Drying dried fruits in production. Dried plum

The production of dried fruits is a serious, promising and highly profitable business. Most people try to eat natural foods that have not been frozen or canned.

In addition, dried fruits allow you to vitaminize and diversify a meager menu in the winter.

The main and most attractive aspect of organizing such a business is relatively small investments with high profitability. The production of dried fruits, if properly organized, can be an excellent income and an initial step towards expansion in this market segment.

Among others, there are several advantages of this business:

• The absence of a complex technological process - automatic drying complexes can minimize the number of employees in production and minimize wage costs;
• An extensive market for the purchase of raw materials - the raw materials are fruits and berries, both domestic and foreign origin. In addition, for this production, fruits with poor presentation are most often used, which means they can be purchased at a low price;
• Expanded opportunities for marketing products - dried fruits can be supplied both to large retail chains and to catering establishments.

Disadvantages of business. Such a business probably has one drawback. The production of dried fruits is a seasonal business, since in the summer the majority of the country's population prefers to eat fresh fruits, which are also in abundance.

Business organization

To start production, you need to rent a room to which sewerage, water supply, and electricity are connected. It would be good if the building had at least 5 rooms for workshops and good access roads for transport. The following structural units should be organized in the building:

• Procurement workshop;
• Processing workshop;
• Workshop for drying raw materials;
• Packing shop;
• Stock;
• 1-2 rooms for management personnel.

Automatic drying equipment costs about 10 thousand dollars. It performs operations such as drying, washing and slicing fruits. Some models have built-in scales and a filling line.

Dried fruit production technology

The most common method of drying fruits is convective technology. For this, special ovens with electric heating elements are used, which heat the air inside. After washing and slicing, the crushed fruits are distributed on trays in ovens.

Constantly maintained high temperature allows you to dry the fruit, evaporating all the moisture from them. The process continues without stopping, dried fruits are removed and sent to the packaging workshop, and the next batch arrives in their place.

A convection oven for drying vegetables allows you to preserve the maximum amount of valuable substances and vitamins in the finished product.

Raw materials

Fruits should be purchased during their mass ripening season - at the end of summer and autumn. It is most profitable to negotiate with garden farming partnerships, which will bring the raw materials themselves.

By the way, for the production of dried fruits, fruits of irregular shape and spoiled presentation are suitable, so their price can be very low. If you have transport, you can go to villages and gardening associations, where there will always be a huge number of people willing to sell their surplus crops.

Suitable for the production of dried fruits:

• Apples, pears;
• Cherry;
• Figs;
• Dates, prunes;
• Grape;
• Apricots;
• Dried apricots;
• Kaisa;
• Raspberries, ;
• Rose hip;
• Banana;
• Kiwi.

A line for the production of dried herbs - dill, parsley, bay leaves - may also become quite promising.

Benefit

When asked about the benefits of dried fruits for the body, nutritionists unanimously answer that this is the most valuable product, both in dietary nutrition and simply for the full functioning of the body.

Thanks to the use of drying technology, almost all the vitamins, minerals and trace elements necessary for proper functioning of the heart, liver, and gastrointestinal tract remain in the fruits.

In addition, dried fruits contain a large amount of fiber and hard-to-digest fibers, which improves intestinal motility and helps remove toxins from the body.

Dried fruits are an ideal snack option. They contain very few calories, so they can be safely consumed by people who are watching their weight. Dried fruits help diversify dishes during fasting; they are added to porridges and compotes are prepared.

Sales of finished products

There are few products to produce; the profitability and income of a business depend on how sales are organized. And here everything depends on the manager, who must attract as much attention as possible to his products.

• Take care of the company name and logo;
• Develop and order branded packaging of different sizes;
• Provide as much nutritional information as possible on your product packaging;
• If the package contains 1-2 recipes for preparing dishes with dried fruits, this could become your “trick” and attract more customers.

You can sell dried fruits both in hypermarkets and in small retail stores in your city and region. In addition, they are in demand in canteens and institutions where food is provided (schools, kindergartens, military units, canteens at enterprises, etc.).

Well-established sales are the key to the fact that your business will fully pay off within 2 years and there will be funds for its expansion. You can occupy a separate niche in the production of dried fruits if you set up the production of muesli; this mixture of dried berries, fruits and nuts is very popular.

Additional video:

If you managed to take the first steps in this promising business, do not stop and open production branches in neighboring regions. Thus, it is possible to achieve the formation of a huge network for the production of dried fruits.

This material will discuss the creation from scratch of a private (or small) highly profitable enterprise for the procurement of agricultural products of plant origin (fruits, vegetables, etc.) and their processing using industrial drying units with further packaging.

Only organizational issues are considered dried fruit production, excluding accounting.

Enterprise objectives

The main raw material for drying and subsequent packaging are apples. Their yield is periodic - in 2011 there was a peak, therefore, in 2012 the yield will decrease, and next year it will increase again.

But even so, the cost of raw materials will always be very low, since apples are very common throughout Ukraine and the European part of Russia, and practically no one is seriously engaged in their industrial processing using drying units, and even more so in packaging. Meanwhile, packed in a 100 or 200 gram polyethylene colorful bag, they can quickly find a buyer. If we take into account that from 100 grams of dried fruit you can prepare about 3 liters of high-quality compote, then it is easy to calculate that at a cost of up to 3.5 hryvnia (0.45 dollars) for such a package, the cost of a glass of drink will be just over 20 kopecks - cheaper than a glass of tea.

In addition to apple processing, with established dried fruit production You can also use other available local raw materials: cheap and high quality - apricots, cherries, plums, pears. Now such dried fruits are sold almost only in markets and by weight. Sold in bright packaging and even with a minimum of advertising, they will quickly become in demand, since they do not require much trouble when preparing, and their beneficial properties are well known.

In addition to dried fruits, it is advisable to dry herbs, in particular, it is most profitable to use dill and parsley as raw materials. In order to load an enterprise with such raw materials, it is enough to conclude agreements with 5-6 owners of private plots (30-40 acres each) in villages. With the current level of unemployment and the amount of empty land, they will willingly grow such greens even for a minimum wage. You just need to provide them with seeds and pay for the accepted raw materials on time, then you can actually get 3-4 harvests of greenery for drying from their plots per season.

Another type of raw material can be wild raspberries and blackberries in the form of old dry shoots. By concluding an appropriate agreement with the forestry department, it is possible to harvest practically unlimited quantities of dead wood from these plants in winter without violating environmental legislation, since the plants produce fresh shoots by spring. The advantage of such raw materials from medicinal plants for drying is that it can be processed almost until the end of spring.

It is advisable to set up a small enterprise in a small locality, preferably in a regional center. Firstly, all permitting services are located here - from the district council and the tax inspectorate to the sanitary and epidemiological station. Secondly, in such an area it is quite easy to find empty industrial premises for a reasonable price - for purchase or rental.

Enterprise divisions

Even before receiving permitting documents, it is worth choosing a building for a small enterprise or private enterprise for drying and packaging agricultural products. It must meet the following requirements.

Have at least five relatively spacious rooms for setting up workshops, a spacious fenced yard, a water supply and sewerage system, as well as a connection to a three-phase power grid. In the regional center, as already mentioned, finding this is not particularly difficult; in extreme cases, water supply, sewerage and a 380 W power line can be organized in a few weeks.

Main workshops of the enterprise for drying and packaging of agricultural products:

1. Workshop for procurement and storage of raw materials for drying
2. Product processing workshop.
3. Drying shop.
4. Packing shop.
5. Warehouse for storing finished products.

In addition, you will need an office with one or two small rooms.

Raw material procurement and storage workshop

You need to immediately plan that the main work on procuring raw materials for drying will not be concentrated in this place.

To organize the mass procurement of raw materials for the production of dried fruits, it is appropriate to hire 5-6 people - one at a time in the largest settlements in the region (urban towns or large villages), who will accept apples, pears, plums, etc. locally (in personal farmsteads). To do this, it is also necessary to conclude agreements with them and hand over cash to pay for raw materials. They must also have an installation: it is advisable to accept ready-made dried fruits from the population (for this they must be versed in technology). This approach will significantly reduce the costs of transportation and processing of raw materials.

In addition, you need to create one or two mobile teams to procure raw materials. Their task is to accept raw materials or dried fruits from the population on set days and hours (for this it is necessary to post notices with the appropriate content in the village centers). Market days are best suited for this - now they are installed in almost every more or less large village.

They can also independently pick apples or other fruits for drying - in the villages there are now many ownerless orchards (former collective farms), which no one looks after, but which still bring good harvests.

To ensure the operation of the workshop, you will need 2 used pickup trucks and one semi-truck - a Gazelle or a minibus, as well as 3-4 portable scales and a significant amount of packaging (200-300 plastic bags).

Considering that the apple ripening season lasts almost three months (from early varieties to winter varieties), with this approach it is quite possible to prepare up to 100 tons of apples for subsequent drying. Approximately half of this amount should be harvested and dried locally at collection points.

The premises of the raw materials workshop itself should be designed for the simultaneous storage of about 10 tons of apples, tons of apricots and up to two tons of pears. If necessary, raw materials can be temporarily stored in the yard.

Product processing workshop

The tasks of the workshop include preparing raw materials for drying - washing them, cutting them, soaking them in brine and laying them out on trays. On average, this workshop should be able to cut up to 500 kilograms of products daily, but this figure is not systematic.

Since there are no acceptable mechanisms for high-quality cutting of fruits, it would be appropriate to seek help from the regional employment center. Every day you can attract 5-10 people to manually cut fruits, depending on the availability of raw materials. Payment is made at the end of the working day, the duration of which can be agreed upon with each such employee separately. If we assume that in half an hour even an untrained person can easily cut up to 10 kilograms of apples, then for this quantity it is permissible to charge 0.5-0.6 dollars. Thus, a worker can earn at least 5 dollars per day, and with proper skill and extended working hours - up to 10.

The equipment in this workshop requires at least two baths (standard household ones are quite acceptable), running water, hoses for supplying it to the right places, salt for preparing brine, as well as equipment: gowns (disposable medical ones are possible), rubber gloves, buckets (according to two for each worker), knives.

Drying shop

The drying shop can be equipped with chamber-type convective air drying (for example: K-100 or K-300). Information about this type of industrial dryers can be found on our website in the “” section. The price is about 17 and 34 thousand dollars, respectively.

But it is worth noting that the choice of equipment is an individual matter. It should also be taken into account that installing two dryers of lower power is preferable to one large one, since while one is in operation on the other, you can load raw materials or unload the finished product, carry out maintenance work, etc. This is especially true when drying a variety of raw materials.

It would also be an unforgivable omission not to take advantage of natural energy sources. Simply put, with sufficient intensity of solar radiation, it will be much more economical to carry out the primary stage of drying agricultural products in a natural way, because during the first day of drying, the same apples lose weight and size to about half of their original state. And most importantly, during this time the slices stop sticking together and they can be dried in much larger quantities than at the beginning of the process (about three times).

Based on this, it is advisable to make 50-70 trays for drying apples or other products in the open air. For such structures, slats with a cross-section of 2 by 3 centimeters with a base made of construction plaster mesh are suitable, to which the fruit pulp practically does not stick. Using a stapler, two workers can make this number of trays in 4-5 days. If you have a sufficiently spacious farmstead for the production of dried fruits, drying of fruits can be done without the use of equipment at all, as is done at home.

The high cost of gas and electricity brings to mind another fairly common method of drying agricultural products of plant origin. If you allocate a separate room for drying, then you can build a primitive stove with direct exhaust in it. The necessary structure for trays around and on top of it is created in accordance with the configuration of the room. Firewood for raising the temperature will cost much less than any other heat source. You only need a powerful hood to remove moisture.

Finished product storage workshop

After drying the raw materials, it is advisable not to immediately pack them into small packages, but to send them for storage to the finished products workshop (warehouse). That is, dried fruits are poured into plastic bags (they allow the products to “breathe”) and placed in no more than three rows in height in a separate room. When using cardboard boxes, the row height may be higher. The boxes are tightly sealed with tape.

It is advisable to treat the floor, ceiling and walls of such a room with sealant and line it with sheets of tin to protect against rodents. In different places of the room, environmentally safe means of protection for humans and against insects should be placed (the employees of the sanitary and epidemiological station can advise them). In this case, semi-finished dried fruits can be stored for a year.

But, as practice shows, already at the end of autumn you can start packaging and selling dried fruits in small packages.

Packing shop

For the full operation of an enterprise of this type, a semi-automatic packaging machine with an electronic dispenser with a capacity of 900 hundred-gram bags per minute is sufficient. The cost of such models is about $2,500 (for example, from the company “Avanpak Engineering”, Ukraine). Again, the choice of unit largely depends on the amount of raw materials and the region for setting up production facilities.

Colorful packaging can be ordered from specialists (the text will be discussed below), or you can even combine it yourself. The cost of one package for tape production will be approximately 0.01-0.02 dollars, which will have little effect on the overall cost dried fruits produced or other products, but will increase the possibility of their sales.

Office

Standard office furnishings include a computer with an Internet connection, several tables, chairs, a safe, and other office equipment. But it is necessary to have constant communication between the head of the enterprise and all employees. For this purpose, there are now corporate networks from mobile operators - quite affordable.

Staffing table

When organizing a private enterprise for drying agricultural products, it is most practical to hire only the director and production accountant for permanent employment. In addition to them, through the employment center you need to attract a commercial director with the right to conclude small transactions, a chief engineer, a workshop manager and a vehicle fleet manager (all these big names are needed only for entry in work books).

The commercial director is in charge of searching for buyers and communicating with them, the head of the workshop is in charge of product accounting, the chief engineer is in charge of servicing the mechanisms, and the head of the fleet is in charge of cars. Under existing legislation (in Ukraine), when hiring them through an employment center, it pays them full wages in the first year, but with the condition that they will continue to work in the same place for the same period. Taking advantage of this, many employers, when hiring, require such employees to fill out an application for release at their own request without specifying a date.

All other employees of the enterprise production of dried fruits are seasonal workers and work according to contracts certified by a lawyer (up to one-day ones).

Implementation and prospects

The proposed business plan is interesting in that it offers not only drying of products, but also their simultaneous packaging in small containers. If seeds or bread crusts (crackers) are now successfully sold on the market at a price above 0.5 dollars per pack of 100 grams, then the sale of well-presented dried fruits in the same packaging and with normal advertising may well be successful.

Of course, you can also sell semi-finished dried fruits (in bags or boxes) - such products are now readily accepted by military units, schools, preschools, hospitals, and catering organizations.

But without a workshop for packaging dried fruits and other products, it is practically not worth starting the creation of an enterprise of this type. The innovation will be the sale of dried fruits in small colorful packages, each of which will be enough to quickly prepare a wonderful drink for the whole family. With this packaging design for dried fruits, you can sell them to supermarkets and food depots.

At the same time, the following information should be mentioned on the packaging: the use of dried fruits, herbs and medicinal plants for food is in folk traditions, they are very good for health (especially for children), environmentally friendly (non-GMO), their preparation does not take much time, and some don’t need to be cooked at all (dried fruits).

Over time, under favorable circumstances, it is possible to develop a network of procurement and processing workshops for dried fruits (mainly apples) throughout the region. With an initial investment of 30 thousand dollars, with the proper approach to the matter, all costs can be recouped in a year (the operation of the packaging unit can be practically uninterrupted, regardless of the season - the already mentioned medicinal plants will serve for this; if necessary, you can take a batch of the same seeds). Detailed information is not used here as data varies by region. In particular, we are talking about the central part of Ukraine, as the most indicative, but you can make money from the production of dried fruits everywhere.

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Prunes (dried plums)

Prunes are the dried fruits of plums of various pomological varieties, mainly from the Hungarian group, as well as plums of local varieties.

From small plums (225 pcs. in 1 kg) you can prepare pitted prunes, used as a substitute for raisins in the baking industry. This product is also an excellent filling for muffins, puddings and pies. The process of removing seeds is mechanized.

Due to the significant concentration of sugar and other substances and low moisture content (no more than 25%), dried fruits are nutritious, can be stored for a long time and are convenient for transportation. During experimental storage, it was found that under normal conditions, prune fruits with a moisture content of 28.6% or more are subject to mold; Fruits with 25% moisture content tend to be well preserved. You can’t overdry plums. “Overcooked” prunes are very hard, poorly cooked, and not sweet enough.

Requirements for raw materials. For the production of prunes, plums with fleshy pulp (retaining volume and juiciness when dried), with well-separable pits and a high dry matter content are suitable. To obtain good-quality prunes, large, well-ripened fruits are used, including carrion, containing a large amount of sugar and moderate acidity.

The most valuable varieties of plums for drying are: Italian Hungarian, Arton, Azhan, Bulskaya, Wangenheim, common, black golden, Eric raisin, kirk, petit mirabelle and Montfort. Not suitable for drying: Great Blue, Victoria, Jefferson, Renclod Altana, Early Blue, Mirabelle of Nancy, Renclod Ullen and Egg Yellow.

In the USA * the main pomological varieties of plums used for the production of prunes are: Hungarian Azhanska, Sugar Imperial; The Hungarian Italian plum variety is mainly used for fresh consumption and freezing. In most European countries, including the USSR, Italian Hungarian plums are processed into prunes. According to our observations, plums of this variety, which are characterized by good storage, should primarily be used for fresh consumption.

* (See the book by V.V. Kryuss. Industrial processing of fruits. M., Pishchepromizdat, 1963.)

Ripe, fresh fruits not damaged by pests and diseases are used for drying. Green, unripe, stale and other defective plums are not allowed to be dried.

The plums used to make prunes are kept on the tree until they are completely ripe and fall off. Carrion is usually collected 4-5 times a season. To prevent fruit spoilage and speed up harvesting, the soil under the trees is rolled before harvesting.

Features of the technology. Drying plums can be done by solar or fire. In Moldova, plums are sometimes dried in loznitsa (ovens) over low heat (smoke drying) at a temperature of 45-50°. The flue drying process, due to high humidity and low smoke temperature, is so slow that the fermentation process begins in the plums, resulting in a product of very low quality. In Moldova, this method has become widespread because it allows you to quickly and inexpensively organize the drying of plums anywhere.

Solar drying is widely practiced in the southern regions of the country: the republics of Central Asia, the Krasnodar Territory; the product is of quite satisfactory quality.

To speed up drying, it is necessary to remove the waxy coating from the skin of the fruit, for which the plums are blanched in boiling water and a weak (1%) soda solution before drying. In the latter case, the fruits should be thoroughly washed with cold water to remove traces of soda. Blanching time, depending on the variety, ranges from 20 seconds. up to 1.5 min. A “mesh” should appear on the skin. If the wax coating on the fruit remains intact, then during drying the fruit swells, bursts and contaminates the rest of the finished product with its juice.

For solar drying, plums are scattered in one layer on special trays. The most convenient tray size is 1X2 m; The capacity of such a tray when laying fruits in one layer is 30-35 kg. The duration of solar drying is approximately 10-15 days. Product readiness can be easily determined by eye and touch. Drying is considered complete if the fruits are evenly dried; in the middle near the bone they should not be soft and juicy.

For fire drying of prunes, special dryers are used (SPK-90, LKS-40, KSA-80, KPS-20). The air temperature in them is maintained from 80° (first tape) to 60° (fourth or fifth tape). Fresh fruits in the dryer are first placed on the upper tiers, where the temperature is lower; when the plums have dried, the sieves are moved to the lower tiers, where the temperature is higher. The drying time, depending on the size of the fruit and the dry matter content in it, lasts from 6.5 to 16 hours. Good results are obtained when drying plums in continuous steam belt dryers. They begin to dry the plum at a temperature of 45-50°, and finish at 75-80°. Drying time ranges from 15 to 24 hours.

Higher quality prunes are obtained by processing plums in vacuum dryers.

In some areas of the Krasnodar Territory, greenhouses are successfully used to produce high-quality prunes. The air temperature in greenhouses on hot days reaches 70-80°. The process of drying the fruit lasts 7-8 days, and the skin of the fruit acquires a stable, shiny black, varnished surface. Drying of plums ends when the moisture content of the fruit is 12-20%.

After drying, the fruits are kept in chests with a capacity of up to 1 g for two weeks, where the humidity is equalized. Overdried fruits absorb it from wetter specimens; the surface of the fruit is also moistened as a result of the diffusion of moisture from the center of the fruit to the surface.

After equalizing the humidity, the prunes are calibrated, sorted and packaged in wooden boxes or thick kraft bags.

To give prunes a stable shiny surface in a number of countries, for example Yugoslavia and Czechoslovakia, dried fruits, after packing in boxes, are placed in specially designed ovens, where they are kept at a temperature of 100-120° for 10-15 hours. You can restore the shiny surface of prunes after storage by wetting them with a 10% solution of molasses or sucrose; the processed fruit mass must be thoroughly mixed and heated to a temperature of 60-65°. The consumption of molasses or sugar is 1 kg per 1 ton of product.

In the USSR, to give the fruit a shiny surface, a cheaper method of processing prunes is used - glycerin. For this purpose, prunes are dipped for 1-2 minutes. into boiling water or treated with hot steam; after heating, treat with glycerin. 1 ton of prunes consumes 5 kg of glycerin.

Chilled prunes after treatment with glycerin (or without it) are packaged in cardboard, wooden or plywood boxes. Their inner surface should be lined with parchment or waxed paper.

In the USA, the hot method of processing prunes before packaging is most widespread. For this purpose, the dried fruits are immersed in boiling water for several minutes, as a result of which the prunes acquire a shiny surface. In addition, insect pests are destroyed in the fruits. During processing, the fruits, absorbing water, increase in weight by about 6-8%. However, the moisture content of the finished product should not exceed the norm established by the standard.

Quality indicators. Dried plums vary in quality in different harvesting areas. Thus, dried plums prepared from Hungarian plums in the areas of the Black Sea coast are distinguished as the highest quality type - prunes. Dried plums from other areas are referred to in the trade as “dried plums of local varieties.”

Each commercial grade of prune corresponds to a certain number of pieces of fruit per 1 kg: the highest - 60-100, the first - 150-160; in the 2nd, fruits of different sizes are allowed, without calibration. Dried plums of local varieties contain in 1 kg: premium - at least 350 pcs. fruits, 1st - 420 pcs. and 2nd - unlimited quantity.

In addition, when assessing the quality of dried plums, the taste, smell, color, and fleshiness of the fruit are taken into account; the number of fruits with mechanical damage, burnt, spotted, damaged by pests, unripe, candied; contamination with twigs and stalks. The moisture content of dried plums for all commercial varieties should not exceed 25%.

The pit in a properly dried prune does not slip between your fingers when squeezing the fruit; The consistency of the pulp is dense, but not hard.

Storage. Dried plums should be stored in a dry, well-ventilated area at an even temperature without sudden fluctuations. However, storing prunes in refrigerators gives the best results. Dried plums in which barn pests are found are treated with methyl bromide or heated for 25-30 minutes. at 90°, followed by sifting through a sieve with cells with a diameter of 5 mm to separate killed pests. Disinfection of prunes and premises with sulfur dioxide provides good protection against pests.

INSTALLATION FOR DRYING PLUM FRUITS

Dr. Tech. sciences; , Ph.D. tech. sciences

State Scientific Institution All-Russian Scientific Research Institute of Tobacco, Shag and Tobacco Products of the Russian Agricultural Academy, Krasnodar

Dr. Tech. sciences

FSBEI HPE Kuban State Agrarian University, Krasnodar

Drying of plum fruits is carried out both naturally and artificially. Fruits are dried artificially in tunnel and conveyor type dryers.

To date, VNIITTI has experience in developing technological equipment for post-harvest processing of tobacco leaves. For the first time in the world practice of tobacco growing, an industrial-type drying-fermentation production (IFP) was created, designed for drying, fermentation and conditioning of tobacco in a continuous technological process based on three conveyor units.

Using previous experience, the institute, together with the Kuban State Agrarian University, substantiated the technological parameters of the technological line for post-harvest processing of plums with artificial drying in a conveyor-type installation.

First, the plums are dried at a low temperature C) for 3–4 hours, followed by holding for 4–5 hours at a temperature of 20–300 C. The second phase of drying is carried out at a temperature of 55–600 C for 10–12 hours until there is no residual moisture more than 25% Plum drying modes are presented in Table 1.

Table 1

Drying modes for plum fruits

To calculate air flow graphically, an I – d diagram was used. In the drying installation, the product is heated by lowering the air temperature from t1 to t2 . Moisture from the product evaporates and goes into the air; at the same time, the air moisture content increases from d1 to d2 . At the same time, the relative air humidity increases from φ1 to φ2.

When theoretically substantiating the parameters of the dryer, it is assumed that heat is not spent on heating the product, transport devices and losses to the environment; the heat introduced by the air is spent only on the evaporation of moisture. In this case, moisture in the form of steam passes into the air, returns to it all the heat spent on vaporization, and the enthalpy of the air does not change during the drying process, that is, I1 = I2.

The air temperature in the air heater increases from to to t1 , and the enthalpy of air from I0 to I1 at a constant moisture content of the air, i.e. when d0=d1 (Fig. 1). The process of heating air in the air heater is depicted by straight line AB , parallel to the line of constant moisture content.

I- dHumid air chart at barometric

pressure 745 mm Hg. Art.

Rice. 1. Graphic calculation of the modes of the plum drying process (I – d diagram)

The construction of the drying process in the I – d diagram and the determination of air state parameters from it were carried out as follows.

Using the known initial values ​​of temperature t0 and relative humidity φ0 of the outside air, point A and parameters I0 and do were found. Knowing the drying temperature t1 , from point A a vertical line was drawn parallel to the line of constant moisture content until it intersected with the temperature line t1 . The parameters of point B will be: d1= do, I1 and φ1. Then, from point B, a straight line was drawn parallel to the line of constant enthalpy I1 until it intersected with the line of the specified final air temperature t2.

Using the I – d diagram, we determined the parameters of the air condition in the first (Table 2) and third phases of drying (Table 3).

table 2

Results of determining air state parameters using the I – d diagram in the first drying phase

Table 3

Results of determining air state parameters using the I – d diagram in the third drying phase

The diagram of the technological line for post-harvest processing of fruits and the design of a conveyor-type installation for drying plum fruits are substantiated. The technological line has the necessary set of equipment, on which fruit processing is carried out as follows. Fruits that have reached the biological stage of maturity, fresh, not damaged by agricultural pests, with a certain dry matter content in plum fruits from 14 to 19.5%, depending on the area of ​​growth, are sent for drying.

From the vehicle, boxes of raw materials are unloaded by an electric forklift and transported through a box tipper to a fan washing machine with shower rinsing. Drains after washing are calibrated by diameter using a calibrator , inspected on a conveyor and dried in a device for drying plums, after which they are sorted on a conveyor and fed into a bunker.

The installation for drying plum fruits (Fig. 2) is a frame 1 made of rolled steel and covered with quick-release panels. Inside the frame there are: upper conveyor 2, middle conveyor 3 and lower conveyor 4, each with drive and tension drums. The conveyor belt covering the drums is made of stainless steel mesh wire.

1-installation frame 2-upper conveyor 3-middle conveyor 4-lower conveyor 5-upper air duct 6-lower air duct 7-electric heating installation of the upper zone 8-electric heating installation of the lower zone 9-drive station

Rice. 2. Technological diagram of the installation for drying plum fruits

Before being supplied to the installation, the air is heated in electric heating units 7 and 8. The conveyors are driven through the drive station 9.

The technological process of drying plums is carried out as follows. Plum fruits intended for drying, after washing, cleaning and calibration, are fed into the installation onto the inclined part of the first (upper) conveyor 2, installed at an angle of no more than 400. At the same time, the uniform flow and distribution of raw materials over the entire surface of the conveyor belt is monitored.

At the end of the first (upper) conveyor 2, the plum fruits are poured onto the second (middle) conveyor 3. Then, sequentially, the plum fruits are poured onto the third (lower) conveyor 4.

Two electric heater installations make it possible to carry out three phases of drying: Phase I - on the upper conveyor 2 is carried out at air temperature C for 3 hours; Phase II - on the middle conveyor 3 without air supply at a temperature of 20 - 30 degrees for 4 hours; Phase III - on the lower conveyor 4 at an air temperature of 55-600 C for 10 hours.

Based on the calculation, for drying in the first phase we select the electric heating installation SFOTs-16 with a power of 15 kW, and for drying in the third phase we select the electric heating installation EKOTS-5 with a power of 5 kW.

Scientifically based parameters and operating modes of the installation for drying plums are presented in Table 4.

Table 4

Parameters and operating modes of the installation for drying plums

The advantage of the proposed installation for drying plum fruits is that plums are not dried on farms; only freshly harvested products are sold. The price of plums during the period of mass ripening is low, the demand for it is small, so most of the products (85%) are supplied to the cannery at a low price. When using the developed installation, about 80% of the plums are dried and sold by the farm as dried fruits. The price of dried fruits is much higher, the sale of products takes a longer time, which allows increasing farm profits by more than 4.5 times.

Literature

1. , Kukushkina drying production. - M.: Food industry, 1973.

2., Malsky equipment of canning factories. - M.: Food Industry, 1973.

3. Skripnikov fruits and berries and technochemical control. – M.: Kolos, 1979.

4. Drying fruits and vegetables. - M.: Food Industry, 1978.

5. Governors and processing of vegetables, fruits and berries. - M.: Higher School, 1976.

6. Agrotechnological bases for increasing the efficiency of tobacco production. / edited by Krasnodar, 2003. – 370 p.

Prunes are most often any dried plum. Refers to dried fruits. It has good taste and nutritional qualities. Plum belongs to the trees of the Rosaceae family and is the result of a natural crossing of cherry plum and sloe. Currently, plums are actively cultivated in the countries of Asia Minor, the North Caucasus, Moldova, central and southern Russia and Ukraine.

Prunes are produced with or without pits, and production can be done manually or mechanically. Preparing prunes for the winter by hand is more useful, since dried fruits retain their shape well.

Prunes are used in various dishes - from dessert to seasoning for meat. This dried fruit is a popular ingredient in the North African dish tajine. Perhaps the most famous gastronomic prune is the Agen prune. It is often used in the preparation of tzimmes, a traditional Jewish dish in which the main ingredient is diced or sliced ​​carrots. In Scandinavia, prunes are used to make jelly, which is eaten with rice porridge at Christmas. And in Norway it is a component of fruit soup. Prunes are used to make fillings and pies. This dried fruit is used to fill Danish pastries, which are popular in New York and other regions of the East Coast of the United States. Prune ice cream is common in the Dominican Republic.

Production

To obtain prunes, sweet, juicy and ripe fruits should be selected. Then the selected fruits must be blanched in a boiling 1-1.5 percent solution of baking soda (100-150 grams of soda will be needed for 10 liters of water) for 5-20 seconds and immediately rinsed in hot water. Next, the fruits are cooled and dried in a steam dryer.

The drying process has a number of features. At the first stage, the fruits are dried at a temperature of 45-50 degrees Celsius for 3-4 hours until withered, and then at a temperature of about 60 degrees Celsius for the next 1-2 days until ready. To give dried fruits a characteristic dark color, before the immediate end of drying, you should increase the temperature to more than 100 degrees for 2-3 minutes, then the sugar contained in the pulp will come to the surface and caramelize, which will give the prunes first a shiny, and over time a slightly white coating, indicating about complete readiness and high quality.

Beneficial properties of prunes

• The potassium content in prunes creates a weak diuretic effect. This is a great opportunity to “wash” harmful toxins from the body.
• Improved vision, brain activity, metabolism, digestion.
• Restoration of water-salt balance.
• Strengthening the immune system and cardiovascular system.
• There is an improvement in the condition of the skin, nails, and hair. The significant effect of eating prunes for external beauty will be of interest to representatives of the fair half of the population. The natural vitamin should be eaten in small quantities every day: not only for harmonious well-being, but also for glowing, healthy skin.
• Strengthening muscle, skeletal systems, teeth.

Contraindications

Despite the obvious benefits of prunes, they have contraindications. Eating dried fruit can lead to problems with:

• overweight,
• diabetes mellitus,
• allergies to the product,
• breastfeeding (so as not to cause gastric upset in the infant); starting from six months, the baby can be given prune compote.

Also, people suffering from chronic liver and stomach diseases should not get carried away with prunes.

Some people suffer from flatulence and bloating after eating prunes. This is due to the combination of dietary fiber with fructose. This phenomenon is recognized as individual intolerance, which is the reason for excluding the product from the diet.

Quality requirements and storage

Distinctive features of high-quality prunes:

• whole, fleshy and slightly soft fruits,
• absence of rot and mold,
• black color,
• sweet taste with a slight sourness (such berries contain a maximum of vitamin C),
• lack of bitterness.

Dried prunes with pits retain more useful components. To check the quality of prunes, you need to soak them for 30 minutes. Real prunes will turn white in some places. The treated one will retain a uniform color.

Purchased prunes must be scalded with boiling water. Then, after soaking, rinse under running water. Dried berries do not tolerate moisture. It is better to store them in a glass jar, paper bag or plastic container. The container should be in the refrigerator.

The shiny, dark gray color of prunes (the fruits look “fat”) means they have been treated with glycerin. It is made to improve the presentation of dried fruit. It can also shine after treatment with an unknown fat. Sellers often lubricate dried fruit with vegetable oil for shine. But this method of processing promotes the growth of bacteria.

The coffee tint of prunes appears after scalding with boiling water. At best, there are practically no vitamins left in it. Manufacturers perform this “operation” to disinfect dried fruit and extend its shelf life. The brown tint is not the only drawback of this treatment. The berry also tastes bitter.

The most harmful treatment is sulfur dioxide (E220), this type of treatment preserves the original color of the dried fruit. When dried naturally, the berries will definitely darken.