High-protein milk and preparation method thereof

Abstract

The present invention relates to the field of food technology, and in particular to high-protein milk and a preparation method thereof, comprising: sequentially subjecting raw milk to milk purification, fat standardization, primary homogenization, pasteurization, concentration, secondary homogenization, protein retention, ultra-high temperature sterilization, and aseptic filling; fat standardization includes adjusting the fat-to-protein ratio in the raw milk to between 1.11:1 and 1.17:1; and concentration includes concentrating the protein content of the pasteurized milk to above 3.6g / 100g. By adjusting the raw milk fat-to-protein ratio within a specific range during the milk purification and separation process, the present invention effectively addresses the issues of product stability and inconsistent taste of high-protein milk. Furthermore, by optimizing process parameters such as the primary homogenization, secondary homogenization, and ultra-high temperature sterilization processes, the use of food additives can be avoided while effectively ensuring a uniform product taste and system stability.

Description

Technical Field

[0001] The present invention relates to the field of food technology, in particular to high-protein milk and a preparation method thereof. Background Art

[0002] As consumers' demand for food nutrition increases, high-protein milk is widely favored by the market due to its nutritional value.

[0003] Currently, the processing technology for producing high-protein products primarily relies on milk concentration and sterilization. The specific process includes: raw milk inspection, milk purification, pasteurization, concentration, homogenization, ultra-high temperature sterilization (UHT), and aseptic filling. Specifically, in the raw milk inspection phase, raw milk is tested in accordance with GB 19301, the National Food Safety Standard for Raw Milk. In the milk purification phase, a milk purifier effectively removes impurities from the raw milk at 0-6°C. In the pasteurization phase, the raw milk is sterilized at 75°C for 15 seconds to produce pasteurized milk. In the concentration phase, RO membrane technology is used to concentrate the pasteurized milk to achieve the desired protein content. In the homogenization phase, the pasteurized milk is homogenized at a pressure of 200-240 bar (with a secondary pressure of 40-50 bar) and a temperature of 50-90°C. In the ultra-high temperature sterilization phase, the pasteurized milk is sterilized at 135-140°C for 4-6 seconds. Finally, in the aseptic filling phase, the product is filled using an aseptic filling machine. However, existing technologies cannot guarantee consistent taste and physical and chemical properties, and are difficult to maintain stable throughout the shelf life. Furthermore, the fat and protein content of raw milk (the raw milk) used to produce high-protein milk fluctuates depending on factors such as season, region, and cow breed. This not only leads to inconsistent taste and physical and chemical properties, but also affects product stability throughout its shelf life.

[0004] Generally speaking, the higher the protein content and the longer the shelf life of a product, the lower its stability. To improve product stability, the industry often uses thickeners and emulsifiers. This process includes raw milk testing, milk purification, batching, mixing, concentration, homogenization, pasteurization, ultra-high temperature sterilization, and aseptic filling. Specifically, during the batching stage, the raw milk is heated to the optimal dissolution temperature of the thickener and emulsifier before being added and fully dissolved. During the mixing stage, the batched raw milk is thoroughly mixed with the remaining raw milk. While this technology can ensure product stability, there are still issues with taste and consistency in physical and chemical properties. Furthermore, food additives must be identified in the product ingredient list. Clean product ingredients (labeling) are becoming a trend in the food industry.

[0005] Therefore, it is very important to provide a preparation method for high-protein milk based on clean product ingredients and improvements to traditional processing technology to ensure the product stability of high-protein milk. Summary of the Invention

[0006] The present invention provides high-protein milk and a preparation method thereof, which are used to solve the defects of high-protein milk with a protein content of more than 3.6g / 100g in the prior art, such as product instability or failure to meet the clean product label. Based on clean product ingredients and improvements to traditional processing technology, a preparation method of high-protein milk is provided, which can ensure the product stability of high-protein milk.

[0007] Specifically, the present invention provides a method for preparing high-protein milk, which is characterized by comprising: sequentially subjecting raw milk to milk purification, fat standardization, primary homogenization, pasteurization, concentration, secondary homogenization, protein retention, ultra-high temperature sterilization, and aseptic filling;

[0008] The fat standardization includes adjusting the ratio of fat to protein in raw milk to 1.11:1 to 1.17:1;

[0009] The concentration includes concentrating the protein content of the pasteurized milk to above 3.6 g / 100 g.

[0010] Generally, the fat-to-protein ratio of raw milk that has only undergone impurity removal fluctuates between 0.8:1 and 1.9:1. However, studies have found that fluctuations in the fat-to-protein ratio are a major factor causing inconsistent product taste and system instability. The present invention uses fat standardization to adjust the fat-to-protein ratio in raw milk to 1.11:1-1.17:1. Experimental verification has shown that this can effectively ensure product taste consistency and system stability.

[0011] In the present invention, the ratio of fat to protein is adjusted to 1.11:1 to 1.17:1, for example, it can be any value among 1.11:1, 1.12:1, 1.13:1, 1.14:1, 1.15:1, 1.16:1 and 1.17:1, or a range formed between any values.

[0012] According to the method for preparing high-protein milk provided by the present invention, the secondary pressure of the primary homogenization is 25~35 bar.

[0013] In the present invention, the secondary pressure of the primary homogenization is 25~35 bar, for example, it can be any value among 25 bar, 26 bar, 27 bar, 28 bar, 29 bar, 30 bar, 31 bar, 32 bar, 33 bar, 34 bar and 35 bar, or a range formed between any values.

[0014] According to the method for preparing high-protein milk provided by the present invention, the secondary pressure of the secondary homogenization is 25~35 bar.

[0015] In the present invention, the secondary pressure of the secondary homogenization is 25~35 bar, for example, it can be any value among 25 bar, 26 bar, 27 bar, 28 bar, 29 bar, 30 bar, 31 bar, 32 bar, 33 bar, 34 bar and 35 bar, or a range formed between any values.

[0016] Commonly used homogenization secondary pressure (including primary and secondary homogenization): total pressure ≈ 20%. Research has found that the present invention adopts the above-mentioned secondary pressure to obtain the best homogenization effect and effectively promote the stability of the product system.

[0017] According to the method for preparing high-protein milk provided by the present invention, the protein preservation comprises preserving the protein of the milk after the secondary homogenization at a temperature of 85-95°C.

[0018] In the present invention, the protein is maintained at 85-95°C, wherein the temperature can be, for example, any value among 85°C, 86°C, 87°C, 88°C, 89°C, 90°C, 91°C, 92°C, 93°C, 94°C, 95°C or a range formed between any values.

[0019] According to the method for preparing high-protein milk provided by the present invention, the ultra-high temperature sterilization is carried out at 136-138°C.

[0020] Generally, the ultra-high temperature sterilization parameters of the ultra-high temperature sterilization process are set to 135-140° C. The present invention adopts the above range, which is beneficial to the taste and stability of the high-protein milk of the present invention.

[0021] In the present invention, the reaction is carried out at a temperature of 136-138° C., wherein the temperature can be, for example, any value among 136° C., 137° C. and 138° C., or a range formed between any values.

[0022] According to the method for preparing high-protein milk provided by the present invention, the fat standardization adopts a milk separator with fat standardization capability to adjust the ratio of fat and protein.

[0023] The milk purifying separator adopted in the present invention can take into account the functions of milk purification and fat standardization, realizing "one machine with multiple effects".

[0024] According to the method for preparing high-protein milk provided by the present invention, the concentration uses an RO membrane to concentrate the protein content of the pasteurized milk to 3.6-4.5 g / 100 g.

[0025] In the experiment, it was found that if the protein content is greater than 4.5g / 100mL, on the one hand, the acidity of the product will be higher than 18, and on the other hand, the product system will be unstable.

[0026] In the present invention, the protein content is concentrated to 3.6~4.5g / 100g, for example, it can be any value among 3.6g / 100g, 3.7g / 100g, 3.8g / 100g, 3.9g / 100g, 4.0g / 100g, 4.1g / 100g, 4.2g / 100g, 4.3g / 100g, 4.4g / 100g and 4.5g / 100g, or a range formed between any values.

[0027] The method for preparing high-protein milk provided by the present invention comprises the following process steps in sequence: milk separation, cooling and storage, primary homogenization, pasteurization, cooling, concentration, cooling and storage, secondary homogenization, stable maintenance, ultra-high temperature sterilization, cooling, aseptic storage and aseptic filling;

[0028] The clean milk separation includes milk cleaning and the fat standardization.

[0029] The preparation method of the present invention comprises the following specific steps:

[0030] (1) Milk separation: remove impurities from raw milk and perform fat standardization at a temperature of 45-55°C.

[0031] The milk purification and separation process of the present invention is carried out at a temperature of 45-55° C., which can ensure the effects of milk purification and fat separation and minimize the troubleshooting loss of the separator.

[0032] (2) First cooling storage: chilling the fat-standardized raw milk to 0-4°C.

[0033] (3) Primary homogenization: homogenize the raw milk after the first cooling and storage under the conditions of a total homogenization pressure of 100-120 bar and secondary pressure parameters.

[0034] (4) Pasteurization: The raw milk after the primary homogenization is pasteurized to prepare pasteurized milk; the pasteurization temperature is 75° C. and the time is 15 seconds.

[0035] (5) First cooling: cool the pasteurized milk to 1-7°C.

[0036] (6) Concentration: The milk after the first cooling is concentrated using an RO membrane.

[0037] (7) Second cooling storage: Cool the pasteurized milk to 1-7°C.

[0038] (8) Secondary homogenization: The milk after the second cooling storage is homogenized under the following parameters: total pressure of 220-250 bar, secondary pressure, and homogenization temperature of 70-80°C.

[0039] (9) Protein retention: The milk after the secondary homogenization is subjected to protein retention for 60 to 120 seconds.

[0040] (10) Ultra-high temperature sterilization: The milk after the protein is retained is ultra-high temperature sterilized for 4 to 6 seconds.

[0041] (11) Second cooling: Cool the ultra-high temperature sterilized milk to 15-35°C.

[0042] (12) Aseptic storage: The milk after the second cooling step is stored as an aseptic liquid.

[0043] (13) Aseptic filling: The milk after aseptic storage is filled into products.

[0044] Further preferably, the method for preparing high-protein milk of the present invention adopts a continuous production line for production.

[0045] Wherein, the clean milk separation is carried out using a Tetra Pak clean milk separator.

[0046] The first cooling storage is performed using Tetra Pak cold plates.

[0047] The primary homogenization is performed using a Tetra Pak homogenizer.

[0048] The pasteurization is carried out using a pasteurizer from Tetra Pak.

[0049] The first cooling is performed using a Tetra Pak cold plate.

[0050] The concentration adopts Tetra Pak RO membrane (reverse osmosis membrane).

[0051] The second cooling storage is performed using Tetra Pak cold plates.

[0052] The secondary homogenization is performed using a Tetra Pak homogenizer.

[0053] The protein retention is performed using a tubular retention tube.

[0054] The ultra-high temperature sterilization is carried out using a Tetra Pak ultra-high temperature sterilizer.

[0055] The second cooling is performed using a Tetra Pak tubular cooling tube.

[0056] The aseptic storage is carried out using Tetra Pak aseptic tanks.

[0057] The aseptic filling is carried out using a Tetra Pak aseptic filling machine.

[0058] The present invention also provides high-protein milk prepared by the above-mentioned high-protein milk preparation method.

[0059] The high-protein milk provided by the present invention has a protein content of 3.6 g / 100 g or more.

[0060] The present invention provides a high-protein milk and a preparation method thereof, which can effectively solve the problems of product stability and inconsistent taste of high-protein milk by adjusting the ratio of raw milk fat to protein in the milk separation process to control it within a specific range.

[0061] Furthermore, the present invention limits the total homogenization pressure and secondary pressure in the primary homogenization process to promote product system stability while also achieving energy conservation and consumption reduction. In the secondary homogenization process, the total homogenization pressure, secondary pressure, and homogenization temperature are also limited to promote product system stability. During the ultra-high temperature sterilization process, the sterilization temperature range is limited to avoid the use of food additives while effectively ensuring a uniform product taste and system stability. This overall improves upon traditional processing techniques, providing a method for producing high-protein milk based on clean product ingredients. DETAILED DESCRIPTION

[0062] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0063] If no specific techniques or conditions are specified in the examples, the experiments were carried out according to the techniques or conditions described in the literature in the field or according to the product instructions. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased through regular channels.

[0064] All raw milk used in the present invention is inspected and accepted according to the standard "GB 19301 National Food Safety Standard for Raw Milk" and used after passing the inspection. However, in different embodiments and comparative examples, the fat to protein ratio of the raw milk used fluctuates between 0.8:1 and 1.9:1.

[0065] Example 1

[0066] This embodiment provides a method for preparing high-protein milk, the steps of which are as follows:

[0067] (1) Milk separation process: Tetra Pak's milk separator with fat standardization capability is used to remove impurities in raw milk at a temperature of 45°C and adjust the ratio of fat to protein in the raw milk to 1.11:1.

[0068] (2) First cooling and storage process: Use Tetra Pak's cold plate to cool the raw milk after the milk separation process to 2°C.

[0069] (3) Primary homogenization process: Tetra Pak homogenizer is used to homogenize the chilled raw milk under the parameters of a total homogenization pressure of 100 bar and a secondary pressure of 25 bar.

[0070] (4) Pasteurization process: The raw milk after the homogenization process is pasteurized using a Tetra Pak pasteurizer to prepare pasteurized milk; the pasteurization temperature is 75°C and the time is 15 seconds.

[0071] (5) First cooling process: Use Tetra Pak cold plates to cool the pasteurized milk to 1°C.

[0072] (6) Concentration process: The milk after the first cooling process is concentrated using Tetra Pak RO membrane to concentrate its protein content to 3.6g / 100g.

[0073] (7) Second cooling and storage process: Use Tetra Pak cold plates to cool the concentrated milk to 1°C.

[0074] (8) Secondary homogenization process: The milk after the second cooling and storage process was homogenized using a Tetra Pak homogenizer under the following parameters: total pressure of 220 bar, secondary pressure of 25 bar, and homogenization temperature of 70 °C.

[0075] (9) Protein retention process: A tubular retention tube is used to retain the protein of the milk after the secondary homogenization process at 85°C and 60s.

[0076] (10) Ultra-high temperature sterilization process: The milk after the protein retention process is sterilized using Tetra Pak's ultra-high temperature sterilizer at 136°C and 5s.

[0077] (11) Second cooling process: Use Tetra Pak tubular cooling tubes to cool the milk after the ultra-high temperature sterilization process to 15°C.

[0078] (12) Aseptic storage process: Use Tetra Pak aseptic tanks to store the milk after the second cooling process as aseptic liquid.

[0079] (13) Aseptic filling process: Tetra Pak aseptic filling machine is used to fill the milk after the aseptic storage process.

[0080] Example 2

[0081] This embodiment provides a method for preparing high-protein milk, the steps of which are as follows:

[0082] (1) Milk separation process: Tetra Pak's milk separator with fat standardization capability is used to remove impurities in raw milk at a temperature of 50°C and adjust the fat to protein ratio in the raw milk to 1.14:1.

[0083] (2) First cooling and storage process: Use Tetra Pak's cold plate to cool the raw milk after the milk separation process to 3°C.

[0084] (3) Primary homogenization process: Tetra Pak homogenizer is used to homogenize the chilled raw milk under the parameters of a total homogenization pressure of 110 bar and a secondary pressure of 30 bar.

[0085] (4) Pasteurization process: The raw milk after the homogenization process is pasteurized using a Tetra Pak pasteurizer to prepare pasteurized milk; the pasteurization temperature is 75°C and the time is 15 seconds.

[0086] (5) First cooling process: Use Tetra Pak cold plates to cool the pasteurized milk to 4°C.

[0087] (6) Concentration process: The milk after the first cooling process is concentrated using Tetra Pak RO membrane to concentrate its protein content to 4g / 100g.

[0088] (7) Second cooling and storage process: Use Tetra Pak cold plates to cool the concentrated milk to 4°C.

[0089] (8) Secondary homogenization process: The milk after the second cooling and storage process was homogenized using a Tetra Pak homogenizer under the following parameters: total pressure of 235 bar, secondary pressure of 30 bar, and homogenization temperature of 75 °C.

[0090] (9) Protein retention process: A tubular retention tube is used to retain the protein of the milk after the secondary homogenization process under the parameter conditions of 90°C and 90s.

[0091] (10) Ultra-high temperature sterilization process: The milk after the protein retention process is sterilized using Tetra Pak's ultra-high temperature sterilizer at 137°C and 5s.

[0092] (11) Second cooling process: Use Tetra Pak tubular cooling tubes to cool the milk after the ultra-high temperature sterilization process to 25°C.

[0093] (12) Aseptic storage process: Use Tetra Pak aseptic tanks to store the milk after the second cooling process as aseptic liquid.

[0094] (13) Aseptic filling process: Tetra Pak aseptic filling machine is used to fill the milk after the aseptic storage process.

[0095] Example 3

[0096] This embodiment provides a method for preparing high-protein milk, the steps of which are as follows:

[0097] (1) Milk separation process: Tetra Pak's milk separator with fat standardization capability is used to remove impurities in raw milk at a temperature of 55°C and adjust the ratio of fat to protein in the raw milk to 1.17:1.

[0098] (2) First cooling and storage process: Tetra Pak cold plates are used to cool the raw milk after the milk separation process to 4°C.

[0099] (3) Primary homogenization process: Tetra Pak homogenizer is used to homogenize the chilled raw milk under the parameters of a total homogenization pressure of 120 bar and a secondary pressure of 35 bar.

[0100] (4) Pasteurization process: The raw milk after the homogenization process is pasteurized using a Tetra Pak pasteurizer to prepare pasteurized milk; the pasteurization temperature is 75°C and the time is 15 seconds.

[0101] (5) First cooling process: Use Tetra Pak cold plates to cool the pasteurized milk to 7°C.

[0102] (6) Concentration process: The milk after the first cooling process is concentrated using Tetra Pak RO membrane to concentrate its protein content to 4.5g / 100g.

[0103] (7) Second cooling and storage process: Use Tetra Pak cold plates to cool the concentrated milk to 7°C.

[0104] (8) Secondary homogenization process: The milk after the second cooling and storage process was homogenized using a Tetra Pak homogenizer under the following parameters: total pressure of 250 bar, secondary pressure of 35 bar, and homogenization temperature of 80 °C.

[0105] (9) Protein retention process: A tubular retention tube is used to retain the protein of the milk after the secondary homogenization process at 95°C and 120s.

[0106] (10) Ultra-high temperature sterilization process: The milk after the protein retention process is sterilized using Tetra Pak's ultra-high temperature sterilizer at 138°C and 5s.

[0107] (11) Second cooling process: The milk after the ultra-high temperature sterilization process is cooled to 35°C using Tetra Pak tubular cooling tubes.

[0108] (12) Aseptic storage process: Use Tetra Pak aseptic tanks to store the milk after the second cooling process as aseptic liquid.

[0109] (13) Aseptic filling process: Tetra Pak aseptic filling machine is used to fill the milk after the aseptic storage process.

[0110] Example 4

[0111] This embodiment provides a method for preparing high-protein milk, the steps of which are as follows:

[0112] (1) Milk separation process: Tetra Pak's milk separator with fat standardization capability is used to remove impurities in raw milk at a temperature of 55°C and adjust the ratio of fat to protein in the raw milk to 1.17:1.

[0113] (2) First cooling and storage process: Tetra Pak cold plates are used to cool the raw milk after the milk separation process to 4°C.

[0114] (3) Primary homogenization process: Tetra Pak homogenizer is used to homogenize the chilled raw milk under the parameters of a total homogenization pressure of 120 bar and a secondary pressure of 35 bar.

[0115] (4) Pasteurization process: The raw milk after the homogenization process is pasteurized using a Tetra Pak pasteurizer to prepare pasteurized milk; the pasteurization temperature is 75°C and the time is 15 seconds.

[0116] (5) First cooling process: Use Tetra Pak cold plates to cool the pasteurized milk to 7°C.

[0117] (6) Concentration process: The milk after the first cooling process is concentrated using Tetra Pak RO membrane to concentrate its protein content to 3.6g / 100g.

[0118] (7) Second cooling and storage process: Use Tetra Pak cold plates to cool the concentrated milk to 7°C.

[0119] (8) Secondary homogenization process: The milk after the second cooling and storage process was homogenized using a Tetra Pak homogenizer under the following parameters: total pressure of 250 bar, secondary pressure of 35 bar, and homogenization temperature of 80 °C.

[0120] (9) Protein retention process: A tubular retention tube is used to retain the protein of the milk after the secondary homogenization process at 95°C and 120s.

[0121] (10) Ultra-high temperature sterilization process: The milk after the protein retention process is sterilized using Tetra Pak's ultra-high temperature sterilizer at 138°C and 5s.

[0122] (11) Second cooling process: The milk after the ultra-high temperature sterilization process is cooled to 35°C using Tetra Pak tubular cooling tubes.

[0123] (12) Aseptic storage process: Use Tetra Pak aseptic tanks to store the milk after the second cooling process as aseptic liquid.

[0124] (13) Aseptic filling process: Tetra Pak aseptic filling machine is used to fill the milk after the aseptic storage process.

[0125] Example 5

[0126] This embodiment provides a method for preparing high-protein milk, the steps of which are as follows:

[0127] (1) Milk separation process: Tetra Pak's milk separator with fat standardization capability is used to remove impurities in raw milk at a temperature of 45°C and adjust the ratio of fat to protein in the raw milk to 1.11:1.

[0128] (2) First cooling and storage process: Use Tetra Pak's cold plate to cool the raw milk after the milk separation process to 2°C.

[0129] (3) Primary homogenization process: Tetra Pak homogenizer is used to homogenize the chilled raw milk under the parameters of a total homogenization pressure of 100 bar and a secondary pressure of 25 bar.

[0130] (4) Pasteurization process: The raw milk after the homogenization process is pasteurized using a Tetra Pak pasteurizer to prepare pasteurized milk; the pasteurization temperature is 75°C and the time is 15 seconds.

[0131] (5) First cooling process: Use Tetra Pak cold plates to cool the pasteurized milk to 1°C.

[0132] (6) Concentration process: The milk after the first cooling process is concentrated using Tetra Pak RO membrane to concentrate its protein content to 4.5g / 100g.

[0133] (7) Second cooling and storage process: Use Tetra Pak cold plates to cool the concentrated milk to 1°C.

[0134] (8) Secondary homogenization process: The milk after the second cooling and storage process was homogenized using a Tetra Pak homogenizer under the following parameters: total pressure of 220 bar, secondary pressure of 25 bar, and homogenization temperature of 70 °C.

[0135] (9) Protein retention process: A tubular retention tube is used to retain the protein of the milk after the secondary homogenization process at 85°C and 60s.

[0136] (10) Ultra-high temperature sterilization process: The milk after the protein retention process is sterilized using Tetra Pak's ultra-high temperature sterilizer at 136°C and 5s.

[0137] (11) Second cooling process: Use Tetra Pak tubular cooling tubes to cool the milk after the ultra-high temperature sterilization process to 15°C.

[0138] (12) Aseptic storage process: Use Tetra Pak aseptic tanks to store the milk after the second cooling process as aseptic liquid.

[0139] (13) Aseptic filling process: Tetra Pak aseptic filling machine is used to fill the milk after the aseptic storage process.

[0140] Example 6

[0141] This embodiment provides a method for preparing high-protein milk, the steps of which are as follows:

[0142] (1) Milk separation process: Tetra Pak's milk separator with fat standardization capability is used to remove impurities in raw milk at a temperature of 45°C and adjust the ratio of fat to protein in the raw milk to 1.11:1.

[0143] (2) First cooling and storage process: Use Tetra Pak's cold plate to cool the raw milk after the milk separation process to 2°C.

[0144] (3) Primary homogenization process: Tetra Pak homogenizer is used to homogenize the chilled raw milk under the parameters of a total homogenization pressure of 100 bar and a secondary pressure of 25 bar.

[0145] (4) Pasteurization process: The raw milk after the homogenization process is pasteurized using a Tetra Pak pasteurizer to prepare pasteurized milk; the pasteurization temperature is 75°C and the time is 15 seconds.

[0146] (5) First cooling process: Use Tetra Pak cold plates to cool the pasteurized milk to 1°C.

[0147] (6) Concentration process: The milk after the first cooling process is concentrated using Tetra Pak RO membrane to concentrate its protein content to 4g / 100g.

[0148] (7) Second cooling and storage process: Use Tetra Pak cold plates to cool the concentrated milk to 1°C.

[0149] (8) Secondary homogenization process: The milk after the second cooling and storage process was homogenized using a Tetra Pak homogenizer under the following parameters: total pressure of 220 bar, secondary pressure of 25 bar, and homogenization temperature of 70 °C.

[0150] (9) Protein retention process: A tubular retention tube is used to retain the protein of the milk after the secondary homogenization process at 85°C and 60s.

[0151] (10) Ultra-high temperature sterilization process: The milk after the protein retention process is sterilized using Tetra Pak's ultra-high temperature sterilizer at 136°C and 5s.

[0152] (11) Second cooling process: Use Tetra Pak tubular cooling tubes to cool the milk after the ultra-high temperature sterilization process to 15°C.

[0153] (12) Aseptic storage process: Use Tetra Pak aseptic tanks to store the milk after the second cooling process as aseptic liquid.

[0154] (13) Aseptic filling process: Tetra Pak aseptic filling machine is used to fill the milk after the aseptic storage process.

[0155] Example 7

[0156] This embodiment provides a method for preparing high-protein milk, the steps of which are as follows:

[0157] (1) Milk separation process: Tetra Pak's milk separator with fat standardization capability is used to remove impurities in raw milk at a temperature of 54°C and adjust the fat to protein ratio in the raw milk to 1.14:1.

[0158] (2) First cooling and storage process: Use Tetra Pak's cold plate to cool the raw milk after the milk separation process to 3°C.

[0159] (3) Primary homogenization process: Tetra Pak homogenizer is used to homogenize the chilled raw milk under the parameters of a total homogenization pressure of 110 bar and a secondary pressure of 30 bar.

[0160] (4) Pasteurization process: The raw milk after the homogenization process is pasteurized using a Tetra Pak pasteurizer to prepare pasteurized milk; the pasteurization temperature is 75°C and the time is 15 seconds.

[0161] (5) First cooling process: Use Tetra Pak cold plates to cool the pasteurized milk to 4°C.

[0162] (6) Concentration process: The milk after the first cooling process is concentrated using Tetra Pak RO membrane to concentrate its protein content to 4g / 100g.

[0163] (7) Second cooling and storage process: Use Tetra Pak cold plates to cool the concentrated milk to 4°C.

[0164] (8) Secondary homogenization process: The milk after the second cooling and storage process was homogenized using a Tetra Pak homogenizer under the following parameters: total pressure of 235 bar, secondary pressure of 30 bar, and homogenization temperature of 75 °C.

[0165] (9) Protein retention process: A tubular retention tube is used to retain the protein of the milk after the secondary homogenization process under the parameter conditions of 90°C and 90s.

[0166] (10) Ultra-high temperature sterilization process: The milk after the protein retention process is sterilized using Tetra Pak's ultra-high temperature sterilizer at 137°C and 5s.

[0167] (11) Second cooling process: Use Tetra Pak tubular cooling tubes to cool the milk after the ultra-high temperature sterilization process to 25°C.

[0168] (12) Aseptic storage process: Use Tetra Pak aseptic tanks to store the milk after the second cooling process as aseptic liquid.

[0169] (13) Aseptic filling process: Tetra Pak aseptic filling machine is used to fill the milk after the aseptic storage process.

[0170] Comparative Example 1

[0171] This comparative example provides a method for preparing high-protein milk, the steps of which are as follows:

[0172] (1) Milk purification process: Tetra Pak milk purifier is used to remove impurities in raw milk.

[0173] (2) The first cooling and storage process: Tetra Pak cold plates are used to cool the raw milk after the milk purification process to 3°C.

[0174] (3) Mixing process: Heat a portion of raw milk to 75°C, then add carrageenan and monoglyceride and fully dissolve them.

[0175] (4) Mixing process: fully mix the raw milk after mixing with the remaining raw milk.

[0176] (5) Primary homogenization process: Tetra Pak homogenizer is used to homogenize the mixed raw milk under the parameters of a total homogenization pressure of 150 bar and a secondary pressure of 30 bar.

[0177] (6) Pasteurization process: The raw milk after the homogenization process is pasteurized using a Tetra Pak pasteurizer to prepare pasteurized milk; the pasteurization temperature is 75°C and the time is 15 seconds.

[0178] (7) First cooling process: Use Tetra Pak cold plates to cool the pasteurized milk to 4°C.

[0179] (8) Concentration process: The milk after the first cooling process is concentrated using Tetra Pak RO membrane to concentrate its protein content to 3.6g / 100g.

[0180] (9) Second cooling and storage process: Use Tetra Pak cold plates to cool the pasteurized milk to 4°C.

[0181] (10) Secondary homogenization process: The milk after the second cooling and storage process is homogenized using a Tetra Pak homogenizer under the following parameters: total pressure of 235 bar, secondary pressure of 47 bar, and homogenization temperature of 75 °C.

[0182] (11) Protein retention process: A tubular retention tube is used to retain the protein of the milk after the secondary homogenization process at 90°C and 60s.

[0183] (12) Ultra-high temperature sterilization process: The milk after the protein retention process is sterilized using Tetra Pak's ultra-high temperature sterilizer at 137°C and 5s.

[0184] (13) Second cooling process: Use Tetra Pak tubular cooling tubes to cool the milk after the ultra-high temperature sterilization process to 25°C.

[0185] (14) Aseptic storage process: Use Tetra Pak aseptic tanks to store the milk after the second cooling process as aseptic liquid.

[0186] (15) Aseptic filling process: Tetra Pak aseptic filling machine is used to fill the milk after the aseptic storage process.

[0187] Comparative Example 2

[0188] This comparative example is basically the same as Example 1, except that in the milk separation process, the ratio of fat to protein in the raw milk is adjusted to 1.1:1.

[0189] Comparative Example 3

[0190] This comparative example is basically the same as Example 1, except that in the milk separation process, the ratio of fat to protein in the raw milk is adjusted to 1.18:1.

[0191] Comparative Example 4

[0192] This comparative example is basically the same as Example 4, except that in the milk separation process, the ratio of fat to protein in the raw milk is adjusted to 1.18:1.

[0193] Comparative Example 5

[0194] This comparative example is basically the same as Example 3, except that in the milk separation process, the ratio of fat to protein in the raw milk is adjusted to 1.1:1.

[0195] Comparative Example 6

[0196] This comparative example is basically the same as Example 3, except that in the milk separation process, the ratio of fat to protein in the raw milk is adjusted to 1.18:1.

[0197] Comparative Example 7

[0198] This comparative example is basically the same as Example 5, except that in the milk separation process, the ratio of fat to protein in the raw milk is adjusted to 1.18:1.

[0199] Comparative Example 8

[0200] This comparative example is basically the same as Example 1, except that in the primary homogenization process, the secondary pressure is 24 bar.

[0201] Comparative Example 9

[0202] This comparative example is basically the same as Example 1, except that in the secondary homogenization process, the secondary pressure is 24 bar.

[0203] Comparative Example 10

[0204] This comparative example is basically the same as Example 1, except that in the first homogenization process, the secondary pressure is 36 bar.

[0205] Comparative Example 11

[0206] This comparative example is basically the same as Example 1, except that in the secondary homogenization process, the secondary pressure is 36 bar.

[0207] Comparative Example 12

[0208] This comparative example is substantially the same as Example 5, except that in the concentration step, the protein content is concentrated to 4.6 g / 100 g.

[0209] Comparative Example 13

[0210] This comparative example is substantially the same as Example 3, except that the temperature is 84° C. during the protein holding step.

[0211] Comparative Example 14

[0212] This comparative example is substantially the same as Example 3, except that the temperature is 96° C. during the protein holding step.

[0213] Comparative Example 15

[0214] This comparative example is basically the same as Example 1, except that the sterilization temperature is 135° C. in the ultra-high temperature sterilization process.

[0215] Comparative Example 16

[0216] This comparative example is basically the same as Example 1, except that the sterilization temperature is 139° C. in the ultrahigh temperature sterilization process.

[0217] The milk obtained in the above embodiment and comparative example was tested, and the testing method was as follows:

[0218] Product taste test: The difference between the samples prepared in the comparative example and the standard samples was analyzed using the "GB / T12311-2012 Sensory Analysis Method Three-Point Test".

[0219] Product sensory inspection: After the samples are stored at room temperature for 180 days, the sensory requirements of GB25190-2010 "National Food Safety Standard Sterilized Milk" are used for evaluation.

[0220] Among them, the selection of standard samples for taste analysis: Principle ⑴ Collect product data throughout the year, first summarize the product fat and protein data, generate a histogram using Minitab software, and then select samples with the most concentrated fat and protein detection values ​​as standard samples; Principle (2) The protein labeled values ​​of the standard sample and the control sample in the product nutritional ingredient table must be the same.

[0221] The test results are as follows:

[0222]

[0223] It can be seen from the above test results that the present invention can avoid the use of food additives when producing high-protein milk products with a protein content of 3.6g / 100mL~4.5g / 100mL through the above method, while effectively ensuring the uniform taste and stable system of the high-protein milk products.

[0224] The resulting product was analyzed for taste using the "GB / T12311-2012 Sensory Analysis Method Three-Point Test." At the same protein content, the product's taste was not significantly different from the standard sample. The product's stability was analyzed using the sensory requirements of the "National Food Safety Standard for Sterilized Milk" and met the standards. The product also met the acidity requirement of 12-18 as specified in GB25190-2010, "National Food Safety Standard for Sterilized Milk."

[0225] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for preparing high-protein milk, characterized in that: include: The raw milk is sequentially processed through milk purification, fat standardization, primary homogenization, pasteurization, concentration, secondary homogenization, protein retention, ultra-high temperature sterilization, and aseptic filling; The fat standardization includes adjusting the ratio of fat to protein in raw milk to 1.11:1 to 1.17:1; The secondary pressure of the primary homogenization is 25~35bar; The concentration uses an RO membrane to concentrate the protein content of the pasteurized milk to 3.6-4.5 g / 100 g; The secondary pressure of the secondary homogenization is 25~35bar; The protein preservation comprises maintaining the protein of the milk after the secondary homogenization at a temperature of 85-95° C.; The ultra-high temperature sterilization is carried out at 136-138°C.

2. The method for preparing high-protein milk according to claim 1, wherein: The fat standardization uses a milk separator with fat standardization capability to adjust the ratio of fat and protein.

3. The method for preparing high-protein milk according to claim 1 or 2, characterized in that: The process flow includes: milk separation, cooling storage, primary homogenization, pasteurization, cooling, concentration, cooling storage, secondary homogenization, stabilization, ultra-high temperature sterilization, cooling, aseptic storage and aseptic filling. The clean milk separation includes milk cleaning and the fat standardization.

4. High-protein milk obtained by the method for preparing high-protein milk according to any one of claims 1 to 3.

5. The high-protein milk according to claim 4, characterized in that The protein content of the high-protein milk is 3.6-4.5g / 100g.

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