A system for producing casein and whey proteins

Abstract

The utility model discloses a casein and whey protein production system, the raw material storage tank, pasteurization machine, milk fat separator, primary filter device and microfiltration device in it are connected gradually to separate out skim milk, and first ultrafiltration device and second ultrafiltration device are connected with microfiltration device respectively to extract casein, whey protein respectively, and first dialysate storage tank is connected with first ultrafiltration device and second ultrafiltration device respectively to receive the dialysate after ultrafiltration and carry out pH adjustment, simultaneously, first dialysate storage tank and nanofiltration device, reverse osmosis device are connected gradually to separate out other byproducts, and, primary filter device and reverse osmosis device are connected with microfiltration device and second ultrafiltration device, and the dialysate of primary filter device and reverse osmosis device is used as the rinse water of microfiltration device and second ultrafiltration device.

Description

Technical Field

[0001] This utility model relates to the field of dairy processing technology, specifically to a casein and whey protein production system. Background Technology

[0002] Casein and whey protein are two major proteins in cow's milk, and their production processes are based on their different physicochemical properties for separation and purification. Casein accounts for about 80% of the total protein content in cow's milk. It is a phosphoprotein, and its key characteristic is that it denatures and coagulates at pH 4.6, which is the key principle for its separation. Industrially, it is mainly produced through the "acid precipitation method" or the "rennet method." The former is used to manufacture casein products, and the latter is used in the production of raw cheese. Whey protein accounts for about 20% of the total protein content in cow's milk. It is a water-soluble protein mixture, and its key characteristic is that it remains soluble even at pH 4.6, the same pH condition where casein coagulates. Therefore, whey protein is essentially a byproduct of casein production and requires further purification to obtain a high-purity product. However, current production processes for both casein and whey protein require a large amount of external water, resulting in excessively high production costs and the generation of large amounts of wastewater, which negatively impacts the environment. Utility Model Content

[0003] The purpose of this invention is to provide a casein and whey protein production system that, while extracting casein and whey protein, separates byproducts such as lactose and reduces the load on external water. To achieve the above objective, this invention adopts the following technical solution: This utility model discloses a casein and whey protein production system, including: a raw material storage tank, a pasteurizer, a milk fat separator, a primary filter, a microfiltration device, a first ultrafiltration device, a second ultrafiltration device, a first dialysate storage tank, a nanofiltration device, and a reverse osmosis device.

[0004] The raw material storage tank, pasteurizer, milk fat separator, primary filter and microfiltration device are connected in sequence to separate skim milk. The first ultrafiltration device and the second ultrafiltration device are respectively connected to the microfiltration device to extract casein and whey protein respectively.

[0005] The first dialysate storage tank is connected to the first ultrafiltration device and the second ultrafiltration device respectively to receive the ultrafiltration dialysate and adjust its pH. The first dialysate storage tank is connected in sequence to the nanofiltration device and the reverse osmosis device to separate other by-products.

[0006] Furthermore, the primary filtration device and the reverse osmosis device are connected to the microfiltration device and the second ultrafiltration device, and the dialysate of the primary filtration device and the reverse osmosis device is used as the washing water for the microfiltration device and the second ultrafiltration device.

[0007] Preferably, the primary filtration device is provided with a semi-permeable membrane or a nanofiltration membrane, the molecular weight cutoff of the semi-permeable membrane or nanofiltration membrane is a, a<100 Da, and the pressure in the primary filtration device is b, 10≤b≤40 Bar.

[0008] Preferably, the microfiltration device is provided with a microfiltration membrane, the pore size of the microfiltration membrane is c, 0.05≤c≤0.2 μm, and the pressure in the microfiltration device is d, 0.1≤d≤2 Bar.

[0009] Preferably, the first and second ultrafiltration devices are provided with ultrafiltration membranes with a pore size of e, 3k≤e≤20k Da, and the pressure in the first and second ultrafiltration devices is f, 1≤f≤10 Bar.

[0010] Preferably, the nanofiltration device is provided with a nanofiltration membrane, the nanofiltration membrane has a molecular weight cutoff of g, 100≤g≤800 Da, and the pressure in the nanofiltration device is h, 10≤h≤40 Bar.

[0011] Preferably, the reverse osmosis device is provided with a semi-permeable membrane, the molecular weight cutoff of the semi-permeable membrane is i, i < 100 Da, and the pressure in the reverse osmosis device is j, 10 ≤ j ≤ 40 Bar.

[0012] Furthermore, the casein and whey protein production system further includes a spray drying tower, which is connected to the first ultrafiltration device to spray dry the ultrafiltration concentrate, and a first feed pump is also provided between the first ultrafiltration device and the spray drying tower.

[0013] Furthermore, the casein and whey protein production system further includes: a cream storage tank, a first concentrate storage tank, and a second concentrate storage tank. The cream storage tank is connected to the milk fat separator to receive the separated cream. The first concentrate storage tank is connected to the second ultrafiltration device to receive the ultrafiltration concentrate. The second concentrate storage tank is connected to the nanofiltration device to receive the filtered concentrate.

[0014] Furthermore, the casein and whey protein production system further includes: a third concentrate storage tank and a second dialysate storage tank, wherein the third concentrate storage tank is connected to the reverse osmosis unit to receive the concentrate after reverse osmosis.

[0015] The second dialysate storage tank is connected to the reverse osmosis unit and the primary filtration unit respectively to receive the dialysate after reverse osmosis and the dialysate after primary filtration. The second dialysate storage tank is also connected to the microfiltration unit and the second ultrafiltration unit respectively to supply washing water to the microfiltration unit and the ultrafiltration unit respectively.

[0016] A second feed pump is provided between the primary filtration device and the second dialysate storage tank, a third feed pump is provided between the reverse osmosis device and the second dialysate storage tank, and a fourth feed pump is provided between the second dialysate storage tank and the microfiltration device and the second ultrafiltration device.

[0017] After adopting the above technical solution, the present invention has the following effects: This invention separates raw milk into cream and skim milk in one step through processes such as fat separation, nanofiltration, microfiltration, ultrafiltration, and reverse osmosis, and gradually extracts major nutrients such as casein and whey protein. At the same time, byproducts such as lactose are obtained. The lactose is concentrated by nanofiltration, and the dialysate from the reverse osmosis process is recycled for use in the front-end microfiltration and ultrafiltration washing water, which reduces the load of external water, lowers production costs, and reduces wastewater discharge. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the system of this utility model.

[0019] Figure 2 This is a process flow diagram of the present invention.

[0020] Main component symbols: 1: Raw material storage tank; 2: Pasteurizer; 3: Milk fat separator; 4: Cream storage tank; 5: Primary filter; 6: Microfiltration device; 7: First ultrafiltration device; 8: Spray drying tower; 9: Second ultrafiltration device; 10: First concentrate storage tank; 11: First dialysate storage tank; 12: Nanofiltration device; 13: Second concentrate storage tank; 14: Reverse osmosis device; 15: Third concentrate storage tank; 16: Second dialysate storage tank; 17: First feed pump; 18: Second feed pump; 19: Third feed pump; 20: Fourth feed pump. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0022] like Figure 1 As shown, this utility model discloses a casein and whey protein production system, including: a raw material storage tank 1, a pasteurizer 2, a milk fat separator 3, a primary filter 5, a microfiltration device 6, a first ultrafiltration device 7, a second ultrafiltration device 9, a first dialysate storage tank 11, a nanofiltration device 12, and a reverse osmosis device 14.

[0023] The raw material storage tank 1, pasteurizer 2, milk fat separator 3, primary filter 5 and microfiltration device 6 are connected in sequence to separate skim milk. The first ultrafiltration device 7 and the second ultrafiltration device 9 are respectively connected to the microfiltration device 6 to extract casein and whey protein respectively.

[0024] In this embodiment, the primary filtration device 5 is equipped with a semi-permeable membrane with a molecular weight cutoff of a, where a < 100 Da, and the pressure in the primary filtration device 5 is b, where 10 ≤ b ≤ 40 Bar. In some other embodiments, a nanofiltration membrane with the same molecular weight cutoff is used instead of the semi-permeable membrane in the primary filtration device.

[0025] The microfiltration device 6 is equipped with a microfiltration membrane with a pore size of c, where 0.05 ≤ c ≤ 0.2 μm, and the pressure in the microfiltration device 6 is d, where 0.1 ≤ d ≤ 2 Bar. The microfiltration membrane is typically made of polyethersulfone (PES), but in some other embodiments, it may also be made of polyvinylidene fluoride (PVDF) or a ceramic membrane.

[0026] The first ultrafiltration device 7 and the second ultrafiltration device 9 are equipped with ultrafiltration membranes with a pore size of e, where 3k≤e≤20kDa, and the pressure in the first ultrafiltration device 7 and the second ultrafiltration device 9 is f, where 1≤f≤10 Bar.

[0027] In this embodiment, the casein and whey protein production system further includes: a cream storage tank 4, a first concentrate storage tank 10, and a spray drying tower 8.

[0028] The cream storage tank 4 is connected to the cream separator 3 to receive the separated cream.

[0029] The first concentrate storage tank 10 is connected to the second ultrafiltration device 9 to receive the concentrate after ultrafiltration. After subsequent processing, the concentrate in the first concentrate storage tank 10 yields WPC whey protein.

[0030] The spray drying tower 8 is connected to the first ultrafiltration device 7 to spray dry the concentrated liquid after ultrafiltration to obtain MCC casein. A first feed pump 17 is also provided between the first ultrafiltration device 7 and the spray drying tower 8.

[0031] Secondly, the first dialysate storage tank 11 is connected to the first ultrafiltration device 7 and the second ultrafiltration device 9 respectively to receive the ultrafiltration dialysate and adjust the pH. The first dialysate storage tank 11 is connected to the nanofiltration device 12 and the reverse osmosis device 14 in sequence to separate other by-products.

[0032] In this embodiment, the nanofiltration device 12 is equipped with a nanofiltration membrane with a molecular weight cutoff of g, where 100 ≤ g ≤ 800 Da, and the pressure in the nanofiltration device 12 is h, where 10 ≤ h ≤ 40 Bar. The reverse osmosis device 14 is equipped with a semipermeable membrane with a molecular weight cutoff of i, where i < 100 Da, and the pressure in the reverse osmosis device 14 is j, where 10 ≤ j ≤ 40 Bar.

[0033] Furthermore, the primary filtration device 5 and the reverse osmosis device 14 are connected to the microfiltration device 6 and the second ultrafiltration device 9, and the dialysate from the primary filtration device 5 and the reverse osmosis device 14 is used as the washing water for the microfiltration device 6 and the second ultrafiltration device 9.

[0034] In addition, in this embodiment, the casein and whey protein production system further includes: a second concentrate storage tank 13, a third concentrate storage tank 15, and a second dialysate storage tank 16.

[0035] The second concentrate storage tank 13 is connected to the nanofiltration device 12 to receive the filtered concentrate. After subsequent processing, the concentrate in the second concentrate storage tank 13 yields lactose.

[0036] The third concentrate storage tank 15 is connected to the reverse osmosis unit 14 to receive the concentrate after reverse osmosis. The concentrate in the third concentrate storage tank 15 is usually not subjected to further processing and is directly collected and discharged as wastewater.

[0037] The second dialysate storage tank 16 is connected to the reverse osmosis unit 14 and the primary filter unit 5 respectively to receive the dialysate after reverse osmosis and the dialysate after primary filtration. The second dialysate storage tank 16 is also connected to the microfiltration unit 6 and the second ultrafiltration unit 9 respectively to supply washing water to the microfiltration unit 6 and the second ultrafiltration unit 9 respectively.

[0038] A second feed pump 18 is provided between the primary filtration device 5 and the second dialysate storage tank 16, a third feed pump 19 is provided between the reverse osmosis device 14 and the second dialysate storage tank 16, and a fourth feed pump 20 is provided between the second dialysate storage tank 16 and the microfiltration device 6 and the second ultrafiltration device 9.

[0039] Combination Figure 2 As shown, the process for producing casein and whey protein using this invention includes the following steps: S1. Separation of Skim Milk: Raw milk from raw material storage tank 1 is sequentially passed through pasteurizer 2 and milk fat separator 3 to separate the raw milk into cream and skim milk. At this point, the fat content of the skim milk is 0.06% (generally below 0.1%). During this process, the temperature of pasteurizer 2 is around 75 ℃ (generally 70-80 ℃ is sufficient), and the pasteurization time is approximately 15-20 seconds. The table below shows the component content of raw milk after pasteurization and milk fat separation:

[0040] S2. Obtaining Standardized Skim Milk: The skim milk separated in step S1 is passed through a primary filtration device 5 and concentrated under a pressure of 30 Bar using a semi-permeable membrane (or nanofiltration membrane) with a molecular weight cutoff of 80 Da, to obtain standardized skim milk with a fat content of 9% or higher. The following table shows the component contents of the standardized skim milk:

[0041] S3. Separation of Casein and Whey Protein: The standardized skim milk after initial filtration in step S2 is passed through a microfiltration device 6 and a 0.1 μm microfiltration membrane (PES) under a pressure of 1 Bar to separate casein and whey protein. During this process, water is added for washing, with a water ratio of 1:1 (generally, a water ratio of 0-2:1 is sufficient). The table below shows the component content of the concentrated solution and dialysate after microfiltration:

[0042] S4. Concentration of Casein: The microfiltration concentrate separated in step S3 is passed through the first ultrafiltration device 7 at a pressure of 5 Bar through an ultrafiltration membrane with a pore size of 5 kDa to concentrate the casein, increasing the solids content to 18% (generally, an increase to 12-20% is sufficient). The table below shows the component contents of the casein ultrafiltration concentrate:

[0043] After ultrafiltration, the casein ultrafiltration concentrate can be dried using a spray drying tower.

[0044] S5. Concentration of whey protein: The microfiltration dialysate separated in step S3 is passed through a second ultrafiltration device 9 at a pressure of 5 Bar through an ultrafiltration membrane with a pore size of 5 kDa to concentrate the whey protein. During this process, water is added for washing, with a water ratio of 0.15 (generally, a water ratio of 0-2 times is sufficient). The table below shows the component content of the whey protein concentrate after ultrafiltration:

[0045] After ultrafiltration, the whey protein ultrafiltration concentrate can be processed through subsequent steps to obtain whey protein.

[0046] S6. pH adjustment of ultrafiltration dialysis solution: Collect the ultrafiltration dialysis solution from steps S4 and S5, and adjust the pH to 6.3 using citric acid (or lactic acid) (generally, pH 5.8-6.5 is sufficient).

[0047] S7. Concentration of Ultrafiltration Dialysate: The ultrafiltration dialysate, after pH adjustment in step S6, is concentrated by passing it through nanofiltration device 12 at a pressure of 25 Bar through a nanofiltration membrane with a molecular weight cutoff of 450 Da. The following table shows the component contents of the nanofiltration concentrate:

[0048] After nanofiltration, the concentrated nanofiltration solution can be processed to obtain lactose.

[0049] S8. Treatment and Recovery of Dialysate: Since the dialysate after nanofiltration in step S7 is a brine with a high salt content, further treatment is required. The nanofiltration dialysate from step S7 is passed through a reverse osmosis device 14 at a pressure of 30 Bar through a semi-permeable membrane with a molecular weight cutoff of 80 Da to recover 50-80% of the water. This water is then collected together with the dialysate from step S2 and subsequently fed into steps S3 and S5 as wash water.

[0050] The above description is only a preferred embodiment of the present utility model. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. A casein and whey protein production system, characterized in that, include: Raw material storage tank, pasteurizer, milk fat separator, primary filter, microfiltration device, first ultrafiltration device, second ultrafiltration device and first dialysis liquid storage tank, nanofiltration device and reverse osmosis device; The raw material storage tank, pasteurizer, milk fat separator, primary filter and microfiltration device are connected in sequence to separate skim milk. The first ultrafiltration device and the second ultrafiltration device are respectively connected to the microfiltration device to extract casein and whey protein respectively. The first dialysate storage tank is connected to the first ultrafiltration device and the second ultrafiltration device respectively to receive the ultrafiltration dialysate and adjust the pH. The first dialysate storage tank is connected to the nanofiltration device and the reverse osmosis device in sequence to separate other by-products. Furthermore, the primary filtration device and the reverse osmosis device are connected to the microfiltration device and the second ultrafiltration device, and the dialysate of the primary filtration device and the reverse osmosis device is used as the washing water for the microfiltration device and the second ultrafiltration device.

2. The casein and whey protein production system as described in claim 1, characterized in that: The primary filtration device is equipped with a semi-permeable membrane or a nanofiltration membrane, the molecular weight cutoff of the semi-permeable membrane or nanofiltration membrane is a, a<100 Da, and the pressure in the primary filtration device is b, 10≤b≤40 Bar.

3. The casein and whey protein production system as described in claim 1, characterized in that: The microfiltration device is equipped with a microfiltration membrane with a pore size of c, where 0.05 ≤ c ≤ 0.2 μm, and the pressure in the microfiltration device is d, where 0.1 ≤ d ≤ 2 Bar.

4. The casein and whey protein production system as described in claim 1, characterized in that: The first and second ultrafiltration devices are equipped with ultrafiltration membranes with a pore size of e, where 3k≤e≤20kDa, and the pressure in the first and second ultrafiltration devices is f, where 1≤f≤10 Bar.

5. The casein and whey protein production system as described in claim 1, characterized in that: The nanofiltration device is equipped with a nanofiltration membrane, the molecular weight cutoff of the nanofiltration membrane is g, 100≤g≤800 Da, and the pressure in the nanofiltration device is h, 10≤h≤40 Bar.

6. The casein and whey protein production system as described in claim 1, characterized in that: The reverse osmosis device is equipped with a semi-permeable membrane, the molecular weight cutoff of the semi-permeable membrane is i, i < 100 Da, and the pressure in the reverse osmosis device is j, 10 ≤ j ≤ 40 Bar.

7. A casein and whey protein production system according to any one of claims 1-6, characterized in that: Also includes: A spray drying tower is connected to the first ultrafiltration device to spray dry the concentrated liquid after ultrafiltration, and a first feed pump is also provided between the first ultrafiltration device and the spray drying tower.

8. A casein and whey protein production system according to any one of claims 1-6, characterized in that: Also includes: Cream storage tank, first concentrate storage tank, and second concentrate storage tank. The cream storage tank is connected to the cream separator to receive the separated cream; The first concentrate storage tank is connected to the second ultrafiltration device to receive the concentrate after ultrafiltration; The second concentrate storage tank is connected to the nanofiltration device to receive the filtered concentrate.

9. A casein and whey protein production system according to any one of claims 1-6, characterized in that: Also includes: The third concentrate storage tank is connected to the reverse osmosis unit to receive the concentrate after reverse osmosis. The second dialysate storage tank is connected to the reverse osmosis unit and the primary filtration unit respectively to receive the dialysate after reverse osmosis and the dialysate after primary filtration. The second dialysate storage tank is also connected to the microfiltration unit and the second ultrafiltration unit respectively to supply washing water to the microfiltration unit and the ultrafiltration unit respectively.

10. A casein and whey protein production system as claimed in claim 9, characterised in that: A second feed pump is provided between the primary filtration device and the second dialysate storage tank, a third feed pump is provided between the reverse osmosis device and the second dialysate storage tank, and a fourth feed pump is provided between the second dialysate storage tank and the microfiltration device and the second ultrafiltration device.

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