RU2520142C2 - Fruit-and-vegetable chips production method - Google Patents

Abstract

FIELD: food industry.

SUBSTANCE: invention relates to food industry, in particular, to food concentrates production in apparatus using UHF-energy and may be used for fruit-and-vegetable chips production. The method involves sorting, washing, inspection, calibration, cutting, blanching, treatment with a water solution, drying and packaging. Before moisture-and-heat treatment, loaded and cut fruit-and-vegetable raw material is preliminarily heated with an exhaust heat medium. Moisture-and-heat treatment is performed in five sequential stages The ready product is cooled and packaged into sealed bags.

EFFECT: invention usage allows to manufacture a ready product.

3 dwg, 1 tbl

Description

The invention relates to the food industry, in particular to the production of food concentrates in devices using microwave energy, and can be used for the production of fruit and vegetable chips, including apple, pumpkin and pear.

A known method of producing a food product from fruit and vegetable raw materials [US Pat. RF №2304885, IPC A23L 1/212, A23L 3/00. Method for the production of a food product from fruit and vegetable raw materials [Text] ./ A.V. Gurevich, V. B. Pento, A. A. Korolev, S. P. Anikeeva; Applicant and patent holder A.V. Gurevich. - No. 2006126611/13; declared 07/24/2006; publ. August 27, 2007], including preparation of raw materials, drying to intermediate humidity, treatment with chitosan solution, drying in a gaseous coolant stream with a pulsed supply of microwave energy to a residual moisture content of 3-5%, packaging in an oxygen-free medium in packages of combined polymer-foil material -polymer.

The disadvantages of this method are the low quality of the finished product.

A known method of continuous drying of food products using convective and microwave energy supply [US Pat. RF №2369284, IPC А23L 3/01, А23В 7/01. The method of continuous drying of food products using convective and microwave energy supply [Text] / S.T. Antipov, A. A. Selin, A. M. Barbashin, D. A. Kazartsev; Applicant and patent holder: State Educational Institution of Higher Professional Education Voronezh State Technological Academy. - No.2008120287 / 13; declared 05/21/2008; publ. 10.10.2009], including loading the product, drying and removing the product, while the drying process is carried out in three stages. At the first stage, the product is preheated using a microwave energy supply to the temperature of the wet thermometer. At the second stage, upon reaching a period of constant drying speed, by the combined action of a continuous convective and periodic microwave energy supply. At the third stage, in the period of the decreasing drying speed, drying is carried out by the combined action of a continuous convective and continuous microwave energy supply.

The disadvantages of this method are the increased specific energy consumption.

The closest in technical essence and the achieved effect is a method of producing a food product from apples [Pat. RF №2277351, IPC А23L 1/212, А23В 7/02. Method for the production of a food product from apples [text] ./ A.V. Gurevich, A.A. Korolev, V.B. Pento, V.Ya. Yavchunovsky; applicant and patent holder A.The. Gurevich. - No. 2005117180/13; declared 06/06/2005; publ. 10.06. 2006], which includes slicing apples into slices 2-4 mm thick, processing with an aqueous solution at a temperature of 60-75 ° C for 3-6 minutes, after which drying is carried out by a convective method at a coolant temperature of not higher than 90 ° C and its consumption of at least 40 m ³ per 1 kg of prepared apples to a residual moisture content of 28-31%, and then dried in a gaseous coolant stream with a pulsed supply of microwave energy to a residual moisture content of 5-7% and packaged in an oxygen-free environment in packages made of a combined polymer-foil material polymer.

The disadvantages of this method are the low quality of the dried product, the duration of the manufacturing process of the finished product and, as a result, the oxidation of substances, a decrease in its nutritional value, increased specific energy costs associated with a low heating rate of the product and irrational energy supply.

An object of the invention is to obtain a finished product of high quality, increasing thermal efficiency and intensification of thermal treatment, including drying of fruit and vegetable raw materials.

The technological task of the invention is achieved by the fact that in the proposed method for the production of fruit and vegetable chips, including sorting, washing, inspection, calibration, cutting, sulphonation (blanching), processing with an aqueous solution, drying and packaging, it is new that pre-heat loaded , chopped, fruit and vegetable raw materials with spent heat carrier, and then heat and moisture treatment is carried out in five consecutive stages, at the first stage, heated raw materials subjected to stepwise convective drying with stepwise processing modes and sequentially repeatedly alternating stages: in the first stage, the plate of fruit and vegetable raw materials is treated in a dense layer with superheated atmospheric pressure steam, the duration of the first stage being 180 s, in the second stage the processing is carried out in a fluidized bed with a duration of 60 s and fluidization period 4 s; the temperature of superheated steam during the first 15 minutes is 417 ... 419 K, from 15 minutes to the end of drying - 422 ... 424 K, and the speed of superheated steam during drying in a dense layer during the first 10 minutes is 2.0 ... 2, 2 m / s, from 10 minutes to 20 minutes - 1.1 ... 1.4 m / s, from 20 minutes to the end of the drying process - 0.8 ... 1 m / s; and during drying in the fluidized bed - during the first 10 minutes, 6.0 ... 6.2 m / s, from 10 minutes to 20 minutes - 5.3 ... 5.5 m / s, from 20 minutes until the end of the drying process - 3.6 ... 3.8 m / s, the first stage is carried out up to a mass fraction of moisture in chopped fruit and vegetable raw materials 42 ... 45%; at the second stage, the processing of raw materials is carried out in an inert coolant stream with the supply of microwave energy at a constant magnetron power to a moisture mass fraction of 28 ... 32%; at the third stage, the fruit and vegetable raw materials are saturated with water by immersing the product in a heated aqueous solution with a temperature of 303 ... 308 K or spraying liquid through humidifiers; at the fourth stage, a product saturated or coated with an aqueous solution is dried in the microwave field with increasing magnetron power and simultaneously supplying an inert gaseous coolant to a residual moisture content of 5 ... 7%, after which the finished product is cooled and packaged in sealed bags.

The technical result of the invention is to obtain a finished product of high quality, increasing its nutritional and biological value, thermal efficiency and intensification of heat and heat treatment, including drying, due to the use of superheated atmospheric pressure steam as an inert heat carrier during stepwise convective drying with stepwise processing modes, variable microwave -energy supply and inclusion of an intermediate stage of moisture saturation between drying the product in accordance with kinetic laws styami vlagoteplovoj processing raw produce.

In FIG. Figure 1 shows the experimental drying curves U = f (τ) (1) and drying rates dU / dτ = f (U) (2) of apple plates, the temperature curve T _к = f (τ) (3), where U is the moisture content of apples, kg / kg, τ - time, s; T _to - the temperature of the plates; in FIG. 2 is a diagram of a change in speed v _p and temperature T of superheated steam over time; in FIG. 3 is a flow diagram of a method for continuously processing raw material plates.

A method of producing fruit and vegetable chips is as follows.

As the object of study, apples, pears and pumpkins are used that meet the requirements of the current GOST 27572-87 “Fresh apples for industrial processing”, GOST 21713-76 “Fresh pears of late ripening varieties”, GOST 7975-68 “Fresh food pumpkin”.

Fresh apples used for processing must meet the following requirements in terms of quality:

in appearance: the fruits are fresh, whole, disease-free, dry, unpolluted, not cracked, without damage by agricultural pests, of the same variety, of the same size;

according to the internal structure: the pulp is juicy, white, light yellow or light cream in different shades, depending on the characteristics of the variety;

by the size of the fruit (by the largest transverse diameter) - 45 ... 55 mm;

the absence of fruits with size deviations, with mechanical damage with a depth of more than 2 mm, with healed cracks, with cuts, light wilting;

the absence of withered fruits, with signs of wrinkling, rotten, steamed and frostbitten.

Pears based on GOST 21713-76 in quality should be fully developed, whole, clean, healthy, without excessive external moisture, without any foreign smell and taste, and must meet the following requirements and standards:

in appearance: the fruits are typical in shape and color for this pomological variety, without damage by pests and diseases, with a whole or broken stalk;

by the size of the fruit (by the largest transverse diameter) - 55 ... 60 mm;

maturity: fruits are uniform in maturity, but not lower than removable and not overripe;

The following are allowed: mechanical damage of not more than two hailstones that do not spoil the shape and appearance of the fetus, the absence of the stalk without traces of damage to the skin, slight abrasion and pressure with a total area of not more than 5 cm ² ;

allowed: damage by pests and diseases, healed skin lesions that do not spoil the appearance of the fetus, with a total area of not more than 1 cm ² , not more than 2% of the fruit, not more than two dried injuries by the moth;

not allowed: rotten fruits, browning of the skin, subcutaneous spotting, boring of the pulp.

Pumpkin in accordance with GOST 7975-68 in its quality must meet the following requirements:

in appearance: the fruits must be fresh, ripe, whole, healthy, uncontaminated, without disease, with the color and shape of the fruits characteristic of this botanical variety, with or without a stalk. Fruits are allowed with deviations from the regular shape, but not ugly, with healed (tinned) damage to the bark from cuts and scratches. In the batch, admixture of other honeycombs of the same ripening period of not more than 10% is allowed;

size along the largest transverse diameter, cm, not less than: for varieties with an elongated shape of 12 cm, for varieties with a flat and round shape of 15 cm;

not allowed: contents of fruits crushed, cracked and rumpled.

Note. Ripe fruits include fruits that have a flesh color characteristic of this botanical variety, seeds that are ripe or close to ripening.

Apples, pears and pumpkin, previously washed and peeled, were cut into plates (2 to 4 mm thick).

Before drying, the plates of fruits and vegetables are blanched at a temperature of 333 ... 348 K for 2.0 ... 5.0 minutes and treated with an aqueous solution by immersing the plates in the solution.

The sliced raw material plates thus treated are pre-heated with the spent heat carrier to a temperature of T = 353 K, placed in the working chamber of the dryer, and subjected to moisture and heat treatment in five successive stages.

To increase the efficiency of the thermal and thermal treatment, stepwise convective drying is carried out in the first stage with stepwise processing modes and successively alternating stages: in the first stage, the fruit and vegetable raw material plates are treated in a dense layer with superheated atmospheric pressure steam, the duration of the first stage being 180 s, and in the second stage, the processing in a fluidized bed with a duration of 60 s and a fluidization period of 4 s; the temperature of superheated steam during the first 15 minutes is 417 ... 419 K, from 15 minutes to the end of drying - 422 ... 424 K, and the speed of superheated steam during drying in a dense layer during the first 10 minutes is 2.0 ... 2, 2 m / s, from 10 minutes to 20 minutes - 1.1 ... 1.4 m / s, from 20 minutes to the end of the drying process - 0.8 ... 1 m / s; and during drying in the fluidized bed - during the first 10 minutes, 6.0 ... 6.2 m / s, from 10 minutes to 20 minutes - 5.3 ... 5.5 m / s, from 20 minutes until the end of the drying process - 3.6 ... 3.8 m / s, the first stage is carried out up to a mass fraction of moisture in chopped fruit and vegetable raw materials 42 ... 45%; at the second stage, the processing of raw materials is carried out in an inert coolant stream with the supply of microwave energy at a constant magnetron power to a moisture mass fraction of 28 ... 32%; at the third stage, the fruit and vegetable raw materials are saturated with water by immersing the product in a heated aqueous solution with a temperature of 303 ... 308 K or spraying liquid through humidifiers; at the fourth stage, a product saturated or coated with an aqueous solution is dried in the microwave field with increasing magnetron power and simultaneously supplying an inert gaseous coolant to a residual moisture content of 5 ... 7%, after which the finished product is cooled and packaged in sealed bags.

An analysis of the drying curves and the drying speed, for example, apples (Fig. 1, curves 1 and 2) shows that there is a warm-up period, a period of constant and falling drying speeds. The duration of the warm-up period is 6 ... 7 minutes.

One of the main reasons for the intensification of the drying process of fruit and vegetable raw materials at the stage of processing in a pulsed fluidized bed with superheated atmospheric pressure steam 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. 1 , curve 3).

During the thermal and thermal treatment of fruit and vegetable raw materials, the temperature of superheated steam during the first 15 minutes is 417 ... 419 K, from 15 minutes to the end of drying - 422 ... 424 K (Fig. 2). The choice of the temperature regime for processing plates of fruit and vegetable raw materials with superheated steam was selected experimentally and depended on the nature of the change in moisture content of the product during drying. With drying, the humidity of the plates of fruits and vegetables decreased, their temperature increased. In order for the temperature of the plates of fruits and vegetables not to exceed the maximum permissible temperature (above which the thermal decomposition of valuable nutrients occurs), a gradual and controlled change in the temperature of superheated steam was required to achieve uniform processing of the plates of raw materials. Failure to comply with this time and temperature conditions led either to overdrying, warping, and thermal decomposition of fruit and vegetable plates, or, conversely, to underdrying and obtaining a product with high humidity, which was a violation of the current GOST.

The choice of the layer height of the plates of fruit and vegetable raw materials 60 mm is due to the fact that steam condensation flows uniformly throughout the entire volume of the layer and a uniform condensate film forms on the surface of the plates to ensure the normal course of the drying process.

An increase in the layer height of the plates of fruit and vegetable raw materials, for example, up to 70 mm, leads to overmoistening of the lower layers and insufficient moistening with condensate of the upper layers. At the same time, the lower layers were boiled, while the upper layers were overdried due to a lack of moisture. In the process of combined convective microwave drying with a constant (given) power of the microwave source, partial adhesion of the upper layers of the plates of fruits and vegetables was observed due to the lack of uniform boiling. Either a bubble regime of vapor motion through the layer of plates was observed, or a jet regime of vapor motion through the layer of plates.

Reducing the height of the layer layer of plates of fruit and vegetable raw materials, for example, to 40 mm leads to excessive waterlogging of all layers of raw materials and their rapid adhesion and loss of presentation.

Sliced fruit and vegetable raw materials on plates larger than a predetermined thickness, for example, 5 mm, significantly increase the drying time and reduce the productivity of the process of moisture and heat treatment.

Sliced fruit and vegetable raw materials on plates smaller than a predetermined thickness, for example, 1.0 mm, lead to strong warping of fruit and vegetable chips, their cracking and loss of presentation.

The first stage is carried out in the form of stepwise convective drying with stepwise processing modes and sequentially repeatedly alternating stages.

The choice of the speed regime for processing plates of fruit and vegetable raw materials with superheated steam (the speed of superheated steam during drying in a dense layer was 2.0 ... 2.2 m / s during the first 10 minutes, 1.1 ... 1.4 m from 10 minutes to 20 minutes / s and from 20 minutes to the end of the drying process - 0.8 ... 1 m / s (Fig. 2)) was selected experimentally and depended on the nature of the change in moisture content of the product during drying.

The choice of the duration of the drying process in a dense layer is 180 s and is due to the fact that partial condensation of steam occurs at the beginning of the drying process. With more frequent stirring, i.e. when the duration of the first stage was less than 180 s, for example 100 s, there was a breakdown of the condensate film from the surface of the fruit and vegetable plates during processing in a fluidized bed, which led to uneven drying. And, on the contrary, with a duration of the first stage of more than 180 s, for example 200 s, there was a deoxidation of the fruits and vegetables plates due to their overmoistening, which also led to poor-quality drying. The choice of the high-speed regime for processing plates of fruit and vegetable raw materials with superheated steam was selected experimentally and depended on the nature of the change in moisture of the product during drying.

In the second stage, when drying fruit and vegetable raw materials in the active phase of a pulsed fluidized bed (IPS), the speed of superheated steam was 6.0 ... 6.2 m / s during the first 10 minutes, 5.3 ... 5.5 from 10 minutes to 20 minutes m / s, from 20 minutes to the end of the drying process - 3.6 ... 3.8 m / s. (Fig. 2). The processing time of the plates of fruit and vegetable raw materials in the fluidized bed was 60 s, with a fluidization period of 4 s. If the stage lasted less than 60 s, for example, 30 s, there was insufficiently uniform and complete mixing of the fruit and vegetable plates during processing in the fluidized bed, which led to incomplete and poor-quality drying. Conversely, with a stage duration of more than 60 s, for example 90 s, intense heat transfer from the surface of the plates occurred during processing in the fluidized bed, which leads to drying of the raw material plates and unreasonably high energy costs.

With drying, the moisture of the plates of fruits and vegetables decreased, their mass also became less. When drying fruits and vegetables, shrinkage was observed, i.e. reduction in plate size and product layer height. Therefore, for uniform processing of the plates, an adjustable heat supply was required, which was ensured by this law of change in the velocity of the coolant. Failure to comply with this time and speed regimes led either to overdrying and burning of the raw material plates, or, conversely, to underdrying and obtaining a product with high humidity, which was a violation of the current GOST.

The use of a microwave frequency of 2450 MHz (wavelength 12.25 cm) is due to the international standard for microwave ovens. This is necessary to avoid interference with the operation of the equipment.

The production method of fruit and vegetable, for example apple, chips is illustrated by the following example.

Apples are washed in a fan washer. Then washed apples are subjected to inspection and sorting, which are carried out manually or by machine on a sorting and inspection conveyor. Next, peeled and sorted apples are cut into thin plates from 2 to 4 mm thick. The high content of reducing sugars in partially dried apples makes the product sensitive to browning. Therefore, before drying, the apple plates were blanched at 333 K for 2 minutes and processed by immersing the apple plates in an aqueous solution.

After blowing and preheating with spent coolant to a temperature of T = 353 K, the plates of apples are placed in the working chamber of the dryer and subjected to moisture and heat treatment in five successive stages.

The first stage is carried out in the form of stepwise convective drying with stepwise processing modes and sequentially repeatedly alternating stages: at the first stage, the plates of fruit and vegetable raw materials are treated in a dense layer with superheated atmospheric pressure steam, the duration of the first stage being 180 s, and at the second stage, the processing is carried out in a fluidized bed with 60 s and a fluidization period of 4 s; the temperature of superheated steam during the first 15 minutes is 418 K, from 15 minutes to the end of drying - 423 K, and the speed of superheated steam during drying in a dense layer is 2.0 m / s during the first 10 minutes, from 10 minutes for 20 minutes - 1.3 m / s, from 20 minutes to the end of the drying process - 0.8 m / s; and during drying in a fluidized bed - during the first 10 minutes 6.0 m / s, from 10 minutes to 20 minutes - 5.3 m / s, from 20 minutes to the end of the drying process - 3.7 m / s, the first the stage is carried out up to a mass fraction of moisture in chopped fruit and vegetable raw materials 42 ... 45%.

At the second stage, the processing of raw materials is carried out in an inert coolant stream with the supply of microwave energy at a constant magnetron power up to a moisture mass fraction of 28 ... 32%.

The penetrating effect of microwaves and their high absorption by water molecules intensifies the volume dehydration process. The absorbed energy quickly turns into heat inside the dried products, as a result of which the pressure in the inner layers of the material rises to such an extent that the particles increase in volume. The result is a porous dried product with improved ability to recover.

At the third stage, the fruit and vegetable raw materials are saturated with water by immersing the product in a heated aqueous solution with a temperature of 303 ... 308 K or spraying the liquid through humidifiers.

At the fourth stage, a product saturated or coated with an aqueous solution is dried in the microwave field at a variable magnetron power and the continuous supply of an inert gaseous coolant to a residual moisture content of 5 ... 7%, after which the finished product is cooled and packaged in sealed bags.

For samples of the control fresh raw materials and the finished product, data were obtained on the chemical composition of fresh apples and apple chips (Table 1).

Table 1

Options Fresh apples Apple chips Total moisture% 86.5 ± 0.04 5.65 ± 0.04 Mass fraction of starch,% 0.77 ± 0.02 1.209 ± 0.04 Ash% 0.5 ± 0.04 0.54 ± 0.04 Carbohydrates (total sugar),% 19.88 ± 0.04 92.57 ± 0.02 Mineral composition Sodium (Na), mg% 25.74 ± 0.02 47.63 ± 0.04 Potassium (K), mg% 247.73 ± 0.04 425.49 ± 0.04 Calcium (Ca), mg% 17.26 ± 0.04 35.87 ± 0.02 Magnesium (Mg), mg% 8.61 ± 0.02 20.12 ± 0.02 Iron (Fe), mg% 2.24 ± 0.04 3.68 ± 0.04 Phosphorus (P), mg% 11.40 ± 0.04 28.82 ± 0.02 Amino acid composition (essential) Valine, mg / 100 g 15.74 ± 0.04 16.53 ± 0.04 Isoleucine, mg / 100 g 31.07 ± 0.04 32.00 ± 0.04 Leucine, mg / 100 g - - Lysine, mg / 100 g 7.26 ± 0.04 6.23 ± 0.04 Methionine + cystine, mg / 100 g 36.21 ± 0.04 33.14 ± 0.04 Threonine, mg / 100 g 10.93 ± 0.04 13.52 ± 0.04 Phenylalanine + tyrosine, mg / 100 g - - Heavy metal content Mercury (Hg), mg / g - - Lead (Pb), mg / g - - Arsenic (As), mg / g - - Cadmium (Cd), mg / g - -

), мг/гCesium ( $C{s}^{\mathrm{one}37}$

), mg / g - - Strontium ( $S{r}^{90}$

), mg / g - - Pesticide content HCCH, mg / kg - - DDT, mg / kg - - microbiological indicators KMAFANM, CFU / g 95 65 S. aureus, CFU / g - - BGKP (coliforms), CFU / g - - Vitamin Composition Thiamine ( $B_{\mathrm{one}}$

), mg% 0.017 ± 0.004 0.051 ± 0.004 Riboflavin ( $B_2$

), mg% 0.026 ± 0.004 0,057 ± 0,004 Vitamin E, mg% 0.357 ± 0.002 0.785 ± 0.004 Vitamin C, mg% 13.849 ± 0.004 15.173 ± 0.004 Niacin (PP), mg% 0.321 ± 0.004 0.394 ± 0.004

The proposed method for the production of fruit and vegetable chips, including preheating and combined moisture and heat treatment of fruit and vegetable raw materials, can increase the energy efficiency of the process, reduce processing time and improve the quality of the finished product.

Thus, the best option for processing plates of fruit and vegetable raw materials for all quality and energy indicators is the above method with a phased combined heat and moisture treatment and justification of each parameter given at a processing temperature in the range T = 417 ... 424 K, coolant velocity in a dense layer v = 2.2 ... 0.8 m / s and in the fluidized bed v = 6 ... 3.6 m / s. This is due to the uniformity of drying throughout the volume of the plates 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 the plates of fruits and vegetables.

At the same time, the plates of fruits and vegetables 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 the velocity of the coolant with alternating drying time intervals in a dense and fluidized bed, periodic alternation of microwave action and stage moisture saturation during thermal treatment, but also the selected equivalent plate size of raw materials. 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, ensures minimal energy consumption for the coolant. The use at the initial stage of superheated steam of atmospheric pressure, and then microwave energy, also ensures minimal energy consumption and provides a high-quality product.

The heating of mono- and disaccharides at a temperature of 373 K and higher leads to a change in their chemical composition, while the color of the products increases, and the content of reduced substances increases. The depth of these processes, and therefore the composition of the substances formed, depends on the composition of sugars, their concentration, degree and duration of heat exposure, pH of the medium and the presence of impurities.

Disaccharides are built from interconnected residues of two monosaccharide molecules. Disaccharides are glycosides, since the connection of two monosaccharide molecules occurs due to the glycosidic hydroxyl of one monosaccharide and one of the hydroxyl groups of the other monosaccharide, as a result one water molecule is released and a disaccharide molecule is formed.

One of the components of the chemical composition of apples is starch, the content of which in one hundred grams of the product is 0.8%. Apple starch consists of amylose, which is a polysaccharide. The content of amylose and amylopectin in starch can vary depending on the type of feedstock and on what part of the plant it is derived from. In apples, dietary fiber (fiber) ranges from 0.6 to 1.8%. Fiber is a polysaccharide that makes up the bulk of the cell walls of plants. Fiber is not soluble in water, but only swells in it. In the process of heating, fiber is completely converted into glucose. With a weaker moisture and thermal exposure, cellobiosis is obtained from fiber.

 The content of pectin in apples is about 1%. These are high molecular weight carbohydrate compounds. In plants, pectin substances are present in the form of insoluble protopectin, which is a compound of methoxylated polygalacturonic acid with galactone and araban cell wall. Protopectin passes into soluble pectin only after treatment with dilute acids or under the action of a special enzyme protopectinase. Soluble pectin is precipitated from the aqueous solution with alcohol.

Pectin substances play an important role in the ripening, storage and industrial processing of various fruits and vegetables. During fetal development, protopectin is deposited in the cell walls and can accumulate in significant amounts in the fruit. Fruit ripening is characterized by the conversion of protopectin to soluble pectin. So, in apples, the content of pectin substances reaches a maximum approximately by the period of fruit harvesting. During subsequent storage of fruits at temperatures close to 274 K, the content of protopectin gradually decreases and soluble pectin accumulates.

Evaluation of the effectiveness of the proposed method for the production of fruit and vegetable (apple, pear, pumpkin, etc.) chips and factory technology for producing apple chips 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 apple chips prepared according to factory technology is 5430 kJ / kg. The specific energy consumption per 1 kg of apple chips prepared using the proposed technology is 4230 kJ / kg.

Thus, the above analysis shows the high thermal efficiency of the proposed technology for the production of fruit and vegetable (apple, pear, pumpkin, etc.) chips in comparison with the factory technology.

When assessing the organoleptic properties according to GOST 8756.1-79, it was found that the target product obtained by the described technology has a sweet and sour taste and natural color of the feedstock, is a plate with a brittle crisp texture, characteristic of chips, and also has a pronounced aroma feedstock. According to physical and chemical parameters, dried pome fruits must comply with GOST 28561-90

Thus, the proposed method for the production of fruit and vegetable chips makes it possible:

- get a food product with a unique harmonious combination of organoleptic properties of chips.

- to achieve uniform moisture and heat treatment of the product due to alternating moisture and heat exposure by steam flow, microwave energy and humidification, as well as the use of "soft" temperature and "gentle" modes of product movement while maintaining the maximum particle shape of the processed product;

- combined stage-by-stage implementation of the convective microwave drying process taking into account the kinetic laws of the process, which increases the thermal efficiency of the process;

- to intensify the process of moisture removal during drying due to the use of microwave energy;

- to carry out simple control of the technological regime and control of the drying process;

- improving the quality of the finished product through the use of a rational hydrodynamic regime of the dispersed product layer, ensuring the microbiological well-being of the finished product and reducing the negative impact of the thermal process on the thermolabile product;

- ensuring optimal hydration due to the use of fluid heating in the preliminary hydrothermal treatment (PHT) and the possibility of moisture saturation due to spraying or direct contact with the liquid, depending on the type of raw material.

Claims (1)

Method for the production of fruit and vegetable chips, including sorting, washing, inspection, calibration, cutting, blanching, processing with an aqueous solution, drying and packaging, characterized in that after blanching, the fruit and vegetable raw materials are heated by the used heat-transfer medium and processed in five successive stages, at the first stage, the heated raw materials are subjected stepwise convective drying with stepwise processing modes and sequentially repeatedly alternating stages: at the first stage of the plate of fruit and vegetable raw materials yvayut a dense layer with superheated steam of atmospheric pressure, wherein the duration of the first stage is 180, the second stage treatment is carried out in a fluidized bed with a duration of 60 seconds and the period of 4 to fluidization; the temperature of superheated steam during the first 15 minutes is 417 ... 419 K, from 15 minutes to the end of drying - 422 ... 424 K, and the speed of superheated steam during drying in a dense layer during the first 10 minutes is 2.0 ... 2, 2 m / s, from 10 minutes to 20 minutes - 1.1 ... 1.4 m / s, from 20 minutes to the end of the drying process - 0.8 ... 1 m / s; and during drying in the fluidized bed - during the first 10 minutes, 6.0 ... 6.2 m / s, from 10 minutes to 20 minutes - 5.3 ... 5.5 m / s, from 20 minutes until the end of the drying process - 3.6 ... 3.8 m / s, the first stage is carried out up to a mass fraction of moisture in chopped fruit and vegetable raw materials 42 ... 45%; at the second stage, the processing of raw materials is carried out in an inert coolant stream with the supply of microwave energy at a constant magnetron power to a moisture mass fraction of 28 ... 32%; at the third stage, moisture saturation of fruit and vegetable raw materials is carried out by immersing the product in a heated aqueous solution with a temperature of 303 ... 308 K or spraying the liquid through humidifiers; at the fourth stage, a product saturated or coated with an aqueous solution is dried in the microwave field with increasing magnetron power and simultaneously supplying an inert gaseous coolant to a residual moisture content of 5 ... 7%, after which the finished product is cooled and packaged in sealed bags.

Images