This invention relates to chemical technologies, more specifically, to liquid-phase extraction of target products from various types of raw materials, and can be used in various branches of science and technology.

Known is (SU Inventor's Certificate 77251 8, published 23.10.1980) a method of producing concentrated protein from marine fauna raw materials. In accordance with said known method, the raw material is crushed, treated with an alkaline solution, acid-deposited with agitation and separated from the solution, wherein, aiming at increasing the quality of the target product and its storage life, the alkaline solution treatment of the raw material is carried out at pH 10- 1 1 , acid is used to deposit the lipid-protein complex and the protein concentrate is separated by treating the deposited complex with a mixture of ethyl alcohol and a haloid-organic solvent at 10-20°C.

Disadvantages of said known method are its narrow application range (only marine fauna raw materials), the complexity and long duration of the process and the low quality of the target product.

Also known is (SU Inventor's Certificate 1009400, published 07.04.1983) a method of producing protein from fish comprising raw material crushing, high temperature extraction with a water solution of hydrochloric acid at pH 1.5-2.5, cooling, centrifuging, protein deposition from the water solution with a sodium alkali at pH 5.5-5.6 and deposit filtering and drying, wherein, aiming at increasing protein output from fish by its more complete separation, the as-filtered liquid phase is alkalinized to pH 8-10 and filtered, and the separated sediment is neutralized with hydrochloric acid to pH 5.5-5.6, followed by spray drying.

Disadvantages of said known method are the complexity and long duration of the process and the low quality of the target product.

Further known is (SU Inventor's Certificate 1035056, published 15.08.1983) a method of degreasing fish food by fish crushing and extraction of fats and fish protein mass with an organic solvent, wherein, aiming at reducing process duration, said organic solvent is a 0.2% chitosan solution in 0.5% acetic acid and extraction is carried out for 5-10 min with a 1 :2— 1 :4 fish protein mass to solution ratio.

Disadvantages of said known method are its narrow application range (only fish raw materials), use of a relatively rare extraction agent (chitosan solution) and the insufficient quality of the target product.

The closest counterpart of the technical solution provided herein is (WO 01/40418, published 07.06.2001 ) a method of producing protein from non-fatty tissues of marine fauna species, preferably, seals, comprising protein deposition using at least one organic solvent and separation of lipids contained in the lipid phase by evaporating said at least one organic solvent from said deposit followed by separation of said protein from said deposit, wherein said separated protein is substantially pure and free from high concentrations of heavy metals or pesticides, further wherein said organic solvent is selected from a group comprising acetone, a lower aliphatic alcohol and ethyl acetate.

Disadvantages of said known method are long process duration caused by non-optimum target product separation conditions and the use of solvents that are not approved for food production (acetone and ethyl acetate) which limits the applications of the target product.

The technical task solved using the technical solution provided herein is developing a technology of obtaining a protein product from protein raw materials of animal or vegetable origin, said technology being suitable for use in the food industry.

The technical result achieved using said technical solution is optimization of protein product process conditions leading to an acceleration of the process combined with broadening the application range of the target product making it suitable for the food industry.

It is suggested to achieve said technical result by using the method for the production of a protein product from a protein raw material as described herein. In accordance with the method provided herein said protein raw material is high pressure treated with an organic extraction agent that is approved for use in the food industry followed by grinding the degreased and dehydrated protein raw material.

The use of an extraction agent that is approved for use in the food industry allows the use of the target protein product obtained as per the process provided herein in the food industry because it does not contain any impurities that are not permitted in food products. The high pressure treatment of the protein raw material with an organic extraction agent significantly accelerates the extraction process.

The grinding of said degreased and dehydrated protein raw material broadens its application range in the food industry.

Said protein raw material can be fish, sea food, vegetable raw materials and animal raw materials, including processing waste of carcasses of birds and animals, including marine ones.

In the preferred embodiment of the technology provided herein, before treatment with an extraction agent said protein raw material is cut into pieces of within 10 cm in size. This increases the area of contact between the protein raw material being treated and the extraction agent and hence improves the quality of processing combined with its acceleration.

In some embodiments said treatment is carried out in perforated containers installed inside air-proof tanks, the pressure in said container being within 15 atm. Operation experience suggests that increasing pressure to above 15 atm. is not expedient. Said perforated container is preferably installed so as to provide a gap relative to the tank bottom. This gap is used for feeding a mixture comprising the fat of said protein raw material, water and said extraction agent. Following that said mixture is preferably directed to a separator for separation into the above three components, i.e. fat, water and extraction agent. Said extraction agent is preferably further directed for regeneration and then recycled back to the process. Typically said extraction agent is hexane, heptane, various alcohols or dimethyl ether. This list does not limit the choice of reactants which can be used as extraction agents.

The thickness of the raw material layer loaded into the process depends on a number of factors, yet typically it is within 1 m.

The time of treatment process completion is usually identified by stopping of the accumulation of the water and fat phases carried by the extraction agent out of the treated raw material.

It is suggested to achieve said technical result by using the line for the production of a protein product from a protein raw material as described herein. Said production line comprises at least one tank capable of operation under pressures of within 15 atm. and at least one mill capable of grinding treated raw material to powder, wherein a perforated container is installed inside said tank, and said tank comprises a hatch for loading said protein raw material and unloading the degreased and dehydrated protein raw material, a port for feeding the organic reactant and ports for the removal of the liquid phase and fat.

The use of the production line comprising the abovementioned components allows implementing any embodiments of the method provided herein.

In some embodiments of the technical solution provided herein said container may further comprise a port for the removal of the extraction agent, fat and water mixture to a separator for the separation of said mixture into extraction agent, fat and water. However, in other embodiments of the technical solution provided herein said mixture can be removed through a loading/unloading hatch.

The production line provided herein may further comprise a separator for the separation of said extraction agent, fat and water mixture.

Said production line may further comprise a mill for preliminary crushing of the protein raw material.

Preferably said production line comprises at least two or, more preferably, four tanks installed in parallel.

Said production line may further comprise a device for pumping said extraction agent, fat and water mixture to said separator.

Preferably said perforated container is installed so as to provide a gap relative to the tank bottom.

Typically said perforated container is made from metallic mesh.

The technical solution provided herein will be further exemplified with the following embodiments.

1. A percolator (an extractor) is loaded with 600 kg of raw material (chick carcasses) preliminarily crushed to 3-10 cm sized pieces. The extractor is pressurized. The extraction agent (gaseous dimethyl ether) is fed into the percolator (extractor) under an 8 atm. pressure. The duration of the extraction cycle is 3 h. During this time, 90 kg water and 210 kg fat are extracted from the poultry raw material. Upon its completion the percolator (extractor) contains poultry protein and a mineral residue in a total quantity of 300 kg. Dimethyl ether with extracted fat and water are directed for the separation of the extracted fat and water phases from each other and from the extraction agent. The output protein is directed for grinding to standard milling equipment.

The final protein product can be used.

2. A percolator (an extractor) is loaded with 500 kg of skinless and boneless raw material (pork, veal etc.). The extractor is pressurized. The extraction agent (gaseous hexane) is fed into the percolator (extractor) under an 8-10 atm. pressure. The duration of the extraction cycle is 4 h. During this time, 120 kg water and 200 kg animal fat are extracted from the animal raw material. Upon its completion the percolator (extractor) contains animal protein in a quantity of 180 kg. Hexane with extracted animal fat and water are directed for the separation of the extracted fat and water phases. The output protein is directed for grinding to standard milling equipment.

The final protein product can be used in various branches of the food industry.