MD938Z - Process for producing sweetened dried cherries and sour cherries - Google Patents

Abstract

The invention relates to food industry, namely to a process for producing sweetened dried cherries and sour cherries.The process, according to the invention, comprises the preliminary preparation of fruits, filling thereof with a solution of orthophosphoric acid, taken in a ratio and concentration ensuring the attainment in the fruits of a pH of 1.9…2.3, storage of fruits in said solution for 0.5…12 months, separation of fruits from the solution, neutralization of the solution of orthophosphoric acid with calcium carbonate or oxide taken in stoichiometric amounts, washing of fruits with the neutralized solution to the attainment in the fruits of a pH of 2.9…3.5 and a residual content of orthophosphoric acid of at most 275 mg/kg (expressed in P2O5), separation of the washed fruits from the solution and its concentration to a content of soluble dry substances of 20…75%, filling of fruits with the concentrated solution with a temperature of 25…85°C and maintenance thereof up to the attainment of the content of soluble dry substances in the fruits of 27…43%, afterwards the fruits are separated and dried at a temperature 25…65°C to a humidity of 14…32%.

Description

The invention relates to the food industry, namely to a process for obtaining sweetened dried cherries and cherries.

A process for preserving fruits with sulfur dioxide is known, with the production of a semi-finished product for further processing. According to this process, prepared fresh fruits, including whole cherries and cherries with or without pits, are covered with a sulfur dioxide solution with a concentration of 1...2%, the container is hermetically sealed and stored until further processing [1]. Before processing, for example to obtain candied fruits, fruits containing 0.06...0.12% sulfur dioxide are desulfitized by boiling for 10...15 minutes until the sulfurous acid content in the fruits is maximum 0.02% [2].

The disadvantage of these processes is the need for desulphitation, during which the fruits are subjected to a heat treatment by boiling, which leads to softening of the fruits, degradation of thermolabile compounds and, consequently, a deterioration of their quality, while the working conditions of the workers are harmful.

A process for obtaining sweetened dried stone fruits is also known, which includes preliminary preparation of the fruits, removal of inedible parts, covering the fruits with a solution at a temperature of 25...85°C containing, in wt.%: sugars 45.0...75.0, potassium sorbate 0.07...0.23, sulfurous substances recalculated for SO2 0.03...0.17, organic acid 0.1...1.0, taken in the amount necessary to reach a pH of 3.0...3.5, maintaining the fruits in solution until the content of soluble dry substances in the fruits and the solution is balanced, separating the fruits and drying them at a temperature of 45...65°C to a humidity of 14...32% [3].

This procedure has the following disadvantages:

- the limited number of consumers of the product due to the presence of a residual amount of sulfurous substances, as there is a certain group of people (children with gastrointestinal tract diseases, etc.) for whom products containing SO2 are contraindicated, even in permissible concentrations;

increased demand for human resources and technical equipment during the fresh fruit processing season;

reduced sugar return, therefore, inefficient use of circulating materials, due to prolonged storage of fruits in solutions with a high sugar concentration.

The problem solved by the claimed invention is to improve the quality of sweetened dried cherries and cherries, as well as to increase the economic efficiency of production.

The invention solves the problem by proposing a process for obtaining sweetened dried sour cherries and cherries, which includes preliminary preparation of the fruits, coating the fruits with an orthophosphoric acid solution taken in a ratio and concentration that ensures the achievement of a pH of 1.9…2.3 in the fruits, storing the fruits in the mentioned solution for 0.5…12 months, separating the fruits from the solution, neutralizing the orthophosphoric acid solution with calcium oxide or carbonate taken in stoichiometric amounts of orthophosphoric acid and calcium, washing the fruits with the neutralized solution until the fruits reach a pH of 2.9…3.5 and a residual orthophosphoric acid content of no more than 275 mg/kg (expressed in P2O5), separating the washed fruits from the solution and concentrating it to a soluble dry matter content of 20…75%, coating the fruits with the concentrated solution with a temperature of 25…85°C and maintaining them until the content of soluble dry substances in fruits reaches 27…43%, after which the fruits are separated and dried at a temperature of 25…65°C to a humidity of 14…32%.

At the same time, the additional orthophosphoric acid solution contains 11…21% sugar and 0.11…0.17% potassium sorbate, and the fruits are covered with the orthophosphoric acid solution at a temperature of 2…15°C.

In the proposed process, the washing of fruits with the neutralized solution is performed repeatedly, by keeping them in the solution, with the subsequent neutralization and use of the separated solution. The concentration of the solution obtained from washing the fruits is achieved by adding sugar and/or by evaporation, at the same time, commercial granulated sugar or commercial granulated sugar with the addition of caramel molasses, or maltose in an amount of 10…15% of the added sugars is used. The maintenance of fruits in the concentrated solution is performed in one or more stages, at the same time, the concentration of dry soluble substances of the solution is increased by 5…15% at each subsequent stage.

Thus, the advantages of the claimed method are: preservation of fresh fruits without the use of sulfur dioxide, improving the appearance, color and biological value of the finished product by reducing the thermal load on the processed product and due to the antioxidant properties of orthophosphoric acid, which prevent the degradation of anthocyanins in sour cherries and cherries during the processing process. An additional advantage is also the fact that the production of sweetened dried sour cherries and cherries is possible throughout the year.

Examples of embodiments of the invention

Example 1

Fresh cherries, dry matter (DS) by refractometer 16.4%, pH = 3.25.

The whole fruits with seeds are washed, the stalk is removed, placed in a container and covered with orthophosphoric acid solution, in a ratio of 67:33, which corresponds to 49 parts by mass of solution per 100 parts of fruit.

The solution contains, g/100 g: sugar -16.4; orthophosphoric acid (85%) - 2.36. In the semi-finished product obtained after storage for 2 weeks, pH = 2.3 was established.

No microbiological alteration was detected in the semi-finished product stored under ambient conditions for 6 months, the fruits having a dense structure and the color of boiled cherries.

After storage in the semi-finished product, the ratio between fruit and solution was established as 66:34, the soluble dry matter content according to the refractometer being 16.1%.

The seeds are removed from the fruit, with waste and losses constituting 14.3% of the mass of the preserved fruit, the ratio between seedless fruit and solution constituting 62.5:37.5 parts by mass.

After which the neutralization process of the orthophosphoric acid used is calculated and carried out.

Neutralization is carried out in 7 stages, using calcium carbonate.

Step 1. To the separated fruit solution was added 0.2662 g /37.5 g calcium carbonate, the solution was stirred intensively and then filtered through “medium filtration” filter paper. The pitted fruits were covered with the filtered solution and left for 24 hours, stirring periodically.

Step 2. The seedless fruits are separated from the solution, calcium carbonate is added to the solution in an amount of 0.1664 g /37.5 g of solution, the solution is shaken vigorously and then filtered. The seedless fruits are covered with the filtered solution and kept for 3…4 hours, the solution is periodically pumped through the fruits.

Steps 3-7 are performed similarly to step 2, at each step, amounts of calcium carbonate calculated using the stoichiometric ratio (g/37.5 g solution) were added: 3-0.1040; 4-0.06498; 5-0.04061, 6-0.02539; 7-0.01587. After the 7th neutralization step, the pH reached 3.20.

The seedless fruits are separated from the solution. From the separated solution, a sweetening solution is prepared with a soluble dry matter concentration of 37.7%. Citric acid is added to the sweetening solution, namely about 0.5% by weight of the solution.

The seedless fruits, obtained from the orthophosphoric acid neutralization process, are immersed in the sweetening solution, taken in a ratio of 62.5 g:56.25 g and maintained until equilibrium (SU = 27% according to the refractometer).

In order to speed up the sweetening process, the used solution is periodically separated and poured over the fruit again.

Then the pitted fruits are separated from the solution. 59 g of sweetened pitted fruits are obtained, which are dried at 45°C to a moisture content of 16%. The mass of the sweetened and dried pitted fruits is about 19.8 g (it decreases by 2.98 times). The finished product is fleshy, has a dark red color, a pleasant sweet-sour taste and a characteristic smell of dried cherries, easy to chew.

Calculating the amount of calcium carbonate needed to neutralize the orthophosphoric acid used

The amount of calcium carbonate required to neutralize the orthophosphoric acid contained in the solution obtained after separating the fruits is determined according to the stoichiometric ratio between СаСО3 and orthophosphoric acid (85%) (0.8681:1.000) in the following chemical reaction:

H3 PO4 + CaCO3 + H2O →↓ Ca HPO4 x 2H2O + ↑CO2 (1).

The total amount of acid added in this example, per 100 g of semi-finished product, is 2.36 x 0.33 = 0.7788 g or per 100 g of product after removing the pit: 0.7788 x 1.05 = 0.8177 g.

The total amount of calcium carbonate required to neutralize the added orthophosphoric acid is calculated as follows: 0.7788 x 0.8681 = 0.6761g/100g of initial semi-finished product or recalculated for the product obtained after removal of the core: 0.6761 x 1.05 = 0.7099g/100g.

Note: 1.05 - correction coefficient of the average concentration of orthophosphoric acid in the solution, after removing the seed from the fruit (acid losses in the seed were not taken into account).

The amount of orthophosphoric acid in the solution at each neutralization stage is determined as the mass fraction, obtained after establishing equilibrium in the process of maintaining the fruits in solution.

Thus, to neutralize the solution (37.5 g), contained in 100 g of semi-finished product (seedless fruit - solution), the required amount of calcium oxide is:

Stage 1

(0.8177 x 0.375) x 0.8681= 0.3066 x 0.8681= 0.2662;

Stage 2

(0.8177 - 0.3066) x 0.375 x 0.8681= 0.1917 x 0.8681=0.1664;

Stage 3

(0.5111 - 0.197) x 0.375 x 0.8681= 0.1198 x 0.8681= 0.1040;

Stage 4

(0.3194 - 0.1198) x 0.375 x 0.8681= 0.0745 x 0.8681= 0.06498;

Stage 5

(0.1996 - 0.07485) x 0.375 x 0.8681= 0.04680 x 0.8681= 0.04061;

Stage 6

(0.1248 - 0.04680) x 0.375x 0.8681= 0.0292 x 0.8681= 0.02539;

Stage 7

(0.078 - 0.0292) x 0.375 x 0.8681 = 0.0182 x 0.8681 = 0.01587.

After step 7, there remain (0.04875 - 0.01828) = 0.03047 g of 85% acid, per 100 g s/f, which corresponds to 0.0259 g of 100% acid, or expressed in P2O5 - 0.0177 g per 100 g s/f, or 177 mg/kg.

Calculating the concentration of the sweetening solution

The concentration of the sweetening solution is determined depending on the ratio of components and the SU content in the semi-finished product, taking into account the predetermined value of the content of soluble substances in the sweetened fruits (27.0%) and establishing the initial ratio of fruit: solution at the beginning of sweetening 1.0:0.9.

In this example, 100 g of semi-finished product (SU = 16.1%), taken for sweetening, contains 62.5 g of seedless fruit and 37.5 g of solution. If the initially determined ratio of fruit: solution is 1.0:0.9, 62.5 x 0.9 = 56.25 g of solution is required to process 62.5 g of seedless fruit, the total mass of the mixture is 118.75 g.

The amount of SU required to obtain 118.75 g of mixture with a soluble dry substance concentration SU = 27.0% was calculated:

118.75 x 0.27 = 32.06 grams.

Since 118.75 g of mixture includes 100 g of s/f with an initial SU content of 100 x 0.161 = 16.1 g, the amount of sugar that is required to be added will be 32.06 -16.1 = 15.96 g.

After adding sugar, the mass of the solution should reach 37.5 +15.96 = 53.46 g. The lack of mass was 56.25-53.46 = 2.79 g, which was replaced with water; 56.25 g of solution contain 21.19 g of soluble dry substances, including SU contained in the cherry semi-finished solution until sweetening 0.161 x 37.5 = 5.23 g, the sugar added in the sweetening process - 15.96 g. Thus, the concentration of the solution was 21.19 x 100/56.25 = 37.7%.

Example 2

Fresh sour cherries of the Erdi Urojainaia variety, dry matter according to refractometer 15.2%, pH = 2.97. The whole fruits with stones are washed, the stalk is removed, placed in a container and covered with orthophosphoric acid solution, in a ratio of 63:37, which corresponds to 59 parts by mass of solution 100 parts of fruit.

Composition of the solution, in g/100 g: sugar - 16.0; potassium sorbate - 0.14, orthophosphoric acid (85%) - 1.91. In the semi-finished product obtained after storage for 2 weeks, pH = 1.95 was established.

In the semi-finished product stored under ambient conditions for 11 months, no microbiological alteration was detected, the fruits having a fairly dense structure and red color.

After storage in the semi-finished product, the fruit to solution ratio was established at 61:39 and the soluble dry matter content at 15.0% (according to refractometer).

The seeds are removed from the fruit (waste and losses constitute about 10.0% of the mass of preserved fruit) and the ratio of seedless fruit: solution is determined, which is 55:45 parts by mass.

After which the neutralization process of the orthophosphoric acid used is calculated and carried out.

Neutralization is carried out in 5 stages using calcium oxide.

Step 1. Calcium oxide is added to the separated fruit solution in an amount of 0.1935 g/45 g of solution, the solution is shaken vigorously, then filtered through “medium filtration” filter paper. The pitted fruits are covered with filtered neutralized solution and left for 24 hours, stirring periodically.

Step 2. The seedless fruits are separated from the solution. Calcium oxide is added to the separated solution in an amount of 0.1064 g / 45 g of solution, the solution is shaken vigorously and then filtered. The seedless fruits are covered with filtered neutralized solution and left for 3-4 hours, periodically pumping the solution through the fruits.

Steps 3-5 are performed similarly to treatment step 2, with the following estimated amounts of calcium oxide (g/45g solution) added to each step: 3 - 0.05852; 4 - 0.03219; 5 - 0.0182.

After step 5 of neutralization of the solution, the pH reaches the level of 3.0.

The seedless fruits are separated from the solution. From the separated solution, the sweetening solution is prepared.

The concentration of the sweetening solution is determined by the predetermined soluble dry matter content in the sweetened fruits (39.0%) and the initially established fruit:solution ratio at the beginning of sweetening 1.0:1.0.

The amount of sugar required for addition and the concentration of the sweetening solution are calculated similarly to example 1.

The following calculated values are obtained:

- mass of the mixture (g) in the sweetening process: 55 fruit + 55 solution = 110;

- SU content in the mixture (g): 110 x 0.39=42.9;

- SU content in the initial semi-finished product (g): 100x0.15=15.0;

- amount of sugar needed to add (g): 42.9-15.0 = 27.9.

Sugar (90%) and caramel molasses with reduced saccharification SU = 78% are added as sugars: molasses 100% - 2.79 g, molasses SU = 78% - 3.58 g, sugar 27.9-2.79 = 25.11 g.

The mass of the solution is 45 +25.11 +3.58 = 73.69 g, the excess mass - (73.69-55.00) = 18.69 g. To achieve the desired mass of 55 g, the initial solution in an amount of 45 g is boiled to a mass of (45-18.69) = 26.31 g, 25.11 g of sugar and 3.58 g of molasses are dissolved in the solution. Thus, 55 g of sweetening solution with a soluble solids concentration of 63.0% is obtained.

The seedless fruits obtained from the orthophosphoric acid neutralization process are covered with the sweetening solution and maintained until a SU of 39% is obtained according to the refractometer.

In order to accelerate the sweetening process, the periodically used solution is separated, heated to 85°C and poured over the fruit.

Then the pitted fruits are separated from the syrup. 59.15 g of sweetened pitted fruits are obtained, which are dried at 60°C to a mass of 28.85 g (reduced by 2.05 times), which corresponds to 18% humidity. The finished product has a pleasant appearance, red in color, fleshy, pleasant sweet-sour taste and characteristic smell of dried cherries, easy to chew.

Calculating the amount of calcium oxide needed to neutralize the orthophosphoric acid used

The amount of calcium oxide required to neutralize orthophosphoric acid is determined according to the stoichiometric ratio between CaO and orthophosphoric acid (85%) (0.5714:1.000) in the following chemical reaction:

H3PO4 + CaO + H2O→↓Ca HPO4 x H2O + H2O (2).

In this example, the total amount of acid added per 100 g of semi-finished product 1.91 x 0.37= 0.7067 g or per 100 g of product after removing the pit: 0.7067 x 1.065=0.7526 g.

The total amount of calcium oxide required to neutralize the added orthophosphoric acid is calculated as follows:

0.7067 x 0.5714 = 0.4038 g/100 g of initial semi-finished product or recalculation to the product obtained after removing the seed: 0.4038 x 1.065 = 0.4300 g.

Note: 1.065 - coefficient of variation of the average concentration of orthophosphoric acid in solution, after removing the seed from the fruit (acid losses in the seed were not taken into account)

The amount of orthophosphoric acid in the solution at each neutralization stage is determined as the mass fraction, obtained after establishing equilibrium in the process of maintaining the fruits in solution.

Thus, to neutralize the solution (45 g), contained in 100 g of semi-finished product (seedless fruit - solution), the required amount of calcium oxide was:

Step 1: (0.7526 x 0.45) x 0.5714 = 0.3387 x 0.5714 = 0.1935;

Step 2: (0.7526 - 0.3387) x 0.45 x 0.5714 = 0.1863 x 0.5714 = 0.1064;

Step 3: (0.4139 - 0.1863) x 0.45 x 0.5714 = 0.1024 x 0.5714 = 0.05852;

Step 4: (0.2276 - 0.102) x 0.45 x 0.5714 = 0.05634 x 0.5714 = 0.03219;

Step 5: (0.1252 - 0.05454) x 0.45 x 0.5714 = 0.0318 x 0.5714 = 0.0182.

After the 5th step, there remain (0.07066 - 0.038) = 0.0389 g of 85% acid per 100 g s/f or 0.03307 x 0.685 g of 100% acid per 100 g s/f, or expressed in P2O5- 0.0226 g per 100 g s/f or 226 mg / kg.

Example 3

For processing, fresh sour cherries with a dry matter content of 12.7% according to the refractometer, pH=3.12 were taken. The sour cherries were washed, the stalk and the stone were removed, placed in a container and covered with orthophosphoric acid solution, in a ratio of 61:39, which corresponds to 64 parts by mass of solution to 100 parts of fruit.

Composition of the solution in g/100 g: sugar - 12.7; potassium sorbate - 0.14, orthophosphoric acid (85%) - 1.82. In the semi-finished product obtained after storage for 2 weeks, pH = 2.15 was established.

In the semi-finished product stored under ambient conditions for 11 months, no microbiological alteration was detected, the fruits having a fairly dense structure and pleasant color.

After storage in the semi-finished product, the fruit:solution ratio was established at 59:41 and the soluble dry matter content was 12.4% (according to the refractometer).

Neutralization of the solution and washing of the fruits is carried out in 6 stages:

Step 1. Calcium oxide is added to the separated fruit solution in an amount of 0.1663 g / 41 g of solution, the solution is shaken vigorously and then filtered through “medium filtration” filter paper. The filtered solution is poured over the fruit and left for 24 hours, with periodic shaking.

Step 2. The fruits are separated from the solution, calcium oxide is added to the solution in an amount of 0.0981 g / 41 g of solution, the solution is shaken vigorously and then filtered. The fruits are covered with the filtered solution and left for 3-4 hours, periodically pumping the solution through the fruits.

Steps 3-6 are performed similarly to step 2 of the treatment, at each step the following estimated amounts of calcium oxide (g/41g solution) are added: 3-0.0579; 4-0.0342; 5-0.0202; 6-0.0119. After the 6th step of neutralization of the solution, the pH reaches the level of 3.1.

In the solution remaining after neutralization, 12 g sugar/100 g solution is added and the sweetening solution with a concentration of 20% is obtained. The seedless fruits obtained after the orthophosphoric acid neutralization process are covered with the sweetening solution, taken in the ratio of (59.0 g fruit : 53.0 g solution), and maintained until an SU of approximately 16% is obtained according to the refractometer.

During the sweetening process, the solution is periodically separated from the fruit, heated to 60°C and poured over the fruit again.

In the second stage, the solution obtained after the first stage is concentrated under vacuum at a temperature of 60°C, in order to reduce the mass by 12 g for every 100 g of solution. After dissolving the sugar, a solution with a concentration of 29.3% is obtained. In this solution, taken in a ratio of (0.9 : 1.0), the fruits obtained after the 1st stage of sweetening are immersed and maintained until the SU according to the refractometer in solution is approximately 22.3%.

During the sweetening process, the solution is periodically separated from the fruit, heated to 60°C and poured over the fruit again.

In the third stage, the solution obtained after the second stage is concentrated under vacuum at a temperature of 60°C, to reduce the mass by 15 g for every 100 g of solution. A solution with a concentration of 46.0% is obtained. The fruits obtained after the second stage of sweetening are immersed in the solution obtained in a ratio of (1: 0.9) and maintained until the SU according to the refractometer in solution is approximately 33.5%.

During the sweetening process, the solution is periodically separated from the fruit, heated to 60°C and poured over the fruit again.

Then the seedless fruits are separated from the used solution. 61 g of sweetened seedless fruits are obtained, which are dried at 60°C to a mass of 27.1 g (reduced by 2.25 times), which corresponds to 22% moisture.

The finished product has a pleasant appearance, red in color, fleshy, pleasant sweet-sour taste and characteristic smell of dried cherries, easy to chew.

Calculating the amount of calcium oxide needed to neutralize orthophosphoric acid

The calculation is performed similarly to the calculation in example 2.

The total amount of acid added in this example, per 100 g of semi-finished product, 1.82 x 0.39 = 0.7098 g.

The total amount of calcium oxide required to neutralize the added orthophosphoric acid is 1.82 x 0.39 x 0.5714=0.4056 g/100 g of initial semi-finished product.

Thus, for neutralization (41 g) contained in 100 g of semi-finished product (seedless fruit - solution), the required amount of calcium oxide is:

Stage 1:

(0.7098 x 0.41) x 0.5714 = 0.2910 x 0.5714 = 0.1663;

Stage 2:

(0.7098 - 0.290) x 0.41 x 0.5714 = 0.1717 x 0.5714 = 0.0981;

Stage 3:

(0.4188 - 0.177) x 0.41 x 0.5714 = 0.1013 x 0.5714 = 0.0579;

Stage 4:

(0.2471 - 0.103) x 0.41 x 0.5714 = 0.0598 x 0.5744 = 0.0342;

Stage 5:

(0.1458 - 0.059) x 0.41 x 0.5714 = 0.0353 x 0.5714 = 0.0202;

Stage 6:

(0.086 - 0.0353) x 0.41 x 0.5714 = 0.0208 x 0.5714 = 0.0119.

After the 6th stage, there remain (0.0508-0.0208) = 0.0300 g of 85% acid per 100 g s/f or 0.0255 g of 100% acid per 100 g s/f, or expressed in P2O5 - 0.0175 g per 100 g s/f which constitutes 175 mg/kg.

Example 4

Fresh sour cherries of the Erdi Urojainaia variety, dry matter according to refractometer 15.2%, pH =2.97.

Whole stone fruits are washed, the stalk and stones are removed, placed in a container and covered with orthophosphoric acid solution, in a ratio of 65:35, which corresponds to 54 parts of solution to 100 parts of fruit.

Solution composition in g/100 g: orthophosphoric acid (85%) - 1.91. In the semi-finished product obtained after storage for 2 weeks, pH=1.95 was established.

In the semi-finished product stored under ambient conditions for 11 months, no microbiological alteration was detected, the fruits having a fairly dense structure and a pleasant color.

After storage in the semi-finished product, the average soluble dry matter content was established at 9.8% (according to refractometer) at a fruit to solution ratio of 65:35 parts by mass.

After which the neutralization process of the orthophosphoric acid used is calculated and carried out similarly to example 2.

Neutralization was carried out in 7 stages, using the calculated amount of calcium oxide for each stage. After the 7th neutralization stage, the pH reached 3.15.

The seedless fruits are separated from the solution. From the separated solution, a sweetening solution is prepared.

The concentration of the sweetening solution is determined by the predetermined soluble dry matter content in the sweetened fruits (29.0%) and the initial fruit:solution ratio established at the beginning of sweetening of 1.0:1.0.

The amount of sugar required to be added and the concentration of the sweetening solution are calculated similarly to example 1.

The following calculated values are obtained:

mass of the mixture (g) in the sweetening process: 65 fruit + 65 solution = 130;

SU content in the mixture (g): 130 x 0.29 = 37.7;

SU content in the initial semi-finished product (100 g): 100 x 0.098=9.8;

amount of sugar needed to add (g): 37.7 - 9.8 = 27.9.

Granulated sugar is used as sugar.

The mass of the solution should be 35 + 27.9 = 62.9 g, and the lack of mass, which is equal to (65.0-62.9) = 2.1 g, was made up with water. This gives 65 g of sweetening solution with a soluble solids concentration of 71.9%.

The seedless fruits obtained from the orthophosphoric acid neutralization process are covered with the sweetening solution and maintained until a SU of 29.0% is obtained according to the refractometer.

In order to accelerate the sweetening process, the periodically used solution is separated, heated to 85°C and poured over the fruit.

Then the seedless fruits are separated from the solution. 66.0 g of sweetened seedless fruits are obtained, which are dried at 60°C to a mass of 24.3 g (reduced by 2.72 times), which corresponds to a humidity of 18%.

The finished product has a pleasant appearance, red color, fleshy, pleasant sweet-sour taste and characteristic smell of dried cherries, easy to chew.

Calculating the amount of calcium oxide needed to neutralize orthophosphoric acid

The calculation is similar to the calculation in example 2.

The total amount of acid added in this example, per 100 g of semi-finished product, 1.91 x 0.35 = 0.6685 g.

The total amount of calcium oxide required to neutralize the added orthophosphoric acid is 0.6685 x 0.5714=0.3820 g /100 g of initial semi-finished product.

Thus, the required amount of calcium oxide for neutralization, in g/35 g of solution, is:

Stage 1:

(0.6685 x 0.35) x 0.5714 = 0.2340 x 0.5714 = 0.1337;

Stage 2:

(0.6685 - 0.2340) x 0.35 x 0.5714 = 0.1521 x 0.5714 = 0.0869;

Stage 3:

(0.4345 - 0.1521) x 0.35 x 0.5714 = 0.0988 x 0.5714 = 0.0565;

Stage 4:

(0.2824 - 0.0988) x 0.35 x 0.5714 = 0.0643 x 0.5714 = 0.0367;

Stage 5:

(0.1836 - 0.0643) x 0.35 x 0.5714 = 0.0418 x 0.5714 = 0.0239;

Stage 6:

(0.1193 - 0.0418) x 0.35 x 0.5714 = 0.0271 x 0.5714 = 0.0155;

Stage 7:

(0.0775 - 0.0271) x 0.35 x 0.5714 = 0.0176 x 0.5714 = 0.0101.

After the 7th stage, there remain (0.0504-0.0176) = 0.0328 g of 85% acid per 100 g s/f or 0.0279 g of 100% acid per 100 g s/f, or expressed in P2O5 - 0.0191 g per 100 g s/f which constitutes 191 mg/kg.

1. Technological instruction on preservation of fruits and berries with sulfuric anhydride. Collection of technological instructions. Moscow, Food Industry, Vol. 2, 1977, p. 334-349

2. Technological instruction for the production of candies. Collection of technological instructions. Moscow, Food Industry, Vol. 2, 1992, p. 29-57

3. MD 433 Y 2011.11.30

Claims (7)

1. Process for obtaining sweetened dried cherries and cherries, which includes preliminary preparation of the fruits, covering the fruits with an orthophosphoric acid solution taken in a ratio and concentration that ensures the achievement of a pH of 1.9…2.3 in the fruits, storing the fruits in the said solution for 0.5…12 months, separating the fruits from the solution, neutralizing the orthophosphoric acid solution with calcium oxide or carbonate taken in stoichiometric amounts of orthophosphoric acid and calcium, washing the fruits with the neutralized solution until the fruits reach a pH of 2.9…3.5 and a residual orthophosphoric acid content of no more than 275 mg/kg (expressed in P2O5), separating the washed fruits from the solution and concentrating it to a soluble dry matter content of 20…75%, covering the fruits with the concentrated solution with a temperature of 25…85°C and maintaining them until the content of soluble dry substances in fruits reaches 27…43%, after which the fruits are separated and dried at a temperature of 25…65°C to a humidity of 14…32%. 2. Process according to claim 1, wherein the additional orthophosphoric acid solution contains 11…21% sugar. 3. Process according to claim 1, wherein the additional orthophosphoric acid solution contains 0.11...0.17% potassium sorbate. 4. Process according to claim 1, wherein the fruits are covered with an orthophosphoric acid solution at a temperature of 2…15°C. 5. Process according to claim 1, wherein the washing of the fruits with the neutralized solution is performed repeatedly, by keeping them in the solution, with subsequent neutralization and use of the separated solution. 6. Process according to claim 1, in which the concentration of the solution resulting from washing the fruits is achieved by adding sugar and/or by evaporation, while commercial granulated sugar or commercial granulated sugar with the addition of caramel molasses or maltose in an amount of 10...15% of the added sugars is used. 7. Process according to claim 1, wherein the maintenance of the fruits in the concentrated solution is carried out in one or more stages, while the concentration of dry soluble substances of the solution is increased by 5...15% at each subsequent stage.