A lactose-free, low-fat, high-protein milk and its preparation method

Abstract

This invention discloses a lactose-free, low-fat, high-protein milk and its preparation method, comprising the following raw materials by mass percentage: skimmed raw milk, hydrolyzed whey protein, light cream, medium-chain triglycerides, lactase, stabilizer, and water to a final volume of 100%. The preparation method includes the following steps: (1) mixing hydrolyzed whey protein, light cream, medium-chain triglycerides, skimmed raw milk, stabilizer, and water to obtain liquid A; (2) pasteurizing liquid A to obtain liquid B; (3) cooling liquid B, adding lactase, and stirring while maintaining the temperature to obtain liquid C; (4) homogenizing liquid C, sterilizing, cooling, and filling to obtain the final product. This invention adds hydrolyzed whey protein to skimmed raw milk, meeting the special needs of athletes and fitness enthusiasts for whey protein, and solving the problem that whey protein is not resistant to UHT high-temperature sterilization and easily generates bubbles during production, thus achieving room-temperature preservation.

Description

Technical Field

[0001] This invention relates to the technical field of dairy product processing, specifically to a lactose-free, low-fat, high-protein milk and its preparation method. Background Technology

[0002] With the improvement of people's living standards, the strengthening of health awareness, and the deepening of health concepts, exercise and fitness are becoming increasingly popular. The "2017 China Marathon Annual Work Report" shows that China held 1,102 large-scale marathons in 2017, compared to only 22 in 2011, a 50-fold increase in seven years. The number of participants in Chinese marathons increased from 2.8 million in 2016 to 4.98 million, a growth of 77.9%. Furthermore, the "National Fitness Program (2016-2020)" clearly states that by 2020, public awareness of physical fitness will be generally enhanced, the number of people participating in physical exercise will increase significantly, the number of people participating in physical exercise at least once a week will reach 700 million, and the number of people regularly participating in physical exercise will reach 435 million.

[0003] Most fitness activities involve moderate-intensity exercise, and post-exercise fatigue can affect residents' enthusiasm for exercise and reduce their athletic performance. Therefore, the market for sports nutrition products targeting exercise fatigue is expected to grow significantly. Currently, most sports drinks on the Chinese market focus on replenishing energy, vitamins, water, and electrolytes, lacking ready-to-drink products that supplement high-quality protein. Existing research indicates that 20-25g of high-quality protein daily is particularly suitable for post-exercise recovery. Protein replenishes the energy supply to skeletal muscles, enhancing their adaptability to exercise and restoring their function. It also promotes the uptake of amino acids by muscles, improves protein metabolism, leads to muscle growth, facilitates the reduction of body fat, and alleviates central nervous system fatigue.

[0004] Currently, lactose-free, low-fat, high-protein milk using whey protein has the problem that the system is not resistant to UHT treatment to achieve room temperature storage, and whey protein is prone to generating bubbles, which can easily lead to production and filling problems. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a lactose-free, low-fat, high-protein milk and its preparation method. This method overcomes the problem that whey protein is not resistant to UHT treatment and that it is not easy to generate bubbles during the production process. The resulting milk has a protein content of 8-10% and a good taste.

[0006] Specifically, on the one hand, a method for preparing lactose-free, low-fat, high-protein milk includes the following raw materials by weight percentage: 80-85% skim raw milk, 6.32-8.38% hydrolyzed whey protein, 0.80-1.00% light cream, 0.80-1.10% medium-chain triglycerides, 0.06-0.08% lactase, 0.16-0.20% stabilizer, and water to 100%;

[0007] Its preparation method includes the following steps:

[0008] (1) Mix hydrolyzed whey protein, light cream, medium-chain triglycerides, skimmed raw milk, stabilizer and water to obtain liquid A;

[0009] (2) Pasteurize liquid A to obtain liquid B;

[0010] (3) Cool the solution B, add lactase, keep warm and stir to obtain solution C;

[0011] (4) Homogenize liquid C, sterilize, cool, and fill to obtain the final product.

[0012] Furthermore, the hydrolyzed whey protein contains ≥90% protein.

[0013] Furthermore, the stabilizer is composed of soybean lecithin and sodium stearoyl lactylate in a mass ratio of 4:5 to 5:4.

[0014] Furthermore, the enzyme activity of the lactase is ≥5000 NLI / g.

[0015] Furthermore, in step (1), the mixing is a stirring mixture, the mixing temperature is 50-60℃, and the mixing time is 10-20min.

[0016] Furthermore, in step (2), the pasteurization temperature is 85-95℃ and the time is 15-20s.

[0017] Furthermore, in step (3), the heat preservation and stirring time is 60-90 min, and the stirring rate is 90-120 r / min.

[0018] Furthermore, in step (4), the homogenization temperature is 60-70℃ and the pressure is 18-22MPa.

[0019] Furthermore, in step (4), the sterilization is ultra-high temperature sterilization, with a sterilization temperature of 135-140℃ and a sterilization time of 4-6s.

[0020] Secondly, the present invention also provides lactose-free, low-fat, high-protein milk prepared by the aforementioned method.

[0021] The beneficial effects of this invention are as follows:

[0022] (1) The lactose-free, low-fat, high-protein milk prepared by this invention has a protein content of 8.0-10%, a lactose content of ≤0.3%, and a fat content of ≤1.5%, which solves the problem of the prevalence of lactose intolerance among the Chinese population, the concerns of athletes and fitness enthusiasts about fat, and the need of athletes and fitness enthusiasts for 20-25g of high-quality protein per day.

[0023] (2) This invention adds hydrolyzed whey protein to skimmed raw milk, which meets the special needs of sports and fitness people for whey protein, and solves the problem that whey protein is not resistant to UHT high temperature sterilization and is prone to producing bubbles during the production process, thus achieving the effect of room temperature storage. Detailed Implementation

[0024] To more clearly illustrate the technical solution of the present invention, the following will further describe the technical solution of the present invention in conjunction with specific embodiments:

[0025] In one specific embodiment, a method for preparing lactose-free, low-fat, high-protein milk is provided, comprising the following raw materials by weight percentage: 80-85% skim raw milk, 6.32-8.38% hydrolyzed whey protein, 0.80-1.00% light cream, 0.80-1.10% medium-chain triglycerides, 0.06-0.08% lactase, 0.16-0.20% stabilizer, and water to a final volume of 100%.

[0026] Its preparation method includes the following steps:

[0027] (1) Mix hydrolyzed whey protein, light cream, medium-chain triglycerides, skimmed raw milk, stabilizer and water to obtain liquid A;

[0028] (2) Pasteurize liquid A to obtain liquid B;

[0029] (3) Cool the solution B, add lactase, keep warm and stir to obtain solution C;

[0030] (4) Homogenize liquid C, sterilize, cool, and fill to obtain the final product.

[0031] This invention optimizes the formulation and preparation process of raw materials, and solves the problems of whey protein being intolerant to UHT high-temperature sterilization and the easy generation of bubbles during the production process that prevents production by adding hydrolyzed whey protein and medium-chain triglycerides, thereby achieving the effect of room temperature storage.

[0032] In this invention, the hydrolyzed whey protein is partially hydrolyzed whey protein with a protein content of ≥90%. The light cream has a fat content of ≥40%; the percentages are by weight. The medium-chain triglycerides are preferably derived from coconut oil. The water is conventional in the art, and preferably softened water.

[0033] The hydrolyzed whey protein preferred in this invention has the function of supplementing protein. Through repeated experiments, it has been found that only hydrolyzed whey protein can withstand high-temperature processing under neutral conditions. The preferred medium-chain triglycerides are functional fats that can be rapidly digested and absorbed in the body, providing a quick energy supply.

[0034] In this invention, the stabilizer comprises soybean lecithin and sodium stearoyl lactylate in a mass ratio of 4-5:4-5, with the preferred mass ratio of soybean lecithin to sodium stearoyl lactylate being 1:1. Soybean lecithin and sodium stearoyl lactylate act as emulsifiers and defoamers. Soybean lecithin and sodium stearoyl lactylate can maintain the homogeneity and stability of the system; furthermore, in systems with high protein content, bubbles are easily generated during production processes such as stirring and filling. Adding soybean lecithin and sodium stearoyl lactylate can quickly defoam, ensuring normal production.

[0035] In this invention, the lactase is conventional in the art, and preferably has an enzyme activity ≥5000 NLI / g.

[0036] Preferably, the raw material may further include flavoring substances. The flavoring substances are conventional flavoring substances in the dairy industry, preferably selected from one or more of flavorings, fragrances, and taste improvers, and more preferably milk flavorings. The amount of the flavoring substances used is conventional in the dairy industry, not exceeding the amount of conventional food additives, preferably 0.06-0.10%, more preferably 0.08%.

[0037] In step (1) of this invention, hydrolyzed whey protein, light cream, medium-chain triglycerides, skimmed raw milk, stabilizer, and water are mixed to obtain liquid A. The mixing temperature is 50-60℃, more preferably 55℃; the mixing time is 10-20 min, more preferably 15 min; and the mixing is preferably carried out by stirring.

[0038] In step (2) of the present invention, liquid A is pasteurized to obtain liquid B. The pasteurization temperature is preferably 85-95℃, more preferably 90℃, and the pasteurization time is preferably 15-20s, more preferably 15s.

[0039] In step (3) of this invention, the liquid B is cooled and then added to lactase, followed by incubation and stirring. In step (3), the cooling is conventional in the art, with a preferred temperature of 37-43°C, more preferably 40°C; the incubation and stirring time is preferably 60-90 min, more preferably 60 min; and the stirring rate is preferably 90-120 r / min, more preferably 100 r / min.

[0040] In step (4) of this invention, the liquid material C is homogenized, sterilized, cooled, and filled. The homogenization temperature is 60-70℃, more preferably 65℃. The homogenization pressure is 18-22MPa, more preferably 20MPa. The sterilization method and conditions are conventional methods and conditions in the art, and the sterilization method can be plate-type ultra-high temperature sterilization, tubular ultra-high temperature sterilization, and immersion ultra-high temperature instantaneous sterilization. The ultra-high temperature sterilization temperature is 135-140℃. The ultra-high temperature sterilization time is 4-6s. The cooling is conventional in the art, preferably reducing the final product temperature to 25-30℃, more preferably 25℃. The filling is conventional aseptic filling in the art.

[0041] Secondly, the present invention also provides lactose-free, low-fat, high-protein milk prepared by the method for preparing the lactose-free, low-fat, high-protein milk.

[0042] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or as selected according to the product instructions.

[0043] In the following examples, hydrolyzed whey protein was purchased from Davylin International Trading (Shanghai) Co., Ltd., skimmed raw milk and cream were purchased from Bright Dairy & Food Co., Ltd., soybean lecithin was purchased from Danisco (China) Co., Ltd., medium-chain triglycerides were purchased from Ahuskars Oils (Zhangjiagang) Co., Ltd., sodium stearoyl lactylate was purchased from KAIRE Ingredients Trading (Shanghai) Co., Ltd., and lactase was used. The LGI 5000 was purchased from DSM Trading (Shanghai) Co., Ltd.

[0044] Example 1

[0045] The ingredient formula for a lactose-free, low-fat, high-protein milk is shown in Table 1.

[0046] Table 1 Raw material formula for Example 1

[0047] raw material Technical indicators Amount added (wt%) skimmed raw milk Protein content ≥2.9% 80 Hydrolyzed whey protein Protein content ≥90% 6.32 Whipping cream Fat: 40% 0.80 medium-chain triglycerides food grade 0.80 stabilizer Soybean phospholipids: Sodium stearoyl lactylate = 4:5 0.16 lactase Enzyme activity ≥5000 NLI / g 0.06 water softened water 11.86 total 100

[0048] The preparation method of this lactose-free, low-fat, high-protein milk includes the following steps:

[0049] (1) Mix hydrolyzed whey protein, light cream, medium-chain triglycerides, skimmed raw milk, stabilizer and water at a mixing temperature of 50°C for 10 min to obtain liquid A.

[0050] (2) The feed solution A is pasteurized (85℃, 15s) to obtain feed solution B;

[0051] (3) Cool the solution B to 37°C, add lactase, keep warm and stir for 60 min (90 r / min) to obtain solution C;

[0052] (4) Homogenize liquid C (60℃, 18MPa), sterilize (135℃, 4s), cool (25℃), and aseptically fill to obtain the product.

[0053] Example 2

[0054] The ingredient formula for a lactose-free, low-fat, high-protein milk is shown in Table 2.

[0055] Table 2 Raw material formula for Example 2

[0056] raw material Technical indicators Amount added (wt%) skimmed raw milk Protein content ≥2.9% 85 Hydrolyzed whey protein Protein content ≥90% 8.38 Whipping cream Fat: 40% 1.00 medium-chain triglycerides food grade 1.10 stabilizer Soybean phospholipids: Sodium stearoyl lactylate = 5:4 0.20 lactase Enzyme activity ≥5000 NLI / g 0.08 water softened water 4.24 total 100

[0057] The preparation method of this lactose-free, low-fat, high-protein milk includes the following steps:

[0058] (1) Mix hydrolyzed whey protein, light cream, medium-chain triglycerides, skimmed raw milk, stabilizer and water at 60°C for 20 minutes to obtain liquid A.

[0059] (2) The feed solution A is pasteurized (95℃, 20s) to obtain feed solution B;

[0060] (3) Cool the solution B to 43°C, add lactase, keep warm and stir for 90 min (120 r / min) to obtain solution C;

[0061] (4) Homogenize liquid C (70℃, 22MPa), sterilize (140℃, 6s), cool (30℃), and aseptically fill to obtain the product.

[0062] Example 3

[0063] The ingredient formula for a lactose-free, low-fat, high-protein milk is shown in Table 3.

[0064] Table 3 Raw material formula for Example 3

[0065] raw material Technical indicators Amount added (wt%) skimmed raw milk Protein content ≥2.9% 80 Hydrolyzed whey protein Protein content ≥90% 8.38 Whipping cream Fat: 40% 0.80 medium-chain triglycerides food grade 1.10 stabilizer Soybean phospholipids: Sodium stearoyl lactylate = 4:5 0.20 lactase Enzyme activity ≥5000 NLI / g 0.08 water softened water 9.44 total 100

[0066] The preparation method of this lactose-free, low-fat, high-protein milk includes the following steps:

[0067] (1) Mix hydrolyzed whey protein, light cream, medium-chain triglycerides, skimmed raw milk, stabilizer and water at a mixing temperature of 50°C for 20 minutes to obtain liquid A.

[0068] (2) The feed solution A is pasteurized (85℃, 20s) to obtain feed solution B;

[0069] (3) Cool the liquid B to 37°C, add lactase, and keep warm while stirring for 90 min (120 r / min);

[0070] (4) Homogenize liquid C (60℃, 22MPa), sterilize (137℃, 6s), cool (25℃), and aseptically fill to obtain the product.

[0071] Example 4

[0072] The ingredient formula for a lactose-free, low-fat, high-protein milk is shown in Table 4.

[0073] Table 4 Raw material formula for Example 4

[0074] raw material Technical indicators Amount added (wt%) skimmed raw milk Protein content ≥2.9% 85 Hydrolyzed whey protein Protein content ≥90% 6.32 Whipping cream Fat: 40% 1.00 medium-chain triglycerides food grade 0.80 stabilizer Soybean phospholipids: Sodium stearoyl lactylate = 5:4 0.16 lactase Enzyme activity ≥5000 NLI / g 0.06 water softened water 6.66 total 100

[0075] The preparation method of this lactose-free, low-fat, high-protein milk includes the following steps:

[0076] (1) Mix hydrolyzed whey protein, light cream, medium-chain triglycerides, skimmed raw milk, stabilizer and water at a mixing temperature of 60°C for 10 min to obtain liquid A.

[0077] (2) The feed solution A is pasteurized (95℃, 15s) to obtain feed solution B;

[0078] (3) Cool the solution B to 43°C, add lactase, keep warm and stir for 60 min (90 r / min) to obtain solution C;

[0079] (4) Homogenize liquid C (70℃, 18MPa), sterilize (140℃, 4s), cool (25℃), and aseptically fill to obtain the product.

[0080] Example 5

[0081] The ingredient formula for a lactose-free, low-fat, high-protein milk is shown in Table 5.

[0082] Table 5 Raw material formulation for Example 5

[0083] raw material Technical indicators Amount added (wt%) skimmed raw milk Protein content ≥2.9% 82 Hydrolyzed whey protein Protein content ≥90% 7.30 Whipping cream Fat: 40% 0.90 medium-chain triglycerides food grade 0.95 stabilizer Soybean phospholipids: Sodium stearoyl lactylate = 1:1 0.18 lactase Enzyme activity ≥5000 NLI / g 0.07 water softened water 8.6 total 100

[0084] The preparation method of this lactose-free, low-fat, high-protein milk includes the following steps:

[0085] (1) Mix hydrolyzed whey protein, light cream, medium-chain triglycerides, skimmed raw milk, stabilizer and water at a mixing temperature of 55°C for 15 min to obtain liquid A.

[0086] (2) The feed solution A is pasteurized (90℃, 15s) to obtain feed solution B;

[0087] (3) Cool the solution B to 40°C, add lactase, keep warm and stir for 75 min (100 r / min) to obtain solution C;

[0088] (4) Homogenize liquid C (65℃, 20MPa), sterilize (137℃, 5s), cool (25℃), and aseptically fill to obtain the product.

[0089] Example 6

[0090] The ingredient formula for a lactose-free, low-fat, high-protein milk is shown in Table 6.

[0091] Table 6 Raw material formula for Example 6

[0092] raw material Technical indicators Amount added (wt%) skimmed raw milk Protein content ≥2.9% 82 Hydrolyzed whey protein Protein content ≥90% 6.80 Whipping cream Fat: 40% 0.90 medium-chain triglycerides food grade 1.00 stabilizer Soybean phospholipids: Sodium stearoyl lactylate = 1:1 0.17 lactase Enzyme activity ≥5000 NLI / g 0.07 water softened water 9.06 total 100

[0093] The preparation method of this lactose-free, low-fat, high-protein milk includes the following steps:

[0094] (1) Mix hydrolyzed whey protein, light cream, medium-chain triglycerides, skimmed raw milk, stabilizer and water at a mixing temperature of 60°C for 15 minutes to obtain liquid A.

[0095] (2) The feed solution A is pasteurized (95℃, 18s) to obtain feed solution B;

[0096] (3) Cool the solution B to 43°C, add lactase, keep warm and stir for 75 min (100 r / min) to obtain solution C;

[0097] (4) Homogenize liquid C (70℃, 20MPa), sterilize (140℃, 5s), cool (28℃), and aseptically fill to obtain the product.

[0098] Example 7

[0099] A formula for a lactose-free, low-fat, high-protein milk (see Table 7):

[0100] Table 7 Raw material formula for Example 7

[0101] raw material Technical indicators Amount added (wt%) skimmed raw milk Protein content ≥2.9% 82 Hydrolyzed whey protein Protein content ≥90% 7.91 Whipping cream Fat: 40% 0.90 medium-chain triglycerides food grade 0.95 stabilizer Soybean phospholipids: Sodium stearoyl lactylate = 1:1 0.16 lactase Enzyme activity ≥5000 NLI / g 0.07 water softened water 8.01 total 100

[0102] The preparation method of this lactose-free, low-fat, high-protein milk includes the following steps:

[0103] (1) Mix hydrolyzed whey protein, light cream, medium-chain triglycerides, skimmed raw milk, stabilizer and water at 50°C for 15 min to obtain liquid A.

[0104] (2) The feed solution A is pasteurized (85℃, 18s) to obtain feed solution B;

[0105] (3) Cool the solution B to 37°C, add lactase, keep warm and stir for 75 min (100 r / min) to obtain solution C;

[0106] (4) Homogenize liquid C (60℃, 20MPa), sterilize (137℃, 5s), cool (28℃), and aseptically fill.

[0107] Example 1

[0108] Sensory evaluations were conducted on the products of Examples 1-7. Thirty professional sensory evaluators were selected and randomly divided into three groups of 10 each. The lactose-free, low-fat, high-protein milk was evaluated on five indicators: color, consistency, smoothness, taste, and stability. The total score of the five indicators was used as the sample evaluation score, and the average score of the 30 evaluators was used as the final evaluation score. The scoring rules are shown in Table 8, and the experimental results are recorded in Table 9.

[0109] Table 8

[0110]

[0111] Table 9 Sensory Evaluation Results

[0112] sample Color Thickness Smoothness taste stability Total Score Example 1 9 28 18 16 18 89 Example 2 7 25 15 16 15 78 Example 3 7 25 16 15 15 78 Example 4 9 28 18 19 18 92 Example 5 8 28 17 19 18 90 Example 6 8 28 17 19 18 90

[0113] As shown in Table 9, the milk prepared by this invention has been generally recognized in terms of color, consistency, smoothness, taste, and stability, and has a refreshing and smooth taste with a rich milky aroma.

[0114] Example 2

[0115] The protein, fat, and lactose content of the milk obtained in Examples 1-7 of this invention are shown in Table 10. The protein content was determined according to the method of GB 5009.5; the fat content was determined according to the method of GB 5413.3; and the lactose was determined according to the method of GB 5413.5.

[0116] Table 10

[0117] per 100g Protein (g) Fat (g) Lactose (g) Example 1 8.00 1.12 0.2 Example 2 10.00 1.50 0.10 Example 3 9.86 1.42 0.08 Example 4 8.15 1.20 0.25 Example 5 8.95 1.31 0.05 Example 6 8.50 1.36 0.15 Example 7 9.50 1.31 0.10

[0118] As shown in Table 10, the milk product prepared by this invention has a protein content of 8.0-10%, a lactose content of ≤0.3%, and a fat content of ≤1.5%.

[0119] Comparative Example 1

[0120] The stabilizers used in Comparative Example 1 were mono- and diglyceride fatty acid esters and / or sucrose fatty acid esters, and the remaining process steps and conditions were the same as in Example 4.

[0121] In Comparative Example 1, a large number of bubbles were generated during the production process, making it impossible to continue production and thus preventing the realization of the present invention.

[0122] Finally, it should be noted that the above embodiments are only used to help understand the technical solutions and core ideas of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features, and such modifications or substitutions also fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing lactose-free, low-fat, high-protein milk, characterized in that, It comprises the following ingredients by weight percentage: 80-85% skim raw milk, 6.32-8.38% hydrolyzed whey protein, 0.80-1.00% light cream, 0.80-1.10% medium-chain triglycerides, 0.06-0.08% lactase, 0.16-0.20% stabilizer, to a final volume of 100% water; The stabilizer is composed of soybean lecithin and sodium stearoyl lactylate in a mass ratio of 4-5:4-5; Its preparation method includes the following steps: (1) Mix hydrolyzed whey protein, light cream, medium-chain triglycerides, skimmed raw milk, stabilizer and water to obtain liquid A; (2) Pasteurize liquid A to obtain liquid B; (3) Cool the solution B, add lactase, keep warm and stir to obtain solution C; (4) Homogenize, sterilize, cool, and fill liquid C to obtain the product; In step (4), the sterilization is ultra-high temperature sterilization, with a sterilization temperature of 135-140℃ and a sterilization time of 4-6s.

2. The method for preparing lactose-free, low-fat, high-protein milk according to claim 1, characterized in that, The hydrolyzed whey protein contains ≥90% protein.

3. The method for preparing lactose-free, low-fat, high-protein milk according to claim 1, characterized in that, The enzyme activity of the lactase is ≥5000 NLI / g.

4. The method for preparing lactose-free, low-fat, high-protein milk according to claim 1, characterized in that, In step (1), the mixing is a stirring mixture, the mixing temperature is 50-60℃, and the mixing time is 10-20min.

5. The method for preparing lactose-free, low-fat, high-protein milk according to claim 1, characterized in that, In step (2), the pasteurization temperature is 85-95℃ and the time is 15-20s.

6. The method for preparing lactose-free, low-fat, high-protein milk according to claim 1, characterized in that, In step (3), the heat preservation and stirring time is 60-90 min, and the stirring rate is 90-120 r / min.

7. The method for preparing lactose-free, low-fat, high-protein milk according to claim 1, characterized in that, In step (4), the homogenization temperature is 60-70℃ and the pressure is 18-22MPa.

8. Lactose-free, low-fat, high-protein milk prepared by the method of any one of claims 1-7.

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