A dual-temperature layered infusion processing method for maintaining milk cover bubble structure

Abstract

The present application relates to the technical field of tea beverage processing, and particularly discloses a double-temperature layered filling processing method for maintaining the bubble structure of milk cover, which comprises the following steps: S1, liquid pretreatment, bottom drink liquid and whipped milk cover liquid are prepared respectively, and a large number of fine bubbles are generated in the milk cover liquid after the whipping treatment; S2, liquid viscosity adjustment, viscosity adjustment is performed on the bottom drink liquid and the milk cover liquid respectively, and the viscosity of the milk cover liquid is ensured to be greater than that of the bottom drink liquid after the adjustment. In the present application, a double-temperature independent temperature control processing scheme is adopted, the bottom drink liquid and the milk cover liquid are isolated from each other before filling, the milk cover liquid maintains a lower second temperature, and the heat conduction efficiency of the bottom drink liquid upward is weakened at the interface position of the two liquids in contact, so that the heat transfer to the bubble film in the milk cover is reduced from the physical processing technology level.

Description

Technical Field

[0001] This invention relates to the field of tea beverage processing technology, and in particular to a dual-temperature stratified filling process method for maintaining the bubble structure of milk foam. Background Technology

[0002] Milk foam drinks are a popular type of freshly made and pre-packaged tea beverage products on the market. The core selling point of the product is that the top layer of milk foam has a fluffy and dense bubble structure, and the milk foam layer and the bottom drinking liquid are clearly separated, bringing consumers a dual experience of visual and taste.

[0003] Currently, the common practice in the industry for producing milk foam beverages is to first fill the bottom drinking liquid, and then pour or spray the whipped milk foam mixture directly onto the bottom drinking liquid. A significant problem with this existing process is that the bottom drinking liquid is typically at room temperature or a relatively high temperature. The whipped milk foam mixture is filled with fragile air bubbles. When the milk foam mixture comes into contact with the hotter bottom drinking liquid, heat is rapidly transferred to the milk foam mixture. The air bubbles weaken quickly due to heat, making them prone to bursting. Adjacent small bubbles merge, resulting in rapid defoaming and collapse of the milk foam layer, a rapid thinning of the milk foam layer, and continuous downward penetration of the milk foam mixture into the bottom drinking liquid, blurring the layering interface and causing gelatinization and layer mixing. Therefore, to address this issue, a dual-temperature layered filling process that maintains the air bubble structure of the milk foam is proposed. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a dual-temperature stratified filling process that maintains the bubble structure of milk foam.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A dual-temperature stratified filling process for maintaining the bubble structure of milk foam, the process comprising the following steps:

[0007] S1 liquid pretreatment is used to prepare the bottom drinking liquid and the whipped milk foam liquid. After whipping, a large number of fine bubbles are generated inside the milk foam liquid.

[0008] S2 viscosity adjustment: The viscosity of the bottom drinking liquid and the milk foam liquid are adjusted separately. After adjustment, the viscosity of the milk foam liquid is ensured to be greater than that of the bottom drinking liquid.

[0009] S3 liquid temperature control allows for independent temperature control of the bottom drinking liquid and the milk foam liquid. The bottom drinking liquid is maintained at a first temperature, while the milk foam liquid is maintained at a second temperature. The second temperature is set lower than the first temperature. Before the pouring operation begins, the bottom drinking liquid and the milk foam liquid are isolated from each other to prevent them from coming into contact and mixing in advance.

[0010] S4 bottom layer filling: Position the container holding the finished product to the filling station, and fill the container with the bottom layer drinking liquid. During the filling process, control the impact intensity of the bottom layer drinking liquid falling to reduce the amplitude of the churning and disturbance of the liquid surface inside the container. After filling to the preset bottom layer liquid level, stop the supply of bottom layer drinking liquid.

[0011] S5 milk foam is poured in layers. The container is kept still throughout the process without any shaking or rotating. The milk foam liquid is poured along the inner wall of the container. The milk foam liquid at low temperature spreads steadily to the surface of the bottom drinking liquid due to its own viscosity, thus forming the milk foam layer.

[0012] The S6 finished product retains its foam and is formed after all the filling processes are completed. It uses the viscosity difference caused by the temperature difference between the two liquids to block the heat conducted upward by the bottom drinking liquid, reduce the heat's damaging effect on the bubble film inside the milk foam liquid, and inhibit the occurrence of bubble expansion and bursting, bubble merging, and milk foam collapse and defoaming.

[0013] Preferably, the first temperature is 10-25℃, the second temperature is 0-8℃, and the temperature difference between the bottom drinking liquid and the milk foam liquid is controlled at 8-20℃; the viscosity of the bottom drinking liquid is adjusted to 10-80mPa・s, and the viscosity of the milk foam liquid is adjusted to 120-400mPa・s.

[0014] Preferably, in the S4 bottom filling process, the distance between the bottom drinking liquid outlet and the initial liquid level of the container is controlled at 5-25mm, the bottom drinking liquid filling flow rate is set to 150-450mL / min, and the bottom drinking liquid drop point is always located at the central axis of the container during the filling process.

[0015] Preferably, in the S5 milk foam layered filling process, the outlet of the milk foam liquid is arranged close to the inner side wall of the container, the distance between the outlet of the milk foam liquid and the liquid surface of the bottom drinking liquid is 3-12mm, and the filling flow rate of the milk foam liquid is set to 60-220mL / min.

[0016] Preferably, in the S1 liquid pretreatment process, the milk foam liquid is whipped using a high-speed stirring method with a stirring speed of 800-2200 r / min, a whipping ratio of 1.8-3.2 times, and an average particle size of air bubbles inside the milk foam liquid of 20-120 μm.

[0017] Preferably, in the S3 liquid temperature control process, the bottom drinking liquid is kept at a constant temperature by an external water bath jacket, and the milk foam liquid is temperature controlled by a sealed cooling tank. The milk foam liquid cooling tank is equipped with a heat insulation jacket, and the inside of the heat insulation jacket is filled with polyurethane heat insulation cotton to avoid the ambient temperature from interfering with the temperature of the milk foam liquid.

[0018] Preferably, throughout the entire process of bottom layer filling (S4) and layered filling (S5), the container is fixed in position solely by the positioning fixture. The positioning fixture does not apply rotational or reciprocating oscillation drive to the container, and the container does not move actively throughout the entire filling process.

[0019] Preferably, after the S5 milk foam layering is completed and the S6 finished product foam preservation and molding stage is reached, the temperature of the finished product container transportation environment is controlled at 2-22℃, and the container is protected from external impact and violent shaking during the transportation process.

[0020] Preferably, the bottom drinking liquid is any one of tea, fruit tea, or coffee-based beverages; the milk foam liquid ingredients include milk base ingredients, emulsified salt, and sweeteners, and the mass ratio of stabilizers added to the milk foam liquid is less than 0.15%.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. This invention employs a dual-temperature independent temperature control processing scheme. Before pouring, the bottom drinking liquid and the milk foam liquid are isolated from each other, and the milk foam liquid maintains a lower second temperature. Relying on the viscosity difference caused by the temperature, the upward heat conduction efficiency of the bottom drinking liquid is weakened at the interface where the two liquids meet. This reduces the transfer of heat to the internal bubble film of the milk foam from a physical processing level. It does not simply rely on a large dose of stabilizer in the formula to achieve the foam retention effect. This method can reduce the proportion of stabilizer added in the milk foam liquid, avoid the heavy and sticky taste caused by high doses of colloidal stabilizers, and the finished milk foam can retain the original fresh and smooth taste of milk, without sacrificing the product flavor for foam retention time, while reducing the consumption of colloidal raw materials.

[0023] 2. The processing method of this invention limits the drop height and flow rate of the two processes of bottom layer pouring and milk foam layer pouring. At the same time, it limits the container to remain stationary throughout the process without rotation or shaking. The bottom layer drinking liquid pouring controls the falling impact intensity, and the milk foam liquid relies on the inner wall of the container for guidance and spreading. This can minimize the surface disturbance caused by fluid impact during the pouring process and avoid the problems of bubble breakage and premature mixing of the two layers of liquid during the pouring stage. This invention abandons the method of container rotation and disturbance layering, and relies solely on the physical properties of the liquid itself to complete the layering. This reduces the mechanical damage to the milk foam bubble structure caused by the pouring process itself. The milk foam bubble integrity is high in the initial state after pouring, which lays a physical foundation for long-term foam preservation.

[0024] 3. In this invention, the viscosity of the bottom drinking liquid and the milk foam liquid are controlled separately. The viscosity of the milk foam liquid is higher than that of the bottom drinking liquid. The viscosity parameter and the dual-temperature control process work together. The low temperature condition will further increase the viscosity of the milk foam liquid itself. The high viscosity of the milk foam liquid can slow down the escape rate of gas inside the bubbles and improve the mechanical strength of the bubble film itself. On the other hand, it can inhibit the downward flow of the milk foam liquid under the action of gravity and alleviate the downward seepage and gelatinization of the milk foam liquid. The temperature parameter and the viscosity parameter work together. Relying solely on adjusting the viscosity or solely on temperature difference control cannot achieve the same foam retention effect. After the two are combined, the finished product can still maintain a clear layer interface within several hours of storage, extend the shelf life of the finished product, and increase the sales circulation window of the pre-packaged milk foam beverage. Attached Figure Description

[0025] Figure 1 This is a flowchart of a dual-temperature stratified pouring process for maintaining the bubble structure of milk foam, as proposed in this invention.

[0026] Figure 2 This is a composition diagram of the bottom layer of drinking liquid in a dual-temperature stratified filling process for maintaining the bubble structure of milk foam proposed in this invention.

[0027] Figure 3 This is a diagram showing the raw material composition of the milk foam liquid in a dual-temperature stratified pouring process method for maintaining the bubble structure of milk foam proposed in this invention. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0029] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0030] Reference Figure 1-3 A dual-temperature stratified filling process for maintaining the bubble structure of milk foam, the process comprising the following steps:

[0031] S1 liquid pretreatment is used to prepare the bottom drinking liquid and the whipped milk foam liquid. After whipping, a large number of fine bubbles are generated inside the milk foam liquid.

[0032] S2 viscosity adjustment: The viscosity of the bottom drinking liquid and the milk foam liquid are adjusted separately. After adjustment, the viscosity of the milk foam liquid is ensured to be greater than that of the bottom drinking liquid.

[0033] S3 liquid temperature control allows for independent temperature control of the bottom drinking liquid and the milk foam liquid. The bottom drinking liquid is maintained at a first temperature, while the milk foam liquid is maintained at a second temperature. The second temperature is set lower than the first temperature. Before the pouring operation begins, the bottom drinking liquid and the milk foam liquid are isolated from each other to prevent them from coming into contact and mixing in advance.

[0034] S4 bottom layer filling: Position the container holding the finished product to the filling station, and fill the container with the bottom layer drinking liquid. During the filling process, control the impact intensity of the bottom layer drinking liquid falling to reduce the amplitude of the churning and disturbance of the liquid surface inside the container. After filling to the preset bottom layer liquid level, stop the supply of bottom layer drinking liquid.

[0035] S5 milk foam is poured in layers. The container is kept still throughout the process without any shaking or rotating. The milk foam liquid is poured along the inner wall of the container. The milk foam liquid at low temperature spreads steadily to the surface of the bottom drinking liquid due to its own viscosity, thus forming the milk foam layer.

[0036] The S6 finished product retains its foam and is formed after all the filling processes are completed. It uses the viscosity difference caused by the temperature difference between the two liquids to block the heat conducted upward by the bottom drinking liquid, reduce the heat's damaging effect on the bubble film inside the milk foam liquid, and inhibit the occurrence of bubble expansion and bursting, bubble merging, and milk foam collapse and defoaming.

[0037] As a technical optimization of the present invention, the first temperature is 10-25℃, the second temperature is 0-8℃, and the temperature difference between the bottom drinking liquid and the milk foam liquid is controlled at 8-20℃; the viscosity of the bottom drinking liquid is adjusted to 10-80mPa・s, and the viscosity of the milk foam liquid is adjusted to 120-400mPa・s.

[0038] As a technical optimization of the present invention, in the S4 bottom filling process, the distance between the bottom drinking liquid outlet and the initial liquid level of the container is controlled at 5-25mm, the bottom drinking liquid filling flow rate is set to 150-450mL / min, and the bottom drinking liquid drop point is always located at the central axis of the container during the filling process.

[0039] As a technical optimization of the present invention, in the S5 milk foam layered filling process, the outlet of the milk foam liquid is arranged to fit against the inner side wall of the container, the distance between the outlet of the milk foam liquid and the liquid surface of the bottom drinking liquid is 3-12mm, and the filling flow rate of the milk foam liquid is set to 60-220mL / min.

[0040] As a technical optimization of the present invention, in the S1 liquid pretreatment process, the milk foam liquid is whipped using a high-speed stirring method with a stirring speed of 800-2200 r / min, a whipping ratio controlled at 1.8-3.2 times, and an average particle size of air bubbles inside the milk foam liquid controlled at 20-120 μm.

[0041] As a technical optimization of the present invention, in the S3 liquid temperature control process, the bottom drinking liquid is kept at a constant temperature by an external water bath jacket, and the milk foam liquid is temperature controlled by a sealed cooling tank. The milk foam liquid cooling tank is equipped with a heat insulation jacket, and the inside of the heat insulation jacket is filled with polyurethane heat insulation cotton to avoid the ambient temperature from interfering with the temperature of the milk foam liquid.

[0042] As a technical optimization of the present invention, in the entire process of bottom layer filling (S4) and layered filling of milk cap (S5), the container is fixed in position only by the positioning fixture. The positioning fixture does not apply rotation or reciprocating swing drive to the container, and the container does not move actively during the entire filling process.

[0043] As a technical optimization of the present invention, after the S5 milk foam layering is completed and the S6 finished product foam preservation and molding stage is completed, the temperature of the finished product container transportation environment is controlled at 2-22℃, and the container is protected from external impact and violent shaking during the transportation process.

[0044] As a technical optimization of the present invention, the bottom drinking liquid is any one of tea, fruit tea, or coffee-based beverage; the milk foam liquid raw materials include milk base raw materials, emulsified salt, and sweeteners, and the mass ratio of the stabilizer added inside the milk foam liquid is less than 0.15%.

[0045] Example 1

[0046] S1 Pretreatment of the liquid: The bottom drinking liquid and the whipped milk foam liquid are prepared separately. In this embodiment, the bottom drinking liquid is a green tea base beverage, and the tea leaves are extracted, filtered and blended according to conventional processes. The milk foam liquid is composed of light cream, milk, white sugar and emulsified salt. Sodium carboxymethyl cellulose is used as the stabilizer, and the stabilizer is added at a mass ratio of 0.12%. The prepared milk foam liquid is transferred to a whipping tank and whipped using a high-speed whipping device. The whipping speed is set to 1400 r / min and the whipping ratio is controlled at 2.3 times. After whipping, the average particle size of the bubbles inside the milk foam liquid is 65 μm. After whipping, a large number of fine bubbles are generated inside the milk foam liquid. After whipping, the milk foam liquid is immediately transferred to the milk foam cooling tank to avoid the bubbles from dissipating prematurely due to prolonged exposure to the environment.

[0047] S2 Viscosity Adjustment: The viscosity of the bottom drinking liquid and the milk foam liquid is adjusted. The bottom drinking liquid is diluted and adjusted to a viscosity of 42 mPa·s; the milk foam liquid is adjusted by changing the proportion of light cream to a viscosity of 240 mPa·s. After adjustment, the viscosity of the milk foam liquid is greater than that of the bottom drinking liquid. Viscosity testing in this step is performed entirely using a rotational viscometer. The testing temperature corresponds to the subsequent temperature control temperature of each liquid, ensuring that the test values ​​match the actual processing conditions.

[0048] S3 liquid temperature control: The bottom drinking liquid is stored in the bottom liquid water bath jacketed tank, and the water bath circulation is activated to maintain the bottom drinking liquid at a first temperature of 16℃; the milk foam cooling tank is activated to maintain the milk foam liquid at a second temperature of 4℃; the temperature difference between the bottom drinking liquid and the milk foam liquid is 12℃. Before the filling operation, the two liquid delivery pipelines for the bottom drinking liquid and the milk foam liquid are independent, and the two liquids do not come into contact with each other, so there is no premature mixing. The polyurethane insulation cotton inside the heat insulation jacket of the milk foam cooling tank continuously isolates the external ambient heat to prevent the ambient temperature from rising to the actual temperature of the milk foam liquid.

[0049] S4 Bottom Layer Filling: An empty container is placed inside the positioning fixture for positioning. The fixture only limits and fixes the container, without causing it to rotate or swing. The bottom layer liquid outlet is aligned with the central axis of the container, 14mm above the initial bottom surface. The delivery pump is turned on to fill the bottom layer of drinking liquid at a flow rate of 300mL / min. The liquid always falls along the central axis of the container, flowing downwards along the middle. The impact intensity is controlled to prevent violent turbulence on the liquid surface. Filling continues until the preset bottom layer level is reached (350mL in this embodiment). Once the level is reached, the bottom layer liquid delivery pump is turned off, stopping the supply of bottom layer drinking liquid. After filling, the container remains inside the positioning fixture throughout the process, without being removed or moved.

[0050] S5 Milk Foam Layered Pouring: The container remains stationary throughout the process, without any shaking or rotation. The milk foam dispensing nozzle is moved to fit against the inner wall of the container, with a distance of 7mm from the bottom drinking liquid surface. The milk foam delivery pump is activated, and the pouring flow rate is set to 130mL / min. The milk foam flows downwards along the inner wall of the container. The low-temperature milk foam, relying on its own viscosity, spreads smoothly on the surface of the bottom drinking liquid, forming a milk foam layer. In this embodiment, the milk foam pouring volume is 80mL. After pouring, the milk foam delivery pump is turned off. Throughout the pouring process, the milk foam flows slowly down the side wall, without directly impacting the lower liquid surface or breaking through the interface between the two layers.

[0051] S6 Finished Product Foaming and Shaping: After all filling operations are completed, the finished milk foam beverage is obtained. Utilizing the viscosity difference caused by the temperature difference between the bottom drinking liquid and the milk foam liquid, the heat transferred upwards from the bottom drinking liquid is reduced, minimizing heat damage to the internal bubble film of the milk foam and inhibiting bubble bursting, bubble merging, and milk foam collapse and defoaming. In this embodiment, the stabilizer addition ratio is only 0.12%, eliminating the need for large doses of stabilizer to maintain the fluffy bubble structure of the milk foam for a long time. The finished product container transport environment temperature is set at 12℃, and impacts and bumps are avoided during transport. The finished product is left to stand, and the milk foam layer thickness and downward mixing depth are recorded at 0h, 2h, and 4h. The initial milk foam layer thickness is 21mm; after 2 hours, the milk foam layer thickness is 19.2mm, and the mixing depth is 1.4mm; after 4 hours, the milk foam layer thickness is 17.8mm, and the mixing depth is 2.1mm. The milk foam layer thickness decreases by 15.2%, with no obvious collapse or gelatinization, and the layered interface is clear.

[0052] Example 2

[0053] S1 Pretreatment of Ingredients: The bottom drinking liquid is a coffee base extracted from Colombian coffee beans, which is then cooled and filtered. The milk foam liquid ingredients include light cream, milk, sweetener, emulsified salt, and sodium carboxymethyl cellulose stabilizer at a mass ratio of 0.10%. The milk foam liquid is whipped at high speed (1000 r / min) with a whipping ratio of 1.9 times. The average particle size of the air bubbles inside the milk foam liquid is 90 μm. After whipping, it is transferred to the milk foam cooling tank.

[0054] S2 Liquid Viscosity Adjustment: Adjust the viscosity of the bottom drinking liquid to 25 mPa·s, and the viscosity of the milk foam liquid to 180 mPa·s. The viscosity of the milk foam liquid is greater than that of the bottom drinking liquid.

[0055] S3 liquid temperature control: The first temperature of the bottom drinking liquid is set at 12℃, and the second temperature of the milk foam liquid is set at 2℃, with a temperature difference of 10℃; the bottom liquid water bath jacket tank maintains a constant temperature for the coffee base, and the milk foam cooling tank has an insulated jacket to isolate environmental heat interference, and the two liquids do not come into contact with each other before pouring.

[0056] S4 Bottom Filling: The container is fixed in the positioning fixture, the bottom liquid outlet is 8mm above the bottom of the container, the filling flow rate is 220mL / min, the drop point is on the central axis of the container, the bottom drinking liquid is filled to the preset bottom liquid level of 320mL, the feeding is stopped, and the container is kept in place and stationary.

[0057] S5 Milk Foam Layered Pouring: The milk foam dispensing nozzle is attached to the inner wall of the container, with the nozzle 5mm above the bottom drinking liquid surface. The milk foam dispensing flow rate is 90mL / min, and it is poured along the inner wall of the container. 70mL of milk foam dispensing liquid is poured in, spreading to form a milk foam layer. The container does not rotate or shake during the entire pouring process.

[0058] The S6 finished product was foam-preserving and molded, and the finished product was transported at an ambient temperature of 8℃. The initial thickness of the milk foam layer was 18mm; after 4 hours of storage, the thickness of the milk foam layer was 15.6mm, with a thickness reduction of 13.3%, and a downward penetration depth of 1.7mm. The milk foam bubbles maintained a good fluffy state, and the layered interface was clear.

[0059] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A dual-temperature stratified pouring process for maintaining the bubble structure of milk foam, characterized in that, The processing method includes the following steps: S1 liquid pretreatment is used to prepare the bottom drinking liquid and the whipped milk foam liquid. After whipping, a large number of fine bubbles are generated inside the milk foam liquid. S2 viscosity adjustment: The viscosity of the bottom drinking liquid and the milk foam liquid are adjusted separately. After adjustment, the viscosity of the milk foam liquid is ensured to be greater than that of the bottom drinking liquid. S3 liquid temperature control allows for independent temperature control of the bottom drinking liquid and the milk foam liquid. The bottom drinking liquid is maintained at a first temperature, while the milk foam liquid is maintained at a second temperature. The second temperature is set lower than the first temperature. Before the pouring operation begins, the bottom drinking liquid and the milk foam liquid are isolated from each other to prevent them from coming into contact and mixing in advance. S4 bottom layer filling: Position the container holding the finished product to the filling station, and fill the container with the bottom layer drinking liquid. During the filling process, control the impact intensity of the bottom layer drinking liquid falling to reduce the amplitude of the churning and disturbance of the liquid surface inside the container. After filling to the preset bottom layer liquid level, stop the supply of bottom layer drinking liquid. S5 milk foam is poured in layers. The container is kept still throughout the process without any shaking or rotating. The milk foam liquid is poured along the inner wall of the container. The milk foam liquid at low temperature spreads steadily to the surface of the bottom drinking liquid due to its own viscosity, thus forming the milk foam layer. The S6 finished product retains its foam and is formed after all the filling processes are completed. It uses the viscosity difference caused by the temperature difference between the two liquids to block the heat conducted upward by the bottom drinking liquid, reduce the heat's damaging effect on the bubble film inside the milk foam liquid, and inhibit the occurrence of bubble expansion and bursting, bubble merging, and milk foam collapse and defoaming.

2. The dual-temperature stratified pouring process for maintaining the bubble structure of milk foam according to claim 1, characterized in that, The first temperature is 10-25℃, the second temperature is 0-8℃, and the temperature difference between the bottom drinking liquid and the milk foam liquid is controlled at 8-20℃; the viscosity of the bottom drinking liquid is adjusted to 10-80mPa・s, and the viscosity of the milk foam liquid is adjusted to 120-400mPa・s.

3. The dual-temperature stratified pouring process for maintaining the bubble structure of milk foam according to claim 2, characterized in that, In the S4 bottom filling process, the height of the bottom drinking liquid outlet from the initial liquid level of the container is controlled at 5-25mm, the bottom drinking liquid filling flow rate is set at 150-450mL / min, and the bottom drinking liquid drop point is always located at the central axis of the container during the filling process.

4. The dual-temperature stratified pouring process for maintaining the bubble structure of milk foam according to claim 3, characterized in that, In the S5 milk foam layered filling process, the outlet of the milk foam liquid is arranged close to the inner side wall of the container, the height of the milk foam liquid outlet from the liquid surface of the bottom drinking liquid is 3-12mm, and the milk foam liquid filling flow rate is set to 60-220mL / min.

5. The dual-temperature stratified pouring process for maintaining the bubble structure of milk foam according to claim 4, characterized in that, In the S1 liquid pretreatment process, the milk foam liquid is whipped using a high-speed stirring method with a stirring speed of 800-2200 r / min and a whipping ratio controlled at 1.8-3.2 times. The average particle size of the air bubbles inside the milk foam liquid is controlled at 20-120 μm.

6. The dual-temperature stratified pouring process for maintaining the bubble structure of milk foam according to claim 5, characterized in that, In the S3 liquid temperature control process, the bottom drinking liquid is kept at a constant temperature by an external water bath jacket, while the milk foam liquid is temperature controlled by a sealed cooling tank. The milk foam liquid cooling tank is equipped with a heat insulation layer, and the inside of the heat insulation layer is filled with polyurethane heat insulation cotton to avoid the ambient temperature from interfering with the temperature of the milk foam liquid.

7. The dual-temperature stratified pouring process for maintaining the bubble structure of milk foam according to claim 6, characterized in that, Throughout the entire process of S4 bottom layer filling and S5 milk cap layer filling, the container is fixed in position solely by the positioning fixture. The positioning fixture does not apply rotation or reciprocating swing drive to the container, and the container does not move actively throughout the entire filling process.

8. The dual-temperature stratified pouring process for maintaining the bubble structure of milk foam according to claim 7, characterized in that, After the S5 milk foam layering is completed, the S6 finished product foam preservation and molding stage begins. The temperature of the finished product container during transportation is controlled at 2-22℃, and the container is protected from external impact and violent shaking during transportation.

9. The dual-temperature stratified pouring process for maintaining the bubble structure of milk foam according to claim 8, characterized in that, The base beverage liquid can be any one of tea, fruit tea, or coffee-based beverages; the milk foam liquid ingredients include milk base ingredients, emulsified salt, and sweeteners, and the mass ratio of stabilizers added to the milk foam liquid is less than 0.15%.

Images