A thick emulsion and its preparation method

Abstract

This invention relates to the field of dairy product technology, providing a thickened milk and its preparation method. The preparation method of the thickened milk includes: shearing and mixing a first raw material containing raw milk and a stabilizer until the resulting liquid is observed to be of acceptable quality under a polarizing microscope; then mixing, adjusting the volume, homogenizing, sterilizing, and cooling before filling to obtain the thickened milk; the stabilizer includes microcrystalline cellulose and / or sodium carboxymethyl cellulose; the acceptable image is defined as the absence of aggregation of white short rod-shaped patterns observed in the image. This invention allows for rapid determination of the stability of thickened milk products obtained from a specific formulation using a polarizing microscope, during the first step of material preparation in experiments and production. For thickened milk products containing microcrystalline cellulose and sodium carboxymethyl cellulose, this method effectively shortens the stability observation time, reduces the research and development cycle, and fills the gap in rapidly determining the stability of thickened milk.

Description

Technical Field

[0001] This invention relates to the field of dairy technology, and to a thick milk and its preparation method, particularly to a high-protein, high-fat thick milk and its preparation method. Background Technology

[0002] Thick milk is a dairy product obtained through specific processing techniques. It has a higher milk fat content and differs significantly from regular milk or milk beverages in taste and texture. Thick milk typically has a higher milk fat content than regular milk, giving it a rich milky aroma and a full-bodied taste. Furthermore, its thick consistency allows it to mix more effectively with other ingredients during food processing. For example, in coffee preparation, thick milk can add a richer flavor profile; in baked goods, it makes the finished product more moist. The rich, creamy taste of thick milk is created by its high milk fat content and special processing techniques, providing consumers with a unique taste experience.

[0003] In recent years, thick milk has become increasingly popular due to its excellent flavor and rich texture. However, because of its higher protein and fat content, thick milk is prone to issues such as fat settling and protein precipitation during its shelf life. Currently, adding stabilizers is a common method in the preparation of thick milk, with commonly used stabilizers including microcrystalline cellulose and sodium carboxymethyl cellulose.

[0004] Microcrystalline cellulose is a white powder made from lignocellulose, exhibiting good chemical stability and water solubility. It has extremely strong water absorption and, under strong shear in an aqueous medium, can form a gel. Sodium carboxymethyl cellulose is an ionic polymer that effectively increases the viscosity and stability of aqueous solutions. In food production, sodium carboxymethyl cellulose can be used as a thickener, emulsifier, and adhesive, providing excellent thickening and stability, and improving the taste and quality of food. In food, it can be used as a thickener, stabilizer, dispersant, bulking agent, and solidifying agent, and is widely used in dairy products, fruit juices, chocolate, beverages, and lactic acid cheese as a stabilizing and dispersing agent. The combination of microcrystalline cellulose and sodium carboxymethyl cellulose can be dispersed in dairy beverages to form a three-dimensional network structure, improving the stability of thick milk without affecting its viscosity and rheological properties, while also acting as a fat substitute.

[0005] However, even with the aforementioned stabilizers, some products still exhibit instability during their shelf life, such as fat precipitation, protein sedimentation, flocculation, and stratification. Therefore, providing a thick emulsion with a good shelf life and stable product condition is of great significance. Summary of the Invention

[0006] This invention provides a thick emulsion and its preparation method to solve the problem of instability in existing thick emulsion products containing stabilizers such as microcrystalline cellulose and / or sodium carboxymethyl cellulose during shelf life, such as fat floating, protein precipitation, flocculation, and stratification. This invention controls the characteristics of the liquid by monitoring the specific parameters of the liquid during the ingredient preparation stage, thereby avoiding product instability during shelf life.

[0007] Specifically, in a first aspect, the present invention provides a method for preparing thick milk, comprising: shearing and dissolving a first raw material containing raw milk and a stabilizer until the resulting liquid is observed to be qualified under a polarizing microscope, and then mixing, adjusting the volume, homogenizing, sterilizing, cooling and filling to obtain the thick milk;

[0008] The stabilizer includes microcrystalline cellulose and / or sodium carboxymethyl cellulose;

[0009] The image being deemed acceptable includes the absence of clusters of white, short, rod-shaped patterns observed in the image.

[0010] In this invention, the absence of clustering of white short rod-shaped patterns means that there are no more than four white short rod-shaped patterns clustered together and / or stacked in the image measured by the polarizing microscope, or that the white short rod-shaped patterns are separated from each other in the image measured by the polarizing microscope, with gaps between any adjacent white short rod-shaped patterns.

[0011] According to the thick emulsion preparation method provided by the present invention, the image qualification further includes: the equivalent diameter of the regular or irregular granular patterns observed in the image is smaller than the equivalent diameter of the white short rod-shaped pattern.

[0012] According to the preparation method of the thick milk provided by the present invention, the thick milk has a protein content ≥3.5% and a fat content ≥10.0%.

[0013] The method of this invention is more advantageous than other methods for controlling the shelf-life stability of the above-mentioned type of thick cream.

[0014] According to the preparation method of the thick emulsion provided by the present invention, the content of microcrystalline cellulose in the thick emulsion is 0.1~2.0%.

[0015] According to the preparation method of the thick emulsion provided by the present invention, the content of sodium carboxymethyl cellulose in the thick emulsion is 0.1~2.0%.

[0016] Generally, the higher the content of microcrystalline cellulose and sodium carboxymethyl cellulose in thick emulsions, the easier they are to aggregate in the feed liquid. Studies have found that when the content of microcrystalline cellulose and sodium carboxymethyl cellulose is within the above-mentioned range, the thick emulsion obtained by the method of the present invention has better shelf-life stability.

[0017] According to the preparation method of the thick milk provided by the present invention, the raw materials of the thick milk, based on 100 parts by weight, include: 70-80 parts of cow's milk, 10-20 parts of condensed milk, 5-10 parts of milk fat, 0.1-2.0 parts of microcrystalline cellulose, 0.1-2.0 parts of sodium carboxymethyl cellulose, 0.1-1 parts of emulsifier, 0.1-1 parts of buffer salt, and the balance being water.

[0018] Preferably, the emulsifier is selected from one or more of mono- and diglycerides of fatty acids, sucrose fatty acid esters, soybean lecithin, Tween 80, polyglycerol fatty acid esters, diacetyl tartaric acid mono- and diglycerides, and lactic acid fatty acid glycerides.

[0019] More preferably, the emulsifier comprises mono- and diglyceride fatty acid esters and / or sucrose fatty acid esters.

[0020] In thick emulsions, the degree of dispersion of each material is related to the emulsifier and its content in the liquid. Studies have found that when the thick emulsion of the present invention uses the above-mentioned formulation, the resulting thick emulsion has better stability during the shelf life.

[0021] According to the thick emulsion preparation method provided by the present invention, the process of obtaining a qualified image of the resulting liquid material under a polarizing microscope includes:

[0022] Place the liquid material on a glass slide, and cover the glass slide with a coverslip to obtain a sample section;

[0023] The sample slice was placed on the stage of a polarizing microscope;

[0024] The image is obtained by adjusting the objective lens, eyepiece, polarizer, and light source of the polarizing microscope.

[0025] While polarizing microscopes are commonly used to observe microstructures, there is little existing use in the art of using polarizing microscopes for monitoring the shelf-life stability of dairy products. Through extensive experimentation, this invention has found that, compared to other similar low-light testing methods, the polarizing microscope used in this invention possesses comprehensive advantages such as speed, accuracy, and efficiency.

[0026] More importantly, this invention allows for the observation of the feed solution during the first step of ingredient preparation, enabling the prediction of the shelf-life stability of the resulting thick emulsion product. The method of this invention effectively shortens the stability observation time and the R&D cycle, filling the gap in rapidly determining the stability of thick emulsions. This method, as demonstrated in the scheme of this invention, has been proven to possess good accuracy and reproducibility.

[0027] According to the thick emulsion preparation method provided by the present invention, the step of obtaining a qualified image of the resulting liquid material under a polarizing microscope includes:

[0028] (1) Place the liquid on a glass slide, cover the glass slide with a coverslip to obtain a sample slice, and then place it on the stage of a polarizing microscope.

[0029] (2) Select the low-power objective lens of the polarizing microscope and align it with the light aperture. Adjust the coarse adjustment knob to bring the objective lens close to the sample slice and adjust the eyepiece.

[0030] (3) Insert a polarizing filter into the filter slot of the polarizing microscope.

[0031] (4) Rotate the eyepiece to adjust the color and eliminate glare.

[0032] (5) Use the focusing wheel on the polarizing microscope to adjust the sharpness and magnify to obtain the image.

[0033] In the method for preparing the thick emulsion provided by the present invention, the eyepiece is a 10x eyepiece.

[0034] According to the preparation method of the thick emulsion provided by the present invention, the low magnification objective lens is a 5x to 40x objective lens.

[0035] According to the method for preparing the thick emulsion provided by the present invention, a polarizing lens is fitted onto the eyepiece.

[0036] By employing the aforementioned detection parameters, this invention enables accurate and efficient monitoring of the liquid material.

[0037] According to the method for preparing thick emulsion provided by the present invention, the preparation steps of the thick emulsion include:

[0038] (1) Shearing: After heating a portion of raw milk, microcrystalline cellulose, sodium carboxymethyl cellulose and emulsifier are added to it, and shearing is carried out until the resulting liquid is observed to be qualified under a polarizing microscope;

[0039] Preferably, the heating temperature is 60~80℃;

[0040] Preferably, the concentration of the chemical is <5%;

[0041] (2) Mixing: Add condensed milk, milk fat and the remaining raw milk to the material obtained in step (1) in sequence;

[0042] (3) Fixed volume;

[0043] (4) Homogenization and cooling: After heating the material, homogenize it under a pressure of 0~250 bar, cool it after homogenization, and let it stand for 10~60 min;

[0044] Preferably, the material is heated to 60-70°C and then homogenized.

[0045] Preferably, the homogenized material is cooled to 4~20°C.

[0046] (5) Sterilization: Sterilize at a temperature of 72~145℃ for 3~90s;

[0047] (6) Cooling and filling: The material is filled after cooling.

[0048] Thirdly, the present invention also provides a thick emulsion prepared by the method described above.

[0049] Preferably, the thick emulsion produces a satisfactory image when observed under a polarizing microscope.

[0050] When the obtained thickened milk product shows satisfactory images under a polarizing microscope, its shelf-life stability is better. Observing the thickened milk product at this stage is also helpful in predicting its shelf-life stability.

[0051] The thick emulsion and its preparation method provided by this invention can quickly determine the stability of thick emulsion products obtained from a specific formula during the first step of material preparation in experiments and production using a polarizing microscope. For thick emulsion products with added microcrystalline cellulose and sodium carboxymethyl cellulose, the method of this invention can effectively shorten the stability observation time, shorten the research and development cycle, and fill the gap in rapidly determining the stability of thick emulsions. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0053] Figure 1 This is a process flow diagram of the thick emulsion in Embodiment 1 provided by the present invention.

[0054] Figure 2 The image is a qualified one in Test Example 1 provided by this invention.

[0055] Figure 3 This is an image of the liquid material obtained by shearing the material in Example 1 of the present invention.

[0056] Figure 4 This is an image of the thick breast of Embodiment 1 provided by the present invention.

[0057] Figure 5 This is an image of the liquid material obtained by shearing and processing according to Example 2 of the present invention.

[0058] Figure 6 This is an image of the thick breast of Embodiment 2 provided by the present invention.

[0059] Figure 7This is an image of the liquid material obtained by shearing the material in Example 3 of the present invention.

[0060] Figure 8 This is an image of the thick breast in Embodiment 3 provided by the present invention.

[0061] Figure 9 This is an image of the thick breast in Embodiment 4 provided by the present invention.

[0062] Figure 10 This is an image of the liquid material obtained by shearing the material in Comparative Example 1 provided by the present invention.

[0063] Figure 11 This is an image of the thick breast of Comparative Example 1 provided by the present invention.

[0064] Figure 12 This is an image of the liquid material obtained from the shearing process of Comparative Example 2 provided by the present invention.

[0065] Figure 13 This is an image of the thick breast in Comparative Example 2 provided by the present invention.

[0066] Figure 14 This is an image of the liquid material obtained by shearing the material in Comparative Example 3 provided by the present invention.

[0067] Figure 15 This is an image of the thick breast of Comparative Example 3 provided by the present invention.

[0068] Figure 16 This is an image of the thick breast in Comparative Example 4 provided by the present invention. Detailed Implementation

[0069] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0070] The following is combined with Figures 1-16 The present invention describes the thick emulsion and its preparation method.

[0071] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels.

[0072] This embodiment first provides a method for preparing thick milk, including: shearing and dissolving a first raw material containing raw milk and a stabilizer until the resulting liquid is observed to be qualified under a polarizing microscope, and then mixing, adjusting the volume, homogenizing, sterilizing, cooling and filling to obtain the thick milk;

[0073] The stabilizer includes microcrystalline cellulose and / or sodium carboxymethyl cellulose;

[0074] The image being deemed acceptable includes the absence of clusters of white, short, rod-shaped patterns observed in the image.

[0075] In a specific embodiment of the present invention, the image qualification further includes: the equivalent diameter of the regular or irregular granular patterns observed in the image is smaller than the equivalent diameter of the white short rod-shaped pattern.

[0076] In a specific embodiment of the present invention, the thick milk has a protein content ≥3.5% and a fat content ≥10.0%.

[0077] In a specific embodiment of the present invention, the content of microcrystalline cellulose in the thick emulsion is 0.1~2.0%;

[0078] In a specific embodiment of the present invention, the content of sodium carboxymethyl cellulose in the thick emulsion is 0.1~2.0%.

[0079] In a specific embodiment of the present invention, the raw materials of the thick milk, based on 100 parts by weight, include: 70-80 parts of cow's milk, 10-20 parts of condensed milk, 5-10 parts of milk fat, 0.1-2.0 parts of microcrystalline cellulose, 0.1-2.0 parts of sodium carboxymethyl cellulose, 0.1-1 parts of emulsifier, 0.1-1 parts of buffer salt, and the balance being water;

[0080] In a specific embodiment of the present invention, the emulsifier includes diglyceride fatty acid esters and / or sucrose fatty acid esters.

[0081] In a specific embodiment of the present invention, the process of observing a qualified image of the obtained liquid under a polarizing microscope includes:

[0082] Place the liquid material on a glass slide, and cover the glass slide with a coverslip to obtain a sample section;

[0083] The sample slice was placed on the stage of a polarizing microscope;

[0084] The image is obtained by adjusting the objective lens, eyepiece, polarizer, and light source of the polarizing microscope.

[0085] In a specific embodiment of the present invention, the step of observing a qualified image of the obtained liquid under a polarizing microscope includes:

[0086] (1) Place the liquid on a glass slide, cover the glass slide with a coverslip to obtain a sample section, and then place it on the stage of a polarizing microscope.

[0087] (2) Select the low-power objective lens of the polarizing microscope and align it with the light aperture. Adjust the coarse adjustment knob to bring the objective lens close to the sample slice and adjust the eyepiece.

[0088] (3) Insert a polarizing filter into the filter slot of the polarizing microscope;

[0089] (4) Rotate the eyepiece to adjust the color and eliminate glare.

[0090] (5) Use the focusing wheel on the polarizing microscope to adjust the sharpness and magnify to obtain the image.

[0091] In a specific embodiment of the present invention, the eyepiece is a 10x eyepiece.

[0092] In a specific embodiment of the present invention, the low-magnification objective lens is 5x to 40x.

[0093] In a specific embodiment of the present invention, a polarizing lens is fitted onto the eyepiece.

[0094] In a specific embodiment of the present invention, the preparation steps of the thick emulsion include:

[0095] (1) Shearing: After heating a portion of raw milk, microcrystalline cellulose, sodium carboxymethyl cellulose and emulsifier are added to it, and shearing is carried out until the resulting liquid is observed to be qualified under a polarizing microscope;

[0096] Preferably, the heating temperature is 60~80℃;

[0097] Preferably, the concentration of the chemical is <5%;

[0098] (2) Mixing: Add condensed milk, milk fat and the remaining raw milk to the material obtained in step (1) in sequence;

[0099] (3) Fixed volume;

[0100] (4) Homogenization and cooling: After heating the material, homogenize it under a pressure of 0~250 bar, cool it after homogenization, and let it stand for 10~60 min;

[0101] Preferably, the material is heated to 60-70°C and then homogenized.

[0102] Preferably, the homogenized material is cooled to 4~20°C.

[0103] (5) Sterilization: Sterilize at a temperature of 72~145℃ for 3~90s;

[0104] (6) Cooling and filling: The material is filled after cooling.

[0105] This embodiment also provides a thick emulsion prepared by the method described above;

[0106] In a specific embodiment of the present invention, the thick emulsion was observed to be of acceptable quality under a polarizing microscope.

[0107] This embodiment also provides a method for predicting the shelf-life stability of thick milk. The preparation process of the thick milk includes: shearing, mixing, volume adjustment, homogenization, sterilization, and cooling and filling a first raw material containing raw milk and a stabilizer to obtain the thick milk; the stabilizer includes microcrystalline cellulose and / or sodium carboxymethyl cellulose; the prediction method further includes: taking a sample from the outlet of the sheared material and observing the image of the obtained sample under a polarizing microscope.

[0108] The fewer aggregated states of the white short rod-shaped patterns observed in the image, the better the stability of the corresponding thick cream during its shelf life.

[0109] In this invention, the aggregated state of the white short rod-shaped patterns refers to the shape formed by four or more white short rod-shaped patterns clustering together and / or stacking in the image measured by the polarizing microscope.

[0110] Specifically, the method for determining whether the image observed under a polarizing microscope of the liquid material is qualified in the embodiments of the present invention is as follows:

[0111] (1) Place the sample liquid to be tested on a glass slide, cover it with a coverslip to obtain a sample slice, and then place it on the stage of a polarizing microscope.

[0112] (2) Select the 10× objective lens of the polarizing microscope and align it with the light aperture. Adjust the coarse adjustment knob to bring the objective lens close to the sample slice. Adjust the 10× eyepiece and put a polarizing mirror on the eyepiece. Rotating the eyepiece can eliminate glare.

[0113] (3) Insert a polarizing filter into the filter slot of the polarizing microscope to eliminate glare and clear the image.

[0114] (4) Use the focusing wheel on the polarizing microscope to adjust the clarity and magnify to obtain the image.

[0115] When white short rod-shaped patterns are observable in the image in step (4), and the observed white short rod-shaped patterns do not cluster, such as Figure 2 If the image shows a satisfactory result, the liquid material can proceed to the next process. Furthermore, if the equivalent diameter of all regular or irregular granular shapes observed in the image is smaller than the equivalent diameter of the white short rod-shaped shape, the liquid material in the image is in a better state and can proceed to the next process.

[0116] This invention utilizes a polarizing microscope to examine the microstructure and distribution of the feed solution, enabling a rapid and efficient determination of the stability of a thick dairy product system. It provides a quick, simple, and cost-effective detection method for adjusting the thick dairy process and selecting suitable auxiliary components.

[0117] The use of polarizing digital microscopy not only overcomes the complexity of observation using existing electron and optical microscopes, providing a relatively simple observation method and reducing cumbersome sample preparation steps, but also addresses the issue of insufficient intuitiveness in current observation methods. By utilizing the characteristics of polarizing microscopy, it can more clearly present microscopic features and improve the visualization of observations.

[0118] The following describes the thick emulsion of the present invention and its preparation method with reference to specific implementation examples.

[0119] Example 1

[0120] This embodiment provides a method for preparing thick emulsion, the process flow is as follows: Figure 1 As shown, the steps are as follows:

[0121] Based on 100 parts by weight, the ingredients are: 70 parts by weight of raw milk, 10 parts by weight of milk fat, 15 parts by weight of condensed milk, emulsifiers (0.25 parts by weight of mono- and diglycerides of fatty acids, 0.05 parts by weight of sucrose fatty acid esters), stabilizers (0.1 parts by weight of sodium carboxymethyl cellulose, 0.1 parts by weight of microcrystalline cellulose, 0.005 parts by weight of carrageenan), and the balance being water.

[0122] The thick emulsion preparation process in this embodiment is as follows:

[0123] (1) Shearing: Weigh 20 parts of raw milk, heat to 70℃, add microcrystalline cellulose, sodium carboxymethyl cellulose and emulsifier, the concentration of the emulsion is <5%, shear the emulsion for 10 min to obtain mixture A, take a sample, and observe the image of the obtained liquid under a polarizing microscope according to the method of Test Example 1. The image is as follows. Figure 3 As shown.

[0124] (2) Mixing and volume adjustment: According to the product formula, accurately weigh the condensed milk, milk fat, mixture A and the remaining raw milk in sequence. After weighing, adjust the volume.

[0125] (4) Homogenization and cooling: Heat the material to 65°C and then homogenize it at a pressure of 20 MPa. After homogenization, cool the material to 10°C and let it stand for 15 minutes.

[0126] (5) Sterilization: Sterilize the sample. Sterilization procedure: Sterilization temperature: 140℃, 4s.

[0127] (6) Cooling and packaging: After sterilization, the sample is cooled and then aseptically filled at a filling temperature of 20°C to obtain thick milk.

[0128] The thickened milk prepared in this embodiment has a protein content of 4.0-4.2% and a fat content of 10.0-10.2%.

[0129] Before the thick emulsion enters its shelf life, samples are taken, and the resulting liquid is observed under a polarizing microscope according to the method in Test Example 1. The image is as follows: Figure 4 As shown.

[0130] Example 2

[0131] This embodiment provides a method for preparing thick emulsion, the process flow is as follows: Figure 1 As shown, the steps are as follows:

[0132] Based on 100 parts by weight, the ingredients are: 80 parts by weight of raw milk, 15 parts by weight of milk fat, 10 parts by weight of condensed milk, emulsifiers (0.3 parts by weight of mono- and diglycerides of fatty acids, 0.02 parts by weight of soybean lecithin), stabilizers (0.2 parts by weight of sodium carboxymethyl cellulose, 0.1 parts by weight of microcrystalline cellulose, 0.005 parts by weight of carrageenan), and the balance being water.

[0133] The thick emulsion preparation process in this embodiment is as follows:

[0134] (1) Shearing: Weigh 20 parts of raw milk, heat to 70℃, add microcrystalline cellulose, sodium carboxymethyl cellulose and emulsifier, the concentration of the emulsion is <5%, shear the emulsion for 10 min to obtain mixture A, take a sample, and observe the image of the obtained liquid under a polarizing microscope according to the method of Test Example 1. The image is as follows. Figure 5 As shown.

[0135] (2) Mixing and volume adjustment: According to the product formula, accurately weigh the condensed milk, milk fat, mixture A and the remaining raw milk in sequence. After weighing, adjust the volume.

[0136] (4) Homogenization and cooling: Heat the material to 65°C and then homogenize it at a pressure of 20 MPa. After homogenization, cool the material to 10°C and let it stand for 15 minutes.

[0137] (5) Sterilization: Sterilize the sample. Sterilization procedure: Sterilization temperature: 140℃, 4s.

[0138] (6) Cooling and packaging: After sterilization, the sample is cooled and then aseptically filled at a filling temperature of 20°C to obtain thick milk.

[0139] The thickened milk prepared in Example 2 had a protein content of 5.5-5.7% and a fat content of 12.4-12.6%.

[0140] Before the thickened emulsion enters its shelf life, samples are taken, and the resulting liquid is observed under a polarizing microscope according to the method in Test Example 1. The image is as follows: Figure 6 As shown.

[0141] Example 3

[0142] This embodiment provides a method for preparing thick emulsion, the process flow is as follows: Figure 1 As shown, the steps are as follows: 80 parts by weight of raw milk, 15 parts by weight of milk fat, 10 parts by weight of condensed milk, emulsifier (0.3 parts by weight of mono- and diglycerides of fatty acids, 0.02 parts by weight of soybean lecithin), stabilizer (0.2 parts by weight of sodium carboxymethyl cellulose, 0.1 parts by weight of microcrystalline cellulose, 0.005 parts by weight of carrageenan), and the balance water.

[0143] The thick emulsion preparation process in this embodiment is as follows:

[0144] (1) Shearing: Weigh 9 portions of raw milk, heat to 70°C, add microcrystalline cellulose, sodium carboxymethyl cellulose, and emulsifier. The concentration of the emulsion is <5%. Shear the emulsion for 10 minutes to obtain mixture A. Take a sample, and observe the resulting liquid under a polarizing microscope according to the method in Test Example 1. The image is qualified. The image is as follows: Figure 7 As shown.

[0145] (2) Mixing and volume adjustment: According to the product formula, accurately weigh the condensed milk, milk fat, mixture A and the remaining raw milk in sequence. After weighing, adjust the volume.

[0146] (4) Homogenization and cooling: Heat the material to 65°C and then homogenize it at a pressure of 20 MPa. After homogenization, cool the material to 10°C and let it stand for 15 minutes.

[0147] (5) Sterilization: Sterilize the sample. Sterilization procedure: Sterilization temperature: 140℃, 4s.

[0148] (6) Cooling and packaging: After sterilization, the sample is cooled and then aseptically filled at a filling temperature of 20°C to obtain thick milk.

[0149] The thickened milk prepared in Example 3 had a protein content of 5.5-5.7% and a fat content of 12.4-12.6%.

[0150] Before the thickened emulsion enters its shelf life, samples are taken, and the resulting liquid is observed under a polarizing microscope according to the method in Test Example 1. The image is as follows: Figure 8 As shown.

[0151] Example 4

[0152] Example 4 is a commercially available thickened milk product, characterized by the following ingredients: water, raw milk, light cream, white sugar, sodium caseinate, microcrystalline cellulose, and sodium carboxymethyl cellulose; its protein content is 3.5% and fat content is 12.5%. The shelf life is 4 months. An image of the thickened milk product observed under a polarizing microscope is shown below. Figure 9As shown, compared with the example, the observed image is qualified and its condition is good.

[0153] Comparative Example 1

[0154] The process is essentially the same as in Example 1, except that the shearing time in step (2) is shortened to 5 minutes. Images of the resulting liquid and thick emulsion samples from step (2) under a polarizing microscope are shown below. Figures 10-11 As shown, compared with Example 1, the observed images were unqualified for both the sample after chemical shearing and the thick emulsion sample.

[0155] Comparative Example 2

[0156] The process is essentially the same as in Example 1, except that the shearing time in step (2) is extended to 30 min. Images of the resulting liquid and thick emulsion samples from step (2) under a polarizing microscope are shown below. Figures 12-13 As shown, compared with Example 1, the observed images were unqualified for both the sample after chemical shearing and the thick emulsion sample.

[0157] Comparative Example 3

[0158] The process is essentially the same as in Example 1, except that the concentration of the chemical in step (2) is increased to >5%. Images of the resulting liquid and thick emulsion samples from step (2) under a polarizing microscope are shown below. Figures 14-15 As shown, compared with Example 1, the observed images were unqualified for both the sample after chemical shearing and the thick emulsion sample.

[0159] Comparative Example 4

[0160] Comparative Example 4 is a commercially available thickened milk product. Its ingredient list includes raw milk, cream, mono- and diglycerides, microcrystalline cellulose, and white sugar. It contains 4.0% protein and 11.5% fat. The shelf life is 3 months. Images of the thickened milk product observed under a polarizing microscope are shown below. Figure 16 As shown, compared with Example 1, the observed image is unqualified, and its state shows obvious gelation and fat floating phenomenon.

[0161] Furthermore, the thick creams of the above embodiments and comparative examples were subjected to shelf-life tracking to test their product status, viscosity growth rate, and fat float rate. The results are shown in Tables 1, 2, and 3 below.

[0162] Table 1

[0163]

[0164] As shown in Table 1, the thick-film samples exhibited good stability in the short term (within 60 days), but as time progressed, varying degrees of instability occurred, such as gelation and fat floating. Different examples showed differences in long-term stability. Overall, throughout the entire testing period, the products of Examples 1, 2, 3, and 4 showed better stability than the other examples, which corresponds to the observation results of the polarizing microscope.

[0165] Table 2

[0166]

[0167] Table 2 shows that the viscosity of the thick emulsion samples at room temperature increased with time during the tracking period. The viscosity varied among the different examples. Throughout the test period, the viscosity growth rates of Examples 1, 2, 3, and 4 were relatively low, at 35.5%, 32.4%, 30.5%, and 16.5%, respectively, while Comparative Example 3 showed a relatively high viscosity growth rate of 50.7%. This may be because the aggregation of microcrystalline cellulose and sodium carboxymethyl cellulose, due to their structural characteristics and interactions within the system, leads to extensive physical cross-linking or molecular entanglement, increasing the internal friction and viscosity of the system, causing a rapid increase in viscosity. Over time, phenomena such as fat buoyancy and protein aggregation gradually intensify. In summary, during this shelf-life tracking, Examples 1, 2, 3, and 4 showed better product condition than the other comparative examples, with the lowest viscosity growth rate at room temperature, demonstrating the best performance. This is consistent with the results observed under polarized light microscopy and can provide a reference example for adjusting thick emulsion formulations and processes.

[0168] Table 3

[0169]

[0170] Table 3 shows that the fat buoyancy of the thick milk samples increased with time during the tracking period. The fat buoyancy varied among the different examples. Throughout the testing period, the fat buoyancy of Examples 1, 2, 3, and 4 was relatively low, at 11.5%, 10.5%, 12.6%, and 5.1%, respectively. Comparative Example 3 had a relatively high fat buoyancy of 34.0%. The combination of microcrystalline cellulose and sodium carboxymethyl cellulose can disperse in milk beverages to form a three-dimensional network structure, improving the stability of thick milk without affecting its rheological properties. The high fat buoyancy may be due to poor shear dispersion of microcrystalline cellulose and sodium carboxymethyl cellulose in the system, resulting in the failure to form a three-dimensional network structure or the gradual dispersion of the formed network structure over time, thus exacerbating fat buoyancy. In summary, during this shelf-life tracking study, the products of Examples 1, 2, 3, and 4 showed better performance than the other comparative examples, with the lowest fat floating rate. This is consistent with the results observed under a polarizing microscope and can provide a reference example for adjusting the thick cream formula and process.

[0171] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not 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 of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a thick emulsion, characterized in that, The raw materials for the thick milk, based on 100 parts by weight, include: 70-80 parts of cow's milk, 10-20 parts of condensed milk, 5-10 parts of milk fat, 0.1-2.0 parts of microcrystalline cellulose, 0.1-2.0 parts of sodium carboxymethyl cellulose, 0.1-1 parts of emulsifier, 0.1-1 parts of buffer salt, and the balance being water. The preparation method includes: shearing and dissolving the first raw material containing raw cow's milk and stabilizer until the resulting liquid is observed to be qualified under a polarizing microscope, followed by mixing, volume adjustment, homogenization, sterilization, and cooling and filling to obtain the thick milk. The stabilizers include microcrystalline cellulose and sodium carboxymethyl cellulose; The image being deemed acceptable includes the absence of clusters of white short rod-shaped patterns observed in the image; The shearing process involves heating a portion of raw milk, then adding microcrystalline cellulose, sodium carboxymethyl cellulose, and an emulsifier, and shearing until the resulting liquid meets the acceptable image requirements under a polarizing microscope; the concentration of the shearing agent is <5%.

2. The method for preparing thick emulsion according to claim 1, characterized in that, The image qualification also includes: the equivalent diameter of the regular or irregular granular patterns observed in the image is smaller than the equivalent diameter of the white short rod-shaped pattern.

3. The method for preparing thick emulsion according to claim 1 or 2, characterized in that, The thick milk has a protein content of ≥3.5% and a fat content of ≥10.0%.

4. The method for preparing thick emulsion according to claim 1 or 2, characterized in that, The emulsifier is selected from one or more of mono- and diglycerides of fatty acids, sucrose fatty acid esters, soybean lecithin, Tween 80, polyglycerol fatty acid esters, diacetyl tartaric acid mono- and diglycerides, and lactic acid fatty acid glycerides.

5. The method for preparing thick emulsion according to claim 3, characterized in that, The emulsifier is selected from one or more of mono- and diglycerides of fatty acids, sucrose fatty acid esters, soybean lecithin, Tween 80, polyglycerol fatty acid esters, diacetyl tartaric acid mono- and diglycerides, and lactic acid fatty acid glycerides.

6. The method for preparing thick emulsion according to any one of claims 1, 2, and 5, characterized in that, The process of obtaining a qualified image of the liquid material under a polarizing microscope includes: Place the liquid material on a glass slide, and cover the glass slide with a coverslip to obtain a sample section; The sample slice was placed on the stage of a polarizing microscope; The image is obtained by adjusting the objective lens, eyepiece, polarizer, and light source of the polarizing microscope.

7. The method for preparing thick emulsion according to claim 3, characterized in that, The process of obtaining a qualified image of the liquid material under a polarizing microscope includes: Place the liquid material on a glass slide, and cover the glass slide with a coverslip to obtain a sample section; The sample slice was placed on the stage of a polarizing microscope; The image is obtained by adjusting the objective lens, eyepiece, polarizer, and light source of the polarizing microscope.

8. The method for preparing thick emulsion according to claim 4, characterized in that, The process of obtaining a qualified image of the liquid material under a polarizing microscope includes: Place the liquid material on a glass slide, and cover the glass slide with a coverslip to obtain a sample section; The sample slice was placed on the stage of a polarizing microscope; The image is obtained by adjusting the objective lens, eyepiece, polarizer, and light source of the polarizing microscope.

9. The method for preparing thick emulsion according to any one of claims 1, 2, 5, 7-8, characterized in that, The steps for obtaining a qualified image of the liquid material under a polarizing microscope include: (1) Place the liquid on a glass slide, cover the glass slide with a coverslip to obtain a sample section, and then place it on the stage of a polarizing microscope. (2) Select the low-power objective lens of the polarizing microscope and align it with the light aperture. Adjust the coarse adjustment knob to bring the objective lens close to the sample slice and adjust the eyepiece. (3) Insert a polarizing filter into the filter slot of the polarizing microscope; (4) Rotate the eyepiece to adjust the color and eliminate glare; (5) Use the focusing wheel on the polarizing microscope to adjust the sharpness and obtain the image.

10. The method for preparing thick emulsion according to claim 3, characterized in that, The steps for obtaining a qualified image of the liquid material under a polarizing microscope include: (1) Place the liquid on a glass slide, cover the glass slide with a coverslip to obtain a sample section, and then place it on the stage of a polarizing microscope. (2) Select the low-power objective lens of the polarizing microscope and align it with the light aperture. Adjust the coarse adjustment knob to bring the objective lens close to the sample slice and adjust the eyepiece. (3) Insert a polarizing filter into the filter slot of the polarizing microscope; (4) Rotate the eyepiece to adjust the color and eliminate glare; (5) Use the focusing wheel on the polarizing microscope to adjust the sharpness and obtain the image.

11. The method for preparing thick emulsion according to claim 4, characterized in that, The steps for obtaining a qualified image of the liquid material under a polarizing microscope include: (1) Place the liquid on a glass slide, cover the glass slide with a coverslip to obtain a sample section, and then place it on the stage of a polarizing microscope. (2) Select the low-power objective lens of the polarizing microscope and align it with the light aperture. Adjust the coarse adjustment knob to bring the objective lens close to the sample slice and adjust the eyepiece. (3) Insert a polarizing filter into the filter slot of the polarizing microscope; (4) Rotate the eyepiece to adjust the color and eliminate glare; (5) Use the focusing wheel on the polarizing microscope to adjust the sharpness and obtain the image.

12. The method for preparing thick emulsion according to claim 6, characterized in that, The steps for obtaining a qualified image of the liquid material under a polarizing microscope include: (1) Place the liquid on a glass slide, cover the glass slide with a coverslip to obtain a sample section, and then place it on the stage of a polarizing microscope. (2) Select the low-power objective lens of the polarizing microscope and align it with the light aperture. Adjust the coarse adjustment knob to bring the objective lens close to the sample slice and adjust the eyepiece. (3) Insert a polarizing filter into the filter slot of the polarizing microscope; (4) Rotate the eyepiece to adjust the color and eliminate glare; (5) Use the focusing wheel on the polarizing microscope to adjust the sharpness and obtain the image.

13. The method for preparing thick emulsion according to claim 9, characterized in that, The eyepiece is a 10x eyepiece; And / or, the low-power objectives are 5x to 40x objectives; And / or, a polarizing lens is placed over the eyepiece.

14. The method for preparing thick emulsion according to any one of claims 10 to 12, characterized in that, The eyepiece is a 10x eyepiece; And / or, the low-power objectives are 5x to 40x objectives; And / or, a polarizing lens is placed over the eyepiece.

15. The method for preparing thick emulsion according to any one of claims 1, 2, 5, 7-8, 10-12, characterized in that, The preparation steps of the thick emulsion include: (1) Shearing: After heating a portion of raw milk, microcrystalline cellulose, sodium carboxymethyl cellulose and emulsifier are added to it, and shearing is carried out until the resulting liquid is observed to be qualified under a polarizing microscope; (2) Mixing: Add condensed milk, milk fat and the remaining raw milk to the material obtained in step (1) in sequence; (3) Fixed volume; (4) Homogenization and cooling: After heating the material, homogenize it under a pressure of 0~250 bar, cool it after homogenization, and let it stand for 10~60 min; (5) Sterilization: Sterilize at a temperature of 72~145℃ for 3~90s; (6) Cooling and filling: The material is filled after cooling.

16. The method for preparing thick emulsion according to claim 3, characterized in that, The preparation steps of the thick emulsion include: (1) Shearing: After heating a portion of raw milk, microcrystalline cellulose, sodium carboxymethyl cellulose and emulsifier are added to it, and shearing is carried out until the resulting liquid is observed to be qualified under a polarizing microscope; (2) Mixing: Add condensed milk, milk fat and the remaining raw milk to the material obtained in step (1) in sequence; (3) Fixed volume; (4) Homogenization and cooling: After heating the material, homogenize it under a pressure of 0~250 bar, cool it after homogenization, and let it stand for 10~60 min; (5) Sterilization: Sterilize at a temperature of 72~145℃ for 3~90s; (6) Cooling and filling: The material is filled after cooling.

17. The method for preparing thick emulsion according to claim 4, characterized in that, The preparation steps of the thick emulsion include: (1) Shearing: After heating a portion of raw milk, microcrystalline cellulose, sodium carboxymethyl cellulose and emulsifier are added to it, and shearing is carried out until the resulting liquid is observed to be qualified under a polarizing microscope; (2) Mixing: Add condensed milk, milk fat and the remaining raw milk to the material obtained in step (1) in sequence; (3) Fixed volume; (4) Homogenization and cooling: After heating the material, homogenize it under a pressure of 0~250 bar, cool it after homogenization, and let it stand for 10~60 min; (5) Sterilization: Sterilize at a temperature of 72~145℃ for 3~90s; (6) Cooling and filling: The material is filled after cooling.

18. The method for preparing thick emulsion according to claim 6, characterized in that, The preparation steps of the thick emulsion include: (1) Shearing: After heating a portion of raw milk, microcrystalline cellulose, sodium carboxymethyl cellulose and emulsifier are added to it, and shearing is carried out until the resulting liquid is observed to be qualified under a polarizing microscope; (2) Mixing: Add condensed milk, milk fat and the remaining raw milk to the material obtained in step (1) in sequence; (3) Fixed volume; (4) Homogenization and cooling: After heating the material, homogenize it under a pressure of 0~250 bar, cool it after homogenization, and let it stand for 10~60 min; (5) Sterilization: Sterilize at a temperature of 72~145℃ for 3~90s; (6) Cooling and filling: The material is filled after cooling.

19. The method for preparing thick emulsion according to claim 9, characterized in that, The preparation steps of the thick emulsion include: (1) Shearing: After heating a portion of raw milk, microcrystalline cellulose, sodium carboxymethyl cellulose and emulsifier are added to it, and shearing is carried out until the resulting liquid is observed to be qualified under a polarizing microscope; (2) Mixing: Add condensed milk, milk fat and the remaining raw milk to the material obtained in step (1) in sequence; (3) Fixed volume; (4) Homogenization and cooling: After heating the material, homogenize it under a pressure of 0~250 bar, cool it after homogenization, and let it stand for 10~60 min; (5) Sterilization: Sterilize at a temperature of 72~145℃ for 3~90s; (6) Cooling and filling: The material is filled after cooling.

20. A thick emulsion prepared by the method of any one of claims 1 to 19.

21. The thick emulsion according to claim 20, characterized in that, The thick emulsion was observed to be of acceptable quality under a polarizing microscope.

Images