Device for obtaining protein concentrate, protein flour and barley oil from wet brewer's grains

Abstract

Apparatus for the production of food from brewer's spent grain, consisting of: a mill configured to grind brewer's grains to a particle size of less than 1 mm without adding anything to the brewer's grains; a mixer configured to add an aqueous liquid to the ground brewer's grain to obtain a suspension; a separator configured to separate the suspension into an insoluble part and a soluble part; and a processor configured to process the insoluble part into a protein flour and the soluble part into a protein concentrate containing less than 2% by weight liquid and at least 70% by weight protein.

Description

[0001] The innovation concerns a device for obtaining protein concentrate, protein meal and barley oil from wet brewer's spent grain, particularly in the processing of brewery waste.

[0002] The innovation group focuses on the food industry. It enables highly efficient processing of the brewing industry's main waste, brewer's spent grain, to produce three main products: protein concentrate, protein flour, and barley oil. Protein products are widely used in the food industry to enrich baked goods, meat products, and dairy products with protein. Barley oil is extremely effective in the perfume and cosmetics industries.

[0003] In the brewing industry, a large amount of waste is generated during beer production. This waste consists of the remains of the grain husk and the water-insoluble nutritional component of the grain, namely the protein- and fat-rich spent grain. Of all the secondary raw materials in the brewing industry, spent grain is the most interesting for processing. It is produced in large quantities. On average, 1,300 kg of spent grain is produced per 1,000 kg of barley malt.

[0004] Brewer's grains are obtained during the final stage of filtration of the beer mash after saccharification of the barley malt according to beer production technology. Brewer's grains with a moisture content of 85% contain at least 15% dry matter. This consists primarily of protein, fiber, and fats. Breweries around the world produce several million tons of brewer's grains annually. The majority of this is used as animal feed. Some of the brewer's grains are recycled, causing significant environmental damage.

[0005] Currently, brewer's spent grain is not used on a large scale because it is difficult to transport and store. Fermentation processes begin in the spent grain just six hours after production, making it unsuitable for further use.

[0006] Widely used devices for processing brewer's spent grains as a feed additive are known from the prior art. These are based on drying the spent grains and subsequent granulation or grinding (EP0694609A2; WO9822751A1; WO2010053493A1; WO2010117288A1). EP3915391A1 describes a protein concentrate from brewer's spent grains that has a maximum moisture content of 7% and contains proteins, fats, fibers, and ash. At the same time, the protein content in such a suspension is at least 50 wt.%. The device for producing this protein concentrate is characterized by the fact that the original brewer's spent grains are loosened to obtain a homogeneous mass. Mechanical impurities are removed. This mass is then ground into a paste-like mass with the addition of water or centrate, resulting in a paste-like mass with a maximum moisture content of 95%.This mass is freed from the ground husk, and a suspension is created. The suspension is subjected to vibration filtration and dried to obtain a concentrate with a maximum moisture content of 7%, containing proteins, fats, fibers, and ash.

[0007] However, these methods do not fully exploit the nutritional potential of spent grains. The indigestible fiber, which makes up 80% of spent grains, cannot be separated from the nutritional component of the spent grains. In this form, spent grains can be used in animal husbandry. Furthermore, the fats contained in dried spent grains, which contain at least 8% fat, cause disturbances in the animals' digestive systems. This prevents the required amount of spent grains from being incorporated into the animal feed. Furthermore, drying spent grains requires significant energy expenditure. This process results in low profits and a low price for the final product.

[0008] Devices for further processing brewery waste are known from the prior art. In particular, there is a device for processing liquid brewer's spent grains with a moisture content of 90-92%. The raw material is brought to a moisture content of 70-75% in the first stage and 40-45% in the second stage through a two-stage pressing process. Furthermore, a two-stage drying process is provided: in the first stage, to a moisture content of 20-25% and in the second stage, to a moisture content of 10%, producing a dry feed additive (RU2215426).

[0009] A disadvantage of this method is that a significant portion of the protein is removed from the concentrate during the pressing process. Therefore, additional processing capacity is required to purify the concentrate. Furthermore, the final product is rich in insoluble fiber and fat.

[0010] A device for producing a protein product from brewer's spent grain with a protein content of 60% to 90% is known from the prior art (WO2018136234A1). The device consists of the chemical-thermal treatment of brewer's spent grain. A mixture of brewer's spent grain and water is added to the hydrolysis tank with constant stirring. Glucoamylase is then added. The resulting mixture is heated to a temperature of 30°C to 70°C. The grain particles are ground to an average size of less than 500 microns. The pH of the mixture is then adjusted to approximately 7 to 10.5. An alkaline protease is added to dissolve the protein. The resulting mixture is sieved through a sieve with a hole diameter of 5 to 500 µm. Ultrafiltration using membranes with a pore size of 20 KDA to 40 KDA is then carried out, followed by nanofiltration.

[0011] A disadvantage of the method is the use of sophisticated and expensive equipment, as well as a long technological cycle of 60 to 105 minutes to obtain a protein product. Crushing takes 30 to 60 minutes, and hydrolysis takes 30 to 45 minutes. Another disadvantage is the use of hazardous substances in this process, i.e., hydrochloric or carbonic acids and alkali. It is also known that protein hydrolysis destroys all long amino acid chains. Protein losses during hydrolysis can reach up to 70%. In addition, the processing of brewer's spent grains requires a large amount of water at a ratio of 8:1 to 11:1 to brewer's spent grains. This process generates a significant amount of concentrate, which is a production waste. Therefore, additional facilities are required for its disposal.

[0012] There is also a protein composition obtained from waste grain raw materials during beer production. It contains 40 to 60% protein, 12 to 18% fat, 2 to 6% fiber, and 1 to 4% ash, based on dry weight (manufacturing process EP0694609A2). The device involves pressing brewer's spent grains with a roller mill and simultaneously wet-hulling the grains and separating the resulting product from the hull.

[0013] A disadvantage of the process is that during pressing with roller mills, some of the usable components are removed from the spent grains, as the grains are not crushed prior to pressing, and some of the protein is bound in the pressed husk particles. Therefore, protein is lost during the subsequent husk removal. Furthermore, to more efficiently separate the husk, the resulting mixture (liquid protein suspension) is washed with a large amount of water using a known device. The resulting suspension is sieved through sieves. The washing and sieving process must be repeated up to five times. This produces a large amount of concentrate, which is then disposed of as production waste. Additional facilities are therefore required to process the concentrate.

[0014] A device for extracting fiber from brewer's spent grains is known from DE 3644600 A1. The device involves adding hot water to the spent grains in a 1:1 ratio. The device also includes intensive mixing and sieving to remove protein, pressing to remove moisture, and drying the resulting fibers, which can be used as fiber.

[0015] This device is not intended to extract proteins; instead, the proteins remain as waste. Furthermore, the device requires the addition of additional water. This is either removed during the process or must be removed as contaminated water. Furthermore, the resulting products still contain fat, which impairs their use as animal feed due to the strain on the digestive system.

[0016] EP 0 609 548 A2 discloses a process for producing a food from brewer’s spent grains.

[0017] WO 2021 / 201711 A1 describes a device for producing a protein product from brewer's spent grains and the protein product.

[0018] EP 0 050 330 B1 describes a device for obtaining fibre- and protein-rich fractions from brewer’s spent grains.

[0019] WO 2018 / 050863 A1 describes a food composition with a high protein content and a device for producing this food composition.

[0020] An internet document entitled “Sustainable Ingredients” (“https: / / sustainable-ingredients.com / wp-content / uploads / 2023 / 03 / All_specification_datasheet_sustainable_ingredients_gersten_protein_01.pdf”) describes a food made from barley that contains barley protein.

[0021] For example, all existing brewer's spent grain treatment systems are aimed at producing protein powders or concentrates. These are characterized by the complexity and duration of protein extraction and a high yield of concentrate, which is a waste product. Additional equipment is required for its disposal.

[0022] There are no known highly efficient devices in the state of the art for obtaining end products from brewer's spent grains, such as protein concentrate and protein flour. These products are characterized by a high protein content and are frequently used as nutritional supplements and feed additives. Furthermore, none of the known devices produce barley oil as a separate product.

[0023] The claims define the scope of the present disclosure.

[0024] In food technology, brewer's grain refers to the residues of brewer's malt that accrue during beer production. Brewer's grain contains husks, undissolved portions of barley or wheat malt, and coagulated, insoluble protein.

[0025] A device for producing protein concentrate and protein flour from brewer's spent grain is disclosed. It comprises: a. Provision of brewer’s spent grains; b. Milling of the spent grains. This step includes, in particular, grinding the spent grains to a grain size of less than 1, 0.5, or 0.1 mm. Nothing is added to the spent grains until this grain size is reached. c. Addition of aqueous liquid to the ground spent grains; d. Obtaining a suspension of ground brewer’s spent grains and aqueous liquid; e. Separating the suspension into an insoluble and a soluble part; f. Processing the insoluble part into a protein flour and the soluble part into a protein concentrate.

[0026] The device offers the advantage that no water, aqueous solutions or suspensions, concentrates, or other additives—i.e., no liquid water or steam—need to be added until the milling process is complete. In particular, no substances such as solutions, suspensions, or concentrates that were created during the subsequent process are used during the milling process. It has been found that this allows the protein content of the final product obtained from the spent grains to be increased compared to processes in which liquid water, aqueous solutions, or steam are added during the initial milling step. The addition of steam, in particular, requires a more complex design and incurs additional construction costs and energy consumption.

[0027] This method enables more efficient utilization of brewery waste. It also enables the extraction of barley oil. Barley oil extraction was not possible with previous devices.

[0028] The brewer's grains used as the starting product (brewer's grains or spent grains) may contain 60-90% water by weight. They can be used within 6 hours of production. The brewer's grains may have a temperature of 0.5 to 90°C upon entry into production and / or during milling. The milling of the brewer's grains can take place in a mill (also called a milling processor). After milling, the brewer's grains may have an average particle diameter of 0.01-5 mm. After milling, the brewer's grains may be in the form of a pasty, homogeneous mass (i.e., slurry). The viscosity of the pasty mass is 500-1500 cps (measured at 30°C in a type B viscometer). The mill can operate at 5000-6000 rpm, particularly at 5600 rpm.

[0029] The addition of aqueous liquid, especially water, can take place in a slurrying device into which the pasty mass is transferred. The slurrying device can be a continuous mixer. The aqueous liquid can be added in a ratio of 1:0.25 to 1:0.75 or 1:0.3 to 1:0.5 (aqueous liquid: pasty mass). The aqueous liquid can be fresh aqueous liquid and / or aqueous liquid that is recovered later in the process, as described below. In the slurrying device, a suspension, i.e., a slurry, is produced.

[0030] The aqueous liquid / water can be mixed with an acid, in particular a food-grade acid, which can completely convert proteins that are borderline insoluble and / or only slightly soluble into the solid phase. This enables a clear separation from the soluble proteins and increases the purity of the soluble proteins. This can be achieved without adjusting the temperature in the filtration process. In principle, a food-grade or human-digestible acid, such as acetic or citric acid, can be used. The acid can be added before or during process step c. The aqueous liquid / water can be mixed with the acid before it is added to the ground brewer's spent grains. The pH of the (still) acidic aqueous liquid / water is preferably >6, particularly preferably 6.5 or >6.5.

[0031] This range lies well outside the pH range of approximately pH 4, which is generally considered the range for the precipitation of soluble proteins in the pomace. Surprisingly, however, it has been found that a slightly acidic environment favors the removal of generally insoluble or poorly soluble proteins from the aqueous portion into the solid phase, thereby increasing the purity of the dissolved proteins.

[0032] The slurried mass (also called suspension) can be transferred to a device for separating soluble and insoluble components of the suspended mass, in particular to a press device. The transfer can be carried out by a pump, in particular an impeller pump. The press device can be a belt press. This comprises pressing means such as rollers and a sieve device as the pressing surface. The pressure in the press device can be 5–10 bar. The press device can contain press rollers. The suspension is pressed out repeatedly (2 to 5 times) via these. The sieve can contain 25–75 or 30–50 openings (i.e., holes) per 1 cm 2 The soluble part is pressed out of the suspension by pressure, leaving the insoluble part behind. Thus, the soluble part passes through the sieve, while the insoluble part remains on the sieve.

[0033] The soluble portion has a water content (moisture content) of 90 - 99 wt% or 93 - 95 wt%.

[0034] The insoluble part has a water content (moisture content) of 80 - 99 wt% or 85 - 90 wt%.

[0035] The insoluble part is processed into a protein meal, and the soluble part into a protein concentrate. This can be achieved by removing liquid from the respective portions of the suspension in the next step, e.g., in suitable devices. The soluble and insoluble parts are transferred to these devices and separated from the liquid.

[0036] For the insoluble fraction (present as a tabular or plate-like mass), this can be achieved in a single step, e.g., using a dryer with hollow blades. In this case, the temperature of the drying medium (e.g., steam or oil), e.g., the medium in the hollow blades, is 160–180°C. This enables particularly efficient, rapid, and gentle drying of the insoluble fraction. The evaporated liquid can be reused in the resuspension step. The removal of the liquid from the soluble fraction can be performed in two steps. The second step can correspond to the removal of water from the insoluble portion.

[0037] In the first stage, the liquid can be fed via a (decanter) separator.

[0038] The drying product is a food cake with a moisture content of 78-80% water by weight, and a recycled liquid with a moisture content of 99-100% or 99-99.8% by weight is produced. The recovered liquid can be reused in the resuspension stage.

[0039] The second stage may correspond to the removal of water from the insoluble part.

[0040] At the end of these liquid removal steps, the protein cake (from the soluble fraction) and the plastic masses (from the insoluble fraction) may each have a moisture content of 2 - 3 wt%.

[0041] Therefore, step 1.f may further comprise removing the aqueous liquid from the soluble part of the suspension and optionally reusing the removed liquid in step 1.c.

[0042] Therefore, step 1.f may further comprise removing the aqueous liquid from the insoluble part of the suspension and optionally reusing the removed liquid in step 1.c.

[0043] Water reuse enables efficient circular economy and reduces or eliminates the need for extraneous water. This can result in ecological and economic benefits. Furthermore, it was surprisingly found that the aqueous liquid removed from the soluble or insoluble part of the suspension contains both dissolved protein and oil (e.g., fatty acid triglycerides) in relevant amounts. The aforementioned aqueous liquid contains 1–5 wt%, 1.5–3 wt%, or 1.5–2.5 wt% protein and 1–5 wt%, 2–4 wt%, or 2.5–3.5 wt% (barley) oil. By recycling the aqueous liquid containing (dissolved) protein and oil, the yield of protein and oil in the final product is increased.The recycling of the aqueous liquid into the process instead of pure water, as is often the case in the state of the art, enables an increase in the protein content by 1.0 - 1.5% and the oil content by 2.0 - 2.5% in the protein flour and protein concentrate.

[0044] Overall, this device offers three advantages: an increase in the protein and oil content in the final product, the saving of a natural resource (water in an amount of 50-100 tons per 50 tons of grain), and the elimination of the construction of a processing plant, the cost of which can reach up to 10% of the total production costs.

[0045] The process eliminates the need for a homogenizer. A homogenizer (treating the feed with at least 90 bar) results in homogeneous comminution of all pellet components, of which at least 70% is fiber. Homogenization ensures that the crushed fibers are evenly distributed throughout the main product – the protein. Even with further screening, the fibers cannot be properly separated because the vibration of the vibrating screen allows fiber particles down to 200 microns to pass through. Furthermore, the moisture content of the separated fibers is at least 80-83%. This means that the fibers contain not only water but also protein and fat dissolved in water. Using the device according to the invention, the fibers can be separated from the suspension using a (belt) press.Separation can occur at a pressure of 3-5 bar on several press rollers, usually 3 or 4. Therefore, the use of a belt press with 2-6 rollers is particularly preferred, as this allows for particularly efficient separation of the dissolved protein.

[0046] At the same time, the moisture content of the pressed fibers reaches 40–45%, which is twice as high as the moisture content of the sieved products. Furthermore, the pressed moisture contains up to 3% protein and up to 4% oil. This increases the total protein and fat content of the suspension to 48–50% protein and up to 16–17% fat. Eliminating the homogenization step therefore has the advantage that the resulting concentrate contains surprisingly more protein. The yield of barley oil, which can be obtained using the steps described below, is increased.

[0047] The resulting protein cake and plastic mass can be stored in a moisture-proof container until further use.

[0048] The device for extracting fats from spent grains may also include: Carrying out the process as described above. This includes the step according to claim 1 f., as well as the extraction of barley oil from the insoluble and soluble parts of the suspension from step e of claim 1) with an organic solvent.

[0049] This step has at least two advantages. By separating oil from the final products through (ethanol) extraction, the protein content in the protein concentrate can be increased to 70% (instead of 62-63% if fat is present) and in the protein-rich meal to 25% (instead of 17-19% if it contains fat). Furthermore, oil is obtained as an additional, separate product. It can be used as intended in the cosmetic industry and does not need to be transferred to animal feed along with protein.

[0050] The organic solvent can be ethanol, for example. Both the protein cake and the plastic mass can each be placed in a suitable device for extracting barley oil with an organic solvent. The organic solvent, especially ethanol, can be added to the protein cake or the plastic mass, for example, in a ratio of 2.5:1 - 4:1 or approximately 3:1.

[0051] This creates a miscella (a solution of barley oil and organic solvent) by dissolving the barley oil in the organic solvent. The extractor temperature can be 1-3°C above the evaporation temperature of the solvent, for example, 78.3°C for ethanol. The extractor is sealed off from the atmosphere. This can result in an overpressure of 2-3 bar.

[0052] By isolating the extractor from the atmosphere (and the resulting overpressure), the extraction process is two to three times faster than without overpressure. The step can therefore take approximately 30 minutes and can be carried out at 69–71°C and 2.8–3.2 bar. This enables energy-efficient extraction of barley oil.

[0053] The miscella can then be removed. The extraction step can be repeated at least twice or exactly twice with fresh organic solvent. Using a total of three extraction steps has proven particularly efficient.

[0054] Furthermore, the extraction efficiency can be further improved by incorporating a drum with rotating blades or paddles into the extractor. The barley oil can then be separated from the organic solvent. This can be done using a vacuum evaporator.

[0055] The separated organic solvent can then be reused if desired. Therefore, the step according to claim 1f may also comprise removing the organic solvent from the solvent-barley oil solution and, optionally, reusing the removed organic solvent in the removal step.

[0056] The protein cake extracted with an organic solvent is called protein concentrate (which is obtained from the soluble part of the suspension).

[0057] Therefore, a protein concentrate is also disclosed which is obtainable by the process described above.

[0058] The protein concentrate may contain less than 2% moisture by weight, a particle diameter of less than 0.2 mm, fat, fiber and / or at least 70% protein by weight.

[0059] The protein concentrate must not contain, based on its dry weight, more than 2.8% by weight of fibre, not more than 0.54% by weight of fat and / or an amino acid content of at least 71.7% by weight.

[0060] The protein concentrate contains a total of 55 - 65% by weight of amino acids.

[0061] The plastic mass extracted with an organic solvent is referred to as protein flour (from the insoluble part of the suspension). Therefore, protein flour is also disclosed, which is obtainable using the device described above.

[0062] The protein flour may contain less than 2% moisture by weight, a particle diameter of less than 0.2 mm, fat, fiber and / or at least 25% protein by weight.

[0063] The protein flour must not contain, based on its dry weight, more than 14.9% by weight of fiber, not more than 1.47% by weight of fat and / or not less than 25.24% by weight of amino acids.

[0064] The protein flour can contain a total of 20 - 30% by weight of amino acids.

[0065] Barley oil which can be obtained by the device described above is also disclosed.

[0066] The barley oil may contain 50-60% w / w or 55-57% w / w linoleic acid and 13-18% w / w or 15-17% w / w oleic acid. The barley oil must not contain less than 56.28% w / w linoleic acid, not less than 16.7% w / w oleic acid, and / or not less than 700 mg / 100 ml vitamin E.

[0067] An extractor with rotating blades can be used to extract the barley oil from the insoluble and soluble parts of the suspension using an organic solvent.

[0068] The technical result of the claimed invention is to obtain processed brewer's spent grain in the form of a protein concentrate with a protein content of at least 70% in dry residue, a protein flour with a protein content of at least 25% in dry residue and a barley oil with a vitamin E content of at least 700 mg per 100 ml.

[0069] The technology for processing brewer's spent grain to obtain a protein concentrate with a moisture content of no more than 8% and a protein content of at least 70%, a protein flour with a moisture content of no more than 8% and a protein content of at least 25%, and a barley oil with a vitamin E content of at least 690 mg per 100 ml consists, in particular, in subjecting brewer's spent grain in its native form with a moisture content of 60-90% to fine grinding with a grinder. The resulting pulp is then mixed with water in a 1:1 ratio. The resulting suspension undergoes multi-stage pressing with a belt press filter. This separates the suspension into a food fraction with a moisture content of 85-95%.Its composition includes the majority of the protein from brewer's spent grains, with a protein content of at least 65% by dry matter, and insoluble fiber with a protein content of at least 25% by dry matter. The suspension is then dewatered in a continuous decanter separator and separated into a protein cake with a moisture content of no more than 80% and a food concentrate with a moisture content of at least 99%. The protein cake and insoluble fiber are then rapidly dried in continuous paddle dryers to obtain a protein concentrate with a moisture content of no more than 2% and a protein flour with a moisture content of no more than 2%. Furthermore, fats are removed from the protein concentrate and protein flour using a cyclic three-stage alcohol extraction method with ethanol, using a cyclic agitator extractor and evaporator.These make up 8-12% of the concentrate and flour composition. After evaporation of the remaining ethanol, the protein flour has a protein content of at least 30%. The miscella obtained by extraction contains 90-92% ethanol. This is subjected to ethanol evaporation in a specially developed evaporator. This allows at least 98% of the ethanol to be recovered, yielding barley oil with an ethanol content of no more than 2%.

[0070] All products can be either ready-to-use products or intermediates from which protein-rich blends and cosmetic preparations containing barley oil can be produced. In this case, the technology is completely waste-free, as the concentrate produced during dewatering by the decanter separator and the moisture evaporated during drying of the intermediate products are recycled back into the process.

[0071] The technical result can be achieved with a protein concentrate, protein flour and barley oil obtained from brewer's spent grain with a moisture content of 80 - 90% and a grain size of up to 10 mm.

[0072] In this case, the optimal composition of protein products is the following proportion of dry residue in wt.%.

[0073] In this case, the optimal composition of barley oil is as follows.

[0074] The technical result can also be achieved using a device for producing protein concentrate, protein flour, and barley oil. The original raw material, native brewer's spent grain, is finely ground in a grinder. The resulting slurry is then diluted with water in a flow mixer at a ratio of 1:0.3 - 1:0.5 (slurry / water). The resulting suspension is pumped into a belt press filter using a screw or impeller pump. This filter undergoes a multi-stage separation of the liquid fraction from the solid part of the suspension. The liquid fraction, with a moisture content of 93-96% and a protein content of at least 70%, is pumped into a continuous decanter via a metering pump. The liquid suspension is then dewatered to form a cake with a moisture content of 78-80%.The food concentrate (the moisture separated from the suspension) is returned to the process when the suspension is mixed with water in a continuous mixer. At the same time, brewer's grains were milled using a milling processor from Urschel Laboratories (USA), model Comitrol 1700, with a milling head rotation frequency of approximately 5600 rpm, motor power 29 kW, and a three-phase power supply of 50 Hz. In this case, the multi-stage separation of the liquid fraction of the suspension from the solid part of the suspension was carried out on a belt press from TC Environmental Inc. (China), model DNY 2.0, press belt width 2000 mm, motor power 3.2 kW, three-phase power 50 Hz. Simultaneously, the protein suspension was dewatered in a continuous decanter separator from KOSUN (China), model DC450-1900, with a centrifugation speed of 3400 rpm, motor power 22 kW, three-phase power 50 Hz.

[0075] Preferably, the grains can be ground at a speed of up to 5600 rpm and more without having to accept the disadvantages of excessive heating of the grains.

[0076] The protein cake obtained with the continuous decanter separator is further dried to a moisture content of 2% in the paddle dryer from ZHENXING (China) and transferred to the protein concentrate storage tank. The moisture evaporated from the suspension is condensed in a storage tank and fed into the process via a continuous mixer.

[0077] The solid part of the suspension obtained after the belt press, with a moisture content of no more than 60% and a protein content of no less than 25%, is further dehydrated in a paddle dryer to a moisture content of 2%. It is then transferred to a storage tank for protein flour. The moisture evaporated from the suspension is condensed in a storage tank and fed into the process in a continuous mixer.

[0078] In this case, the protein cake and the solid part of the suspension were dried in a paddle dryer from Changzhou Haomai Drying Engineering Co. (China), model KJG-70, with a paddle speed of 0.4 - 10 rpm, a motor power of 2.2 kW and a 3-phase network of 50 Hz.

[0079] The same technical result can be achieved by extracting fat from protein concentrate and protein flour (defatted products) by continuously extracting a dry product with a moisture content of no more than 2% in ethanol. The extraction is carried out in a paddle extractor in two stages: Step 1 - Add the dry product and ethanol to the extractor. The ratio of dry product to ethanol is 1:3. The extraction time is 30 minutes at a pressure of 2 bar and a temperature of 80°C. The mixture is then allowed to stand in the extractor for 3 hours and the miscellaneous is transferred to the storage container. Stage 2 - Addition of the ethanol mixture remaining after draining the miscella into the extractor.

[0080] The ratio between the mass of the product and the mass of the ethanol is 1:2. The extraction time is 10 minutes at a pressure of 2 bar and a temperature of 80°C. The mixture is then allowed to rest in the extractor for 3 hours and the miscella is poured into a storage container.

[0081] The same technical result can be achieved if the ethanol from the extracted product is subsequently evaporated directly in the extractor for 3 hours at a temperature of 80°C and a pressure of 0.9 bar. The moisture content after drying is no more than 2%. Furthermore, drying the extracted substances recovers ethanol and returns it to the technical process. The technical result of product defatting can be achieved in the same way for both protein concentrate and protein meal. The fat was extracted from the dried products with a moisture content of 2%. The fat-free products were dried using a device from Zhenxing Drying Equipment Co., model Customized GPG7000, with a speed of 0.4–30 rpm, a motor power of 45 kW, and a 3-phase power supply of 50 Hz.

[0082] The technical result of recovering ethanol and reintroducing it into the process can also be achieved by evaporating ethanol from the miscella in a vacuum evaporator. Evaporating ethanol from the miscella also produces pure barley oil with an ethanol content of no more than 2%. Evaporation takes place at a miscella temperature of no more than 80°C and a pressure of 0.9 bar for 3 hours or until the moisture content of the final product reaches 2%. The finished products, the protein concentrate and protein flour, are stored in storage containers. The evaporation of the ethanol from the miscella took place in our proprietary evaporator with a power output of 7 kW and a 3-phase 50 Hz power supply.

[0083] The resulting protein products, protein concentrate and protein flour, are characterized by their high protein content. They are produced in an efficient and technically cost-effective facility. No recyclable waste is generated. The concentrate and condensate are recycled back into the process.

[0084] The resulting barley oil is characterized by a high vitamin E content and is safe because edible ethanol is used for extraction.

[0085] The invention will now be explained in more detail with reference to the accompanying drawing. It shows: Fig. 1 shows a schematic representation of a production line for carrying out the claimed processes. Where, 1 is the raw material (local brewer’s grains) 2 is a grinding processor, 3 is a continuous mixer, 4 is an impeller pump, 5 is a belt press, 6 is a continuous decanter separator, 7 is a paddle dryer, 8 is a storage container for protein concentrate and protein flour, 9 is a paddle extractor / blade scraper, 10 is a storage container for protein concentrate and protein flour, 11 is a vacuum evaporator for ethanol from miscella, 12 is a tank with ethanol, 13 is a tank for the water circuit / for water circulation and for collecting concentrate and condensate, 14 is a tap water inlet and 15 is barley oil. Example 1

[0086] In food technology, brewer's grain refers to the residues of brewer's malt that accrue during beer production. Brewer's grain contains the husks, the undissolved parts of the barley or wheat malt, and the coagulated, insoluble protein.

[0087] The invention is described in more detail below. This does not limit the scope of the claim of the invention, but rather demonstrates the possibility of implementing the invention with the claimed technical result.

[0088] The original spent grains, with a moisture content of 60-90%, are processed within 6 hours of receipt (from the moment they are generated as waste during beer production). The temperature of the spent grains entering production can range from 0.5 to 90 degrees Celsius. The spent grains 1 ( Fig. ) are fed manually or mechanically with a steady flow into the grist mill 2 ( Fig. ). This ensures perfect grinding of the spent grains to a fraction of 0.01 - 0.5 mm. The temperature of the spent grains treated in the grist mill can range between 0.5 and 90 degrees. The moisture content of the spent grains for processing in the grist mill can range between 60 and 95%. In grist mill 2, the spent grains are finely ground to obtain a pasty, homogeneous mass, a slurry, with a viscosity in the range of 500 - 1500 cps. The spent grains are milled in grinder 2 at a speed of 5600 rpm. This achieves a thick, liquid consistency of the slurry, which allows maximum extraction of the food fraction of the spent grains from the raw material in the subsequent processing stage, the belt press 5 ( Fig. ).

[0089] After the flour processor 2, the finished slurry flows, preferably by gravity, into the continuous mixer 3 ( Fig. ). In this, water is added to the mash in a ratio of 1:0.3 - 1:0.5 (mash / water). The water is fed to the continuous mixer 3 from the storage tank 13 ( Fig. ). This is filled with tap water and watered residues from the treatment in the suspension dewatering stages in a continuous decanter 6 (concentrate) and paddle dryers 7 (condensate). After the continuous decanter 6, the concentrate is a slightly cloudy, light-colored liquid with a moisture content of 99–99.8%, a temperature of 50–70°C, and microscopic inclusions of the nutritional components of brewer's spent grains, including protein and fat. It is technically impossible to separate these from the water in a continuous decanter separator 6. Approximately 850–900 liters of concentrate are obtained from one ton of sludge. The condensate after paddle dryer 7 is a slightly cloudy, light liquid with a moisture content of 99.8 - 99.9%, a temperature of 70 - 90°C and small microscopic inclusions of the nutritional components of brewer's spent grain, including protein and fat.When drying the cake on a paddle dryer, the cake condenses during the evaporation process. Approximately 730–770 liters of condensate are evaporated from 1 ton of cake. The concentrate and condensate are a valuable resource utilized in the technology's recycling cycle. This allows for the reduction of tap water consumed by the technology, increases the production of the technology's end products by 1.0–1.5%, and completely eliminates the disposal of concentrate and condensate. This saves resources that would otherwise be used to purify the concentrate and condensate before discharging it into the sewer system.

[0090] After the continuous mixer 3, the suspension is pumped with the impeller pump 4 ( Fig. ) to belt press 5 ( Fig. ). In belt press 5, the suspension is spread in an even layer on a press belt with a thickness of 2–3 mm. It is then repeatedly pressed out by press rollers at a pressure of 5–10 bar. The belt has approximately 30–50 holes per 1 cm across its entire surface. 2with a diameter of 0.01 mm. The food component of the suspension is pressed through these into the pallet of the belt press. This suspension is then fed further into the process. The suspension has a moisture content of 93-95% and forms a further basis for the protein concentrate. The insoluble part of the suspension (husks, barley awns) is retained on the belt and, after repeated squeezing, scraped off the entire belt surface with a stationary scraper. This plastic mass is then tipped into the collecting trough of the belt press and fed further into the process. The plastic mass has a moisture content of 85-90% and forms a further basis for the protein flour.

[0091] The food suspension (soluble part of the suspension) with a moisture content of 93 - 95% is fed by gravity (the use of a dosing pump is possible) to a continuous decanter 6 ( Fig. ). There, it is dewatered in a continuous process to obtain a food cake with a moisture content of 78-80% and a recycled concentrate with a moisture content of 99-99.8%. The suspension is dewatered using the set parameters of the continuous decanter separator 6 as follows: - inner drum of the decanter 450 mm; - Operating speed 3200 rpm; - Separation factor not less than 3000; - Power of the main electric motor 22 kW; - Power of the auxiliary electric motor 7.5 kW.

[0092] During dewatering, the cake is continuously conveyed to the bottom of the decanter 6. It is then conveyed manually or by any automated device (belt or screw conveyor) into the paddle dryer 7 for the cake ( Fig. ). The concentrate flows continuously by gravity through the pipe into the storage tank 13. There it is constantly mixed with tap water.

[0093] The plastic mass obtained on the belt press 5 (also called sheet mass) is then transferred manually or by any automated device (belt or screw conveyor) into the paddle dryer 7 for the sheet mass ( Fig. ).

[0094] The paddle dryers 7 for cakes and bulk goods are completely identical.

[0095] In paddle dryers, the cake or slab mass is evenly mixed with the transfer of high-temperature hollow blades of the coolant inside the blades and also the dryer's heating jacket through the hollow blades (the coolant can be hot water at a temperature of 95-98°C, steam at a temperature of 140-150°C, or hot oil at a temperature of 160-180°C). As heat is transferred to the drying products (cake or slab mass), the moisture from the products evaporates. The most effective method is to use hot oil at a temperature of 160-180°C as the heat carrier. In this case, the heating of the evaporated raw material to the water evaporation temperature of 100°C is 2-3 times faster than when using hot water or steam as the heat carrier. The evaporated moisture is condensed in the dryer's condenser and discharged by gravity into the storage tank 13.There it is mixed with tap water and then used in the process.

[0096] After evaporation of moisture from the cakes and plastic raw materials, dry products with a moisture content of 2 - 3% are fed into the storage tanks 8 ( Fig. The tanks are completely sealed, preventing moisture from the ambient air from penetrating the dried food.

[0097] Once a sufficient amount of dry product has accumulated in the hopper, the dry products are conveyed to the paddle extractors 9 ( Fig. ) promoted.

[0098] The volume of the extractor 9 filled with the dry product is 50% of the total volume of the extractor 9. After filling the extractor 9 with the dry product, the product is mixed in the extractor. This begins with the addition of ethanol from the ethanol tank 12 ( Fig. Ethanol is added at a rate of 3 liters per 1 kg of dry product. Upon addition of ethanol and mixing of the dry product with ethanol at a speed of 0.5–1.5 rpm, the product fat begins to dissolve in the ethanol. This creates a miscella, a mixture of ethanol and fats. To accelerate the extraction, the mixture in extractor 9 is heated to a temperature of 80°C by the extractor's heating jacket. Since the evaporation temperature of ethanol is 78.3°C, excess pressure is created in the extractor at 80°C due to the boiling of the ethanol. The boiling process ends at a pressure of 2–3 bar. At the elevated temperature of the extracted mixture, the extraction is 2–3 times more efficient than at normal atmospheric pressure and takes no longer than 30 minutes. Stirring in extractor 9 is then stopped. The heating medium is no longer supplied.Over the next 3 hours, the mixture cools to 70°C and settles. The solid fractions of the mixture settle in the lower part of the extractor 9, while the miscella remains in the upper part. The miscella is then transferred to the vacuum evaporator 11 (Fig. Fig. ) to separate the barley oil 15 from the ethanol. After emptying the miscella into the extractor 9, another extraction cycle is carried out at a temperature of 80°C for 10 minutes. Another settling cycle takes place for three hours. The miscella is then drained into the vacuum evaporator 11.

[0099] After fat extraction, the product remaining in extractor 9 is dried at a temperature of 80°C within 2-3 hours to a moisture content of 2%. The evaporated ethanol is cooled in the extraction condenser 9 and returned to the ethanol tank 12.

[0100] After the miscella is discharged from the extractor 9 into the vacuum evaporator 11, it is heated to a temperature of 80°C and a pressure of 0.9 bar. At the same time, the miscella is actively boiled to remove the ethanol. The ethanol is evaporated for 1-2 hours, cooled in the condenser of the evaporator 11, and transferred to the ethanol tank 12. In this way, the ethanol is almost completely recovered during the extraction process. The loss of ethanol is no more than 2% per complete ethanol conversion in the process. This allows us to protect the environment from harmful emissions and achieve high process efficiency.

[0101] The dried product in the extractor 9 (protein concentrate and protein flour) is transferred to storage containers for protein concentrate and protein flour 10 for further use ( Fig. ).

[0102] The analysis shows that the final products of the proposed technology are characterized by high nutritional value and a rich amino acid composition, identical to the amino acid composition of brewer's spent grain.

[0103] The analysis shows the content of the most useful fatty acids: linoleic acid - 56.28%, oleic acid - 16.70%.

[0104] The total processing time for 1,000 kg of spent grain is 8 hours. The longest time, namely 6 hours, is the settling process after extraction.

[0105] The protein concentrate and protein flour obtained by the claimed device are therefore characterized by a high protein content and a low fat and fiber content. Example 2

[0106] 100 kg of spent grain (85% moisture content and 68°C temperature) are passed through a milling processor with a capacity of 4 tons of grain per hour. The milling time for a 100 kg batch is 90-100 seconds. Of the finely ground spent grain emerging from the mill, 90% has a grain size of 0.5-1.0 mm. The remaining 10% has a grain size of 0.01-0.5 mm. The slurry is then mixed with water in a continuous mixer. The water is added in a ratio of 1:0.5, depending on the moisture content of the original spent grain. The total amount of additional water is 50 liters. Mixing the pellets with the water in the continuous mixer takes 20 seconds; the water has a temperature of 22°C. After mixing with water, the resulting homogeneous mash has a moisture content of 90% and a temperature of 47°C. Example 3

[0107] 100 kg of spent grain (88% moisture content and 72°C) are passed through a milling processor with a capacity of 4 tons of grain per hour. The milling time for a 100 kg batch is 90-100 seconds. Of the finely ground spent grain emerging from the mill, 92% has a grain size of 0.45-1.0 mm. The remaining 8% has a grain size of 0.01-0.45 mm.

[0108] The mash is then mixed with water in a continuous mixer (3). The water is added at a ratio of 1:0.4. Depending on the moisture content of the original spent grains, the total amount of additional water is 30 liters. Mixing the pellets with the water in the continuous mixer takes 20 seconds. The water has a temperature of 23°C. After mixing with water, the homogeneous mash has a moisture content of 91% and a temperature of 56°C.

[0109] The following aspects are particularly highlighted: Protein concentrate, protein flour, and barley oil obtained from brewer's spent grains, characterized in that the protein concentrate and protein flour have a moisture content of no more than 2% and a particle size of no more than 0.2 mm, and contain proteins, fats, and fiber. The protein content in the protein concentrate is at least 70% in the protein flour and at least 25% by weight in the dry residue. The barley oil has a vitamin E content of at least 700 mg / 100 ml.

[0110] Protein concentrate according to aspect I, characterized in that the quantitative content of the components in the dry residue (in wt.%) is as follows: fiber not more than 2.8; fat not more than 0.54, while the amino acid content is not less than 71.7.

[0111] Protein flour according to aspect I, characterized in that the quantitative content of the components in the dry residue (in wt.%) is: fiber not more than 14.9; fat not more than 1.47, while the amino acid content is not less than 25.24.

[0112] Barley oil according to aspect I, characterized in that the quantitative content of the components in the barley oil (in wt%) is: linoleic acid not less than 56.28%, oleic acid not less than 16.7% and the content of vitamin E not less than 700 mg / 100 ml.

[0113] Apparatus for obtaining protein concentrate, protein flour, and barley oil according to aspect 1, characterized in that the original brewer's spent grain is milled in a milling machine. Water is then added to a moisture content of no more than 93%. The resulting mass is then divided into two products to obtain final products: protein concentrate containing at least 70% protein by dry matter, and protein flour containing at least 25% protein by dry matter.

[0114] Apparatus for obtaining barley oil according to aspect I, characterized in that fats are extracted from the two end products, barley concentrate and barley meal, in order to obtain barley oil with a vitamin E content of at least 700 mg / 100 ml.

[0115] Device according to aspect I, characterized in that the by-products of the proposed technology, concentrate and condensate, are completely recycled into the process of producing products from brewer's spent grains.

[0116] Device according to aspect I, characterized in that in the extraction of fats from the finished derivative products of brewer's grains, barley concentrate and barley meal, an extractor with rotating blades is used, which allows the fat extraction to be carried out in an accelerated and efficient manner.

[0117] Device according to aspect I, characterized in that in the extraction of fats from the finished derivatives brewer's grains, barley concentrate and barley meal, an extractor is used which offers the possibility of drying the product after extraction without overloading the product.

[0118] Device according to aspect 1, characterized in that a device for complete ethanol recovery is used in the extraction of fats from the finished derivatives brewer's spent grains, barley concentrate and barley flour. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 0694609A2 [0006, 0012] WO 9822751A1

[0006] WO 2010053493A1

[0006] WO 2010117288A1

[0006] EP 3915391A1

[0006] RU 2215426

[0008] WO 2018136234A1

[0010] DE 3644600 A1

[0014] EP 0 609 548 A2

[0016] WO 2021 / 201711 A1

[0017] EP 0 050 330 B1

[0018] WO 2018 / 050863 A1

[0019] Cited non-patent literature

[0000] Sustainable Ingredients” (“https: / / sustainable-ingredients.com / wp-content / uploads / 2023 / 03 / All_specification_datasheet_sustainable_ingredients_gersten_protein_01.pdf

[0020]

Claims

[1] Device for producing foodstuffs from brewer’s spent grains, consisting of: a mill configured to grind spent grains to a particle size of less than 1 mm without adding anything to the spent grains; a mixer configured to add an aqueous liquid to the ground spent grains to obtain a suspension; a separator configured to separate the suspension into an insoluble part and a soluble part; and a processor configured to process the insoluble portion into a protein flour and the soluble portion into a protein concentrate containing less than 2% liquid and at least 70% protein by weight. [2] The apparatus of claim 1, wherein the grinder is configured to grind the spent grains to a grain size of less than 0.5 mm. [3] The apparatus of claim 1, wherein the mixer is configured to add the aqueous liquid to the ground spent grains in a ratio of 1:0.3 to 1:0.5 (ground spent grains:aqueous liquid). [4] The apparatus of claim 1, wherein the separator comprises a belt press filter. [5] The apparatus of claim 4, wherein the belt press filter comprises a belt having 30 to 50 holes per 1 cm2. [6] The apparatus of claim 1 further comprises a decanter separator configured to dewater the soluble portion of the suspension. [7] The apparatus of claim 6, wherein the decanter separator is configured to dewater the soluble portion to a moisture content of 78-80%. [8] The apparatus of claim 1, wherein the processor comprises a dryer configured to dry the insoluble portion and the soluble portion to a moisture content of less than 2%. [9] Apparatus according to claim 8, wherein the dryer is a paddle dryer. [10] The apparatus of claim 1 further comprises an extractor configured to extract barley oil from the protein meal and the protein concentrate. [11] Device according to one of claims 1-10, which is suitable for the production of foodstuffs, in particular protein concentrate and protein flour, from brewer's grains and is timed as follows: a) provision of brewer’s spent grains; b) Grinding the spent grain. This step includes, in particular, grinding the spent grain to a grain size of less than 1 mm. In this device, nothing is added to the spent grain until this grain size is reached. c) adding aqueous liquid to the ground spent grains; d) obtaining a suspension of ground brewer’s spent grains and aqueous liquid; e) separating the suspension into an insoluble and a soluble part; f) processing the insoluble portion into a protein flour and the soluble portion into a protein concentrate, the protein concentrate containing less than 2% by weight of liquid and at least 70% by weight of protein.

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