RU2456805C1 - Peach chips production method - Google Patents

Abstract

FIELD: food industry.

SUBSTANCE: invention relates to food industry. The peach chips production method involves raw material inspection, sorting, washing, cutting into 1.5 mm thick segments and radiative-convective drying. Drying is performed with infrared rays with wave length within the range of 1.16-1.65 mcm and the heat flow density equal to 2.69-5.44 kW/m² with convective blowing with air having initial temperature equal to 293 K in four temporal stages. Sugar syrup with flavour additives is applied onto the peach segments dried till their final moisture content is equal to 7-8%.

EFFECT: method allows to produce a high quality product with increased content of valuable thermolabile substances, adapted for different age groups of the population.

1 dwg, 1 tbl

Description

The invention relates to food, in particular to a vegetable drying and food concentrate industry, and can be used for the production of peach chips.

A known method of drying products of plant origin [US Pat. RF 2216257, IPC A23L 3/54, A23B 7/02. A method of drying products of plant origin [Text] / S.N. Lyubaykin, L.A. Rybalko; Applicant and patent holder S.N. Lyubaykin, L.A. Rybalko. - No. 2002100293/13; declared 01/03/2002; publ. 11/20. 2003]. According to this method, products of plant origin (vegetables, fruits, mushrooms, medicinal raw materials, etc.) are dried using infrared radiation and convective blowing. Heating is carried out by infrared rays with a flux density of 4.5-8.5 kW / m ² to a product temperature of 0.8-0.9 from the maximum allowable drying temperature. Then, by convective blowing, the upper layers of the product are cooled to a temperature of 0.45-0.55 from the maximum drying temperature. The temperature of the blown air is 45-55 ° C. The final moisture content of the product is 10-12%.

The closest in technical essence and the achieved effect is a method of drying high-moisture materials [US Pat. RF 2305235, IPC F26B 3/30, F26B 7/00. The method of drying high-moisture materials [Text] / S.K. Volonchuk, L.P. Shornikova; applicant and patent holder of the GNU Siberian Research and Design Institute of Agricultural Processing. - No. 2006105848/06; declared 02/26/2006; publ. 08/27/2007]. According to this method, pre-washed and crushed materials of plant and animal origin (vegetables, fruits, vegetables, herbs, medicinal herbs, fish meat) are laid out on a pallet and dried in a pulsed mode by heating and cooling with infrared rays to a predetermined humidity. The heating is carried out by infrared rays with a wavelength in the range of 1.2-10.0 μm with a flux density of 6-15 kW / m ² for 3-11 s until the temperature reaches 55-60 ° C, and cooling is carried out for 9 , 0-33.0 s until the temperature reaches 45-50 ° C.

The disadvantages of this method are: the low quality of the finished product due to repeated pulsed heating to the maximum permissible temperature, the long duration of the drying process and high specific energy consumption.

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 a stepped regime of radiation-convective drying of peaches, reducing energy consumption to obtain the finished product, and intensifying the drying process.

The object of the invention is achieved by the fact that in the proposed method for the production of peach chips, including inspection of raw materials, sorting, washing, cutting raw materials, combined radiation-convective drying, the new is that combined radiation-convective drying is carried out by IR rays with a wavelength of in the range 1.16-1.65 μm and a heat flux density of 2.69-5.44 kW / m ² and convective air blowing with an initial temperature of 293 K in four time steps: at the first stage, sliced peach slices 1.5 mm thick heated by infrared rays to a temperature of 318 K while blowing air at a speed of 1.6 m / s for 7.5 min; at the second stage - up to a temperature of 323 K and an air flow rate of 1.2 m / s for 7.5 minutes; at the third stage - up to a temperature of 328 K and an air flow rate of 0.9 m / s for 25 minutes; in the fourth stage, to a temperature of 333 K and an air flow velocity of 0.7 m / s for 20 minutes, then sugar syrup with flavoring is applied to 7-8% of peach wedges dried to a final moisture content.

The technical result of the invention is to improve the quality of the finished product through the use of stepwise modes of combined radiation-convective drying of peaches, increasing thermal efficiency and intensification of the drying process, in reducing energy consumption for obtaining the finished product.

Figure 1 shows the kinetic laws of the stepped regime of combined radiation-convective drying of peach chips: a - drying curve, b - drying speed curve; in - temperature curve; g - thermogram.

Fresh peaches that are processed must be in accordance with OKP 97 6725 specifications and meet the following requirements:

in appearance: selected fruits, typical in shape and color for this pomological variety. The presence of the stalk is not necessary. In the absence of a stalk, the skin of the fetus at the place of attachment to the stalk must be intact, not torn off the pulp;

by maturity - fruits are uniform in maturity, but not green and not overripe;

by the size of the largest transverse diameter, not less than - 56 mm.

Tolerances:

Mechanical damage - in the workpiece places are not allowed; up to two light presses are allowed at the destination.

Damage by pests and diseases is not allowed.

Rotting fruits is not allowed.

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

The shape of the peach is spherical with a groove on one side, the fruit is usually velvety. The bone is wrinkled and bearded with pointed dimples. Peach color: yellow, yellow-red, pale yellow. The diameter of the fetus is not less than 56 mm and more. Root crop weight: small (up to 50 g), medium (100-150 g), large (150-250 g). Pulp color: white, white-yellow, yellow.

Peaches for the production of peach chips should be fresh, healthy, of a suitable color, high in pectin, organic acids and dry soluble substances.

A method of manufacturing peach chips is as follows.

Peaches are washed in a fan washer. For more intensive washing of contaminated fruits in the washing tub of the machine, drilling is created by means of compressed air supplied to the perforated pipes. The washed fruits from the washing bath are moved by an inclined conveyor, in the upper part of which (before unloading) they are rinsed with water from the shower unit. When processing heavily contaminated fruits, you can increase the time they spend in the washing area by occasionally stopping the conveyor.

Then washed peaches are subjected to inspection and sorting, which are carried out manually on a sorting and inspection conveyor. Simultaneously with sorting, an inspection of raw materials is carried out, in which defective specimens (rotten, damaged, broken, moldy, heavily contaminated), foreign impurities and objects are removed. Then the processed peaches are cut into thin plates with a thickness of 1.5 mm.

Cutting peaches into plates of greater than 1.5 mm thickness, for example 2.5 mm, significantly increases the drying time and reduces the productivity of the line.

Cutting peaches into plates of less than 1.5 mm thickness, for example 1.0 mm, leads to severe warping of the chips, their cracking and loss of presentation.

Then the sliced peaches are subjected to combined radiation-convective drying. Moreover, peaches are heated by infrared rays with a wavelength in the range of 1.16-1.65 microns and a heat flux density of 2.69-5.44 kW / m ² while convective air blowing with an initial temperature of 293 K in four time stages.

The choice of wavelengths of infrared rays in the range 1.16-1.65 μm due to the fact that this wavelength range of infrared radiation accounts for the maximum electromagnetic energy and it corresponds to the maximum absorption capacity of peaches. If the product is heated by infrared rays with a wavelength of less than 1.16 μm, for example 0.9 μm, the product will be heated for a long time. If the product is heated by infrared rays with a wavelength of more than 1.65 μm, for example 1.8 μm, then a significant part of the radiant energy supplied will be spent on heating the vaporized vapor, which reduces the thermal efficiency of the drying process.

The choice of the heat flux density of infrared radiation in the range of 2.69-5.44 kW / m ² due to the fact that the product has maximum absorption capacity. If the product is heated by infrared rays with a heat flux density of infrared radiation of less than 2.69 kW / m ² , for example 2.1 kW / m ² , then the product will heat up slowly.

If the product is heated by infrared rays with a heat flux density of infrared radiation of more than 5.44 kW / m ² , for example 6.5 kW / m ² , then a significant part of the supplied radiant energy will be spent inefficiently (for heating the supplied air, the walls of the working chamber ), which reduces the thermal efficiency of the IR-drying process.

Simultaneously with IR heating, peaches are blown with air with an initial temperature of 293 K to remove water vapor evaporated from the product.

The choice of the initial air temperature of 293 K is due to the fact that air is taken from industrial premises, in which, as a rule, this temperature is maintained.

The use of air as a coolant with an initial temperature of more than 293 K, for example 303 K, will necessitate the installation of a heater for additional heating of the air, which may impair the quality of the finished product due to its overheating, increase the cost of products and increase the amount of capital investment due to the installation of additional equipment (heater).

The use of air as a heat carrier with an initial temperature of less than 293 K, for example 283 K, will necessitate the installation of cooling devices for additional air cooling, which during infrared drying can cause unnecessary excessive cooling of the product and lead to an increase in energy consumption and an increase in the cost of products.

The essence of the choice of stepwise modes of combined radiation-convective drying of peach chips is to divide the drying process into four stages of different duration, each of which, depending on the law of change in the current humidity of peaches, selects its rational technological drying mode, i.e. The temperature of heating peach slices with IR radiation and blowing them at a coolant velocity (air flow with an initial temperature of 293 K) 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.

At the first time stage, cut peach plates with a thickness of 1.5 mm are heated by infrared rays to a temperature of 318 K while blowing air at a speed of 1.6 m / s for 7.5 minutes (Fig. 1). In this case, physical and mechanical moisture is removed, i.e. moisture micro- and macrocapillaries and wetting moisture. 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 the initial moment of drying with a high coolant velocity and a low heating temperature of the product. Drying at the first stage most fully meets this requirement.

Heating the product to a lower temperature than 318 K, for example 310 K, will reduce the efficiency of evaporation of physico-mechanical moisture. Heating the product to a higher temperature than 318 K, for example 322 K, will lead to excessive overheating of the product and a decrease in its quality due to the decomposition of valuable thermolabile substances (vitamins, monosugars, amino acids, etc.).

Blowing the product with an air stream at a speed of less than 1.6 m / s, for example 1.3 m / s, will reduce the efficiency of removal of evaporated water vapor, and therefore, reduce the efficiency of heat and mass transfer of the drying process. Blowing the product with air flow at a speed greater than 1.6 m / s, for example 1.9 m / s, will lead to overdrying of the surface layers of peach chips and the formation of a crust on the surface of peaches, which makes it difficult to remove evaporated moisture.

The duration of the first time step (7.5 min) was determined experimentally by analyzing the obtained drying curves. Using a longer duration of the first time step, for example, 8.5 minutes, will dry out the surface layers of the peach chips and make it more difficult to remove the moisture contained in the center layers of the peach. Using a shorter duration of the first time step, for example, 6.5 minutes, will result in the fact that not all physico-mechanical moisture will be removed from peaches, which will entail an increase in the duration of subsequent temporary drying steps and a deterioration in the quality of the finished chips.

At the second time stage, the pre-dried peach plates are heated by infrared rays to a temperature of 323 K while blowing air at a speed of 1.2 m / s for 7.5 minutes (Fig. 1). With the removal of physical and mechanical moisture, the velocity of the coolant, as a determining factor in the intensity of the process, loses its significance. Therefore, in the second stage, it is preferable to carry out drying at a decreasing speed and increasing temperature of the coolant. Due to the fact that the temperature has the greatest influence on the removal rate of osmotic (intracellular) moisture, as a factor determining the intensity of internal moisture transfer, the product is heated by infrared rays to a temperature of 323 K. Heating of the product to a lower temperature than 323 K, for example 317 K , will reduce the evaporation efficiency of osmotic moisture. Heating the product to a higher temperature than 323 K, for example 330 K, will lead to excessive overheating of the product and a decrease in its quality due to the decomposition of valuable thermolabile substances (vitamins, monosugars, amino acids, etc.). Blowing the product with an air stream at a speed of less than 1.2 m / s, for example 0.8 m / s, will not ensure the complete removal of evaporated water vapor, and therefore, will reduce the efficiency of heat and mass transfer of the drying process. Blowing the product with an air stream at a speed greater than 1.2 m / s, for example 1.4 m / s, will lead to the drying out of the surface layers of peach chips and the formation of a crust on the surface of peaches, which makes it difficult to remove evaporated moisture.

The duration of the second time stage (7.5 min) was determined experimentally as a result of the analysis of the obtained drying curves. Using a longer duration of the second time step, for example, 9.0 minutes, will dry out the surface layers of the peach chips and make it more difficult to remove the moisture contained in the center layers of the peach. Using a shorter duration of the second time stage, for example, 6.0 minutes, will result in the fact that not all osmotic moisture will be removed from peaches, which will entail an increase in the duration of subsequent temporary stages of drying and a deterioration in the quality of the finished chips.

At the third time stage, the pre-dried peach plates are heated by infrared rays to a temperature of 328 K while blowing with air at a speed of 0.9 m / s for 25 minutes (Fig. 1). As the osmotic moisture is removed, the velocity of the coolant, as a determining factor in the intensity of the process, loses its significance. Due to the fact that the temperature has the greatest influence on the rate of removal of polyadsorption moisture, as a factor determining the intensity of internal moisture transfer, the product is heated by infrared rays to a temperature of 328 K. Heating the product to a lower temperature than 328 K, for example 321 K, will reduce evaporation efficiency of polyadsorption moisture. Heating the product to a temperature higher than 328 K, for example 332 K, will lead to excessive overheating of the product and a decrease in its quality due to the decomposition of valuable thermolabile substances.

Blowing the product with an air stream at a speed of less than 0.9 m / s, for example 0.7 m / s, will not ensure the complete removal of evaporated water vapor, and therefore, will reduce the efficiency of heat and mass transfer of the drying process. Blowing the product with air flow at a speed greater than 0.9 m / s, for example 1.1 m / s, will lead to the drying out of the surface layers of the peach chips and the formation of a crust on the surface of the peaches, which makes it difficult to remove the evaporated moisture.

The duration of the third time stage (25 min) was determined experimentally as a result of the analysis of the obtained drying curves. Using a longer duration of the third time step, for example, 30 minutes, will dry out the surface layers of the peach chips and make it difficult to remove the moisture contained in the center layers of the peach. Using a shorter duration of the third time step, for example, 20 minutes, will result in the fact that not all polyadsorption moisture will be removed from peaches, which will entail an increase in the duration of subsequent temporary drying steps and a deterioration in the quality of the finished chips.

At the fourth time stage, the pre-dried peach plates are heated by infrared rays to a temperature of 333 K while blowing air at a speed of 0.7 m / s for 20 minutes (Fig. 1). Due to the fact that the temperature has the greatest influence on the rate of removal of monoadsorption moisture, as a factor determining the intensity of internal moisture transfer, the product is heated by infrared rays to a temperature of 333 K. Heating the product to a lower temperature than 333 K, for example 327 K, will reduce the efficiency evaporation of monoadsorption moisture. Heating the product to a temperature higher than 333 K, for example 338 K, will lead to excessive overheating of the product and a decrease in its quality due to the decomposition of valuable thermolabile substances.

Blowing the product with an air stream at a speed of less than 0.7 m / s, for example 0.5 m / s, will not ensure the effective removal of evaporated water vapor, and therefore, will reduce the intensity of heat and mass transfer of the drying process. Blowing the product with an air stream at a speed greater than 0.7 m / s, for example 0.85 m / s, will lead to the drying out of the surface layers of the peach chips and the formation of a crust on the surface of the peaches, which will complicate the removal of evaporated moisture.

The duration of the fourth time step (20 min) was determined experimentally as a result of the analysis of the obtained drying curves. Using a longer duration of the fourth time step, for example, 26 minutes, will dry out the surface layers of the peach chips and make it more difficult to remove the moisture contained in the center layers of the peach. Using a shorter duration of the fourth time step, for example, 15 minutes, will result in the fact that not all monoadsorption moisture will be removed from peaches, which will entail an increase in the duration of subsequent temporary drying steps and a deterioration in the quality of the finished chips.

Adapted in accordance with the basic kinetic laws of the drying process, the coolant supply at the four 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.

Then, on dried to a final moisture content of 7-8% peach wedges, sugar syrup with flavoring is applied.

The table shows the chemical composition of the original peaches and peach chips (without applying sugar syrup with flavors), dried according to the proposed four-stage regime of combined radiation-convection drying.

A method for producing peach chips is illustrated by the following example.

Peaches are washed in a fan washer. Then washed peaches are subjected to inspection and sorting, which are carried out manually on a sorting and inspection conveyor. Next, peaches are cut into thin plates with a thickness of 1.5 mm.

Then, sliced peaches are subjected to combined radiation-convection drying. Moreover, peaches are heated by infrared rays with a wavelength in the range of 1.40 μm and a heat flux density of 4.06 kW / m ² with simultaneous convective air blowing with an initial temperature of 293 K in four time stages. Simultaneously with IR heating, peaches are blown with air with an initial temperature of 293 K to remove water vapor evaporated from the product.

At the first time stage, cut peach plates with a thickness of 1.5 mm are heated by infrared rays to a temperature of 318 K while blowing air at a speed of 1.6 m / s for 7.5 minutes. In this case, physical and mechanical moisture is removed, i.e. moisture micro- and macrocapillaries and wetting moisture.

Measured parameters Peach source Peach chips Total moisture% 86.12 ± 0.04 7.65 ± 0.02 Mass fraction of crude protein,% 0.92 ± 0.02 7.89 ± 0.02 Mass fraction of crude fiber,% 2.13 ± 0.02 9.80 ± 0.02 Ash% 0.62 ± 0.02 0.78 ± 0.02 Carbohydrates (total sugar),% 9.52 ± 0.02 78.98 ± 0.02 The content of NO ^3- , mg / kg 32.12 ± 0.02 32.98 ± 0.02 Mineral composition Sodium (Na), mg% 30.12 ± 0.02 45.12 ± 0.02 Potassium (K), mg% 363.17 ± 0.02 397.05 ± 0.02 Calcium (Ca), mg% 20.17 ± 0.02 29.82 ± 0.01 Magnesium (Mg), mg% 16.08 ± 0.01 18.37 ± 0.02 Iron (Fe), mg% 0.62 ± 0.02 0.79 ± 0.02 Phosphorus (P), mg% 34.78 ± 0.02 39.91 ± 0.02 Amino acid composition (essential) Valine, mg / 100 g 4.17 ± 0.002 4.87 ± 0.002 Isoleucine, mg / 100 g - - Leucine, mg / 100 g - - Lysine, mg / 100 g 21.09 ± 0.002 27.92 ± 0.002 Methionine + cystine, mg / 100 g 12.56 ± 0.002 14.52 ± 0.002 Threonine, mg / 100 g - - Phenylalanine + tyrosine, mg / 100 g 14.09 ± 0.002 15.87 ± 0.002 Heavy metal content Mercury (Hg), mg / g - - Lead (Pb), mg / g 0.019 ± 0.001 0.021 ± 0.002 Arsenic (As), mg / g - - Cadmium (Cd), mg / g - - Cesium (Cs ¹³⁷ ), mg / g - - Strontium (Sr ⁹⁰ ), mg / g - - Pesticide content HCCH, mg / kg - - DDT, mg / kg - - microbiological indicators KMAFANM, CFU / g 102 97 S. aureus, CFU / g
BGKP (coliforms), CFU / g - - - - Vitamin Composition Thiamine (B ₁ ), mg% 0.042 ± 0.002 0,053 ± 0,002 Riboflavin (B ₂ ), mg% 0.081 ± 0.002 0.098 ± 0.002 Vitamin E, mg% 1,577 ± 0,002 1.872 ± 0.002 Vitamin C, mg% 10,230 ± 0,002 12.341 ± 0.001 Niacin (PP), mg% 0.718 ± 0.002 0.871 ± 0.002 Vitamin A, mg% 0.527 ± 0.002 0.646 ± 0.002 Vitamin B ₉ , mg% 8.152 ± 0.002 9.817 ± 0.002

At the second time stage, pre-dried peach plates are heated by infrared rays to a temperature of 323 K while blowing with air at a speed of 1.2 m / s for 7.5 minutes. In this case, osmotic (intracellular) moisture is removed.

At the third time stage, the peach plates are heated by infrared rays to a temperature of 328 K while blowing air at a speed of 0.9 m / s for 25 minutes. At the same time, polyadsorption moisture is removed from peaches.

At the fourth time stage, the peach plates are heated by infrared rays to a temperature of 333 K while blowing air at a speed of 0.7 m / s for 20 minutes. At the same time, monoadsorption moisture is removed from peaches.

Then, on dried to a final moisture content of 7-8% peach wedges, sugar syrup with flavoring is applied. Finished peach chips were analyzed. The analysis data are presented in the table "The chemical composition of the original peaches and peach chips dried by the proposed four-stage drying method."

Analysis of the data given in the table shows that peach chips have a high content of valuable nutrient thermolabile substances. This indicates the correct choice of soft, gentle temperature-hydrodynamic drying regimes.

This treatment of peaches allows you to increase the energy efficiency of the process, reduce the drying time of peaches and improve its quality.

Thus, the use of the proposed method for the production of peach chips allows you to:

- receive high quality peach chips with a high content of valuable thermolabile substances (vitamins, monosugar, amino acids, etc.) and applying to their surface the necessary additional components (sugar syrup, flavorings, stabilizers, etc.), adapted for different age groups of the population ;

- increase the thermal efficiency of the process;

- reduce energy and labor costs for the production of peach chips due to the use of step modes of combined radiation-convection drying.

Claims (1)

Method for the production of peach chips, including inspection of raw materials, sorting, washing, cutting, radiation-convective drying, characterized in that the combined radiation-convective drying is carried out by infrared rays with a wavelength in the range of 1.16-1.65 microns and a heat flux density 2.69-5.44 kW / m ² and convective air blowing with an initial temperature of 293 K in four time steps: at the first stage, sliced slices of peaches 1.5 mm thick are heated by infrared rays to a temperature of 318 K while blowing with an air stream with 1.6 m / s at reading 7.5 min; at the second stage - up to a temperature of 323 K and an air flow rate of 1.2 m / s for 7.5 minutes; at the third stage - up to a temperature of 328 K and an air flow rate of 0.9 m / s for 25 minutes; in the fourth stage, to a temperature of 333 K and an air flow velocity of 0.7 m / s for 20 minutes, then sugar syrup with flavoring is applied to 7-8% of peach wedges dried to a final moisture content.

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