Sterilization method for improving nutritional quality of colored milk
By using INF sterilization technology and homogenization treatment methods in the syringe milk, the problem of sterilization methods in the prior art destroying nutrients of dairy products is solved, and efficient sterilization of syringe milk and effective retention of nutrients is achieved.
Patent Information
- Application Number
- CN202510407033.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-02
- Publication Date
- 2025-06-06
AI Technical Summary
The sterilization methods in the prior art tend to destroy nutrients in dairy products and lead to rapid loss of alkaline phosphatase.
The INF sterilization technology and homogenization treatment method are used to sterilize and homogenize the color milk. The specific steps include sterilization treatment for 0.09 seconds in the INF sterilization equipment, and then homogenization treatment for 80℃-90℃ and pressure treatment for 18MPa-24MPa, and finally cool down to 2℃-8℃ and store.
It effectively realizes the bactericidal effect of the germ of color milk, while preserving nutrients in dairy products to a large extent and reducing the loss of alkaline phosphatase, ensuring the high nutritional quality and safety of the product.
Smart Images
Figure CN120092822A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of dairy product preservation, and in particular relates to a sterilization method for colored milk. Background Art
[0002] Cow's milk is rich in nutrients, with solids accounting for about 13%, including milk fat, milk protein, lactose and minerals, which are all important components of dietary nutrition. However, a series of chemical changes will occur in the milk during the processing and storage period, resulting in a decrease in its nutritional value and stability. Although the heat treatment process used in the processing can effectively kill pathogenic microorganisms in milk, it will also cause heat-labile substances to be destroyed to varying degrees.
[0003] Existing pasteurized milk usually adopts a high-temperature pasteurization method, which selects a high sterilization temperature and a long time, which can better ensure the sterilization efficiency. However, the high sterilization temperature is easy to destroy the nutrients in the milk and also cause the rapid loss of heat processing markers such as alkaline phosphatase in the milk. Ultra-high temperature instantaneous sterilization milk (normal temperature milk) is sterilized at high temperature for a short time, with high sterilization efficiency, but it will destroy more nutrients than pasteurized milk, such as heat-sensitive nutrients.
[0004] Fancy milk is a nutritionally fortified dairy product that has other ingredients added to regular milk, such as chocolate, strawberry, banana, etc., to give it different colors and flavors. Compared to the single taste of regular milk, fancy milk offers a variety of flavors to meet the preferences of different groups of people, and has the characteristics of fortified nutrition, energy supplementation, and easy digestion and absorption. Summary of the invention
[0005] The present invention aims to solve the technical problem that the sterilization method in the prior art is easy to destroy the nutrients in the dairy products and cause the rapid loss of alkaline phosphatase, and provides a sterilization method for improving the nutritional quality of colored milk.
[0006] One of the purposes of the present invention is to provide a sterilization method for improving the nutritional quality of colored milk, the sterilization method comprising the following steps:
[0007] S1: Pass the color milk sample into the INF sterilization equipment for sterilization;
[0008] S2: using a homogenizer, homogenize the colored milk sample after the sterilization treatment in S1, cool it down, and store it.
[0009] In a preferred embodiment of the present invention, the time of the sterilization treatment in S1 is 0.09 s.
[0010] In a preferred embodiment of the present invention, the temperature of the sterilization treatment in S1 is 156°C-158°C.
[0011] In a preferred embodiment of the present invention, the temperature of the homogenization treatment in S2 is 80°C-90°C.
[0012] In a preferred embodiment of the present invention, the pressure of the homogenization treatment in S2 is 18 MPa-24 MPa.
[0013] In a preferred embodiment of the present invention, the cooling in S2 is to a temperature of 2°C-8°C.
[0014] In a preferred embodiment of the present invention, the storage in S2 is carried out in an ultra-clean tank.
[0015] The second object of the present invention is to provide a kind of highly nutritious colored milk, which is prepared by the above-mentioned sterilization method.
[0016] Beneficial effects of the invention: The invention provides a sterilization method for improving the nutritional quality of colored milk, and achieves a sterilization effect on colored milk by utilizing INF sterilization technology and homogenization treatment, and preserves nutrients in dairy products to a large extent and reduces the loss of alkaline phosphatase.
[0017] The present invention utilizes the unique steam penetration of INF sterilization technology during sterilization, thereby achieving the purpose of more thoroughly and comprehensively inactivating heat-resistant microorganisms and ensuring the high safety of the product; and because the INF sterilization time is extremely short and energy-saving, no complex equipment is required, and the operation process is simple. The present invention is aimed at nutritionally fortified dairy product colored milk, which has a variety of tastes and flavors and is rich in nutrients. The parameters related to the INF sterilization technology and homogenization treatment in the sterilization method provided by the present invention are set, and the colored milk prepared by the above sterilization method retains its nutritional components and flavor to a large extent.
[0018] The present invention solves the technical problem that heat sterilization in the existing milk sterilization technology causes more damage to the nutritional components in the milk, and improves the nutritional quality of the heat-sterilized milk; the present invention explores the influence of different heat treatments on active ingredients and heat-sensitive substances, and provides a scientific basis for setting sterilization process parameters for improving the nutritional quality of fancy milk products in industrial production. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 This is the effect of INF sterilization method on the particle size of colored milk whey protein;
[0020] Figure 2 This is the effect of INF sterilization method on the particle size of fancy cheese protein;
[0021] Figure 3 This is the effect of INF sterilization method on the emulsifying activity of colored milk whey protein;
[0022] Figure 4 This is a graph showing the effect of INF sterilization method on the emulsifying activity of fancy cheese protein. DETAILED DESCRIPTION
[0023] Those skilled in the art can refer to the content of this article and appropriately improve the process parameters. It should be particularly noted that all similar replacements and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention. The method and application of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the methods and applications described herein without departing from the content and scope of the present invention to implement and apply the technology of the present invention.
[0024] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments. The experimental methods used in the following examples are all conventional methods unless otherwise specified, and the materials, reagents, methods and instruments used are all conventional materials, reagents, methods and instruments in the art unless otherwise specified, and those skilled in the art can obtain them through commercial channels.
[0025] Example 1: A sterilization method for improving the nutritional quality of colored milk
[0026] S1: The three flavors of chocolate, cocoa and strawberry colored milk samples were respectively introduced into the INF sterilization equipment for sterilization; the sterilization time was 0.09s and the sterilization temperature was 156℃-158℃;
[0027] S2: Use a homogenizer to homogenize the colored milk sample after the sterilization treatment in S1. The homogenization temperature is 80℃-90℃ and the homogenization pressure is 18MPa-24MPa; cool it to a temperature of 2℃-8℃ and store it in an ultra-clean tank.
[0028] The sterilized colored milks obtained in this example are referred to as INF-chocolate, INF-cocoa, and INF-strawberry, respectively.
[0029] Comparative Example 1:
[0030] S1: Using a homogenizer, the three flavors of chocolate, cocoa and strawberry color milk samples were homogenized respectively, with the homogenization temperature being 60℃-85℃ and the homogenization pressure being 14MPa-24MPa;
[0031] S2: The colored milk sample homogenized in S1 is subjected to UHT ultra-high temperature sterilization treatment. The sterilization temperature is then placed in a sterile tank for storage.
[0032] The colored milks obtained after sterilization in this comparative example are referred to as UHT-chocolate, UHT-cocoa and UHT-strawberry, respectively.
[0033] Effect experiment:
[0034] (1) Nutritional composition determination:
[0035] The nutritional components of the three flavors of chocolate, cocoa and strawberry colored milk obtained in Example 1 and Comparative Example 1 were respectively determined, and the nutritional indicators such as protein, fat, total solids, non-fat milk solids and lactose in the colored milk were respectively determined using a milk component analyzer.
[0036] Take 45 mL of the protein solution to be tested and place it in a 50 mL centrifuge tube. Place it in a water bath at 40°C for 30 min and put it into a two-layer ziplock bag to retain some air. Calibrate it twice with 0 liquid (blue) and calibration liquid (transparent) before use. Centrifuge it manually. There will be foam on the top of the centrifuge tube. Measure the sample and click the "green centrifuge tube" button. After the measurement, rinse the pipe with deionized water, calibrate with 0 liquid, calibrate with calibration liquid, and finally rinse the pipe with excess liquid in the conical flask.
[0037] The test results are shown in Table 1. From the comparison results of the milk component content between INF-chocolate and UHT-chocolate, INF-cocoa and UHT-cocoa, and INF-strawberry and UHT-strawberry, it can be concluded that the fancy milk (INF-chocolate, INF-cocoa, INF-strawberry) treated by the sterilization method provided by the present invention has better retained the milk components.
[0038] Table 1
[0039]
[0040]
[0041] (2) Particle size determination:
[0042] The particle sizes of the three flavors of chocolate, cocoa and strawberry colored milk obtained in Example 1 and Comparative Example 1 were measured respectively, and the particle sizes of whey protein and casein in the colored milk were measured respectively using a nano laser particle size analyzer.
[0043] The sample particle size was measured using a nano-laser particle size analyzer. The concentration of the protein solution to be tested was 1 mg / mL. The detection parameters were: particle refractive index 1.450, dispersant refractive index 1.330, and equilibrium time 60 s.
[0044] Protein particle size refers to the size of particles formed by aggregation of protein molecules in milk. The functional properties of protein are affected by the protein particle size. The larger the protein particle size, the higher the degree of protein aggregation, and the protein system is relatively unstable. On the contrary, the smaller the protein particle size, the lower the degree of protein aggregation, and the protein system is relatively stable.
[0045] Test results such as Figure 1-2 As shown, compared with the colored milk (UHT-chocolate, UHT-cocoa, UHT-strawberry) treated by the conventional sterilization process, the protein particle size of the colored milk (INF-chocolate, INF-cocoa, INF-strawberry) treated by the sterilization method provided by the present invention is smaller; it can be seen that the sterilization method provided by the present invention causes different degrees of denaturation of whey protein and casein compared with the traditional sterilization process, and the unfolding, aggregation and dissociation of protein molecules cause the average particle size of the protein to change.
[0046] (3) Determination of alkaline phosphatase content:
[0047] Using a bovine alkaline phosphatase (ALP) ELISA detection kit, the alkaline phosphatase content of the three flavors of chocolate, cocoa, and strawberry obtained in Example 1 and Comparative Example 1 was determined respectively, and the specific steps are as follows:
[0048] S1: Take out the required strips from the aluminum foil bag after equilibration at room temperature for 20 minutes, and seal the remaining strips in a ziplock bag and place them back at 4°C;
[0049] S2: Set standard wells and sample wells, and add 50 μL of standard of different concentrations to each standard well;
[0050] S3: First add 10 μL of the protein solution to be tested to each sample well, then add 40 μL of the sample diluent to each well, and do not add anything to the blank well;
[0051] S4: In addition to the blank wells, add 100 μL of horseradish peroxidase (HRP)-labeled detection antibody to each well of the standard well and sample well, seal the reaction wells with a sealing film, and incubate at 37°C in a water bath or incubator for 60 min;
[0052] S5: Discard the liquid, pat dry on absorbent paper, fill each well with washing solution, let stand for 1 min, shake off the washing solution, pat dry on absorbent paper, and repeat this process 5 times (you can also use a plate washer to wash the plate);
[0053] S6: Add 50 μL of substrate A and B to each well and incubate at 37°C in the dark for 15 min;
[0054] S7: Add 50 μL of stop solution to each well and measure the OD value of each well at a wavelength of 450 nm within 15 min.
[0055] The lactoperoxidase content is an important indicator for evaluating the intensity of heat treatment during milk processing. Lactoperoxidase has antibacterial effects and can participate in the hydrogen peroxide system in milk to inhibit the growth of harmful microorganisms. However, the high temperature conditions in the traditional sterilization process will have a significant impact on the activity of lactoperoxidase. Excessive heat treatment will accelerate the inactivation of lactoperoxidase, thereby affecting the quality and safety of milk.
[0056] The test results are shown in Table 2. Compared with the colored milks (UHT-chocolate, UHT-cocoa, UHT-strawberry) treated by conventional sterilization processes, the colored milks (INF-chocolate, INF-cocoa, INF-strawberry) treated by the sterilization method provided by the present invention better maintained the alkaline phosphatase content; it can be seen that the sterilization method provided by the present invention can effectively reduce the degree of heat damage to colored milk.
[0057] Table 2
[0058] sample Alkaline phosphatase (pg / mL) UHT-Chocolate 50.99 UHT-Cocoa 63.44 UHT-Strawberry 63.15 INF-Chocolate 67.13 INF-Cocoa 65.80 INF-Strawberry 63.66
[0059] (4) Circular dichroism spectroscopy:
[0060] The three flavors of chocolate, cocoa and strawberry colored milk obtained in Example 1 and Comparative Example 1 were respectively subjected to circular dichroism measurements, and the secondary structures of whey protein and casein in the colored milk were respectively determined using a circular dichroism spectrometer.
[0061] 0.05 mg / mL of the protein solution to be tested was added to a 0.1 cm thick cuvette and detected at a scanning wavelength of 200-260 nm. Deionized water and PBS buffer were used as blank groups, respectively. The measurement results were analyzed using CDNN software to analyze the protein secondary structure content.
[0062] The higher the content of random curling, the more it indicates that the structure of the protein changes from ordered to disordered due to strong heat treatment, which reduces the stability of the protein.
[0063] The results of the whey protein secondary structure content detection are shown in Table 3, and the results of the casein secondary structure content detection are shown in Table 4. The α-helix content of the whey protein and casein of the colored milk (INF-chocolate, INF-cocoa, INF-strawberry) treated by the sterilization method provided by the present invention is increased, and the random curl content is reduced, thereby improving the stability of the protein.
[0064] Table 3
[0065] sample α-helix Irregular curl UHT-Chocolate 9.00％ 39.40％ UHT-Cocoa 9.30％ 46.50％ UHT-Strawberry 10.00％ 43.10％ INF-Chocolate 9.20％ 39.30％ INF-Cocoa 11.00％ 45.30％ INF-Strawberry 10.40％ 42.60％
[0066] Table 4
[0067]
[0068]
[0069] (5) Surface hydrophobicity determination:
[0070] The surface hydrophobicity of the three flavors of chocolate, cocoa and strawberry obtained in Example 1 and Comparative Example 1 was measured respectively, and the surface hydrophobicity of whey protein and casein of the colored milk was measured respectively by ANS fluorescent probe method, which specifically includes the following steps:
[0071] Take 20 μL of ANS and add it to 4 mL of the protein solution to be tested. Vortex and shake to mix thoroughly. After 2 minutes of reaction in the dark, use a fluorescence spectrophotometer to measure; the excitation wavelength is 390 nm, the scanning range is 400-600 nm, and the slit width is 10 nm. The peak value of the highest fluorescence intensity represents the hydrophobicity of the protein.
[0072] Surface hydrophobicity reflects the number of hydrophobic groups exposed on the protein surface that can be bonded, which can maintain the stability of the protein.
[0073] The test results are shown in Table 5. The surface hydrophobicity of the colored milk (INF-chocolate, INF-cocoa, INF-strawberry) treated by the sterilization method provided by the present invention is relatively low; it can be seen that the sterilization method provided by the present invention can better maintain the stability of protein in milk.
[0074] Table 5
[0075] sample Whey protein Casein UHT-Chocolate 267.22 357.49 UHT-Cocoa 186.26 331.81 UHT-Strawberry 261.97 264.40 INF-Chocolate 261.33 247.02 INF-Cocoa 184.30 145.60 INF-Strawberry 253.05 164.70
[0076] (6) Emulsifying activity determination:
[0077] The emulsifying activity of the three flavors of chocolate, cocoa and strawberry obtained in Example 1 and Comparative Example 1 was measured respectively, which specifically includes the following steps:
[0078] Prepare the protein solution with a concentration of 1 mg / mL, mix the sample solution and soybean oil in a volume ratio of 4:1 in a 50 mL centrifuge tube, homogenize at 12000 r / min for 2 min, quickly draw 50 μL from 5 mm from the bottom of the emulsion and put it into 5 mL of 0.1% SDS solution, use SDS solution as blank, and measure the absorbance A at 500 nm. 0 , let it stand for 10 minutes, repeat the above method, and measure the absorbance value A after 10 minutes 10 , emulsifying activity (EAI, m 2 / g) is:
[0079]
[0080] Where: DF is the dilution factor: 100; θ is the oil phase ratio: 0.2; is the dish diameter: 1 cm; C is the concentration of the sample to be tested: 0.001 g / mL.
[0081] Emulsifying activity refers to the ability of emulsifier molecules to orient themselves at the oil-water interface and reduce interfacial tension. The emulsifying activity reaction promotes the formation of a stable emulsion between two immiscible liquids.
[0082] Test results such as Figure 3 and Figure 4 As shown, the emulsifying activity of whey protein and casein in the colored milk (INF-chocolate, INF-cocoa, INF-strawberry) treated by the sterilization method provided by the present invention is significantly higher than that of the colored milk (UHT-chocolate, UHT-cocoa, UHT-strawberry) treated by the conventional sterilization process.
[0083] The contents not described in detail in the specification of the present invention are well-known technologies for those skilled in the art. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be based on the definition of the claims.
Claims
1. A sterilization method for improving the nutritional quality of colored milk, characterized in that: The sterilization method comprises the following steps: S1: Pass the color milk sample into the INF sterilization equipment for sterilization; S2: using a homogenizer, homogenize the colored milk sample after the sterilization treatment in S1, cool it down, and store it.
2. The sterilization method according to claim 1, characterized in that: The sterilization treatment time in S1 is 0.09 s.
3. The sterilization method according to claim 1, characterized in that: The temperature of the sterilization treatment in S1 is 156°C-158°C.
4. The sterilization method according to claim 1, characterized in that: The temperature of the homogenization treatment in S2 is 80°C-90°C.
5. The sterilization method according to claim 1, characterized in that: The pressure of the homogenization treatment in S2 is 18MPa-24MPa.
6. The sterilization method according to claim 1, characterized in that: The step of cooling in S2 is to cool the temperature to 2°C-8°C.
7. The sterilization method according to claim 1, characterized in that: The storage described in S2 is to store in an ultra-clean tank.
8. A high-nutrition colored milk, characterized in that: The colored milk is prepared by the sterilization method according to any one of claims 1 to 7.