A method for the flocculation clarification and separation of milk minerals from cheese whey

Abstract

The application discloses a method for flocculating and clarifying cheese whey and separating milk minerals, and belongs to the technical field of dairy processing. The method comprises two parts of whey flocculation and clarification and milk mineral separation. The whey is made clear and transparent by flocculation, and then the milk minerals are separated from the flocculation by multiple centrifugal separation, so that the method is simple and easy to implement. The method greatly improves the clarity and transparency of whey, provides great convenience for enterprises to process and utilize whey, can obtain milk minerals and some protein products, effectively utilizes waste, and improves the profit of enterprises.

Description

Technical Field

[0001] This invention belongs to the field of dairy processing technology, specifically relating to a method for cheese whey flocculation clarification and milk mineral separation. Background Technology

[0002] Cheese whey is a yellowish-green byproduct obtained from the coagulation of cow's milk using acid, heat, or concentrated lactase during the production of cheese or casein. It is an opaque liquid with a solids content of 6-6.5%. The whey obtained from the production of hard cheese, semi-hard cheese, soft cheese, and rennet casein is sweet whey, with a pH of 5.9-6.6; the whey obtained from the hydrochloric acid precipitation process for casein production has a pH of 4.3-4.6 and is acidic whey. Currently, most domestic enterprises treat cheese whey wastewater as wastewater before discharging it, which not only pollutes the environment but also wastes a significant amount of resources. Fully utilizing whey for deep processing and product development is of great practical significance for expanding the application areas of whey, extending the dairy processing industry chain, increasing product added value, and enriching the variety of dairy products.

[0003] Milk mineral salts are rich in lactose, protein, and calcium salts, including calcium citrate, calcium phosphate, and ionized calcium. They also contain abundant nutrients such as zinc, phosphorus, protein, immunoglobulins, growth factors, and lactoferrin. Furthermore, their absorption rate is significantly higher than other common calcium sources, reaching 62%–70%, which is 2.5 times that of calcium carbonate and calcium gluconate, 1.75 times that of calcium lactate, and 5.5 times that of shellfish calcium. Consuming milk calcium does not cause bloating, edema, or constipation, making it the best source of calcium for infants.

[0004] Currently, the most effective and widely used method for whey processing is membrane filtration to separate lactose and whey protein. Ultrafiltration concentrates the protein in whey, while nanofiltration separates smaller substances, achieving lactose concentration and the separation of inorganic salts. However, before using membrane separation, the solution needs to have a high permeability and be clear and transparent; otherwise, membrane clogging and fouling can easily occur. In reality, whey still contains impurities such as casein, fat, and calcium phosphate precipitates, accounting for approximately 0.5% to 1% of the total whey, causing turbidity and preventing direct entry into ultrafiltration equipment. Furthermore, existing processes do not utilize these residues; industrially, they are typically treated as waste, resulting in significant resource waste.

[0005] Therefore, achieving clear and transparent whey and effectively utilizing its impurities are urgent problems to be solved. Summary of the Invention

[0006] In order to overcome the shortcomings of the existing technology, the purpose of this invention is to provide a method for cheese whey flocculation clarification and milk mineral separation. This method can clarify whey, separate milk mineral salts from waste, and improve the value of waste.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A method for cheese whey flocculation clarification and milk mineral separation includes the following steps:

[0009] (1) Whey flocculation clarification: The pH of cheese whey was adjusted to 7-7.5 with alkali solution, then calcium chloride was added and stirred evenly. After flocculation at 45-60℃ for 5-20 minutes, centrifugation was performed to obtain clarified whey and water-containing flocculents.

[0010] (2) Separation of milk minerals: The aqueous flocculent obtained in step (1) is first added to distilled water, stirred and centrifuged; the solid 1 obtained by centrifugation is then added to organic reagents, stirred and centrifuged at 30-50℃; the solid 2 obtained by centrifugation is then added to alkaline solution, stirred and centrifuged at 30-50℃ to obtain solid milk minerals and protein clear liquid.

[0011] As a further preferred embodiment of the technical solution of the present invention, the cheese whey liquid mentioned in step (1) is caseous acid whey liquid or cheese sweet whey liquid.

[0012] As a further preferred embodiment of the technical solution of the present invention, the alkaline solution used in step (1) is a sodium hydroxide or calcium hydroxide solution; more preferably, a sodium hydroxide solution with a mass fraction of 1% to 10% or a clear calcium hydroxide solution with a mass fraction of 30% to 40% is used.

[0013] As a further preferred embodiment of the technical solution of the present invention, the mass of calcium chloride added in step (1) is 0.05 to 0.5% of the mass of the whey.

[0014] As a further preferred embodiment of the technical solution of the present invention, the centrifugal separation speed in step (1) is 1000-10000 r / min and the centrifugal separation time is 5-20 min.

[0015] As a further preferred embodiment of the technical solution of the present invention, in step (2), distilled water is added at a solid-liquid ratio (m / v) of 1:2 to 1:20; more preferably, after adding distilled water, the mixture is stirred, centrifuged and washed 1 to 3 times; the centrifugation speed is 1000 to 10000 r / min.

[0016] As a further preferred embodiment of the technical solution of the present invention, the organic reagent in step (2) is ethanol, petroleum ether or n-hexane.

[0017] As a further preferred embodiment of the technical solution of the present invention, in step (2), the organic reagent is added at a solid-liquid ratio (m / v) of 1:1 to 1:10; more preferably, after adding the organic reagent, the mixture is stirred and washed for 10 to 60 minutes, washed 1 to 3 times, and the centrifugation speed is 1000 to 10000 r / min.

[0018] As a further preferred embodiment of the technical solution of the present invention, the alkaline sodium hydroxide solution mentioned in step (2) is used; even more preferably, a sodium hydroxide solution with a pH of 8 to 10 is used.

[0019] As a further preferred embodiment of the technical solution of the present invention, in step (2), the alkaline solution is added at a solid-liquid ratio (m / v) of 1:2 to 1:20; more preferably, after adding the alkaline solution, the mixture is stirred and washed for 10 to 60 minutes, washed 1 to 3 times, and the centrifugation speed is 1000 to 10000 r / min.

[0020] In the above technical solution, after the final centrifugation separation, an alkaline supernatant and a milk mineral precipitate are obtained; the protein content of the alkaline supernatant after drying is greater than 70%; the milk mineral salt content in the precipitate is greater than 25%, of which the ash content is 70% to 75%, the calcium content is 20% to 30%, and the calcium-to-phosphorus ratio is 2:1.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. This invention uses flocculation to make whey clear and transparent, and provides a method for separating milk minerals from the flocs, which greatly improves the clarity and transparency of whey, provides great convenience for enterprises to process and utilize whey, and can obtain milk minerals and some protein products, making waste utilization and improving enterprise profitability.

[0023] 2. The method of this invention is simple and easy to implement, requiring only simple flocculation and centrifugation separation operations; the final whey clarified liquid obtained by this invention has an A... 500 The turbidity is 0.065 to 0.085, which fully meets the standard. At the same time, this invention separates milk minerals from whey, which can be further effectively utilized in the future, making it highly economical and practical. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments; of course, the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0025] Unless otherwise specified, the experimental methods described in the following examples are conventional methods; the reagents and materials described are commercially available unless otherwise specified.

[0026] Example 1

[0027] A method for cheese whey flocculation clarification and milk mineral separation includes the following steps:

[0028] (1) Whey flocculation clarification: Take 1L of caseous whey, adjust the pH to 7 with 4% sodium hydroxide solution, then add 1.6g of calcium chloride, stir evenly, heat to 55℃, keep warm and stand for 15min, then centrifuge at 10000r / min for 5min to obtain clear whey and water-containing flocculents.

[0029] (2) Separation of milk minerals: Add distilled water to the aqueous flocculent obtained in step (1) at a solid-liquid ratio of 1:10, stir evenly, centrifuge at 10000 r / min for 5 min, take out the supernatant and process it with lactose, add ethanol to solid 1 at a solid-liquid ratio of 1:10, stir and wash at 45℃ for 30 min, centrifuge, pour out the supernatant ethanol, add sodium hydroxide solution with pH 10 to solid 2 at a solid-liquid ratio of 1:10, stir at 45℃ for 30 min, centrifuge, and finally dry the supernatant and precipitate.

[0030] A of the whey clarification solution obtained in this embodiment 500 The turbidity was 0.077, which fully met the standard, and the whey protein content was 0.75%. The total mass of the precipitate was 6.3g, and the final separated milk mineral salts were 2.2g, of which the ash content was 72%, the calcium content was 22.59%, and the calcium-to-phosphorus ratio was 2:1. The protein content of the alkaline supernatant after drying was greater than 70%.

[0031] Example 2

[0032] A method for cheese whey flocculation clarification and milk mineral separation includes the following steps:

[0033] (1) Whey flocculation clarification: Take 1L of cheese sweet whey, adjust the pH to 7 with 4% sodium hydroxide solution, then add 1.6g of calcium chloride, stir evenly, heat to 55℃, keep warm and stand for 15min, then centrifuge at 10000r / min for 5min to obtain clear whey and water-containing flocculents.

[0034] (2) Separation of milk minerals: Add distilled water to the aqueous flocculent obtained in step (1) at a solid-liquid ratio of 1:10, stir evenly, centrifuge at 10000 r / min for 5 min, take out the supernatant and process it with lactose, add ethanol to solid 1 at a solid-liquid ratio of 1:10, stir and wash at 45℃ for 30 min, centrifuge, pour out the supernatant ethanol, add sodium hydroxide solution with pH 10 to solid 2 at a solid-liquid ratio of 1:10, stir at 45℃ for 30 min, centrifuge, and finally dry the supernatant and precipitate.

[0035] A of the whey clarification solution obtained in this embodiment 500 The turbidity was 0.082, which fully met the standard, and the whey protein content was 0.63%. The total mass of the precipitate was 6.9g, and the final separated milk mineral salts were 2.7g, of which the ash content was 70%, the calcium content was 20.42%, and the calcium-to-phosphorus ratio was 2:1. The protein content of the alkaline supernatant after drying was greater than 70%.

[0036] Example 3

[0037] A method for cheese whey flocculation clarification and milk mineral separation includes the following steps:

[0038] (1) Whey flocculation clarification: Take 1L of caseous whey, adjust the pH to 7 with 40% calcium hydroxide supernatant, then add 0.5g of calcium chloride, stir evenly, heat to 55℃, keep warm and stand for 15min, then centrifuge at 10000r / min for 5min to obtain clear whey and water-containing flocculents.

[0039] (2) Separation of milk minerals: Add distilled water to the aqueous flocculent obtained in step (1) at a solid-liquid ratio of 1:10, stir evenly, centrifuge at 10000 r / min for 5 min, take out the supernatant and process it with lactose, add ethanol to solid 1 at a solid-liquid ratio of 1:10, stir and wash at 45℃ for 30 min, centrifuge, pour out the supernatant ethanol, add sodium hydroxide solution with pH 10 to solid 2 at a solid-liquid ratio of 1:10, stir at 45℃ for 30 min, centrifuge, and finally dry the supernatant and precipitate.

[0040] A of the whey clarification solution obtained in this embodiment 500 The turbidity was 0.069, which fully met the standard, and the whey protein content was 0.68%. The total mass of the precipitate was 7.4g, and the final separated milk mineral salts were 2.8g, of which the ash content was 72%, the calcium content was 23.89%, and the calcium-to-phosphorus ratio was 2:1. The protein content of the alkaline supernatant after drying was greater than 75%.

[0041] Example 4

[0042] A method for cheese whey flocculation clarification and milk mineral separation includes the following steps:

[0043] (1) Whey flocculation clarification: Take 1L of caseous whey, adjust the pH to 7 with 4% sodium hydroxide solution, then add 1.6g of calcium chloride, stir evenly, heat to 55℃, keep warm and stand for 15min, then centrifuge at 10000r / min for 5min to obtain clear whey and water-containing flocculents.

[0044] (2) Separation of milk minerals: Add distilled water to the aqueous flocculent obtained in step (1) at a solid-liquid ratio of 1:10, stir evenly, centrifuge at 10000 r / min for 5 min, take out the supernatant and process it with lactose, and centrifuge and wash the solid once more according to the above steps to obtain solid 1. Add ethanol at a solid-liquid ratio of 1:10, stir and wash at 45℃ for 30 min, centrifuge, pour off the supernatant ethanol, and wash once more with ethanol to obtain solid 2. Add sodium hydroxide solution with pH 12 at a solid-liquid ratio of 1:10, stir at 45℃ for 30 min, centrifuge, wash once more with alkaline solution, and finally dry the supernatant and precipitate.

[0045] A of the whey clarification solution obtained in this embodiment 500 The turbidity was 0.077, which fully met the standard, and the whey protein content was 0.75%. The total mass of the precipitate was 6.3g, and the final separated milk mineral salt was 1.9g, of which the ash content was 76%, the calcium content was 25.69%, and the calcium-to-phosphorus ratio was 2:1. The protein content of the alkaline supernatant after drying was greater than 80%.

[0046] Example 5

[0047] A method for cheese whey flocculation clarification and milk mineral separation includes the following steps:

[0048] (1) Whey flocculation clarification: Take 1L of caseous whey, adjust the pH to 7 with 4% sodium hydroxide solution, then add 1.6g of calcium chloride, stir evenly, heat to 55℃, keep warm and stand for 15min, then centrifuge at 10000r / min for 5min to obtain clear whey and water-containing flocculents.

[0049] (2) Separation of milk minerals: Add distilled water to the aqueous flocculent obtained in step (1) at a solid-liquid ratio of 1:10, stir evenly, centrifuge at 10000 r / min for 5 min, take out the supernatant and process it with lactose, and centrifuge and wash the solid once more according to the above steps to obtain solid 1. Add n-hexane at a solid-liquid ratio of 1:10, stir and wash at 45℃ for 30 min, centrifuge, pour out the supernatant to obtain solid 2. Add sodium hydroxide solution with pH 12 at a solid-liquid ratio of 1:10, stir at 45℃ for 30 min, centrifuge, repeat the alkaline washing once, and finally dry the supernatant and precipitate.

[0050] A of the whey clarification solution obtained in this embodiment 500 The turbidity was 0.077, which fully met the standard, and the whey protein content was 0.75%. The total mass of the precipitate was 6.3g, and the final separated milk mineral salts were 1.6g, of which the ash content was 77%, the calcium content was 24.69%, and the calcium-to-phosphorus ratio was 2:1. The protein content of the alkaline supernatant after drying was greater than 75%.

[0051] Finally, it should be noted that the above embodiments do not limit the present invention in any way. Those skilled in the art can make modifications and improvements based on the present invention. Therefore, any modifications or improvements made without departing from the spirit of the present invention are within the scope of protection claimed by the present invention.

Claims

1. A method for cheese whey flocculation clarification and milk mineral separation, characterized in that, Includes the following steps: (1) Whey flocculation clarification: The pH of cheese whey was adjusted to 7~7.5 with alkali solution, then calcium chloride was added and stirred evenly. After flocculation at 45~60℃ for 5~20 min, centrifugation was performed to obtain clear whey and water-containing flocculents. (2) Separation of milk minerals: The aqueous flocculent obtained in step (1) is first added to distilled water, stirred and centrifuged; the solid 1 obtained by centrifugation is then added to organic reagent, stirred and centrifuged at 30~50℃; the solid 2 obtained by centrifugation is then added to alkaline solution, stirred and centrifuged at 30~50℃ to obtain solid milk minerals and protein clear liquid; Wherein, the cheese whey liquid mentioned in step (1) is caseous acid whey liquid or cheese sweet whey liquid; In step (1), the mass of calcium chloride added is 0.05 to 0.5% of the mass of the whey.

2. The method for cheese whey flocculation clarification and milk mineral separation according to claim 1, characterized in that, The alkaline solution used in step (1) is a sodium hydroxide or calcium hydroxide solution.

3. The method for cheese whey flocculation clarification and milk mineral separation according to claim 1, characterized in that, In step (1), the centrifugation speed is 1000~10000 r / min and the centrifugation time is 5~20 min.

4. The method for cheese whey flocculation clarification and milk mineral separation according to claim 1, characterized in that, In step (2), distilled water is added at a solid-liquid ratio of 1:2 to 1:

20.

5. The method for cheese whey flocculation clarification and milk mineral separation according to claim 1, characterized in that, The organic reagent mentioned in step (2) is ethanol, petroleum ether or n-hexane.

6. The method for cheese whey flocculation clarification and milk mineral separation according to claim 5, characterized in that, In step (2), the organic reagents are added at a solid-liquid ratio of 1:1 to 1:

10.

7. The method for cheese whey flocculation clarification and milk mineral separation according to claim 1, characterized in that, The alkaline sodium hydroxide solution mentioned in step (2).

8. The method for cheese whey flocculation clarification and milk mineral separation according to claim 7, characterized in that, In step (2), the alkaline solution is added at a solid-liquid ratio of 1:2 to 1:20.