered to root crops,% - 2.

The total number of tolerances, excluding the tolerance of root crops in size and slightly wilted leaves, should not exceed 15% by weight. In a batch of fresh root celery coming after winter storage, wilted root crops in an amount of not more than 20% by weight are allowed.

Celery root crops contain 90% water, 1.3% protein, 6.7% carbohydrates (including 5.5% mono- and disaccharides and 0.6% starch), 1.0% fiber, 0.1% organic acids (in terms of apple) and 1.0% ash. Root crops of celery a rich set of microelements: sodium - 77; potassium - 393; calcium - 63; magnesium - 33; phosphorus - 27; iron - 0.5 mg per 100 g of the edible part of the product. Celery root crops contain vitamins: β-carotene - 0.01; B ₁ - 0.03; B ₂ - 0.04; PP - 0.30; C - 8 mg per 100 g of the edible part of the product. The dry matter content in celery leaves varies between 9.7 ... 17.8 and sugar - in the range of 0.6 ... 1.4%. In root crops there is also a certain amount of starch and fiber - 0.6 ... 1.1% (in the leaves - 1.1 ... 1.3%). Sugars are represented by glucose, fructose and sucrose; in addition, xylose is present in leaves and root crops, and maltose and raffinose are present in root crops. Acetic and a small amount of butyric acid were found, and chlorogenic acid in the leaves. The energy value of celery root crops is 31 kcal / 100 g [Handbook technologist food-concentrate and vegetable drying production / V.N. Gulyaev, N.V. Dremina, Z.A. Katz et al .; Ed. V.N. Gulyaev. - M .: Light and food industry, 1984. - 488 p., S. 307-308].

The characteristic smell of celery is explained by a significant content of essential oils, which are especially abundant in seeds (2.4 ... 3.0%). Celery root crops contain a small amount of essential oil (5 ... 10 mg in terms of raw material). The oil obtained from celery seeds is a mobile, colorless liquid that contains palmitic, oleic, linoleic and petrozelinic acids. Like other spicy plants, celery has alkaloids and glucosides. The green parts of celery plants are rich in chlorophyll and other pigments; among them cryptocatin was found. Of the flavonoids, apnine should be mentioned.

The chemical composition is unstable and is closely dependent on soil and climatic conditions, cultivation techniques and variety.

Root crop form; rounded, flat-rounded, hoof-like (extended downward). Root crop surface color: grayish-white, yellow-white, brownish. The presence and location of lateral roots: many, few, throughout the root crop, in the lower half, in the lower third. The length of the root crop is 4 ... 10 cm; diameter - 4 ... 10 cm and more. The weight of the root crop: small (up to 200 g), medium (200-300 g), large (300-400 g), very large (more than 400 g).

Pulp color: white, grayish-white. Celery roots have a grayish-white color on the surface, white flesh and a strongly developed core.

Use celery in cooking in a fresh, boiled and fried form. Salads, soups, main dishes and side dishes are prepared from petioles and root vegetables. Fresh, dried and salted leaves and root vegetables are used as seasoning for various dishes, as well as canned vegetables and meat. The value of celery is determined by the characteristic taste that the essential oil gives it. Celery root essential oil is a colorless liquid with a strong smell and taste of celery. It contains limonene - 70 ... 80%, L-selinene - 12 ... 13, a mixture of alcohols and ethers - 5%, sedonolide, sedan and palmetic acid and traces of phenols.

As can be seen from the above, celery roots contain vitamins, organic acids, macro- and microelements, proteins and other substances vital to the body.

Celery has a beneficial effect on the metabolism in the body. This is facilitated by the high content of carotene, vitamins B, C, B ₁ , B ₂ , B ₆ , E, K, PP, folic acid, sugars, pectin, mineral salts of iron, potassium, calcium, phosphorus, magnesium, and valuable amino acids in the plant , organic acids, trace elements. The presence of potassium salts largely explains the beneficial effect of celery on the cardiovascular system, magnesium on the nervous system, and iron on hematopoiesis. Celery is especially useful for older people: it improves water-salt metabolism and has a positive effect on obesity and neurosis.

The plant has a diuretic, mild laxative, antiseptic, anti-inflammatory and wound healing properties. Raises the general tone of the body, increases physical and mental performance.

In folk medicine, celery infusion is used for diseases of the kidneys and bladder, gout, rheumatism. Water infusion of roots or leaves is treated with purulent wounds and ulcers. For this, crushed leaves are applied to wounds and ulcers.

Dried celery roots are used as an integral component of packaged soups, celery cream soups, soup mixes, flavoring salads and seasonings, as well as an independent product. Celery is also used as a seasoning for soups, cold dishes, canned foods and cheeses.

A method of manufacturing dried celery roots is as follows.

Celery has a hard peel with folds and wrinkles, among which, like among the stumps of chopped leaves and roots, various impurities accumulate. Before washing, in order to remove large contaminants and solid “outgrowths” from the surface, it is advisable to carry out friction cleaning for 0.5 min. Then, the celery roots are washed in a drum washer using a high-pressure water-jet washing with a hydromodule of 3: 1. After this, they are inspected: rotten roots with black spots and other defects are manually selected, while the roots are cleaned of side roots.

Then celery roots are cleaned. Peeling can be done mechanically and with an alkaline solution. The essence of the alkaline method consists in treating celery roots with a solution of caustic soda with a concentration of 3 ... 6% at a temperature of 80 ... 85 ° C for 5 minutes, removing the skin and washing off alkali in a washing and cleaning machine. Losses during cleaning, depending on the method of peeling and the quality of raw materials, range from 6 to 17%. Then celery roots are manually cleaned.

Due to the extremely solid consistency of celery roots, they are effectively cut using precision cutting machines.

Celery roots are cut either into columns (shavings) with a section of 3 × 5 mm, a length of at least 5 mm, or into cubes with a face size of 5 ... 9 mm, or onto plates (flakes) with a thickness of not more than 4 mm, length and width 9 ... 12 mm). The celery roots thus treated are placed in the working chamber of the dryer and dried in three time steps (drawing, diagram a). At the first stage, the chopped celery roots are treated in a dense layer with an air flow with a temperature of 328 K and a speed of 2.0 m / s for 15 minutes.

At the second stage, celery roots are treated in a dense layer with an air coolant stream with a temperature of 338 K and a speed of 1.3 m / s for 45 minutes.

At the third stage, celery roots are treated in a dense layer with an air coolant stream with a temperature of 348 K and a speed of 0.4 m / s for 25 minutes.

Throughout the entire drying process, celery roots are mixed in a fluidized bed for 3 s, with the first step every 3 minutes at a speed of 2.8 m / s; on the second - after 4 minutes at a speed of 2.4 m / s; in the third - after 5 minutes at a speed of 1.6 m / s. Using air mixing allows more uniform drying of celery roots.

The following approach is proposed to justify the choice of stepwise drying regimes of celery roots. Its essence consists in dividing the drying process into three stages of different duration, at each of which, depending on the law of change in the current humidity of celery, its rational technological mode of drying is selected, i.e. The temperature and velocity of the coolant assumed fixed values, the values of which were determined experimentally. Moreover, their selection at each stage must be carried out in accordance with the restrictions imposed by technological requirements on the quality of the finished product.

Such a three-stage heat supply mode, i.e. the alternation of temperature and hydrodynamic processing in a dense layer and a change in the duration of the stages is due to the following. At the beginning of the drying process, mechanically bound moisture is removed, i.e. moisture of microcapillaries, macrocapillaries and wetting. The main parameter affecting the intensity of moisture removal during this period is the coolant speed. Therefore, it is most advisable to use drying at a high speed and low temperature at the initial moment of drying. Drying at the first stage most fully meets this requirement.

As the indicated moisture is removed, the velocity of the coolant as a determining factor in the intensity of the process loses its significance. With further drying, osmotic, poly- and monoadsorption moisture is removed, the removal rate of which is most affected by the temperature of the coolant, since only the temperature of the coolant determines the intensity of internal moisture transfer. Therefore, in the second, third and fourth stages, drying is preferable to carry out at a decreasing speed and increasing temperature of the coolant. Thus, if at the beginning of the process the drying speed is mainly limited by the coolant speed, then by its temperature. This leads to a change in the ratio of the durations of the drying stages.

Adapted in accordance with the basic kinetic laws of the drying process, the coolant supply at the three stages of drying the product allows you to choose rational drying modes taking into account changes in the moisture content of the product during the drying process.

Celery roots are dried to a final moisture content of the finished product of 14%. Such treatment of celery roots can increase the energy efficiency of the process, reduce the drying time of celery and improve its quality.

A method of manufacturing dried celery roots is illustrated by the following example.

An example implementation of a method for the production of dried celery roots.

First, celery roots are subjected to friction (mechanical) cleaning for 0.5 min to remove large contaminants and solid “outgrowths” from their surface. Then, the celery roots are washed in a drum washer using a high-pressure water-jet washing with a hydromodule of 3: 1. After this, they are inspected: rotten roots with black spots and other defects are manually selected, while the roots are cleaned of side roots.

Then celery roots are cleaned. Peeling can be done mechanically or alkaline. The essence of the alkaline method consists in treating celery roots with a solution of caustic soda with a concentration of 3 ... 6% at a temperature of 80 ... 85 ° C for 5 minutes, removing the skin and washing off alkali in a washing and cleaning machine. Losses during cleaning, depending on the method of peeling and the quality of raw materials, range from 6 to 17%. Then celery roots are manually cleaned.

Due to the extremely solid consistency of celery roots, they are effectively cut using precision cutting machines.

Celery roots are cut into cubes with a face size of 5 ... 9 mm and placed in the working chamber of the dryer and subjected to drying in three time steps (drawing, diagram a).

At the first stage, the chopped celery roots are treated in a dense layer with an air flow with a temperature of 328 K and a speed of 2.0 m / s for 15 minutes. At the beginning of the drying process, mechanically bound moisture is removed, i.e. moisture of microcapillaries, macrocapillaries and wetting.

The technological parameters of the coolant (temperature 328 K and speed 2.0 m / s) and the duration of the first stage (15 min) are interrelated and their choice is due to the fact that they are complexly aimed at removing mainly mechanically bound moisture, the evaporation of which dominates at the beginning of the drying process. The main parameter affecting the intensity of moisture removal during this period is the coolant speed. Therefore, it is most expedient to use drying at the initial moment of drying with a high speed (2.0 m / s) and a low temperature (328 K).

The use of a coolant velocity of less than 2.0 m / s, for example 1.7 m / s, will reduce the hydrodynamic effect of tearing the liquid film from the surface of the product and, as a result, reduce the evaporation efficiency.

The use of a coolant velocity of more than 2.0 m / s, for example 2.4 m / s, will lead to soaking or even entrainment of particles of celery roots, which will cause increased energy consumption during fan operation.

The use of a coolant with a temperature of less than 328 K, for example, 320 K, will lead to insufficiently rapid heating of the liquid film and, as a result, to a decrease in the efficiency of its evaporation.

The use of a coolant with a temperature of more than 328 K, for example 331 K, will lead to increased energy consumption and incomplete use of the energy potential of the coolant.

An analysis of the drying curves and the drying speed of celery roots (drawing, graph b) shows that there are three periods: heating, constant and decreasing drying speeds. Analysis of the drying curve of celery roots (drawing, graph b) shows that the duration of the warm-up period is very significant and amounts to 14.5 ... 15.0 min. It is this consideration that justifies the choice of the duration of the first stage - 15.0 minutes.

With a shorter duration of the first stage, for example 10 min, mechanically bound moisture did not have time to completely evaporate and the cubes of celery roots tended to stick together and clump. With a longer duration of the first stage, for example, 19 min, mechanically bound moisture completely evaporated, and further heat supply was not rational from an energy point of view.

At the second stage, celery roots are treated in a dense layer with a flow of coolant (air) with a temperature of 338 K and a speed of 1.3 m / s for 45 minutes. The technological parameters of the coolant (temperature 338 K and speed 1.3 m / s) and the duration of the second stage (45 min) are interrelated and their choice is due to the fact that they are complexly aimed at removing osmotically and polyadsorption bound moisture. For intensive removal of osmotically and polyadsorption bound moisture, it is advisable to increase the temperature of the coolant and reduce its speed. Therefore, it is most advisable at this time of drying to use a coolant with a speed of 1.3 m / s and a temperature of 338 K. Using a coolant with a speed of less than 1.3 m / s, for example 1.0 m / s, will reduce the evaporation efficiency osmotically and polyadsorption bound moisture. The use of a heat carrier with a speed of more than 1.3 m / s, for example 1.7 m / s, will lead to the fact that the coolant has been in contact with particles of celery roots for a short time and does not have time to give its heat to them: this will cause increased energy consumption for the process drying.

The use of a coolant with a temperature of less than 338 K, for example 332 K, will lead to insufficiently fast heating of celery root particles and, as a result, to a decrease in evaporation efficiency. The use of a coolant with a temperature of more than 338 K, for example 344 K, will lead to increased energy consumption and incomplete use of the energy potential of the coolant.

Analysis of the drying curve of celery roots (Fig. 1, b) shows that the duration of removal of osmotically and polyadsorption bound moisture is 45 minutes. It is this consideration that justifies the choice of the duration of the second stage - 45 minutes.

With a shorter duration of the second stage, for example 40 min, the osmotically and polyadsorption bound moisture did not have time to completely evaporate. With a longer duration of the second stage, for example, 48 min, the osmotically and polyadsorption bound moisture completely evaporated, and further heat supply was not rational from an energy point of view.

At the third stage, celery roots are treated in a dense layer with an air coolant stream with a temperature of 348 K and a speed of 0.4 m / s for 25 minutes. Technological parameters of the coolant (temperature 348 K and speed 0.4 m / s) and the duration of the third stage (25 min) are interrelated and their choice is due to the fact that they are complexly aimed at removing mainly monoadsorption bound moisture. For intensive removal of monoadsorption bound moisture, it is advisable to increase the temperature of the coolant and reduce its speed. Therefore, it is most advisable to use a coolant at a speed of 0.4 m / s and a temperature of 348 K.

The use of a coolant with a speed of less than 0.4 m / s, for example 0.2 m / s, will reduce the efficiency of evaporation of monoadsorption bound moisture.

The use of a heat carrier with a speed of more than 0.4 m / s, for example 0.6 m / s, will lead to the fact that the heat carrier has been in contact with particles of celery roots for a short time and does not have time to give its heat to them: this will cause increased energy consumption for the process drying.

The use of a coolant with a temperature of less than 348 K, for example 343 K, will lead to insufficiently fast heating of celery root particles and, as a result, to a decrease in the evaporation efficiency.

The use of a coolant with a temperature of more than 348 K, for example 351 K, will lead to increased energy consumption and incomplete use of the energy potential of the coolant.

An analysis of the drying curve of celery roots (drawing, graph b) shows that the duration of the removal of monoadsorption bound moisture is 25 minutes. It is this consideration that justifies the choice of the duration of the third stage - 25 minutes.

With a shorter duration of the third stage, for example, 20 min, monoadsorption bound moisture did not have time to completely evaporate. With a longer duration of the third stage, for example, 30 min, monoadsorption bound moisture completely evaporated, and further heat supply was not rational from an energy point of view.

The choice of the hydrodynamic (high-speed) regime for drying celery root cubes with air (at the first stage of drying, the coolant speed during drying in a dense layer is 2.0 m / s for 15 minutes, at the second stage - 1.3 m / s for 45 minutes; at the third stage - 0.4 m / s for 25 min) was experimentally selected and depended on the nature of the change in humidity of the celery root cubes during drying. With drying, the moisture of the cubes of celery roots decreased, their mass also became less. When drying celery roots, shrinkage was observed, i.e. reducing the size of the cubes. Therefore, for uniform processing of celery root cubes, an adjustable heat supply was required, which was ensured by this law of change in the coolant velocity (drawing, diagram a, see type A, B and C). Failure to comply with this time and speed regimes led either to overdrying and burning of celery roots, or, on the contrary, to underdrying and obtaining a product with high humidity, which was a violation of the applicable specifications.

The temperature regime for drying the celery root cubes was experimentally selected and depended on the nature of the change in product moisture during drying. As drying, the moisture of the celery root cubes decreased, their temperature increased. In order for the temperature of celery roots not to exceed the maximum permissible temperature (above which thermal decomposition of valuable nutrients was observed: melanoid formation, thermolysis, etc.), a gradual and controlled change in the temperature of the coolant was necessary to achieve uniform processing of celery root cubes. Failure to comply with this time and temperature conditions led either to overdrying and thermal decomposition of celery roots, or, conversely, to underdrying and obtaining a product with high humidity, which was a violation of the current technical conditions.

Throughout the entire drying process, celery roots are mixed in a fluidized bed for 3 s, with the first step every 3 minutes at a speed of 2.8 m / s; on the second - after 4 minutes at a speed of 2.4 m / s; in the third - after 5 minutes at a speed of 1.6 m / s (drawing, diagram a). The use of the above speeds at different stages of drying allows for uniform mixing in the fluidized bed. The values of these velocities (2.8 m / s, 2.4 m / s, 1.6 m / s) were established experimentally. At the same time, the coolant flow turbulizes the product layer, mixes it and evens out the average humidity of the particles of celery roots along the volume of the layer. As a result of collisions of particles of celery roots with stirring, gas layers are also disturbed and stagnant zones are eliminated. The use of a pseudo-boiling layer for mixing particles of celery roots allows for more uniform drying. Using a mixing time of less than 3 s, for example 2 s, will not allow to evenly mix the layer of particles of celery roots. Using a mixing time of more than 3 s, for example 6 s, will lead to unnecessary, unnecessary energy consumption for mixing the layer of particles of celery root.

The use of a different time interval between mixing (3 min at the first stage of drying, then 4 min at the second stage of drying and 5 min at the third stage of drying) is due to the different rate of change in the adhesive properties of celery roots. If, at the beginning of drying, the celery root cubes stick together well due to high humidity and need to be mixed more often to prevent conglomeration, then as the surface moisture evaporates, the stickiness of their surfaces decreases, so the need for unnecessarily frequent mixing disappears. Another argument in support of the proposed mixing time intervals is different heating rates (see drawing, thermogram c) of celery root cubes: cubes located on the surface of the gas distribution grid, i.e. directly in contact with fresh coolant, and cubes of celery roots located in the upper part of the layer. The difference between the temperatures of these layers decreases as drying and the need for frequent mixing also disappears. These time intervals were established experimentally.

Thus, the best option for drying celery roots for all quality and energy indicators is the above method with the rationale for each parameter given. This is due to the uniformity of drying over the entire volume of the cubes and the intense evaporation of moisture from their surface. A reduction in the rate of internal heat transfer is achieved in comparison with the rate of movement of moisture and its evaporation from the surface of cubes of celery root roots of this size.

In this case, the heating of the cubes of celery roots occurs more slowly than moisture evaporates from them, which completely eliminates overheating of the product and ensures its high quality. From the energy point of view, the proposed option allows us to provide the most rational energy consumption per 1 kg of the obtained product, which is explained by the hydrodynamics of the process, which changes in time not only by pulsating changes in speed with alternating drying time intervals in a dense and fluidized bed, but also by the chosen equivalent particle size. In this case, the pressure drop in the product layer, corresponding to the mass and heat flow of the coolant for a given processing mode, provides minimal energy consumption for obtaining a quality product. The drying time of celery roots is 85 minutes according to the proposed technology and 3.50 ... 4.13 hours according to the factory. The quality of the dried roots must meet the requirements of GOST 16731-71 “White roots of parsley, celery, dried parsnip”. They were investigated by organoleptic and physico-chemical indicators (see table).

Table
Organoleptic and physico-chemical characteristics of dried celery roots, prepared according to the factory and the proposed technology The name of indicators Characterization of dried white roots cooked according to factory technology proposed technology Appearance Cubes with a face size of 5 ... 9 mm White roots in the form of chips, cubes or plates. Cubes with a face size of 5 ... 9 mm Consistency Shavings and plates are elastic, for dried white roots with low humidity - fragile. Hard cubes Taste and smell Peculiar to dried celery without extraneous smacks and odors Color White with a yellowish tint A brownish shade is allowed - for the second grade Shape and dimensions: shavings Evenly sliced with a thickness of not more than 3 mm, a width of not more than 5 mm and a length of not less than 5 mm. cubes Evenly chopped side sizes 5 ... 9 mm records Evenly sliced not more than 4 mm thick, not more than 12 mm long and wide Moisture content, % 14.0 Mass fraction of chips, cubes or plates fried, with black spots and remnants of the skin,% 6 6 including the mass fraction of chips, cubes or plates with black spots and skin residues,% 3 3 Mass fraction of metallic impurities (particles not more than 0.3 mm in the largest linear dimension),% 0,0003 Mass fraction of mineral impurities (sand),% 0.01

Determination of these indicators allows you to identify structural changes in dried roots that occur during their drying, and to evaluate the quality of the resulting product.

Evaluation of the effectiveness of the method of production of dried celery roots according to the proposed and factory technology was carried out by the value of specific energy consumption per 1 kg of finished product.

The specific energy consumption per 1 kg of dried celery roots, prepared according to the factory technology, is 4980 kJ / kg. The value of specific energy consumption per 1 kg of dried celery roots, prepared according to the proposed technology, is 4740 kJ / kg.

Thus, the above analysis shows the high thermal efficiency of the proposed technology for the production of dried celery roots in comparison with the factory technology.

The proposed method for the production of dried celery roots has the following advantages:

- a significant reduction in the drying time from 3.50 ... 4.13 hours in the factory technology to 85 minutes in the proposed;

- obtaining dried celery roots with a higher content of valuable nutrients (proteins, carbohydrates, etc.);

- a significant reduction in energy consumption for the drying process of celery roots.

Claims (1)

A method for the production of dried celery roots, including washing, inspection, alkaline cleaning, peeling and alkali washing, post-treatment, cutting, drying and inspection, characterized in that the drying is carried out in three time steps: at the first stage, the cut celery roots are processed in a dense layer air flow with a temperature of 328 K and a speed of 2.0 m / s for 15 min; at the second stage - with a coolant air flow with a temperature of 338 K and a speed of 1.3 m / s for 45 minutes; at the third stage - with a flow of air coolant with a temperature of 348 K and a speed of 0.4 m / s for 25 minutes; throughout the entire drying process, celery roots are mixed in a fluidized bed for 3 s, and in the first stage, every 3 min; on the second - after 4 minutes; in the third - after 5 minutes.

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