A high content honeydew milk with stable flavor and morphology and a preparation method thereof

Abstract

The present application relates to the field of dairy products, and provides a high-content melon milk with stable flavor and shape and a preparation method thereof, which is obtained by mixing melon jam with milk for more than 60 min and post-processing, and the mixing is carried out in a material circulating device; the material circulating device comprises a material tank, which comprises a cavity and a stirring shaft arranged at the axis in the cavity; and a multistage propeller arranged on the stirring shaft from top to bottom, the diameter of the multistage propeller decreases from top to bottom, and the inclination angle of the multistage propeller increases from top to bottom; during the mixing process, the rotating speed of the multistage propeller increases from top to bottom. In the mixing stage of the melon milk, in view of the problem that the long feeding time caused by the high addition amount of fruit pulp leads to excessive contact of the material with air, resulting in loss and deterioration of the melon flavor, a multilayer variable frequency stirring mode is adopted in the mixing process, the risk of the fruit pulp being exposed to the air interface is reduced, and the product stability is improved.

Description

Technical Field

[0001] This invention relates to the field of dairy product technology, and in particular to a high-melon milk with stable flavor and form, and its preparation method. Background Technology

[0002] Melon-flavored milk products possess both fruity and milky aromas. However, with a high proportion of added fruit pulp, these products are prone to flavor loss, layering, and sedimentation, severely impacting product quality and stability.

[0003] To improve product stability, color-protecting agents and stabilizers can be used, along with flavor modifiers such as fragrances to enhance or optimize the product's flavor. However, these practices contradict consumers' expectations for products with clean labels.

[0004] Therefore, how to preserve the flavor and maintain the stability of the melon pulp milk system while ensuring a high amount of melon pulp added and avoiding the addition of additional flavorings and stabilizers has become an urgent technical problem to be solved. Summary of the Invention

[0005] During the research and development process, this invention discovered that the main reason why high-content melon milk is prone to flavor loss, stratification, and sedimentation is that the melon pulp is easily subject to flavor loss and oxidative deterioration during grinding and feeding. This is because, in the actual supply chain, melon jam is generally packaged in small packages, while the preparation of high-content melon milk involves a significantly increased amount of melon jam. This leads to a much longer feeding time for the melon jam when producing it using the existing melon milk supply chain (generally with a capacity of 15-20 tons). The longer feeding time in industrial production results in excessive contact between the material and air, which exacerbates flavor decay. At the same time, the unstable components such as fat and protein in the milk system easily cause stratification and sedimentation.

[0006] Based on this, the present invention provides a high-content melon milk with stable flavor and form and its preparation method, which solves the defects of the prior art that the melon milk is prone to flavor loss, layering and precipitation when high content is added, retains the natural fresh flavor of melon to the greatest extent, avoids oxidative deterioration and structural instability, and meets the modern consumer demand for natural and healthy dairy beverages.

[0007] This invention provides a melon milk, comprising: mixing melon jam and milk for more than 60 minutes and then processing the mixture, wherein the mixing is carried out in a batching and circulation device; the batching and circulation device includes a batching tank;

[0008] The mixing tank includes:

[0009] cavity;

[0010] And a stirring shaft located at the central axis of the cavity;

[0011] And a multi-stage propeller arranged on the stirring shaft from top to bottom, wherein the diameter of the multi-stage propeller decreases from top to bottom and the tilt angle of the multi-stage propeller increases from top to bottom;

[0012] During the mixing process, the rotational speed of the multi-stage propellers increases sequentially from top to bottom.

[0013] In this invention, during the mixing stage of melon milk, to address the situation where high amounts of fruit pulp lead to prolonged feeding time and excessive contact between the material and air, resulting in loss and deterioration of melon flavor, this invention proposes a specific mixing process where, under the premise of not being able to shorten the feeding time, a three-layer variable frequency stirring method is used during the mixing process to reduce the risk of prolonged local exposure of fruit pulp to the air interface; and the structure and speed of the multi-stage propeller in the mixing tank are controlled during the stirring process to avoid excessive volatilization of aromatic substances.

[0014] Specifically, conventional single-stage stirring propellers struggle to create an effective circulating flow throughout the tank, often resulting in low-speed zones or dead zones in areas far from the propeller blades (such as near the liquid surface and in the corners of the tank bottom). In contrast, the multi-stage propellers in this invention work together to effectively reduce flavor loss while ensuring uniform mixing.

[0015] When the multi-stage propeller is a three-stage propeller, the three-stage propeller consists of an upper propeller, a middle propeller, and a lower propeller, and their specific coordination relationship is as follows:

[0016] The lower propeller operates at a higher speed, its main task being to lift and suspend the material at the bottom of the chamber, overcoming starting resistance. Its high shear and strong pumping capabilities effectively eliminate dead zones at the bottom. The middle propeller is set at a medium speed, its main function being to promote macroscopic mixing in both the radial and axial directions, pumping the lower fluid upwards and drawing the upper fluid downwards to form a continuous circulating flow covering the middle of the chamber, which is crucial for achieving the main mixing. The upper propeller operates at a lower speed, its main purpose being to gently agitate the liquid surface, promoting the renewal and exchange of materials near the surface, eliminating liquid stratification, and preventing the formation of large vortices at the surface that could engulf headspace due to excessive speed. This reduces liquid-gas interface exchange, minimizing the escape of melon jam flavor compounds from the liquid and reducing the oxidation of dissolved oxygen with milk fats, thus preventing undesirable flavors. The smaller-diameter, larger-angle propeller located at the bottom of the stirring shaft generates strong axial shear force and local turbulence at the same rotational speed, which is beneficial for the rapid dispersion of the melon jam. The middle propeller has a transitional diameter and angle, used to propel the material into a unified vertical circulation flow field, promoting macroscopic homogeneity of the system. The larger-diameter, smaller-angle propeller at the top creates a relatively gentle, covering agitation, which helps stabilize the liquid surface and reduce gas entrainment, preventing adverse effects from excessive shearing in the milk protein system. Through the structural design of progressively decreasing propeller diameters and progressively increasing angles from top to bottom, combined with the synergistic effect of rotational speed parameters, a synergistic mixing effect is achieved within the mixing tank, resulting in a strong lower layer of dispersion, a middle layer of overall circulation, and a gentle upper layer of coverage.

[0017] If the mixing speed is adjusted without adopting the aforementioned multi-stage propeller structural differentiation design, it is difficult to simultaneously ensure the full dispersion of jam particles and the stability control of the emulsion system, which can easily lead to insufficient mixing in the lower layer or excessive shearing in the upper layer.

[0018] In this invention, the tilt angle of the propeller refers to the angle between the propeller blade and the plane of rotation, that is, the acute or obtuse angle between the circumferential plane formed by the rotation of the blade around the axis (perpendicular to the central axis of the propeller) and the working surface of the blade (the side that pushes the material). Its size directly determines the direction and intensity of the force exerted by the blade on the material.

[0019] According to the melon milk provided by the present invention, the melon varieties used in the melon jam include one or more of the following: Yellow River melon, Hami melon, rock sugar melon, Hetao melon, and Meilong melon.

[0020] According to the melon milk provided by the present invention, the melon is matured 15 to 45 days after flowering.

[0021] According to the melon milk provided by the present invention, the total dietary fiber content of the melon is ≥1.00g / 100g.

[0022] According to the melon milk provided by the present invention, the soluble dietary fiber content of the melon is 0.6~1.1g / 100g.

[0023] According to the melon milk provided by the present invention, the firmness of the melon flesh is 4~13 kg / cm. 2 .

[0024] According to the melon milk provided by the present invention, the sugar content of the melon is 7~10°Bx.

[0025] According to the melon milk provided by the present invention, the protein content of the milk is ≥2.5% and the fat content is ≥2.9%.

[0026] This invention, by comparing fruit firmness, sugar content, and dietary fiber content at different harvesting periods, found that these factors all play an important role in the natural flavor and oxidative deterioration of melon jam. This invention also found that using melon raw materials under the above conditions has significant technical advantages in preparing melon milk with structural integrity and high SDF levels.

[0027] According to the melon milk provided by the present invention, the stirring shaft is provided with a multi-stage propeller from top to bottom, the diameter difference between two adjacent propeller stages is 10% to 30% of the inner diameter of the cavity, and the tilt angle difference between two adjacent propeller stages is 10° to 20°.

[0028] According to the melon milk provided by the present invention, the diameter of the uppermost propeller is 70% to 85% of the inner diameter of the cavity, the tilt angle is 15° to 20°, and the rotation speed is 10 to 30 r / min, which is used to form a gentle stirring and covering flow in the upper part of the mixing tank.

[0029] According to the melon milk provided by the present invention, the diameter of the propeller in the middle layer is 50% to 70% of the inner diameter of the cavity, the tilt angle is 30° to 35°, and the rotation speed is 20 to 45 r / min, which is used to drive the melon jam and milk system to form an overall circulating flow field.

[0030] According to the melon milk provided by the present invention, the diameter of the lower propeller is 35% to 50% of the inner diameter of the cavity, the tilt angle is 45° to 50°, and the rotation speed is 35 to 70 r / min, which is used to enhance the shearing, dispersion and mixing effect in the bottom area.

[0031] In this invention, the parameters of each propeller stage can be set independently, or the difference between adjacent propeller stages can be used as a reference. For example, when the diameter of the uppermost propeller is determined to be 70% of the inner diameter of the cavity, the diameter of the middle propeller should be understood as being less than 70% of the inner diameter of the cavity, such as 50%. Correspondingly, the diameter of the lower propeller should be understood as being less than 50% of the inner diameter of the cavity, such as 35%.

[0032] Preferably, the distance between two adjacent propellers is greater than or equal to 1 / 4.

[0033] Preferably, the propeller blades have an arc-shaped leading edge design.

[0034] Preferably, the angle, diameter, and rotational speed of each propeller blade in this invention can be adjusted independently. To achieve independent adjustment of the rotational speed of each propeller, for example, the stirring shaft can be a coaxial transmission assembly composed of an inner shaft, a middle sleeve shaft, and an outer sleeve shaft.

[0035] Preferably, the mixing tank system of the present invention is equipped with a frequency converter, which can adjust the rotation speed of each propeller according to the temperature and viscosity of the dairy products, and optimize the propeller spacing and blade shape through CFD simulation.

[0036] According to the melon milk provided by the present invention, the soluble solids content of the melon jam is 20-40 Brix, and the average particle size is 100-400 μm.

[0037] Preferably, the melon jam is obtained by crushing melons.

[0038] To increase the soluble solids content of the melon jam, preferably, the preparation process includes: centrifuging the crushed pulp at a centrifugal force of 4000-8000g, causing most of the cell debris, coarse fiber, and insoluble particles to settle. More preferably, the supernatant after centrifugation is then concentrated under vacuum or evaporated under reduced pressure at 40-55°C. This invention employs the above-mentioned fruit juice centrifugation clarification and mild concentration techniques to improve the content of soluble components and flavor intensity.

[0039] To improve the texture and stability of the jam and increase the stability of the melon milk, preferably, the melon jam is ground to an average particle size of 100-400 μm.

[0040] More preferably, the method for preparing the melon jam includes the following steps:

[0041] (1) Select the above-mentioned fresh Yellow River melons, wash them, peel and remove the seeds, and cut them into 1-2cm melon pieces for later use.

[0042] (2) Place the melon chunks obtained in step (1) into a crusher and pre-crush them at a speed of 3000~5000r / min for 30~60s to obtain coarse pulp.

[0043] (3) Load the coarse pulp obtained in step (2) into centrifuge tubes and run them with a centrifugal force of 4000~8000g for 5~10 minutes.

[0044] (4) Collect the upper transparent or semi-transparent honeydew melon juice obtained in step (3), which is rich in small molecule sugars, aroma substances and water-soluble dietary fiber. Vacuum concentrate or depressurized evaporation of the supernatant at 40~55℃ to increase its soluble solids to 20~40Brix to obtain honeydew melon centrifuged essence.

[0045] (5) Grind the melon centrifuged extract obtained in step (4) using a colloid mill or wet mill to make the particle size of the mixture reach 100~400μm.

[0046] (6) Heat the material obtained in step (5) to 30~60℃ and stir for 10~40 minutes to promote pectin dissolution, enhance structural uniformity and improve flavor integration. Then add white sugar and mix evenly until it is completely dissolved. The amount of white sugar in the system is 20~45%.

[0047] Using the method described above in this invention, a melon jam with increased soluble solids content, a smoother texture, and a more concentrated flavor can be prepared. Specifically, by optimizing the grinding time, temperature, and particle size, the loss of aromatic components can be reduced and flavor degradation caused by enzymatic oxidation can be inhibited. Centrifugal extraction technology (steps (3) and (4)) is introduced to assist in dehydration, impurity removal, and concentration, thereby improving the extraction efficiency of soluble components.

[0048] According to the melon milk provided by the present invention, the mixed materials are homogenized, and the fat globule particle size in the homogenized material is less than 0.8 μm. Studies have found that when the milk fat globule particle size in the homogenized melon milk system is controlled to be less than 0.8 μm, the fat globules can form a more stable composite dispersion structure with hydrophilic colloids such as pectin and dietary fiber in the melon jam, effectively reducing the aggregation and floating tendency of fat globules, thereby improving the storage stability and smoothness of the product. If the fat globule particle size is higher than this range, fat floating and stratification are likely to occur during standing or storage, affecting the product's appearance and flavor consistency.

[0049] According to the melon milk provided by the present invention, the primary homogenization pressure is 40-50 bar, and the secondary homogenization pressure is 190-240 bar. A gentle homogenization pressure is designed in the homogenization stage to reduce the oxidation of flavor compounds and the masking effect of milk fat.

[0050] According to the melon milk provided by the present invention, the milk is pretreated and then mixed with the melon jam. The pretreatment includes heating the milk to 60-75°C and stirring for 3-10 minutes.

[0051] Preferably, the pretreatment further includes heating the milk to 60-75°C and stirring for 3-10 minutes, then cooling it to 20-40°C. In this invention, gradient temperature control before mixing the materials, especially during the cooling stage, avoids thermal degradation of aromatic substances and quality decline caused by high temperatures, which plays a very important role in improving the flavor and stability of melon milk.

[0052] According to the melon milk provided by the present invention, the mixing process includes: adding melon jam from the first feeding port of the ingredient circulation device according to the mass ratio of melon jam, mixing it with milk cooled to 20~40°C for circulation, completing the feeding process in 60~80 minutes, and continuing the circulation process for 3~10 minutes after the feeding is completed.

[0053] The material flow method in the batching and circulation device is as follows: after the material is fed into the first feeding port, it is heated or cooled by the plate heat exchanger and then enters the batching tank, and then enters the first feeding port from the batching tank to form a cycle.

[0054] According to the melon milk provided by the present invention, the melon jam and the milk are mixed and processed in a continuous production line.

[0055] The continuous production line refers to the interconnection of the batching and circulation device and the device used for post-processing, which cooperate to achieve continuous production. During continuous production, it not only has high capacity, achieving a production capacity of 15 to 20 tons, but also significantly improves the stability of the product system by adopting the aforementioned mixed material method.

[0056] The mixing time mentioned above refers to the effective residence time of the mixed materials in the process section of the batching and circulating device in the continuous production line. For example, if the feeding time for melon jam is 60 minutes, and the mixing continues for another 10 minutes after feeding, then the mixing time is 70 minutes. If this includes cooling to 4°C, then the cooling time is added to the 70 minutes.

[0057] The present invention also provides a method for preparing melon milk as described above, comprising: mixing melon jam with milk for more than 60 minutes, wherein the mixing is carried out in a mixing and circulation device; wherein the mixing and circulation device includes a mixing tank;

[0058] The mixing tank includes:

[0059] cavity;

[0060] And a stirring shaft located at the central axis of the cavity;

[0061] And a multi-stage propeller arranged on the stirring shaft from top to bottom, wherein the diameter of the multi-stage propeller decreases from top to bottom and the tilt angle of the multi-stage propeller increases from top to bottom;

[0062] During the mixing process, the rotational speed of the multi-stage propellers increases sequentially from top to bottom.

[0063] This invention provides a high-content melon milk with stable flavor and form, and its preparation method. By using a multi-layer variable frequency stirring method during the mixing process, the risk of localized prolonged exposure of fruit pulp to the air interface is reduced. During the stirring process, the structure and speed of the multi-stage propeller in the mixing tank are controlled to avoid excessive volatilization of aromatic substances. Attached Figure Description

[0064] 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.

[0065] Figure 1 This is one of the structural schematic diagrams of the ingredient tank provided by the present invention. Detailed Implementation

[0066] 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. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0067] 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.

[0068] The sources or key parameters of some of the raw materials used in this invention are as follows:

[0069] Raw milk: protein content is 3.2%, fat content is 3.5%.

[0070] The honeydew melons used in this example are as follows:

[0071] Table 1

[0072]

[0073] Preparation Example 1

[0074] A method for preparing a melon jam includes the following steps:

[0075] (1) Select the above-mentioned fresh Yellow River melons, wash them, peel and remove the seeds, and cut them into 1-2cm melon pieces for later use.

[0076] (2) Place the melon chunks obtained in step (1) into a crusher and pre-crush them at a speed of 4000 r / min for 45 s to obtain coarse pulp.

[0077] (3) The crude pulp obtained in step (2) is loaded into a centrifuge tube and centrifuged at 6000g for 8 minutes to allow most of the cell debris, crude fiber and insoluble particles in the pulp to settle.

[0078] (4) Collect the upper transparent or semi-transparent honeydew melon juice obtained in step (3), and vacuum concentrate or evaporate the supernatant at 40~55℃ to increase the soluble solids to 20Brix to obtain honeydew melon centrifuged essence.

[0079] (5) Grind the melon centrifuged extract obtained in step (4) using a colloid mill or wet mill to make the particle size of the mixture reach 100 μm.

[0080] (6) Heat the material obtained in step (5) to 40°C and stir for 30 minutes, then add white sugar and mix well until completely dissolved. The amount of white sugar in the system is 35%.

[0081] Preparation Example 2

[0082] The preparation method is basically the same as in Example 1, except that the Yellow River melon is replaced with Hami melon.

[0083] Preparation Example 3

[0084] The preparation method is basically the same as in Example 1, except that the Yellow River melon is replaced with the Hetao melon.

[0085] Preparation Example 4

[0086] The preparation method is basically the same as in Example 1, except that the Yellow River melon is replaced with the Meilong melon.

[0087] Preparation Example 5

[0088] The preparation method is basically the same as in Example 1, except that in step (5), the melon centrifuged extract obtained in step (4) is ground by a colloid mill so that the particle size of the mixed system reaches 200 μm.

[0089] Preparation Example 6

[0090] The preparation method is basically the same as in Example 1, except that in step (5), the melon centrifuged extract obtained in step (4) is ground by a colloid mill so that the particle size of the mixed system reaches 300 μm.

[0091] Preparation Example 7

[0092] The preparation method is basically the same as in Example 1, except that in step (5), the melon centrifuged extract obtained in step (4) is ground by a colloid mill so that the particle size of the mixed system reaches 400 μm.

[0093] Preparation Example 8

[0094] The preparation method is basically the same as in Example 1, except that in step (5), the melon centrifuged extract obtained in step (4) is ground by a colloid mill to make the particle size of the mixed system reach 500 μm.

[0095] Preparation Example 9

[0096] The preparation method is basically the same as in Example 1, except that in step (5), the melon centrifuged extract obtained in step (4) is ground by a colloid mill so that the particle size of the mixed system reaches 50 μm.

[0097] Preparation Example 10

[0098] The preparation method is basically the same as in Example 1, except that in step (4), the soluble solids content of the melon centrifuged extract is increased to 10 Brix.

[0099] Preparation Example 11

[0100] The preparation method is basically the same as in Example 1, except that in step (4), the soluble solids content of the melon centrifuged extract is increased to 30 Brix.

[0101] Preparation Example 12

[0102] The preparation method is basically the same as in Example 1, except that in step (4), the soluble solids content of the melon centrifuged extract is increased to 40 Brix.

[0103] Preparation Example 13

[0104] The preparation method is basically the same as in Example 1, except that in step (4), the soluble solids content of the melon centrifuged extract is increased to 50 Brix.

[0105] The models or key parameters of some of the equipment used in this invention are as follows.

[0106] Equipment Examples 1-2

[0107] This equipment example provides a continuous production line, which includes a batching and circulation device, a homogenizing device, and a sterilization device. The batching and circulation device includes a first feeding port, a plate heat exchanger, and a batching tank. In this batching and circulation device, after the material is fed in through the first feeding port, it is heated or cooled by the plate heat exchanger and then enters the batching tank, and then enters the first feeding port from the batching tank to form a cycle.

[0108] As attached Figure 1 As shown, the mixing tank includes:

[0109] The cavity is cylindrical, with an inner diameter of R.

[0110] And a stirring shaft located at the central axis of the cavity;

[0111] The system includes three propellers arranged on the stirring shaft from top to bottom; the diameter of each propeller stage decreases from top to bottom; the tilt angle of each propeller stage increases from top to bottom; and the rotational speed of each propeller stage increases from top to bottom. The diameter and tilt angle of the three propeller stages are shown in the table below. The spacing between two adjacent propeller stages is 1 / 4, and the blades of each propeller stage adopt an arc-shaped leading edge design.

[0112] And a stirring motor is installed at the top of the stirring shaft, the stirring motor is connected to a controller, the controller is connected to a power supply, and the controller controls the rotational speed of the multi-stage propeller.

[0113] Table 2

[0114]

[0115] Example 1

[0116] A method for preparing a melon milk with high pulp content and stable flavor and appearance, comprising the following steps:

[0117] (1) Pretreatment: Clean the raw milk and then heat it to 60°C through the above-mentioned ingredient circulation device and circulate it for 5 minutes to adjust the conformation of the raw milk protein, enhance its interfacial activity, and reduce the bad flavor of whipped cream caused by long-term whipping.

[0118] (2) Cool the pretreated raw milk to 30°C. Add the melon jam prepared in Example 1 into the first feeding port of the batching and circulating device of Equipment Example 1 at a mass ratio of 3%. Mix it with the cooled raw milk and circulate it. The feeding is completed after 60 minutes (corresponding to a production capacity of 15-20 tons). After the feeding is completed, continue to circulate for 5 minutes. Then adjust the temperature of the plate heat exchanger to 4°C to cool the material in the batching and circulating device to avoid product deterioration. Among them, starting from the melon jam, keep the speed of the top propeller at 10 r / min; the speed of the middle propeller at 20 r / min; and the speed of the bottom propeller at 70 r / min.

[0119] (3) After the chemical process is completed, the mixture is homogenized to obtain material A; wherein, the first homogenization pressure is 40 bar; the second homogenization pressure is 190 bar.

[0120] According to the Malvern particle size analyzer (laser scattering principle), the fat globule size of material A is 0.8 μm.

[0121] (4) Sterilize material A at 122°C for 2 seconds. After sterilization, honeydew melon milk is obtained.

[0122] Example 2

[0123] A method for preparing a melon milk with high pulp content and stable flavor and appearance, comprising the following steps:

[0124] (1) Pretreatment: The pure milk is heated to 63°C through the above-mentioned ingredient circulation device and circulated for 8 minutes to adjust the conformation of the raw milk protein, enhance its interfacial activity, and reduce the bad flavor of whipped cream caused by long-term whipping.

[0125] (2) Cool the pretreated raw milk to 40°C. Add the melon jam prepared in Example 1 into the first feeding port of the batching and circulating device of Equipment Example 2 at a mass ratio of 8%. Mix it with the cooled raw milk and circulate it. The feeding is completed after 70 minutes. After the feeding is completed, continue to circulate for 5 minutes. Then adjust the temperature of the plate heat exchanger to 4°C to cool the material in the batching and circulating device to avoid product deterioration. Among them, starting from the melon jam, keep the speed of the top propeller at 10 r / min; the speed of the middle propeller at 45 r / min; and the speed of the bottom propeller at 50 r / min.

[0126] (3) After the chemical process is completed, the mixture is homogenized to obtain material A; wherein, the first homogenization pressure is 50 bar; the second homogenization pressure is 200 bar.

[0127] According to the Malvern particle size analyzer (laser scattering principle), the fat globule size of material A is 0.6μm.

[0128] (4) Sterilize material A at 124°C for 4 seconds. After sterilization, honeydew melon milk is obtained.

[0129] Example 3

[0130] A method for preparing a melon milk with high pulp content and stable flavor and appearance, comprising the following steps:

[0131] (1) Pretreatment: The pure milk is heated to 66°C through the above-mentioned ingredient circulation device and circulated for 10 minutes to adjust the conformation of the raw milk protein, enhance its interfacial activity, and reduce the bad flavor of whipped cream caused by long-term whipping.

[0132] (2) Cool the pretreated raw milk to 30°C. Add the melon jam prepared in Example 1 into the first feeding port of the batching and circulating device of Equipment Example 1 at a mass ratio of 15%. Mix it with the cooled raw milk and circulate it. The feeding is completed after 80 minutes. After the feeding is completed, continue to circulate for 6 minutes. Then adjust the temperature of the plate heat exchanger to 4°C to cool the material in the batching and circulating device to avoid product deterioration. Among them, starting from the melon jam, keep the speed of the top propeller at 20 r / min; the speed of the middle propeller at 30 r / min; and the speed of the bottom propeller at 40 r / min.

[0133] (3) After the chemical process is completed, the mixture is homogenized to obtain material A; wherein, the first homogenization pressure is 40 bar; the second homogenization pressure is 220 bar.

[0134] According to the Malvern particle size analyzer (laser scattering principle), the fat globule size of material A is 0.4 μm.

[0135] (4) Sterilize material A at 126°C for 6 seconds. After sterilization, honeydew melon milk is obtained.

[0136] Example 4

[0137] A method for preparing a melon milk with high pulp content and stable flavor and appearance, comprising the following steps:

[0138] (1) Pretreatment: The pure milk is heated to 69°C through the above-mentioned ingredient circulation device and circulated for 5 minutes to adjust the conformation of the raw milk protein, enhance its interfacial activity, and reduce the bad flavor of whipped cream caused by long-term whipping.

[0139] (2) Cool the pretreated raw milk to 40°C. Add the melon jam prepared in Example 1 into the first feeding port of the batching and circulating device of Equipment Example 2 at a mass ratio of 3%. Mix it with the cooled raw milk and circulate it. The feeding is completed after 60 minutes. After the feeding is completed, continue to circulate for 6 minutes. Then adjust the temperature of the plate heat exchanger to 4°C to cool the material in the batching and circulating device to avoid product deterioration. Among them, starting from the melon jam, keep the speed of the top propeller at 20 r / min; the speed of the middle propeller at 45 r / min; and the speed of the bottom propeller at 70 r / min.

[0140] (3) After the chemical process is completed, the mixture is homogenized to obtain material A; wherein, the first homogenization pressure is 50 bar; the second homogenization pressure is 190 bar.

[0141] According to the Malvern particle size analyzer (laser scattering principle), the fat globule size of material A is 0.8 μm.

[0142] (4) Sterilize material A at 128°C for 2 seconds. After sterilization, honeydew melon milk is obtained.

[0143] Example 5

[0144] A method for preparing a melon milk with high pulp content and stable flavor and appearance, comprising the following steps:

[0145] (1) Pretreatment: The pure milk is heated to 72°C through the above-mentioned ingredient circulation device and circulated for 8 minutes to adjust the conformation of the raw milk protein, enhance its interfacial activity, and reduce the bad flavor of whipped cream caused by long-term whipping.

[0146] (2) Cool the pretreated raw milk to 30°C. Add the melon jam prepared in Example 1 into the first feeding port of the batching and circulating device of Equipment Example 1 at a mass ratio of 8%. Mix it with the cooled raw milk and circulate it. The feeding is completed after 70 minutes. After the feeding is completed, continue to circulate for 7 minutes. Then adjust the temperature of the plate heat exchanger to 4°C to cool the material in the batching and circulating device to avoid product deterioration. Among them, starting from the melon jam, keep the speed of the top propeller at 30 r / min; the speed of the middle propeller at 40 r / min; and the speed of the bottom propeller at 50 r / min.

[0147] (3) After the chemical process is completed, the mixture is homogenized to obtain material A; wherein, the first homogenization pressure is 40 bar; the second homogenization pressure is 200 bar.

[0148] According to the Malvern particle size analyzer (laser scattering principle), the fat globule size of material A is 0.6μm.

[0149] (4) Sterilize material A at 130°C for 4 seconds. After sterilization, honeydew melon milk is obtained.

[0150] Example 6

[0151] A method for preparing a melon milk with high pulp content and stable flavor and appearance, comprising the following steps:

[0152] (1) Pretreatment: The pure milk is heated to 75°C through the above-mentioned ingredient circulation device and circulated for 10 minutes to adjust the conformation of the raw milk protein, enhance its interfacial activity, and reduce the bad flavor of whipped cream caused by long-term whipping.

[0153] (2) Cool the pretreated raw milk to 40°C. Add the melon jam prepared in Example 1 into the first feeding port of the batching and circulating device of Equipment Example 2 at a mass ratio of 15%. Mix it with the cooled raw milk and circulate it. The feeding is completed after 80 minutes. After the feeding is completed, continue to circulate for 8 minutes. Then adjust the temperature of the plate heat exchanger to 4°C to cool the material in the batching and circulating device to avoid product deterioration. Among them, starting from the melon jam, keep the speed of the top propeller at 30 r / min; the speed of the middle propeller at 45 r / min; and the speed of the bottom propeller at 60 r / min.

[0154] (3) After the chemical process is completed, the mixture is homogenized to obtain material A; wherein, the first homogenization pressure is 50 bar; the second homogenization pressure is 220 bar.

[0155] According to the Malvern particle size analyzer (laser scattering principle), the fat globule size of material A is 0.4 μm.

[0156] (4) Sterilize material A at 135°C for 6 seconds. After sterilization, honeydew melon milk is obtained.

[0157] Examples 7-18

[0158] The preparation method is basically the same as Example 1, except that the melon jam in Preparation Example 1 is replaced with the melon jam in Preparation Examples 2 to 13. The specific correspondence is shown in the table below.

[0159] Table 3

[0160]

[0161] Comparative Example 1

[0162] The only difference from Example 1 is that the pretreated raw milk in step (2) is not cooled down and is directly mixed with melon jam.

[0163] Comparative Example 2

[0164] The only difference from Example 1 is that the first-stage homogenization pressure is 80 bar.

[0165] Comparative Example 3

[0166] The only difference from Example 1 is that the first-stage homogenization pressure is 30 bar.

[0167] Comparative Example 4

[0168] The only difference from Example 1 is that the secondary homogenization pressure is 250 bar.

[0169] Comparative Example 5

[0170] The only difference from Example 1 is that the secondary homogenization pressure is 150 bar.

[0171] Comparative Examples 6-9

[0172] The only difference from Example 1 is that the propeller speed is as follows:

[0173] Table 4

[0174]

[0175] Comparative Example 10

[0176] The only difference from Example 1 is that step (1) is not performed. Instead, the raw milk is directly purified and then cooled to 15-25°C. The melon jam prepared in Example 1 is added from the first feeding port of the feeding and circulating device according to the mass ratio of the melon jam. It is mixed with the cooled raw milk and circulated for 60-80 minutes to complete the feeding.

[0177] Comparative Example 11

[0178] The only difference from Example 1 is that the pretreated raw milk is not cooled to 15~25°C, but the melon jam prepared in Example 1 is added directly from the first feeding port of the feeding and circulating device according to the mass ratio of the melon jam. It is mixed with the raw milk and circulated for 60~80 minutes to complete the feeding.

[0179] Comparative Example 12

[0180] Under the same raw material ratio and chemical conditions as in Example 1, only one low-intensity homogenization process was performed, and the average particle size of milk fat globules was measured to be 1.2 μm after homogenization.

[0181] The resulting melon milk showed obvious fat floating phenomenon after standing at 4℃ for 5 days, forming a milk fat layer on the surface, reducing the uniformity of the system and making the taste rough.

[0182] Test case

[0183] Stability evaluation: The melon milk beverages prepared in the examples and comparative examples were stored at 4°C for 0, 3, 7, 14, and 21 days. The time of initial stratification, whey separation time, pH fluctuation, SDF residue, and sensory quality were recorded. Except for the "time of initial stratification" and "time of whey separation," other indicators required shaking the sample before testing. The test methods involved are as follows:

[0184] SDF residue rate: GB5009.88-2023, the test sample was taken on day 21.

[0185] Sensory quality: The seven-point preference method is used, with the average sensory rating as the result.

[0186] The test results are as follows:

[0187] Table 5

[0188]

[0189]

[0190] Table 6

[0191]

[0192] The data above show that, without the addition of any exogenous colloidal stabilizers, a high SDF retention rate is maintained, and the phenomena of stratification or whey precipitation are significantly improved.

[0193] 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 melon milk, characterized in that, include: The mixture is prepared by mixing melon jam with milk for more than 60 minutes and then processing it. The mixing process is carried out in a batching and circulation device. The batching and circulation device includes a batching tank; The mixing tank includes: cavity; And a stirring shaft located at the central axis of the cavity; And a multi-stage propeller arranged on the stirring shaft from top to bottom, wherein the diameter of the multi-stage propeller decreases from top to bottom and the tilt angle of the multi-stage propeller increases from top to bottom; During the mixing process, the rotational speed of the multi-stage propellers increases sequentially from top to bottom; The multi-stage propeller is a three-stage propeller, consisting of an upper propeller, a middle propeller, and a lower propeller. The upper propeller rotates at a speed of 10-30 r / min; the middle propeller rotates at a speed of 20-45 r / min; and the lower propeller rotates at a speed of 35-70 r / min.

2. The melon milk according to claim 1, characterized in that, The melon varieties used in the melon jam include one or more of the following: Yellow River melon, Hami melon, rock sugar melon, Hetao melon, and Meilong melon.

3. The melon milk according to claim 2, characterized in that, The melons mentioned are matured 15 to 45 days after flowering; The total dietary fiber content of the melon is ≥1.00g / 100g; The soluble dietary fiber content of the melon is 0.6~1.1g / 100g; The flesh firmness of the melon is 4~13 kg / cm. 2 ; The sugar content of the melon is 7~10°Bx; The milk has a protein content of ≥2.5% and a fat content of ≥2.9%.

4. The melon milk according to claim 1, characterized in that, The soluble solids content of the melon jam is increased to 20-40 Brix, and the average particle size is 100-400 μm.

5. The melon milk according to claim 1, characterized in that, The mixed materials are then homogenized, and the homogenized material contains fat globules with a particle size of less than 0.8 μm.

6. The melon milk according to claim 5, characterized in that, The primary homogenization pressure is 40-50 bar, and the secondary homogenization pressure is 190-240 bar.

7. The melon milk according to claim 1, characterized in that, The milk is pretreated and then mixed with the melon jam. The pretreatment includes heating the milk to 60-75°C and stirring for 3-10 minutes.

8. The melon milk according to claim 1, characterized in that, The mixing process includes: adding honeydew melon jam from the first feeding port of the ingredient circulation device according to the mass ratio of the honeydew melon jam, mixing it with milk cooled to 20~40℃ for circulation, completing the feeding process in 60~80 minutes, and continuing the circulation process for 3~10 minutes after the feeding is completed.

9. The melon milk according to any one of claims 1 to 8, characterized in that, The melon jam and the milk are mixed and processed using a continuous production line.

10. A method for preparing melon milk according to any one of claims 1 to 9, characterized in that, include: The honeydew melon jam and milk are mixed for more than 60 minutes in a batching and circulation device. The batching and circulation device includes a batching tank; The mixing tank includes: cavity; And a stirring shaft located at the central axis of the cavity; And a multi-stage propeller arranged on the stirring shaft from top to bottom, wherein the diameter of the multi-stage propeller decreases from top to bottom and the tilt angle of the multi-stage propeller increases from top to bottom; During the mixing process, the rotational speed of the multi-stage propellers increases sequentially from top to bottom.

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