Production technology of sunflower oil. Obtaining vegetable oils - methods, features of purification

Vegetable oil is one of the most high-calorie foods (850-900 kcal per 100 g). It is a source of vitamin E (tocopherol) and essential fatty acids for the human body, does not contain cholesterol, unlike fats of animal origin.

The quality of vegetable oil is standardized according to a number of indicators. Organoleptic indicators: transparency, color, smell and taste. Refined (purified) oil should be completely transparent, without sediment, light yellow in color. In unrefined sunflower oil of the highest and first grades, a slight "net" over the sediment is allowed, and in the second grade - a slight turbidity. The smell and taste should be characteristic of fresh oil without foreign smell, taste and bitterness. Deodorized oil should be without a specific smell. In sunflower oil of the second grade, a slightly musty smell and a slight bitter taste are allowed.

Methods for obtaining vegetable oil

Oil from oilseeds is extracted in two main ways:

mechanical, which is based on the pressing of crushed raw materials; used in oil mills or oil churns of agricultural enterprises; a by-product is cake, in which a significant amount of oil remains (8-10%);

chemical (extraction), in which specially prepared oilseeds are treated with organic solvents; used in oil extraction plants; allows you to extract oil in large quantities, since in the waste, called meal, no more than 1-3% of the oil remains.

Oil extraction by pressing.

The mechanical method of obtaining oil by pressing oilseed material that has undergone preliminary preparation is widespread almost everywhere, not only at pressing oil plants, but also at oil extraction plants, where the main technological scheme is pre-pressing - extraction.

Apply only a continuous method of pressing on screw presses. There are screw presses for preliminary oil removal (forpresses) and for final oil removal (expellers). The original pulp is a loose porous material. With comprehensive compression under the influence of the applied pressure, two closely related processes occur: separation of the liquid part - oil; connection (fusion) of solid particles of the material with the formation of a briquette - cake. Screw presses have the same type of working bodies and a common scheme of design and operation. The main working bodies of the screw press are the screw shaft and the zeer cylinder. The end products of the pressing process are pressing oil and cake. When the screw shaft rotates, placed in a zeer cylinder, i.e., in a drum assembled from strips with small gaps between them, the material is transported from the loading point to the exit and is subjected to compression. At the same time, pressure arises in it, which squeezes the oil out of the pulp. The oil passes through gaps in the sump cylinder and collects in the sump. The pressed oil material (cake) at the outlet of the grain cylinder meets with a device that regulates its thickness at the outlet of the press.

Cold pressing means only that before pressing, a special moisture-thermal treatment of the crushed raw materials is carried out under milder conditions or not carried out at all. The resulting oil retains its natural qualities: color, smell, taste, consistency, while the content of unsaturated fatty acids and vitamins remains unchanged. Cold pressing as a method for the production of vegetable oils is most often used to obtain special-purpose oils from specific raw materials, such as oils from fruit pits (apricot, peach, etc.), from pine nut kernels, etc.

Forpressing - extraction is used for the final extraction of oil from the forpress shell (cake). Solvents used to extract vegetable oils by extraction must meet the requirements for them by the technique and technology of the extraction process. In general, these requirements are determined by the desire to obtain the highest oil yield during extraction, to ensure the best quality indicators of the finished product - oil and meal, to avoid the harmful effects of the solvent on the human body and to ensure the safety of working with it. In the practice of vegetable oil extraction, aliphatic hydrocarbons, in particular, extraction gasolines, hexane, and nefrases, are most widely used. The cake undergoes preliminary processing, the purpose of which is to create an optimal structure for extracting the oil with a solvent, for which it is crushed in crushers (hammer and disk), conditioning is carried out in vat braziers, and flapping on flattening roller machines. The shape of the particles of the material in the form of a petal (plates of material with a thickness of about 0.4 mm) allows you to have in the extractors a mass of material that is easily permeable to the solvent. From under the flattening rollers, the petal is sent by conveyors to the extractor - the main apparatus of the extraction shop, designed to extract oil into a solvent with countercurrent contact. As an extraction solvent, gasoline with a boiling point of 65 ... 68 ° C is used.

In continuous screw extractors, a counterflow of petals and a solvent heated to a temperature of 50 ... 55 ° C is created. The resulting solution is called a miscella, which, after extraction, is filtered on special filters and poured into miscellos collectors. To separate the oil from the solvent, the miscella is sent first to the preliminary and then to the final distiller, where it is treated with hot steam using vacuum until the solvent is completely removed. The filtered solid part in this case is called meal. After the extraction is completed, the meal contains about 1% oil and 40% solvent, it is treated with live steam using a vacuum to evaporate (distillate) the solvent, dried, cooled and crushed.

Direct extraction of raw mint is used mainly in the processing of low-oil raw materials: soybeans, coriander waste. Extraction of the oily material is carried out without prior removal of the oil. It consists only in moisture-thermal treatment, followed by flattening to obtain a petal that goes to the extractor.

Purification of vegetable oils

The purification of crude oils from various impurities is called refining, and oils that have not been subjected to any processing other than filtration after production are called crude oils. They contain a variety of impurities, including unwanted and even harmful ones. Impurities include substances of various nature and origin. However, in addition to undesirable or harmful impurities in fats, there are always accompanying substances that are not only useful, but also necessary for the normal functioning of the human body. Such substances include, for example, fat-soluble vitamins (K, E), carotenoids, sterols, etc.

Refined fats are more easily spoiled, since natural antioxidants (phospholipids, tocopherols) are removed from them during refining. Therefore, the process of refining is sought to be carried out in such a way that, by removing undesirable impurities, it is possible to preserve useful properties. For the same purpose, the depth of oil purification is limited. Depending on the origin of impurities, on the state in which they are in the fat (in the form of a coarse suspension, a colloidal-dissolved state or in a true solution state), and also depending on the purpose of the oil, different refining methods are used.

The sequence of refining processes and the resulting types of oils

In accordance with the mechanism of the processes, refining methods are conditionally divided into physical, chemical and physicochemical.

Physical Methods. These include sedimentation, filtration, centrifugation. With the help of these methods, mechanical impurities and partially colloidal dissolved substances are removed from oils, for example, phospholipids that precipitated, water that got into the oil during the extraction process.

Mechanical impurities(particles of husks, cake) not only worsen the marketable appearance of the oil, but also cause the occurrence of enzymatic, hydrolytic and oxidative processes. All these processes worsen the organoleptic characteristics and the physiological value of oils. Therefore, mechanical impurities are removed immediately after obtaining oils.

Chemical methods. These include alkaline refining or neutralization. Neutralization is the treatment of oil with alkali to remove excess fatty acids. In the process of neutralization, soaps are formed - salts as a result of the interaction of fatty acids and alkali. Soaps are insoluble in neutral fat and form a precipitate - soapstock. For alkaline refining at industrial enterprises, NaOH solutions of various concentrations, Na 2 C0 3 solutions, and sometimes KOH are used.

Physical and chemical methods. With the help of these methods, impurities that form true solutions in oils are removed from oils, without chemical changes in the substances themselves (coloring, flavoring and odorizing substances, etc.)

Hydration of phospholipids- treatment of oil with water when heated to isolate phospholipids, protein and mucous substances, mechanical impurities. As a result of hydration, phospholipids and other impurities lose their solubility in oil and precipitate, which is filtered off.

Freezable sunflower oil is subjected to remove waxy substances. The presence of waxes in the oil impairs its presentation. To isolate waxes, the oil is subjected to special treatment before or after alkaline refining. First, the oil is cooled (“frozen out”) to 10 ... 12 ° C and kept at this temperature, slowly stirring, until wax crystals form. The oil is then filtered from the wax crystals. The filtered oil is transparent, does not become cloudy when cooled even to 5 °C.

oil bleaching- the process of extracting coloring matter from oil by treating it with adsorbents. There are various bleaching clays, which are called bleaching earths or bleaching powders, as well as activated carbon. The bleaching process consists in the fact that the oil is mixed for some time with the adsorbent in special apparatus, and then filtered. In this case, bleaching powder remains on the filter along with adsorbed dyes, and the clarified oil passes through the filter. This oil is used for the production of margarine, mayonnaise, confectionery fat, etc.

Oil deodorization- This is the process of distillation of volatile substances that impart smell and taste to the oil. Deodorization is carried out in order to obtain “impersonal” (almost completely devoid of the smell and taste characteristic of this type) oils, as well as to extract extraneous flavors and odors from the oils. Deodorization is based on the difference in the evaporation temperatures of volatile aromatic substances and the fats themselves (triacylglycerols). Vegetable oil is placed in special devices - deodorizers and at a high temperature (210 ... 230 ° C) volatile substances that give the oil a smell and taste are driven off under vacuum. Deodorization is the most reliable way to remove pesticides from oils, as under these conditions they are completely destroyed.

The business idea for the production of sunflower oil is based on the oil mill. From the position of investment among professionals, the idea has not lost its popularity, it is still in demand and profitable.

However, for many, the issue of income in this area is quite controversial, which is in vain. Let's take a closer look, so as not to rely on the opinions of the majority, but to base our own conclusions on specific figures and facts.

In this business, you can't get enough of butter alone. Profit from its implementation is hardly enough to reach the level of cost. But we must not forget about the additional products obtained from the oil mill, which bring a significant net profit.

Vegetable oil production equipment

The production of vegetable oil at home is limited by financial means. This type of business is attractive due to its flexibility of rapid development. You can start with a minimal production hall and then expand it with additional equipment for the production of by-products. Thus, the assortment is expanding, and profits are growing in progression. A full-fledged plant for the production of vegetable oil should be WASTE-FREE!

The minimum equipment of the line consists of the following equipment:

By and large, these two components are already quite enough to produce and sell 2 products: good sunflower oil and meal. By the way, oilseed meal is widely used for feeding animals and birds in agriculture. Therefore, it sells much faster than the main product. In addition, it is much more at the output of processed raw materials - 65%.

But if you plan to earn more, then you should think about expanding production. Additional technological equipment for the production of vegetable oils allows us to obtain several products at once from one oil mill:

1. Sunflower oil raw.
2. Fried sunflower oil.
3. Oil technical drying oil.
4. Top circles.
5. Shrot.
6. Fuze biochar.
7. Briquettes biofuel from husks.

The oil mill, even at home, can produce 7 types of products with the necessary equipment. It is worth paying attention to other business benefits.

Storage of vegetable oil in production does not require special conditions. A dry room, protected from sunlight, with an air temperature ranging from +5 to +15 degrees, can store unrefined products for 5 months.

You can use different raw materials for the production of vegetable oils. For example, seeds: sunflower, soybean, flax, pumpkin and many other oilseeds. This advantage also has a positive effect on expanding the range and increasing sales. It is possible to re-profile the business for other products without upgrading the line.

Technology for the production of vegetable oils by pressing

Technological scheme of production:

The technological line for the production of vegetable oil is equipped with:

• Separator for coarse and fine cleaning of grain and seeds.
• Shelling machine for sunflower seeds and other oilseeds.
• Oil press twin screw extruder with oilseed heating elements up to +50C (for a quick start).
• Filter for purification of vegetable oils from fuse (food).
• Press for wringing out the fuse (fuzodavka).
• Press for forming cake circles.
• Press for briquetting sunflower husks and other seeds.
• Auxiliary inventory, structures and devices: bunker; pneumatic loader; weight; buckets, shovels, etc.

We will conduct a simple training workshop on the technology of production of vegetable oils.

Waste-free production by cold pressing during pressing takes place in several successive stages:

1. Coarse cleaning of oilseeds (raw materials). From coarse impurities that can damage technological equipment (stones, wire, etc.).
2. Fine cleaning of raw materials. From small premiums that can affect product quality (dust, weed seeds, etc.).
3. Desquamation of the seed coat. This process is carried out immediately before cold pressing. In the non-waste production of vegetable oil, husks are used for biofuel, and kernels are used for oil and cake. The shell of oilseeds can be removed on various types of equipment in a different way: wiping the shell on a specially corrugated surface; shell splitting by impact; pressure compression.
4. Pressing kernels through a screw oil press in order to obtain oil and cake. At this stage, we get 2 semi-finished products.
5. Filtration. The process of filtering the crude product obtained only from the press takes place with the help of filters based on filter fabrics. For example - lavsan. Under air pressure, the liquid hits the surface of the fabric and passes through it, leaving a fuse on the surface.
6. Fuze extraction. The fuz itself obtained after filtering with lavsan contains 80% fat. It is rational to squeeze it out as well. The production of vegetable oils by pressing at this stage ends. Further by-products are produced.
7. Hot pressing of cake. Makukha is best pressed immediately upon exiting the oil press, while it has still retained its temperature from pressure.
8. Briquetting. In order to profitably and quickly sell the husk from seeds, it is necessary to produce a demanded product from them - biofuel. Naturally, this process will require special equipment.

As for the organization of labor in production on such a line, everything here depends on the loading of the workshop with raw materials for processing and the timing. If the load is minimal (for example, 1 ton per day), then even 1 worker is enough. Once the market for all types of goods produced at the oil mill is established, additional labor will be needed to meet deadlines with good production volumes.

Wastes from the production of vegetable oil and their use

A home churn for the production of sunflower oil pays off faster if all its advantages are used rationally. The relevance of waste management should not be underestimated.

At the exit from the oil press, we get unrefined vegetable oil and black in color. It should either be defended or filtered out in a special way from the fuse.

Foose are small particles of husk and cake with a high content of residues of the produced product, which remains after filtration. A fabric filter is considered to be the best method for removing fuse. You should not spare money on the filter, and then it will qualitatively clean the product and prepare it for presentation. When the oil is cleared, the collected fuse can be pressed through the fuzodavka. From it we can still get 20% bio-charcoal + 80% vegetable oil. The processed fuz is further turned into stone, which, in turn, is used as fuel for boilers.

Don't miss the fuzodavka operation, as negligent businessmen do! After all, some firms buy waste from vegetable oil production enterprises very cheaply in order to then squeeze out all the profit from them.

So, a business idea can become an almost waste-free process. You will receive not only a high-quality product, which will not fall in demand at any time of the year, but also a unique fuel and good cake.

Oil mill profitability

So, raw materials for manufacturing (sunflower seeds) cost about 500 dollars (about 480), if we talk about a ton. After the raw materials are processed, about 350 kg of sunflower oil can be obtained from this amount (yield 35%). One liter is easy to sell for one and a half dollars. Thus, for 350 kg, as a result, 525 dollars will come out. 525 - 480 = $45 profit. Of course, $45 per ton is not a big amount. But do not forget that during production, you can earn money on another product - on the top (meal).

Makukha, by the way, is no less a hot commodity than the oil itself. Upon receipt of 350 kg of the main product, the meal will be 650 kg. Most often, meal is bought in whole bags, and not per kilogram, so it will be sold much faster. Makukha is sold out at $0.4 per 1 kg. So, if you multiply 650 kg. by $0.4, the amount will be $260. Given these numbers, the business idea becomes much more interesting.

Vegetable oils are obtained by extracting oilseeds from plants.

The factors that shape the quality of vegetable oils include raw materials and production technology.

According to the classification of V.G. Shcherbakov, oil plants are divided into several groups depending on the use.

Pure oilseeds- these plants are grown for the purpose of obtaining oil, while other products are secondary. These are sunflower, safflower, sesame, tung.

Spinning and oilseeds are plants grown not only to extract oil, but also to obtain fiber. These are cotton, flax, hemp. So, until 1860, cotton was cultivated mainly for fiber, but for more than 140 years, cotton seeds have been used to produce oil.

Essential oil plants - in their seeds, along with fatty ones, essential oils are contained. A representative of this group of plants is coriander. By extracting the essential oil from it, technical fatty oil is obtained.

Conventionally, two more subgroups of plants are distinguished, the nutritional value of which is due to the non-lipid part. This protein and oil culture - soy and peanuts and spicy oil plants, whose representative is mustard.

Along with the seeds of oil-bearing plants, oil-containing parts of the seeds of non-oil plants are used to extract oil - the germs of wheat, corn, rice, fruit pits, etc.

According to the classification of prof. V.V. Beloborodov, the technological processes of modern production of vegetable oils are divided into: mechanical – seed cleaning, seed hulling, separation of fruit and seed coats from the kernels, crushing of the kernel and cake; diffusion And diffusion-thermal – seed conditioning for moisture, roasting mint, oil extraction, distillation of the solvent from the miscella And meal; hydromechanical – pulp pressing, settling And oil filtration; chemical And biochemical processes - hydrolysis and oxidation of lipids, denaturation of proteins, formation of lipid-protein complexes.

On a technological basis, technological processes are divided into six groups: preparation for storage and storage of oilseeds; seed preparation for oil extraction; actual oil extraction; refining of the obtained oil; bottling; packaging and labeling.

PREPARATION FOR STORAGE AND STORAGE OF OIL SEEDS

It includes the following technological processes: seed cleaning from impurities, seed conditioning by moisture content, seed storage.

Purification of seeds from impurities. The seed mass supplied for storage and processing is a heterogeneous mixture of seeds and organic (plant stems; leaves, seed coats), mineral (earth, stones, sand), oilseeds (partially damaged or germinated seeds of the main oilseed) impurities.

Seeds are cleaned from impurities on cleaning machines - separators, aspirators, stoners, using the following methods:

separation of the seed mass by size by sifting through sieves with holes of different sizes and shapes. When sifting, two fractions are obtained: passage (the part passing through the holes) and descent (the part remaining on the sieve);

separating the seed mass according to aerodynamic properties by blowing the seed layer with air;

separation of metal impurities and seeds by ferromagnetic properties.

Moisture conditioning of seeds. Seeds are subject to long-term storage, the moisture content of which is 2-3% lower than the critical one. In addition, moisture conditioning improves the technological properties of seeds. To reduce the moisture content of seeds, the drying method is used in industrial dryers of shaft, drum types and fluidized bed dryers, as well as the method of active ventilation in special storage facilities equipped with devices for supplying and distributing air over the seed mass.

Unlike other oilseeds, cotton seeds are moistened to 11%.

Seed storage pursues the goal of preserving them from spoilage in order to obtain high quality products during processing with minimal losses; improving the quality of seeds for their more efficient processing.

PREPARATION OF SEEDS FOR OIL EXTRACTION

This preparation includes cleaning the seeds from impurities, calibrating the seeds by size, conditioning the seeds by moisture, similar to the corresponding operations before laying the seeds for storage; seed collapse; division of Rushanka into fractions; crushing the core.

Collapse of seeds and separation of the kernel from the shell. According to the nature of the shells, oilseeds are divided into two groups - skinned (sunflower, cotton) and skinless (flax, rapeseed, colza, sesame). Skinned seeds are processed after separation of the shell, skinless - without its separation. .

Collapsing - the destruction of the shells of oilseeds by mechanical action is carried out in seed hoppers of the type MRN, the collapsing elements of which are grates with a wavy surface - decks. A more modern model is the RZ-MOS centrifugal crushing machine. They destroy the shells of cotton seeds on disk (AC-900) and knife hullers. Soybean seeds are subjected to crushing on roller machines before separation of the shell.

As a result of the collapse of the seeds, rushanka, which is a mixture of several fractions: whole seeds - whole grain, partially unhulled seeds - immature, a whole core, halves of a core, a destroyed core - chaff, oil dust And husks(sunflower shells, cotton has husks). The norms for the content of whole grains, underdows, chaff and oilseed dust have been established.

Separation of Rushanka into fractions. To separate the rushanka, aspiration R1-MST seeders, CMP-11 electric separators are used;

Rushanka is divided into a core and a husk (husk).

The separation of the shells from the nucleus is of great importance. At the same time, the quality of the oil increases, since shell lipids containing a large number of related substances do not pass into it; increased equipment performance; oil losses with husks are reduced due to oiling.

Crushing the core. The purpose of this operation is the destruction of the cellular structure of the nucleus for maximum oil extraction during further technological operations. For grinding the kernel and seeds, single-pair, two-pair and five-roll machines with corrugated and smooth surfaces are used. The result is a loose mass mint. When petal grinding on a two-pair flattening rolling machine and a two-pair flattening and rolling machine FV-600, petal- plates of flattened cake with a thickness of less than 1 mm.

ACTUAL OIL EXTRACTION

Oil is extracted in two ways: pressing And extraction. Based on these two methods, the following technological schemes for the production of vegetable oils have been developed: single pressing; double pressing extraction of oil by pre-squeezing - pre-pressing followed by final pressing expelling; cold pressing- extraction of oil from raw materials without preliminary moisture-thermal treatment; pre-pressing— extraction- preliminary degreasing of oil by forpressing with its subsequent extraction by extraction with gasoline; direct extraction- solvent extraction without prior degreasing.

moisture-thermal mint processing - roasting. For efficient extraction of oil from mint, moisture-thermal treatment is carried out with continuous and thorough mixing. Under production conditions, the process of moisture-thermal treatment consists of two stages:

1st stage - moistening of the oilseed and heating in devices for preliminary moisture-thermal processing of oilseed - inactivators or pro-steam-humidifying augers. The mint is heated to a temperature of 80-85 ° C with simultaneous moistening with water or live steam. In this case, selective wetting and a decrease in the binding energy of the oil with the non-lipid part of the seeds on the surface of the mint occur. The moisture content of sunflower seeds after wetting is 8-9%.

2nd stage - drying and heating of moistened mint in braziers of various designs. At the same time, the physical properties of the oil change - viscosity, density and surface tension decrease.

The material obtained by roasting is called pulp.

Oil pre-press— forpressing. Pressing is the extraction of oil from a loose porous mass - pulp. As a result of pressing, 60-85% of the oil is extracted, i.e., preliminary oil extraction is carried out - pre-pressing. For pressing, presses of various designs are used. Depending on the pressure on the pressed material and the oil content of the outgoing cake, the screw presses are divided into pre-oil removal presses - forpresses and presses for the final removal of oil - expellers.

The screw press is a stepped cylinder, inside of which there is a screw shaft. The walls of the cylinder consist of steel plates, between which there are narrow slots for the exit of the pressed material. As a result of forpressing, the pulp is obtained forpress oil(often called press) and forpress pulp. The oil content in the cake is 14-20%. It is sent for additional oil extraction. The pulp is sent for final pressing or to obtain a petal. In industry, forpressors MP-68, ETP-20, FR, G-24.

Final oil extraction - expelling carried out under more severe conditions, as a result of which the oil content in the cake is reduced to 4-7%.

Extraction of oil by extraction with organic solvents more efficient than the pressing method, since the oil content in the extracted material - meal - is less than 1%.

In our country, extraction gasoline grade A is used as solvents for extracting oil from vegetable raw materials. And nefras With boiling point 63-75 °C.

Extraction is a diffusion process, the driving force of which is the difference in concentrations mccelles - solutions of oil in a solvent inside and outside the particles of the material to be extracted. The solvent, penetrating through the cell membranes of the extracted particle, diffuses into the oil, while the oil from the cells diffuses into the solvent. Under the influence of the difference in concentrations, the oil moves

from the particle to the external environment until the oil concentrations in the particle and in the solvent outside the particle equalize. At this point, the extraction stops.

The extraction of oil from oilseeds is carried out in two ways: immersion and stepped irrigation.

Extraction by immersion occurs during the continuous passage of the feedstock through a continuous flow of solvent under countercurrent conditions, when the solvent and feedstock move in the opposite direction relative to each other. Extractors ND-1000, ND-1250, Ollie-200 work according to the immersion method. Such an extractor consists of a loading column, a horizontal cylinder and an extraction column, inside which screws are installed.

Raw material in the form of a petal or grains enters the loading column, is picked up by the turns of the screw, moves to the bottom of the loading column, passes a horizontal cylinder and enters the extraction column, where it rises to its upper part with the help of a screw. Simultaneously with the raw material, gasoline at a temperature of 55–60 °C is fed into the extractor. Gasoline moves towards the raw material and passes successively through the extractor, horizontal cylinder and loading column. The concentration of miscela at the outlet of the extractor is 15-17%.

The fat-free residue of the raw material - the meal leaves the extractor with a high content of solvent and moisture (25-40%), so it is sent to screw or vat (toaster) evaporators, where gasoline is removed from it.

The advantages of extraction by immersion include: high extraction rate, simplicity of the design solution of extraction apparatuses, and safety of their operation. The disadvantages of this method are: low concentrations of the final miscella, high content of impurities in the miscella, which complicates their further processing.

Extraction by stepwise irrigation. With this method, only the solvent is continuously moved, and the raw material remains at rest in the same moving container or moving belt. This method provides a high concentration miscella (25-30%), with fewer impurities. The disadvantages of this method are the long duration of extraction, the increased explosiveness of production.

Our industry uses horizontal belt extractors MEZ-350, T1-MEM-400, DS-70, DS-130, "Lugi-100", "Lurgi-200", bucket extractors "Janatsia", basket extractor "Okrim". More modern is the Extechnik carousel extractor (Germany), which operates on the principle of multi-stage irrigation in the flooded layer mode.

During extraction on the belt extractor of the MEZ, the raw material from the bunker is fed to a moving mesh conveyor belt, passes under nozzles and sprinklers, and is irrigated sequentially with miscella

and gasoline. The extractor has 8 stages with miscella recirculation and accordingly 8 miscellos collectors.

After extraction, the miscella contains up to 1% of impurities, and it is sent to rotary disk or cartridge filters for purification.

Distillation is the distillation of the solvent from the miscella. Three-stage distillation schemes are the most common.

In the first two stages, the miscella is processed in tubular film distillers. At the first stage, the miscella is evaporated. At the second stage, the miscella is treated with live steam at a temperature of 180–220 °C and a pressure of 0.3 MPa, which causes the miscella to boil and the solvent vapor to form. The solvent vapors are sent to the condenser. At the third stage, the highly concentrated miscella enters the spray vacuum distiller, where, as a result of sparging with live steam at a pressure of 0.3 MPa, the final removal of traces of the solvent occurs. After distillation, the oil is sent for refining.

FATS REFINING

This is the process of cleaning fats and oils from related impurities. Impurities include the following groups of substances: substances associated with triglycerides that pass from high-quality raw materials into oil during the extraction process; substances resulting from chemical reactions during the extraction and storage of fat; actual impurities - mineral impurities, particles of pulp or meal, solvent or soap residues.

In addition to undesirable impurities from fats, during refining, substances useful for the body are also removed: fat-soluble vitamins, phosphatides, essential polyunsaturated fatty acids.

Refined fats are more easily subjected to oxidative deterioration, since natural antioxidants - phosphatides and tocopherols - are removed from them. Therefore, refining tends to be carried out in such a way that, with the maximum extraction of undesirable impurities, useful substances are preserved.

The sequence of refining processes and the resulting types of oil are shown in fig. 7.2.

All refining methods are divided into: physical- settling, centrifugation, filtration, which are used to remove mechanical particles and colloidal dissolved substances; chemical- sulfate and alkaline refining, hydration, removal of gossypol, which are used to remove impurities that form true or colloidal solutions in oils with the participation of the removed substances in chemical reactions; physical and chemical - bleaching, deodorization, freezing, which are used to remove impurities that form true solutions in oils without chemically changing the substances themselves.

Physical methods. Mechanical impurities (particles of pulp and cake) not only worsen the commercial appearance of fat, but also cause enzymatic, hydrolytic, oxidative processes. Protein substances contribute to the Maillard reaction (melanoidin formation) and the formation of lipoprotein complexes. Mechanical impurities are removed immediately after oil production.

settling- This is the process of natural sedimentation of particles in suspension in a liquid medium, under the influence of gravity. With prolonged settling of the oil, a part of the colloid-dissolved substances is released from it - phospholipids, mucus, proteins due to their coagulation. The oil after separating the precipitate becomes transparent. At industrial enterprises, mechanized double thickeners with electromechanical vibrators are used for settling.

centrifugation- the process of separation of heterogeneous systems under the action of centrifugal forces. In industry, basket, plate, tubular centrifuges are used, for example, a horizontal continuous centrifuge settling NOGSH-325, an Al-MSP separator. To separate thin systems, high-speed centrifuges are used: separating - for separating two immiscible phases (water-fat) and clarifying - for separating fine mechanical impurities from liquids.

To separate suspensions, hydrocyclones are used, the action of which is based on the use of centrifugal forces and gravity.

Filtration- the process of separating heterogeneous systems using a porous partition that traps solid particles and allows liquid and gas to pass through. Forpress and expeller oils are filtered twice. First, hot filtration is carried out at a temperature of 50-55 ° C to remove mechanical impurities and partly phosphatides. Then - cold filtration at a temperature of 20-25 ° C for coagulation of small particles of phosphatides.

In industry, filter presses are used, consisting of 15-50 vertically arranged filter cells located on one common horizontal frame. The cell contains a filter cloth, which gradually becomes clogged with a sediment called fuzz. Fuz is used to obtain oil by extraction, phosphatides, and the remainder is used in soap making.

Chemical methods. Hydration - the process of treating oil with water to precipitate hydrophilic impurities (phosphatides, phosphoproteins). As a result of hydration, the phosphatides swell, lose their solubility in oil and precipitate, which is filtered off. To completely remove phosphoproteins, weak electrolyte solutions, in particular sodium chloride, are used.

In general, hydration comes down to the fact that the oil is heated to a certain temperature (sunflower and peanut oil - up to 45-50 ° C), mixed with water or bubbled with live steam, aged to form flakes, followed by separation of the oil from the sediment.

Steam, electromagnetic and hydrothermal methods of hydration are used in industry. The equipment is used for intermittent operation, continuous operation with disc-shaped settling tanks and separators "Lurgi" and "Westphalia" (Germany), "Alfa Laval" (Sweden).

As a result of hydration, edible oil, food and feed phosphatide concentrates, oil for further refining are obtained.

alkaline refining- treatment of oil with alkali in order to remove excess free fatty acids. In the process of neutralization, salts of fatty acids are formed - soap. Soaps are insoluble in neutral fat and form a precipitate - soapstock. Soap has a high adsorbing capacity, due to which pigments, proteins, mucus, and mechanical impurities are removed from fat. The soapstock is removed by settling or centrifugation.

The alkaline neutralization process consists of the following operations: treatment with phosphoric acid to destroy non-hydratable phosphatides; neutralization with alkali; the first washing with water at a temperature of 90-95 ° C to remove soap; second rinse with water; treatment with citric acid to remove traces of soap; drying in apparatuses under vacuum.

Neutralization is carried out by continuous and batch methods.

Periodic method of phase separation in a gravitational field with a water-salt lining based on the dissolution of soap in water or in an aqueous solution of sodium chloride. In the batch method, neutralization is carried out in a neutralizer. This is a cylindrical apparatus with a conical bottom, with a steam jacket and a rake mixer for mixing fat and alkali. Alkali is fed from above through atomizers or from below through coils. Salt solution and water are also supplied through sprayers.

Continuous methods:

With the use of separators to separate the oil from the soap stock under the action of centrifugal forces;

With phase separation in a soap-alkaline medium, in which finely dispersed fat is passed through an alkali solution, the resulting soap dissolves in alkali, the neutralized fat floats and is removed from the apparatus;

Miscella refining - refining the oil coming out of the extractor in the form of a miscella, without distillation, the effect of high temperatures on the oil is eliminated.

As a result of alkaline refining, the content of free fatty acids decreases, fats are clarified, and mechanical impurities are removed. In oils refined with alkali, the presence of sediment is not allowed.

Physical and chemical methods. Whitening — the process of extracting coloring substances from fats by treating them with sorbents. To bleach fats and oils, bleaching clays are widely used - bleaching earths (gumbrin, ascanite, bentonin). They are neutral substances of a crystalline or amorphous structure containing silicic acid or aluminosilicates. To enhance the bleaching effect, activated charcoal is added to bleaching clays. In addition, when nickel and copper carbonates are added to the mixture of bleaching clay and coal, sulfur is removed from rapeseed oil. The bleaching process consists in mixing fat with bleaching clay for 20-30 minutes in vacuum bleaching machines. After bleaching, the adsorbent is separated using frame filter presses with manual sediment discharge. Continuously operating lines for fat bleaching are also used, equipped with hermetic self-unloading filters from De Smet and Alfa Laval.

Deodorization - the process of distillation from fat of volatile substances that impart taste and smell to it: hydrocarbons, aldehydes, alcohols, low molecular weight fatty acids, esters, etc. Deodorization is carried out to obtain depersonalized oil, which is necessary in margarine, mayonnaise, and canning industries.

The deodorization process is based on the difference in the evaporation temperature of the aromatics and the oils themselves. i

In industry, methods of periodic and continuous deodorization of fat are used.

periodic method. The main method of deodorization is the distillation of flavoring substances in a stream of water vapor - distillation. Filtered fats are placed in special deodorizers, citric acid is added to increase resistance to oxidation. The fat is heated to 170 °C and flavoring substances are distilled off under vacuum with live steam at a temperature of 250-350 °C. The productivity of intermittent deodorizers is 25 tons/day on average.

Continuous fat deodorization methods are carried out both on domestic and imported installations.

Deodorization of fat at the installation of the company "De Smet" (Belgium), which includes a deodorizer of a film-bubbling type, is carried out in two stages. At the first stage, volatile substances are distilled off by contacting live steam with a thin film of oil, which is formed due to steam flowing down a vertical stack of plates. The final deodorization is carried out in the cubic part of the apparatus by bubbling the oil with live steam at a pressure of 66.5-266 MPa. The productivity of this plant is 80 tons/day. Similar to this installation is the domestic installation A1-MND.

Grease deodorization at Spomash (Poland) and Alfa-Laval installations, including bubbling-type deodorizers in the form of a vertical tray column with an oil layer height on the plate of 30–50 cm, is carried out at a temperature of 200–230 °C. Deodorizers have shoulder strap trapping units, which makes it possible to combine deodorization with the distillation of free fatty acids. The productivity of these units is 100 and 150 tons/day, respectively.

Freezing- the process of removing waxy substances that pass into oils from the seed and fruit shells of oil plants. Freezing is carried out at the beginning or after refining. The essence of the freezing process is to cool the oil to a temperature of 10-12 ° C and then hold it at this temperature with slow stirring to form crystals. wax. Then the oil is heated to 18-20 ° C, to reduce viscosity and filtered. The filtered oil is transparent, does not become cloudy when cooled even to 5 "C.

A feature of the refining of cottonseed oil is the preliminary elimination of gossypol with anthranilic acid. This forms a precipitate of gossypol anthranilate, which is separated from the oil, and the oil is sent for further processing.

All crops that are raw materials for the oil industry can be divided into two groups:

Oil plants, which are grown to produce vegetable oil;

Plants that serve to obtain other products, and then oils are obtained from them.

The first group includes sunflower, castor beans, rapeseed, etc. The second group includes:

Spinning oil plants (cotton, flax, hemp);

Protein-oil plants (soybeans and peanuts);

Spicy oil plants (mustard);

Essential oil plants (coriander);

Depending on the fat content in the kernel, all oilseeds are divided into three groups: low oil with a fat content of 15-35% (soy); medium oil with a fat content of 35-55% (cotton); high oil with a fat content of 55% or more (sunflower, peanuts, flax, etc.).

On a technological basis, all production processes are conditionally divided into six groups:

1. Preparation for storage and storage of oilseeds.

2. Seed preparation for oil extraction.

3. The actual extraction of oils.

4. Refining the obtained oils.

5. Bottling of oils.

6. Packaging and labeling.

Every self-respecting housewife uses vegetable oil every day in her culinary experiments. Unfortunately, modern oils do not please with their quality, and the question of how to choose the most useful product is more relevant than ever.

There is an opinion that unrefined oil is healthier than regular oil, but is this true and what is the difference? Is it worth overpaying for cold-pressed oil and how to determine a really high-quality product? In this article, we will tell you about three ways to produce vegetable oil, and you yourself can draw conclusions and decide for yourself whether it is worth saving to the detriment of your health or buying more expensive but proven brands.

This is the most "natural" way to get oil: using a press. The seeds are placed under the press, and, thanks to strong pressure, it heats up in a natural way. The oil at the outlet is heated no higher than 40-42 degrees: such a low temperature allows you to save all the nutrients.

It turns out that this oil is not processed in any way: neither by temperature, nor by chemistry! After pressing, it is simply defended, then filtered and bottled. In the conditions of modern production, such a "loving" attitude towards raw materials and the quality of the final product is rare and very valuable. Such a liquid, according to the care of manufacturing, resembles freshly squeezed juice, only from seeds!

It is remarkable that with this method of manufacture, only the highest quality seeds can be used. Since the whole process is very careful and careful, only 27% of the total amount of oil is extracted from the seeds. Its value and rich composition can be compared with Extra Virgin oil. And there are even more of some vital elements (for example, vitamin E) in comparison with olive oil!

The second method is cold pressing after pre-treatment.

With this method of manufacturing, the seeds are first processed in braziers. It is certainly more profitable for manufacturers: after all, this way you can get not 27, but 43% of the oil from the total amount that is contained in the original product. And thanks to moisture-thermal treatment, it does not matter which seeds to make from: it is no longer necessarily of the highest grade, this does not affect the final product!

It sounds tempting, but with this method of manufacture, most of the nutrients and various trace elements incorporated in the seeds by mother nature, alas, die. In addition, such oils are carefully filtered, and this increases the acid number of the product, and the amount of vitamins in the composition is further reduced.

Although this method is not as wonderful as the first one, nevertheless, some of the useful properties in the final product are still preserved. When buying this oil in a store, we can be sure that it is safe for health.

Third method. Extraction, or How all refined oils are produced

This method is just a fairy tale for all manufacturers: with it, you can extract 98% of the oil from the feedstock! In addition, it does not matter what quality the product is to take.

But everything is not so simple: something has to be sacrificed. To obtain oil in this way, the seeds are poured with fractions of gasoline. Hexane, for example. When an oil is formed from the seeds, this hexane is removed with water vapor, and its residues are removed with alkali. At the output, various undesirable substances appear in the finished product: resins and pigments. Solvent residues rarely evaporate completely.

Before the oil obtained by extraction can be eaten or used in medicine, it needs to go through several more stages of purification: refining, then hydration, then bleaching, after it - deodorization, and finally a couple more steps of filtration.

There is a phrase about oils that go through 7 stages of purification. It's true! Extraction oil can be endlessly refined, filtered, refined, filtered - to get rid of traces of chemical gasoline components.

What is the result?

A product without the slightest sign of life: without a single color and with a complete absence of any smell. The resulting liquid is bottled, and “oil” is proudly written on all labels, misleading all buyers that it is so.

But it's cheap - and everyone is happy to buy it!

Interestingly, in Russian supermarkets, for example, more of this refined oil is sold per year than the number of all seeds grown in Russia and the CIS! How is this possible? With the help of cheap palm oil, which is diluted with already deodorized, refined and processed oils in all possible chemical ways.

Now I understand why vegetable oil is HARMFUL?

Because it is impossible, even with the longest and highest quality processing, to remove the remnants of chemicals and gasoline from it - they will certainly be present in the finished product. In addition, refined oil that has undergone heat treatment and exposure to chemicals, unlike natural, has a very low content of vitamins, proteins, phosphatides, chlorophyll and carotene. Its composition is saturated with fats and is very different from what was originally “conceived” by nature.

And then we eat it! We fry dishes in oil with gasoline! But few people know that at high temperatures, chemical reactions occur in it, as a result of which new, extremely toxic compounds are formed. Therefore, the oil should never be heated above 150 degrees or reused! And in a frying pan, it reaches a temperature of as much as 250 degrees !!!

Throughout our lives, without thinking at all, we use this super-toxic miracle for food, and even with gasoline, and then we are surprised at our unexpected diseases and poor health. We are indignant at how people get cancer at an early age and age faster than before ...

Is there any safe way to fry?

The most gentle and harmless option is to fry in ghee. Ideally, if you manually melt it yourself. And do it right.

But it’s better to try not to fry at all, of course. Instead of frying, food can be stewed! How good is this cooking method? And the fact that you no longer pour oil into a clean pan, but into water, the temperature of which does not heat up above 100 degrees.

You can fry in oil only if it is cold pressed. It has not yet undergone heat treatment, and when you fry, harmful substances do not form in it immediately. There is also oil from high-oleic sunflower seeds - in this, even after several frying runs, carcinogens are not formed.

And ordinary vegetable oil is better to add to salads. Necessarily unrefined: it contains several times more vitamins and nutrients than refined.

Watch what kind of oil you buy in the store, try to choose preferably cold pressed or just unrefined and don't be fooled by the manufacturers!

Ekaterina Ryzhkova
Photo: www.torange.biz

The extraction of vegetable oils is carried out by pressing and extraction (extraction) with organic fat solvents.

Pressing- this is a mechanical extraction of oil from the prepared oil-bearing material (pulp) on special screw presses. It can be single or double. Depending on the amount of pressure applied during the extraction, the cake may contain from 6 to 14% oil. The cake is used for livestock feed, and the cake of some valuable oilseeds (soybeans, mustard, peanuts, etc.) is used for food purposes. Liquid vegetable oils (salad) obtained by pressing are sold mainly in the retail trade network.

Extraction oils is based on their ability to dissolve in non-polar organic solvents (gasoline, hexane, etc.). When gasoline is repeatedly passed through crushed cake (or seeds), the oil dissolves in gasoline and is almost completely extracted. The fat-free residue (meal) contains less than 1% fat. Extraction oil differs in quality from press oil: it contains more dyes, free fatty acids, and phosphatides. After distillation of gasoline, it is subjected to additional purification.

Refining (purification) of oils is that accompanying substances and impurities are removed from them: phosphatides, pigments, free fatty acids, odorous substances, impurities in the form of scraps of oilseed material.

The diverse composition of accompanying substances determines the various methods of refining: physical methods (settling, centrifugation, filtration); chemical (neutralization); physical and chemical (hydration, deodorization, bleaching, wax freezing).

Mechanical (primary) cleaning of oils is carried out to remove various mechanical impurities and partially colloidal dissolved substances. This purification is carried out by settling, centrifuging or filtering oils.

Hydration of oils carried out to remove phosphatides, mucous and other substances with hydrophilic properties. When oils are treated with hot water, phosphatides swell, do not dissolve in the oil, and precipitate in the form of flakes.

Oil neutralization consists in treating them with alkali solutions in order to remove free fatty acids. The resulting salts of fatty acids (soaps) adsorb other accompanying substances (phosphatides, pigments), so the neutralized oil is more purified than the hydrated one.

At bleaching (adsorption refining) Coloring substances (pigments) are removed from oils. For clarification of oils, solid adsorbents are used: bleaching clays, activated charcoal. Bleaching is applied to oils used in processing to produce margarines and cooking oils.

At deodorization from oils remove substances that cause smell and taste. Deodorization is carried out by distillation of aromatic substances under vacuum with live steam passed through the fat at high temperatures (210-230°C). After deodorization, the oil is impersonal in taste and smell.

During the refining process, substances with antioxidant properties, as well as those of physiological value, such as vitamins, can be removed from oils. Therefore, it is not always advisable to subject the oils entering the retail trade to deep refining. 1

Again, using the example of sunflower oil, we will show one of the possible production options. 16

Cleaning of seeds is carried out on separators, caving and separation of the shell on crushing and winching machines, grinding - on roller machines. The material obtained after grinding the seeds is called mint. In order to effectively extract oil from mint, pulp is prepared, i.e. the mint is heated to higher temperatures, which causes the viscosity of the oil to decrease, while the moisture content in the mint also decreases, and partial denaturation of proteins occurs, which changes the plastic properties of the mint. Mint turns into pulp. Heating the mint to 105°C and drying it to the final moisture content (5...6%) is carried out in braziers. The oil is pressed in screw presses. The pressure developed by the screw press should reach 30 MPa, the degree of pulp compression should be 2.8 ... 4.4 times, the pressing time should be 78 ... 225 seconds, depending on the type of press. The resulting oil is filtered on special filters or natural sludge in storage tanks. The oil cake coming out of the press with an oil content of 4...7% can be used as livestock feed. Completeness includes the necessary set of basic technological equipment.

Part of the equipment:

1. Separator

2. Machine shattering and winding

3. Roller machine

4. Brazier

5. Screw press

8. Washing bath

9. Production table

Quality control includes verification of compliance of product quality indicators with established requirements. Sunflower oil is usually produced and supplied in large batches, therefore, a certain volume from the produced batch of goods is subjected to tests (rules and test methods are specified in GOST 1129-93 "Sunflower oil. Specifications." 17