RU2256379C1 - Method of producing dried jerusalem artichoke - Google Patents

Abstract

FIELD: food-processing industry, in particular, production of powder from tubers of Jerusalem artichoke.

SUBSTANCE: method involves washing, sorting, inspecting, gauging, cleaning and additionally cleaning basic material; cutting prepared material, blanching and exposing to sulfitation; providing drying procedure followed by grinding. Drying procedure is provided in two short-time sequentially performed stages, which are provided in alternation multiple times: first stage involving subjecting cubic pieces of Jerusalem artichoke of predetermined size and supplied in dense layer to treatment with overheated steam of atmospheric pressure for predetermined time interval, and second stage involving treatment in fluidized bed for predetermined time at predetermined temperature.

EFFECT: improved quality of ready product and increased thermal efficiency of drying procedure.

3 dwg, 1 tbl

Description

The invention relates to the food industry, namely the production of dried Jerusalem artichoke, and can be used to produce powder from Jerusalem artichoke tubers.

A known method for the production of dried Jerusalem artichoke, which includes washing, sorting, inspection, calibration, cleaning, tertiary treatment, cutting, blanching and sulfite, drying and subsequent grinding. Jerusalem artichoke is dried on conveyor and drum dryers. The product enters the dryer, is laid out using a conveyor and moves along the conveyor belt, pouring from one belt to another. The initial drying temperature is 95 ... 100 ° C, the temperature in the middle sections of the dryer is 80 ° C, and at the final stage the temperature is 50 ... 60 ° C. Heating of the heat-carrying part of the dryer is carried out using steam, hot air or tubular electric heaters (TEN). The moisture content of the final product 14% [Golubev V.I., Volkova I.V. Jerusalem artichoke. Composition, properties, processing, applications. - Astrakhan: Volga, 1995 - 81 p.].

The disadvantages of this method are significant energy consumption, 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 superheated atmospheric pressure steam and alternating processing regimes of Jerusalem artichoke in a fluidized and dense bed, reducing energy costs for obtaining the finished product, and intensifying the drying process.

The problem is achieved in that in the proposed method for the production of dried Jerusalem artichoke, including washing, sorting, inspection, calibration, cleaning, post-treatment, cutting, blanching and sulphite drying, drying and subsequent grinding, the new is that drying is carried out in two successively repeatedly alternating short-term stage: at the first stage, Jerusalem artichoke cubes with dimensions 6 × 6 × 6 mm are treated in a dense layer with superheated steam of atmospheric pressure, and the duration of the first stage for the first 4.5 minutes is 90 s, then for 16 minutes - 120 s and, finally, for 8 minutes - 240 s, and in the second stage, the treatment is carried out in a fluidized bed, the duration of which during the entire drying process is 4 s; moreover, the temperature of superheated steam during drying during the first 270 s is - 408 K, then within 960 s - 413 K and, finally, within 480 s - 418 K, and the speed of superheated steam during drying in a dense layer during the first 1230 s is 2.8 m / s, then for 480 s - 1.85 m / s; and when drying in a fluidized bed during the first 1230 s - 10.1 m / s, then within 480 s - 8.0 m / s.

The technical result consists in increasing the thermal efficiency and intensification of the drying process, improving the quality of the finished product due to the use of superheated atmospheric pressure steam and alternating processing regimes of Jerusalem artichoke in a fluidized and dense bed, and reducing the energy consumption for obtaining the finished product.

The drawing shows the kinetic dependences of the drying process of Jerusalem artichoke cubes with rational operating parameters: a - diagram of the change in the velocity ν _n and temperature T of superheated steam over time, b - the drying curve U = f (τ) (1) and the drying velocity curve dU / dτ = f (U) (2) Jerusalem artichoke with superheated steam, where U is the moisture content of Jerusalem artichoke, kg / kg, τ is time, s; c - thermogram of the process of drying Jerusalem artichoke with superheated steam T _k = f (τ), where T _k is the temperature of Jerusalem artichoke.

As an object of study, fresh, freshly chilled Jerusalem artichoke tubers with a highly developed fleshy root were used. Jerusalem artichoke tubers can be of various shapes, different colors (white, yellow, lilac-violet, pink-red). They vary in size (from 10 grams to 150 or more grams).

Jerusalem artichoke tubers coming to processing must meet the requirements of TU 10-1155-93 in quality and meet the following requirements:

in appearance: the root crops are fresh, unfading, whole, unpolluted, not affected by agricultural pests, peeled of fibrous roots;

by the size of root crops, mm, not less: by the largest transverse diameter - 20; smallest transverse diameter 10 mm;

according to the content of root crops,%, no more: with mechanical damage - 5; with serif root head, branched, with fibrous roots - 15; branched - no; damaged by pests - 3; withered - 5;

roots infected with diseases, crushed on more than 1/3 of the surface, frozen and frost-bitten, and also rotten - not allowed;

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

The total number of permissible deviations should not exceed 25% by weight, and the tolerances for each indicator should not exceed the norms established for them.

Tubers contain 85% water. Jerusalem artichoke tubers contain protein up to 3.2% (in terms of dry matter) and accumulate up to 16 ... 18% of inulin polysaccharide, easily absorbed by the body. The hydrolysis of this polysaccharide leads to fructose sugar, which is harmless to diabetics. Therefore, the consumption of tubers has a positive effect on the metabolism of diabetes. Tubers are low in fiber (about 4%) and rich in micronutrients.

Jerusalem artichoke excels among cultivated plants and in the accumulation of silicon. The content of this element in tubers in terms of dry matter reaches 8%. By the content of vitamins B ₁ , B ₂ and C, Jerusalem artichoke is richer than potatoes, carrots and beets more than three times.

Dried Jerusalem artichoke powder is used in the food industry as an additive in food production.

Jerusalem artichoke is one of the most important inulin-containing plants in the whole world. From it, preparations are obtained to remove heavy metals, pesticides, pesticides, radioactive elements from the body. Due to the high silicon content (up to 80%) in an easily digestible form, it is especially useful for the elderly.

Ground pear (Jerusalem artichoke) serves as the basis for the production of fructose sugar and syrup, ethyl alcohol, fortified foods of high biological value. So, the pharmacy biologically active additive “Longevity” is made from Jerusalem artichoke tubers, has immunoprotective properties and is recommended by the RF Ministry of Health for widespread use as a therapeutic and prophylactic agent.

In addition, Jerusalem artichoke contains vitamins, organic acids, macro- and microelements, proteins, pectins, bitterness and other substances vital to the body. In this regard, it is useful for inflammatory diseases of the mucous membrane of the stomach, small and large intestines, diseases of the liver, gall bladder, kidneys, and various allergic conditions. It reduces blood sugar, improves metabolism, helps to remove cholesterol from the body. Jerusalem artichoke helps cleanse the body of radioactive and other harmful substances, enhances the activity of the heart, calms the nervous system, and increases the body's defenses.

A method of manufacturing dried Jerusalem artichoke is as follows.

Jerusalem artichoke, previously inspected (substandard roots were manually selected) and washed (in running water with a water: product ratio of 3: 1), are cut into 6x6x6 mm cubes. Then the Jerusalem artichoke cubes are blanched at a temperature of 95 ... 98 ° C for 3 ... 5 minutes and treated with a solution of sodium bisulfite of 0.20 ... 0.25% concentration for 3 minutes.

The Jerusalem artichoke thus treated is placed in the working chamber of the dryer and subjected to drying in two successively repeatedly alternating short-term steps (Fig. 1a). At the first stage, Jerusalem artichoke cubes are treated in a dense layer with superheated steam of atmospheric pressure, and the duration of the first stage for the first 4.5 minutes is 90 s, then for 16 minutes - 120 s and, finally, for 8 minutes - 240 s, and at the second stage, the treatment is carried out in a fluidized bed, the duration of which during the entire drying process is 4 s.

The temperature of superheated steam during drying during the first 270 s is - 408 K, then for 960 s - 413 K and, finally, for 480 s -418 K, and the speed of superheated steam during drying in a dense layer during the first 1230 s it is 2.8 m / s, then for 480 s - 1.85 m / s; and when drying in a fluidized bed during the first 1230 s - 10.1 m / s, then within 480 s - 8.0 m / s.

From the analysis of the drying curves and the drying speed of Jerusalem artichoke (figb), it is seen that there are three periods: heating, constant and decreasing drying speeds. One of the main reasons for the intensification of the drying process of Jerusalem artichoke with superheated steam of atmospheric pressure is the rapid heating of the product to a saturation temperature T _s = 373 K, which is due to condensation of steam on the surface of the particles due to their relatively low initial temperature (Fig. 1c).

Analysis of the drying curves of Jerusalem artichoke (figb) shows that the duration of the heating period is very significant and is 4 ... 5 minutes At the same time, most of the moisture, both condensed from steam and its own product, is actively absorbed by the product. In the period of heating up the drying process of Jerusalem artichoke, qualitative changes in substances occur. So, for example, as a result of denaturation, proteins coagulate, which entails the compaction of flooded gels and the extrusion of a significant part of the moisture contained in them, which is absorbed by carbohydrates. Jerusalem artichoke carbohydrates are high molecular weight carbohydrate compounds characterized by structural characteristics and molecular chain sizes. The swelling of Jerusalem artichoke is also due to the swelling of the proteins contained in them, which absorb water and bind it adsorptively and osmotically.

Due to the high heat transfer coefficients during steam condensation on the surface of the cubes during the heating period, the temperature rises very quickly (Fig. 1c) and with further drying, moisture is removed from the product in the form of steam. The moisture content of the finished product is 14%.

Such processing of Jerusalem artichoke allows you to increase the energy efficiency of the process, reduce the drying time of Jerusalem artichoke and improve its quality.

The method of obtaining Jerusalem artichoke is illustrated by the following example.

An example implementation of the method of obtaining dried Jerusalem artichoke. Jerusalem artichoke, previously cleaned and washed, which was cut into cubes with a side size of 6 × 6 × 6 mm, was used as the object of study.

Before drying, the cubes of Jerusalem artichoke are blanched at a temperature of 96 ° C for 4 minutes and treated with a solution of sodium bisulfite of 0.20% concentration for 3 minutes.

The Jerusalem artichoke cubes thus treated are placed in the working chamber of the dryer and are dried in two successively repeatedly alternating short-term steps (Fig. 1a). At the first stage, Jerusalem artichoke cubes are treated in a dense layer with superheated steam of atmospheric pressure, and the duration of the first stage for the first 4.5 minutes is 90 s, then for 16 minutes - 120 s and, finally, for 8 minutes - 240 s, and at the second stage, the processing is carried out in a fluidized bed, the duration of which during the entire drying process is 4 s, the temperature of superheated steam during the first 270 s is 408 K, then for 960 s - 413 K and finally for 480 s - 418 K, and the speed of superheated steam by drying in a dense layer in the first to 1230 is 2.8 m / s, then during the 480 s - 1.85 m / s; and when drying in a fluidized bed during the first 1230 s - 10.1 m / s, then within 480 s - 8.0 m / s.

The choice of the duration of the first stage (90 s) is due to the fact that steam condensation occurs at the beginning of the drying process. With more frequent stirring, i.e. when the duration of the first stage was less than 90 s, for example 80 s, there was a breakdown of the condensate film from the surface of Jerusalem artichoke cubes during processing in a fluidized bed, which led to incomplete and poor-quality processing. And, conversely, when the duration of the first stage was more than 90 s, for example, 100 s, the surface of Jerusalem artichoke cubes became deoxidized due to their overmoistening.

At the second stage, the processing of Jerusalem artichoke is carried out in a fluidized bed, the duration of which is 4 s. When the duration of the second stage was less than 4 s, for example 2 s, there was insufficiently uniform and complete mixing of Jerusalem artichoke cubes during processing in a fluidized bed, which led to incomplete and poor-quality drying. And, on the contrary, when the duration of the second stage was more than 4 s, for example 6 s, there was a breakdown of the condensate film from the surface of Jerusalem artichoke cubes during processing in a fluidized bed, which led to drying out of Jerusalem artichoke cubes and unreasonably high energy costs.

The choice of the speed regime for processing Jerusalem artichoke cubes with superheated steam (the speed of superheated steam during drying in a dense layer during the first 1230 s is 2.8 m / s, then for 1.85 m / s for 480 s) was experimentally selected and depended on the nature changes in product moisture during drying. With drying, the humidity of Jerusalem artichoke cubes decreased, their mass also became less. When drying Jerusalem artichoke, shrinkage was observed, i.e. reducing the size of the cubes. Therefore, for uniform processing of Jerusalem artichoke cubes, an adjustable heat supply was required, which was provided by this law for changing the speed of superheated steam (Fig. 1a, see view A, B and C). Failure to comply with this time and speed regimes led either to overdrying and burning of Jerusalem artichoke, or, conversely, to underdrying and obtaining a product with high humidity, which was a violation of existing specifications.

At the second stage, when drying Jerusalem artichoke in a fluidized bed, the speed of superheated steam was 10.1 m / s for the first 1230 s, then 8.0 m / s for 480 s (Fig. 1a). The choice of the high-speed regime for processing Jerusalem artichoke cubes with superheated steam was experimentally selected and depended on the nature of the change in product moisture during drying. With drying, the humidity of Jerusalem artichoke cubes decreased, their mass also became less. Therefore, for uniform processing of Jerusalem artichoke cubes in a fluidized bed, a gradual and controlled change in the speed of superheated steam was required. Failure to comply with this time and speed regimes led either to the ablation and drying out of Jerusalem artichoke, or, conversely, to insufficiently uniform boiling and obtaining a product with high humidity, which was a violation of the applicable specifications.

The temperature of superheated steam during drying during the first 270 s is - 408 K, then for 960 s - 413 K and, finally, for 480 s - 418 K. The choice of the temperature regime for processing Jerusalem artichoke cubes with superheated steam was selected experimentally and depended on the nature of the change in humidity of the product during drying. With drying, the humidity of Jerusalem artichoke cubes decreased, their temperature increased. In order for the temperature of Jerusalem artichoke 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 superheated steam was required to achieve uniform processing of Jerusalem artichoke cubes. Failure to comply with this time and temperature conditions led either to overdrying and thermal decomposition of Jerusalem artichoke, or, conversely, to underdrying and obtaining a product with high humidity, which was a violation of the applicable specifications.

Thus, the best option for processing Jerusalem artichoke for all quality and energy indicators is the above method with the rationale for each of the given parameters. 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 Jerusalem artichoke cubes of this size.

In this case, Jerusalem artichoke cubes are heated 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 flux of superheated steam for a given processing mode, provides minimal energy consumption for obtaining a quality product. Drying time for Jerusalem artichoke is 28.5 minutes according to the proposed technology and 45 minutes according to the factory.

The study of quality indicators of Jerusalem artichoke was carried out in accordance with TU 9164-001-17912573-2001 “Powder from Jerusalem artichoke tubers”. It was investigated by organoleptic and physico-chemical indicators. The determination of these indicators allows you to identify structural changes in Jerusalem artichoke that occur during its drying, and to assess the quality of the resulting product.

Organoleptic and physico-chemical characteristics of dried Jerusalem artichoke are given in the table.

Table
Organoleptic and physico-chemical characteristics of dried Jerusalem artichoke prepared according to the factory and proposed technology The name of indicators Characteristics of chicory, cooked by factory technology proposed technology Appearance Parts of tubers in cubes (10-20 × 10-20 × 10-20 mm) Parts of tubers in cubes 6 × 6 × 6 mm Color From cream to light brown in various shades Light gray to cream Taste and smell Inherent to Jerusalem artichoke without extraneous taste and smell Moisture content, % 14.0 Mass fraction of total sugar,% 60.0 65.0 Mass fraction of ash insoluble in 10% hydrochloric acid,% 0.10 0,07 Mass fraction of mineral impurities,% 0.01 Metallomagnetic impurity, mg / kg of product 3.0 Barn pest infestation, impurities Not allowed

Evaluation of the effectiveness of the production method of dried Jerusalem artichoke according to the proposed and factory technology was carried out by the value of specific energy consumption per 1 kg of finished product. The value of specific energy consumption per 1 kg of dried Jerusalem artichoke, prepared according to the factory technology, is 5160 kJ / kg. The value of specific energy consumption per 1 kg of dried Jerusalem artichoke, prepared according to the proposed technology, is 4530 kJ / kg.

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

The proposed method for the production of dried Jerusalem artichoke has the following advantages:

- a significant reduction in the drying time from 45 minutes in the factory technology to 28.5 minutes in the proposed;

- obtaining Jerusalem artichoke with a higher content of valuable nutrients (proteins, carbohydrates, etc.);

- a significant reduction in energy consumption for the drying process of Jerusalem artichoke.

Claims (1)

Method for the production of dried Jerusalem artichoke, including washing, sorting, inspection, calibration, cleaning, tertiary treatment, cutting, blanching and sulfite, drying and subsequent grinding, characterized in that the drying is carried out in two sequentially alternating short-term stages, at the first stage Jerusalem artichoke cubes with dimensions 6 × 6 × 6 mm are treated in a dense layer with superheated steam of atmospheric pressure, and the duration of the first stage for the first 4.5 minutes is 90 s, then for 16 minutes - 120 s and, finally, for 8 minutes - 240 and in the second stage the treatment is carried out in a fluidized bed, the duration of which during the entire drying process is 4 s, and the temperature of the superheated steam during the first 270 s is –408 K, then for 960 s – 413 K, and finally for 480 s - 418 K, and the speed of superheated steam during drying in a dense bed during the first 1230 s is 2.8 m / s, then for 480 s - 1.85 m / s, and when drying in a fluidized bed for the first 123/0 s - 10.1 m / s, then for 480 s - 8.0 m / s.

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