A formula for solving the instant protein powder

Abstract

The present application relates to the technical field of protein powder processing, and discloses a formula for solving instant protein powder. The formula comprises the following components in parts by weight: 70-100 parts of protein base, 2-10 parts of trehalose, 0.5-3 parts of triethyl citrate, and 0.1-1 parts of silicon dioxide. The preparation method adopts a technical route combining controllable enzymolysis, heat preservation and standing, and three-stage temperature control spray drying: first, controllable enzymolysis is used to make the degree of hydrolysis of the protein base reach 7-10%, generating enzymolysis peptide segments; then, after cooling, trehalose and triethyl citrate are added, and nano particles with a particle size of 50-110 nm are formed by heat preservation and standing; finally, three-stage temperature control spray drying is used to obtain instant protein powder particles. The present application forms a protective layer by generating small particles on the surface and inside of the protein particles, so that the protein powder can be quickly dispersed and dissolved in different media such as water, milk, and fruit juice, and can meet the requirements of multi-medium instant dissolution and stable suspension.

Description

Technical Field

[0001] This invention relates to the technical field of protein powder processing, and more particularly to a formula for solving the problem of instant dissolution of protein powder. Background Technology

[0002] Due to its high nutritional value and ease of consumption, protein powder has been widely used in sports nutrition, weight management, and daily dietary supplementation. Currently, commercially available protein powders are mainly made from whey protein, soy protein, and other raw materials, produced through processes such as spray drying. In actual use, consumers often mix protein powder with different media according to their personal taste preferences, such as directly with water, or mixed with milk, yogurt, juice, or coffee. However, when mixed with milk, the high calcium ion content can induce cross-linking and aggregation of the protein, making it difficult to disperse the protein powder particles and forming visible clumps or flocculent precipitates. When mixed with acidic media, the pH of the medium is close to the isoelectric point of the protein, neutralizing the surface charge of the protein molecules and leading to dominant hydrophobic interactions, causing rapid acid denaturation and flocculation of the protein. When mixed with hard water, calcium and magnesium ions in the water can combine with the protein to form insoluble precipitates, resulting in decreased solubility.

[0003] A search revealed that existing technologies primarily focus on improving the water solubility of protein powder. Japanese Patent Publication No. JP7549926B2 discloses granules and their manufacturing method, achieving dual optimization of solubility and flowability in water when protein containing granules is dissolved, while also considering flavor and drinking taste. Chinese Patent Publication No. CN109043118A discloses an instant protein powder and its preparation method, obtained by spraying soybean lecithin slurry onto the outer surface of the main protein powder and then drying it, thus solving the technical defects of poor dispersibility and long dissolution time of protein powder. Chinese Patent Publication No. CN111227101A discloses a protein product and its preparation method, using a two-step granulation method combined with a variable temperature rate control method, achieving rapid dissolution in hot water at ≥85℃.

[0004] Regarding the above and existing related technologies, the inventors believe that the following defects often exist: The current technical bottleneck of instant protein powder lies in the singleness of its formula design. Most products are only targeted and optimized for water as a specific medium, resulting in a lack of universality of the formula for different mixing media and limited application scenarios. Summary of the Invention

[0005] The technical problem to be solved by this invention is that the existing technology has the disadvantage of lacking universality of the formula for different mixing media and having limited application scenarios. To this end, we propose a formula to solve the problem of instant dissolution of protein powder.

[0006] To achieve the above objectives, this application adopts the following technical solution: a fast-dissolving protein powder, comprising: 70-100 parts of protein base material, 2-10 parts of hydrophilic protective agent, 0.5-3 parts of plasticizer, and 0.1-1 parts of anti-caking agent; wherein the hydrophilic protective agent and plasticizer work synergistically on the protein base material that has undergone controlled enzymatic hydrolysis, so that the enzymatically hydrolyzed peptides of the protein base material form nanoparticles and construct a protective layer for the protein particles, and the anti-caking agent improves the dispersibility of the powder, thereby achieving rapid dissolution and stable suspension of the protein powder in multiple media.

[0007] Preferably, the hydrophilic protective agent is trehalose, the plasticizer is triethyl citrate, and the anti-caking agent is silicon dioxide.

[0008] Preferably, the protein base is selected from one or more of whey protein, soy protein, pea protein, rice protein, wheat protein, and casein; the whey protein is whey protein concentrate or whey protein isolate, and the soy protein is soy protein isolate.

[0009] Preferably, the whey protein has a protein content of ≥80%, the soy protein isolate has a protein content of ≥90%, the pea protein and rice protein have a protein content of ≥80%, the wheat protein has a protein content of ≥75%, and the casein protein has a protein content of ≥90%.

[0010] Preferably, the components, by weight, include: 70-100 parts protein base, 3-8 parts hydrophilic protective agent, 1-2 parts plasticizer, and 0.2-0.5 parts anti-caking agent.

[0011] Preferably, the protein base material is subjected to controlled enzymatic hydrolysis, and the degree of hydrolysis after enzymatic hydrolysis is 7-10%, and the enzymatically hydrolyzed protein base material forms nanoparticles of enzymatically hydrolyzed peptides, wherein the nanoparticles have a particle size of 50-110 nm.

[0012] A method for preparing instant protein powder includes the following steps: S1: Prepare a protein base solution with a mass percentage concentration of 10-15%, add protease for controlled enzymatic hydrolysis, control the hydrolysis conditions to achieve a degree of hydrolysis of 7-10% for the protein base, and inactivate the enzyme after hydrolysis; S2: Cool the enzyme-inactivated hydrolysate to 40-45℃, add a hydrophilic protective agent and a plasticizer, stir and let stand for 30-60 minutes to allow the enzymatically hydrolyzed peptides to form nanoparticles; S3: Perform three-stage temperature-controlled spray drying on the nanoparticles, successively passing through high-temperature shelling, medium-temperature drying, and low-temperature cooling stages to obtain protein powder particles; S4: Add an anti-caking agent to the protein powder particles, mix, sieve, and package to obtain instant protein powder.

[0013] Preferably, the protease in step S1 is an alkaline protease with an enzyme-substrate ratio of 1:100-1:200, an enzymatic hydrolysis temperature of 50-55℃, a pH of 7.5-8.0, and a stirring speed of 150-250 rpm; the enzyme inactivation condition is incubation at 80-90℃ for 8-12 minutes; the cooling rate in step S2 is 5-10℃ / min, the stirring speed is 50-80 rpm, and the nanoparticle size is 50-110 nm.

[0014] Preferably, the process parameters for the three-stage temperature-controlled spray drying in step S3 are as follows: inlet air temperature 180-190℃ and outlet air temperature 80-90℃ in the high-temperature shell-forming stage; inlet air temperature 150-160℃ and outlet air temperature 75-85℃ in the medium-temperature drying stage; and inlet air temperature 70-80℃ and outlet air temperature 45-55℃ in the low-temperature cooling stage; the spray drying feed flow rate is 40-60L / h, the atomization pressure is 0.15MPa-0.20MPa, and the negative pressure at the top of the tower is -150Pa to -250Pa.

[0015] Preferably, in step S4, the mixing speed is 10-20 rpm, the mixing time is 15-25 minutes, and the mixture is passed through a 40-60 mesh sieve.

[0016] The technical effects and advantages of this invention are as follows: This invention employs a technical route of controlled enzymatic hydrolysis, incubation at a controlled temperature, and three-stage temperature-controlled spray drying. This generates a protective layer of microparticles on and inside the protein particles, enabling the protein powder to achieve rapid dispersion, dissolution, and stable suspension in various reconstitution media such as water, milk, and juice. This overcomes the limitations of existing technologies that are only applicable to water or rely on high-temperature hot water. Key innovations include: 1. It does not rely on any exogenous additives; instead, controlled enzymatic hydrolysis allows the protein itself to generate enzymatic peptides. These peptides spontaneously arrange themselves into nanoscale microparticles during incubation at a controlled temperature, uniformly distributed within and on the surface of the protein, forming a protective layer; 2. The three-stage temperature-controlled drying process perfectly preserves the protective layer; 3. Trehalose and triethyl citrate work synergistically to protect the structural integrity during drying and optimize the rehydration properties of the particles. Attached Figure Description

[0017] The disclosure of this invention is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings, the same reference numerals are used to refer to the same parts: Figure 1 This is a schematic diagram of a formulation preparation process for solving the problem of instant dissolution of protein powder according to the present invention. Detailed Implementation

[0018] It is readily understood that, based on the technical solution of this invention, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of the invention. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative examples of the technical solution of this invention and should not be considered as the entirety of the invention or as limitations or restrictions on the technical solution of this invention.

[0019] This invention provides a technical solution: a formula for solving the problem of instant dissolution of protein powder, comprising: 70-100 parts of protein base, 2-10 parts of hydrophilic protective agent, 0.5-3 parts of plasticizer, and 0.1-1 parts of anti-caking agent.

[0020] The protein base material refers to the raw material used as the main protein source, selected from one or more of whey protein, soy protein, pea protein, rice protein, wheat protein, and casein.

[0021] Whey protein includes whey protein concentrate and whey protein isolate, wherein whey protein concentrate (WPC 80) has a protein content of ≥80%, and whey protein isolate (WPI 90) has a protein content of ≥90%. Soy protein is soy protein isolate with a protein content of ≥90%; Pea protein and rice protein content ≥80%; Wheat protein content ≥75%; Casein protein content ≥90%; The amphiphilic peptides of whey protein are mainly derived from the enzymatic hydrolysis products of β-lactoglobulin and α-lactalbumin; the amphiphilic peptides of soy protein are mainly derived from the enzymatic hydrolysis products of glycinin and conglycinin.

[0022] The preparation method of the instant protein powder of the present invention includes the following steps: S1: Take the protein base and add water to prepare a solution with a mass percentage concentration of 10-15%. Add alkaline protease for controlled enzymatic hydrolysis. The alkaline protease is food grade with an enzyme activity ≥2.4 AU / g. The enzyme-substrate ratio is 1:100-1:200, the stirring speed is 150-250 rpm, the hydrolysis temperature is controlled at 50-55℃, and the pH is 7.5-8.0, so that the degree of hydrolysis reaches 7-10%, generating enzymatically hydrolyzed peptides.

[0023] S2: After enzymatic hydrolysis, immediately raise the temperature to 80-90℃ and hold for 8-12 minutes to ensure complete inactivation of the alkaline protease. Rapidly cool the hydrolysate using a plate or tubular heat exchanger at a rate of 5-10℃ / min to 40-45℃. Add trehalose and triethyl citrate, both food-grade with a purity ≥99%. After stirring at 50-80 rpm until homogeneous, allow to stand at this temperature for 30-60 minutes to allow the enzymatically hydrolyzed peptides to form nanoparticles with a particle size of 50-110 nm.

[0024] S3: Nanoparticles are pumped into a spray drying tower with zoned temperature control for drying. This drying tower has three independent temperature-controlled zones along its height: the first zone is the upper atomization zone, with an inlet air temperature of 180-190℃ and an outlet air temperature of 80-90℃, allowing for rapid shell formation and locking of the droplets; the second zone is the middle drying zone, with an inlet air temperature of 150-160℃ and an outlet air temperature of 75-85℃, allowing for slow evaporation of internal moisture and promoting the fusion of micelles and the protein matrix; the third zone is the lower cooling zone, with an inlet air temperature of 70-80℃ and an outlet air temperature of 45-55℃, providing gradient cooling to avoid thermal shock. The feed flow rate for spray drying is 40-60 L / h, the atomization pressure is 0.15 MPa-0.20 MPa, and the negative pressure at the top of the tower is -150 Pa to 250 Pa. The total residence time of the material in the tower is 6-10 seconds. After passing through the three temperature-controlled zones, fast-dissolving protein powder particles are obtained.

[0025] S4: Collect the dried powder and add 0.1-1 parts of silica with a particle size of 5-15μm. Mix using a V-type mixer or a double cone mixer at a speed of 10-20 rpm for 15-25 minutes. After mixing, pass the powder through a 40-60 mesh standard sieve to remove large agglomerates, then seal and package it to obtain the instant protein powder product.

[0026] The functions and synergistic mechanisms of each component in the formulation of this invention are as follows: The protein base is partially hydrolyzed to a degree of 7-10%, producing enzymatically hydrolyzed peptides with molecular weights mainly concentrated in the 800-2000 Da range. These peptides contain both hydrophobic and hydrophilic amino acid residues, exhibiting typical amphiphilic molecular characteristics, thus providing a structural basis for subsequent processes.

[0027] Under static conditions at 40-45℃, enzymatically hydrolyzed peptides form core-shell structured nanoparticles through hydrophobic interactions: the total particle size of the nanoparticles is 50-110nm, the hydrophobic regions aggregate to form the hydrophobic core of the particles, and the hydrophilic regions extend outward to form the hydrophilic outer layer, together constituting a stable structure.

[0028] During spray drying, nanoparticles are uniformly distributed inside and on the surface of protein particles, forming a co-continuous phase with the protein matrix and constructing a protective layer of tiny particles on and inside the protein particles. This structure shields the binding of calcium ions to proteins in milk through steric hindrance and neutralizes protons through a hydrophilic outer layer in acidic media, thus achieving rapid dispersion and stable suspension in different media.

[0029] Trehalose forms a solid framework during the drying process, physically encapsulating and stabilizing the nanoparticles and maintaining their core-shell three-dimensional structure. Triethyl citrate acts as a plasticizer to adjust the flexibility of the framework and enhance the structural stability of the particles. The synergistic effect of the two protects the structural integrity during the drying process and optimizes the rehydration properties of the particles.

[0030] Example 1 This embodiment provides a formula for solving the problem of instant dissolution of protein powder, specifically including the following steps: S1: Add 60 parts whey protein isolate and 40 parts whey protein concentrate to an enzymatic hydrolysis tank. Add 800 parts of pure water at a ratio of 1:8, stir until fully dissolved, and adjust the temperature to 52±1℃ and the pH to 7.8±0.1. Add 0.67 parts of alkaline protease at an enzyme-substrate ratio of 1:150, start stirring at 200 rpm, and allow the enzymatic hydrolysis reaction to proceed for 30 minutes. Monitor the degree of hydrolysis in real time using the pH-stat method. When the degree of hydrolysis reaches 8.5%, immediately raise the temperature to 85℃ to inactivate the enzyme for 10 minutes.

[0031] S2: After enzyme inactivation, the enzymatic hydrolysate is rapidly cooled to 42±1℃ using a plate heat exchanger. 8 parts trehalose and 1.5 parts triethyl citrate are added, and the mixture is stirred at 60 rpm until homogeneous. The solution is allowed to stand at this temperature for 45 minutes to allow the enzymatically hydrolyzed peptides to fully form nanoparticles. During this period, samples are taken every 15 minutes to check the micelle size, ensuring that the nanoparticle size remains stable within the 60-90 nm range.

[0032] S3: Nanoparticles are pumped into a spray drying tower with zoned temperature control for drying. This tower has three independent temperature-controlled zones along its height: the upper zone has an inlet air temperature of 185±2℃ and an outlet air temperature of 85±3℃, where the material rapidly dehydrates to form a dense outer shell; the middle zone has an inlet air temperature of 155±2℃ and an outlet air temperature of 80±3℃, where moisture evaporates slowly inside the material, and micelles and the protein matrix fully fuse; the lower zone has an inlet air temperature of 75±2℃ and an outlet air temperature of 50±3℃, where the material experiences gradient cooling to avoid thermal shock. Spray drying parameters: feed flow rate 50L / h, atomization pressure 0.18MPa, tower top negative pressure -200Pa. The total residence time of the material in the tower is approximately 8 seconds, and it is collected after passing through the three temperature-controlled zones sequentially.

[0033] S4: Collect the dried powder, add 0.5 parts of silica, mix in a V-type mixer for 20 minutes at 15 rpm, and pass through a 40-mesh sieve to obtain the instant protein powder product.

[0034] Example 2 This embodiment provides a formula for solving the problem of instant dissolution of protein powder. Compared with Embodiment 1, the difference is: The enzymatic hydrolysis time was extended to 45 minutes, the degree of hydrolysis was controlled to reach 10.0% ± 0.2%, and the incubation time was extended to 60 minutes.

[0035] Example 3 This embodiment provides a formula for solving the problem of instant dissolution of protein powder. Compared with Embodiment 1, the difference is: The enzymatic hydrolysis time was shortened to 20 minutes, the degree of hydrolysis was controlled to reach 7.0%±0.2%, and the incubation time was shortened to 30 minutes.

[0036] Example 4 This embodiment provides a formula for solving the problem of instant dissolution of protein powder. Compared with Embodiment 1, the difference is: The ingredients were 100 parts soy protein isolate, 10 parts trehalose, 1.5 parts triethyl citrate, and 0.5 parts silica, which were basically the same as in Example 1. The enzymatic hydrolysis temperature was adjusted to 55±1℃, the pH to 8.0±0.1, the hydrolysis time to 35 minutes, the degree of hydrolysis to be controlled at 8.2%±0.2%, the standing temperature to 43±1℃, and the time to 50 minutes.

[0037] Example 5 This embodiment provides a formula for solving the problem of instant dissolution of protein powder. Compared with Embodiment 1, the difference is: The same method as in Example 1 was used, consisting of 50 parts whey protein isolate, 50 parts soy protein isolate, 9 parts trehalose, 2 parts triethyl citrate, and 0.5 parts silica. The enzymatic hydrolysis temperature was 53±1℃, the pH was 7.9±0.1, the hydrolysis time was 32 minutes, the degree of hydrolysis was controlled at 8.8%±0.2%, the standing temperature was 44±1℃, and the time was 50 minutes.

[0038] Example 6 This embodiment provides a formula for solving the problem of instant dissolution of protein powder. Compared with Embodiment 1, the difference is: Take 100 portions of pea protein, and follow the same procedure as in Example 1. The enzymatic hydrolysis temperature is 52±1℃, the pH is 7.8±0.1, the enzymatic hydrolysis time is 28 minutes, the degree of hydrolysis is controlled at 8.0%±0.2%, the standing temperature is 42±1℃, and the time is 45 minutes.

[0039] Example 7 This embodiment provides a formula for solving the problem of instant dissolution of protein powder. Compared with Embodiment 1, the difference is: Take 100 portions of rice protein, and follow the same procedure as in Example 1. The enzymatic hydrolysis temperature is 50±1℃, the pH is 7.5±0.1, the enzymatic hydrolysis time is 25 minutes, the degree of hydrolysis is controlled at 7.5%±0.2%, the standing temperature is 40±1℃, and the time is 40 minutes.

[0040] Example 8 This embodiment provides a formula for solving the problem of instant dissolution of protein powder. Compared with Embodiment 1, the difference is: Take 100 portions of casein, and follow the same procedure as in Example 1. The enzymatic hydrolysis temperature is 50±1℃, the pH is 7.5±0.1, the enzymatic hydrolysis time is 35 minutes, the degree of hydrolysis is controlled at 8.5%±0.2%, the standing temperature is 42±1℃, and the time is 50 minutes.

[0041] Comparative Example 1 This comparative example provides a formulation for solving the problem of instant dissolution of protein powder. The difference between this formulation and Example 1 is that: Concentrated whey protein powder, without any enzymatic hydrolysis or instant dissolution treatment.

[0042] Comparative Example 2 This comparative example provides a formulation for solving the problem of instant dissolution of protein powder. The difference between this formulation and Example 1 is that: 60 parts whey protein isolate, 40 parts whey protein concentrate, 8 parts trehalose, 1.5 parts triethyl citrate, and 0.5 parts silica were added directly to a V-type mixer and mixed for 30 minutes at 15 rpm. The mixture was then passed through a 40-mesh sieve. No enzymatic hydrolysis or self-assembly treatment was performed.

[0043] Comparative Example 3 This comparative example provides a formulation for solving the problem of instant dissolution of protein powder. The difference between this formulation and Example 1 is that: Enzymatic hydrolysis was performed according to the method in Example 1, with a degree of hydrolysis of 8.5%. After enzyme inactivation, trehalose and triethyl citrate were added directly without self-assembly and allowed to stand. After stirring evenly, spray drying was carried out with an inlet air temperature of 180°C and an outlet air temperature of 85°C. Three-stage temperature control was not performed.

[0044] Comparative Example 4 This comparative example provides a formulation for solving the problem of instant dissolution of protein powder. The difference between this formulation and Example 1 is that: Enzymatic hydrolysis was performed according to the method in Example 1, with a degree of hydrolysis of 8.5%. The mixture was kept at 42°C for 45 minutes, with an inlet air temperature of 180°C and an outlet air temperature of 85°C. Three-stage temperature control was not performed.

[0045] Comparative Example 5 This comparative example provides a formulation for solving the problem of instant dissolution of protein powder. The difference between this formulation and Example 1 is that: Enzymatic hydrolysis was performed according to the method in Example 1, with the hydrolysis time controlled at 12 minutes and the degree of hydrolysis at 5.0%. After standing for 30 minutes, samples were taken for testing: no stable micelles were detected.

[0046] Comparative Example 6 This comparative example provides a formulation for solving the problem of instant dissolution of protein powder. The difference between this formulation and Example 1 is that: Enzymatic hydrolysis was performed according to the method in Example 1, with the hydrolysis time controlled at 55 minutes and the degree of hydrolysis at 12.0%. After standing for 60 minutes, samples were taken for measurement: the particle size was 25.6 nm, the distribution was wide, and the particle size was unstable.

[0047] Comparative Example 7 This comparative example provides a formulation for solving the problem of instant dissolution of protein powder. The difference between this formulation and Example 1 is that: 60 parts whey protein isolate, 40 parts whey protein concentrate, 1.5 parts triethyl citrate, and 0.5 parts silica.

[0048] Comparative Example 8 This comparative example provides a formulation for solving the problem of instant dissolution of protein powder. The difference between this formulation and Example 1 is that: 60 parts whey protein isolate, 40 parts whey protein concentrate, 8 parts trehalose, and 0.5 parts silica.

[0049] Comparative Example 9 This comparative example provides a formulation for solving the problem of instant dissolution of protein powder. The difference between this formulation and Example 1 is that: Instant protein powder samples were prepared according to the formula and preparation method described in CN115176861A. The formula for this sample is as follows: 30% isolated whey protein, 47% whey protein concentrate, 3% maltitol, 13% resistant dextrin, 1.2% sunflower seed oil, 1% polyglycerol fatty acid ester, 2% cocoa powder, 1.5% alkalized cocoa powder, 1.14% edible flavoring, and 0.16% sucralose. The preparation method involves mixing the protein powder with the excipients, preparing a slurry using binders, oils, and emulsifiers, and then spraying, drying, and sieving the slurry using a high-speed shear granulator.

[0050] Comparative Example 10 This comparative example provides a formulation for solving the problem of instant dissolution of protein powder. The difference between this formulation and Example 1 is that: Enzymatic hydrolysis and self-assembly were performed according to the method in Example 1. Spray drying was carried out using conventional single-stage temperature control: inlet air temperature 180°C and outlet air temperature 85°C, without three-stage temperature control.

[0051] Comparative Example 11 This comparative example provides a formulation for solving the problem of instant dissolution of protein powder. The difference between this formulation and Example 1 is that: Prepared according to the method in Example 1, without adding silica, and directly sieved and packaged.

[0052] Samples of the protein powders prepared in Examples 1-8 and Comparative Examples 1-11 were taken and tested. The specific testing details are as follows: The degree of hydrolysis (DH) refers to the percentage of hydrolyzed peptide bonds in a protein, determined using the pH-stat method. The reaction system was 500 mL, the temperature was kept constant at 50 ± 0.5℃, the pH was kept constant at 7.8 ± 0.02, and the magnetic stirring speed was 300 rpm. The amount of alkali consumed was automatically recorded every 30 seconds, and an alarm was automatically triggered and the reaction terminated when the degree of hydrolysis reached the set value. A Mettler Toledo T7 automatic potentiometric titrator was used to record the consumption of 0.5 mol / L NaOH solution in real time during the enzymatic hydrolysis process. The degree of hydrolysis was calculated using the following formula: Where V represents the volume of NaOH solution consumed (mL); N represents the equivalent concentration of NaOH solution (0.5 mol / L); α is the degree of amino dissociation, taken as 0.98 at pH 7.8 and 50℃; M p The amount of protein (g) involved in the reaction; h tot The number of millimoles of peptide bonds per gram of protein is 8.8 for whey protein and 7.8 for soy protein.

[0053] The nanoparticle size distribution was determined using a Malvern Zetasizer Nano ZS90 dynamic light scattering particle size analyzer. Measurement parameters: temperature 25℃, equilibration time 120 seconds, three parallel measurements per sample, and the average particle size was recorded. Sample pretreatment: 1 mL of solution was diluted 10-fold with deionized water, filtered through a 0.45 μm filter membrane, and measured immediately.

[0054] The particle size of the finished product was determined using a Malvern Mastersizer 3000 laser particle size analyzer equipped with an Aero S dry dispersion system. Measurement parameters: dispersion pressure 0.2 MPa, feed rate 50%, shading 0.5-2.0%, background measurement time 10 seconds, sample measurement time 10 seconds, each sample was measured in triplicate, and the volume average particle size D40 was taken.

[0055] The angle of repose is the maximum angle between the inclined plane of a powder accumulation cone and the horizontal plane. It is used to evaluate the flowability of powder; the smaller the angle, the better the flowability. The angle of repose was measured using an FT-104B angle of repose measuring instrument via the injection method. Operating procedures: Place the circular horizontal platform in the center of the instrument; fix the funnel 10cm directly above the platform, with a lower opening diameter of 5mm; weigh 50.0g of sample and slowly pour it into the funnel, allowing the sample to fall freely onto the platform; after the sample has accumulated to a stable cone, after approximately 30 seconds, measure the angle between the inclined plane of the cone and the horizontal plane using a protractor; repeat the measurement three times for each sample and take the average value.

[0056] Table 1 Note: Comparative Example 9 is a granulated product with a relatively large particle size, but Table 2 shows that its solubility in room temperature water is poor, indicating that simply increasing the particle size cannot solve the problem of rapid dissolution in multiple media.

[0057] As shown in Table 1, the angle of repose of Examples 1-5 is better than that of Comparative Example 1, indicating that the protein powder prepared by this invention has good flowability. The degree of hydrolysis has a significant impact on nanoparticle formation: stable nanoparticles can be formed within the range of 7-10%; below 7%, nanoparticles cannot form; above 10%, the nanoparticle size is too small and the stability is poor. Trehalose and triethyl citrate have a certain influence on the nanoparticle size; their synergistic effect can obtain the optimal particle size.

[0058] Solubility time determination: Weigh 10.0g of sample and add it to 100mL of pure water at 25±1℃. Immediately turn on the magnetic stirrer at 300rpm and start the stopwatch simultaneously. Observe the time when the sample is completely dispersed and dissolved without any visible particles; this is the dissolution time. Repeat the measurement 3 times for each sample and take the average value. Dissolution time test medium in milk: Commercially available whole milk was used, and the test was conducted under refrigerated conditions at 4℃ and constant temperature conditions at 25℃. The test method is the same as for dissolution time in water. Dissolution time test medium in fruit juice: Commercially available 100% orange juice with a pH of 3.8±0.1 was used, and the test was conducted under constant temperature conditions at 25℃. The test method is the same as for dissolution time in water, while observing whether flocculation occurs.

[0059] Table 2 The results showed that the dissolution time was only 12 seconds in room temperature water at 25℃, 18 seconds in refrigerated milk at 4℃, 15 seconds in milk at 25℃, and 26 seconds in orange juice at pH 3.8, while maintaining a solubility of 97.5% even in hard water. In contrast, commercially available products dissolved in room temperature water for over 120 seconds, and exhibited severe flocculation and dispersibility in milk and orange juice. Comparative Example 9 dissolved rapidly in 85℃ hot water but required 32 seconds in room temperature water at 25℃, with significant flocculation. The data demonstrates that this invention, through the construction of an endogenous nanomicelle protection network, enables rapid dissolution of protein powder in various media such as water, milk, and juice. At temperatures ranging from 4℃ to 50℃, and in both soft and hard water conditions, a solution with rapid dispersion within 30 seconds and a stratification rate of less than 5% after 1 hour can be obtained.

[0060] Determination of layer separation rate: The protein beverage prepared according to the above method, with a protein concentration of 10%, was immediately transferred to a 25 mL stoppered graduated cylinder and allowed to stand at room temperature for 1 hour. 2 mL of the supernatant was carefully pipetted off, and the protein content was determined using the Kjeldahl method. The layer separation rate was calculated using the following formula: Wherein, C0 is the initial protein concentration (g / 100mL), that is, the protein concentration sampled immediately after complete dissolution, and C1 is the protein concentration (g / 100mL) of the supernatant after standing for 1 hour.

[0061] Table 3 As shown in Table 3, Example 1 exhibited a separation rate of only 2.8% in milk and 4.5% in orange juice after standing for 1 hour, indicating excellent static stability. The separation rates of Comparative Examples 3-4 were higher than those of Example 1, demonstrating the crucial role of the self-assembly process and three-stage temperature control in stability. The separation rates of Comparative Examples 7-8 fell between those of Comparative Examples 3-4 and Example 1, proving that the addition of trehalose and triethyl citrate further improved stability.

[0062] A UV-1800 UV-Vis spectrophotometer was used to measure the wavelength at 600 nm. Procedure: The sample was dispersed in the test medium at a 1:10 ratio and magnetically stirred for 30 seconds; 10 mL of the dispersion was taken and centrifuged at 3000 rpm for 10 minutes; the supernatant was placed in a 1 cm quartz cuvette, and the A600 value was measured using the corresponding medium as a blank; each sample was measured in triplicate, and the average value was taken.

[0063] Table 4 As shown in Table 4, the turbidity of Example 1 in milk was higher than that of Comparative Example 1, indicating that the protein powder prepared by this invention can form a more stable colloidal dispersion system in milk. The turbidity of Example 1 in orange juice was nearly 6 times that of Comparative Example 1, demonstrating its anti-acid flocculation effect. The turbidity of Comparative Examples 3-11 was all lower than that of Example 1, demonstrating the necessity of the complete process chain.

[0064] Simulated milk systems containing different concentrations of CaCl2 were prepared: CaCl2 was added to deionized water to achieve calcium ion concentrations of 2, 4, 6, 8, and 10 mmol / L, respectively. The calcium ion concentration in milk was approximately 30 mmol / L. This experiment used gradient concentrations to assess tolerance. The sample was dispersed in the above solutions at a ratio of 1:10, magnetically stirred for 30 seconds, and allowed to stand for 5 minutes. Observation was performed to check for precipitation and the turbidity A600 was measured.

[0065] Table 5 As shown in Table 5, in Example 1, the turbidity decreased by only 15.7% when the calcium ion concentration increased from 2 mM to 10 mM, demonstrating calcium ion tolerance. In Comparative Example 1, the turbidity decreased to 0.085 at a calcium ion concentration of 8 mM and only 0.048 at 10 mM, a decrease of 87.5%, indicating that the commercially available protein powder is highly sensitive to calcium ions. The turbidity decreases in Comparative Examples 3-4 were between those of Comparative Example 1 and Example 1, proving that the self-assembled structure has a certain shielding effect on calcium ions.

[0066] Prepare citrate-sodium citrate buffer solutions with pH values ​​of 3.0, 3.5, 4.0, 4.5, 5.0, and 5.5. Disperse the sample in the buffer solutions at a ratio of 1:10, stir magnetically for 30 seconds, let stand for 5 minutes, observe for flocculation, and measure the turbidity A600.

[0067] Table 6 As shown in Table 6, Example 1 maintained a turbidity above 0.68 within a pH range of 3.0-5.5, especially near the isoelectric point of the protein, indicating that the self-assembled structure effectively shielded against isoelectric point-induced aggregation. Comparative Example 1 showed a turbidity of only 0.085 at pH 3.0 and complete flocculation at pH 4.0-4.5, consistent with typical whey protein behavior. Comparative Examples 3-4 exhibited turbidities of 0.42-0.50 within a pH range of 3.0-4.5.

[0068] To verify the solubility of the protein powder of the present invention under different water quality conditions, samples from Example 1 and Comparative Example 1 were selected and their solubility was measured using deionized water, tap water with a hardness of about 150 mg / L, and hard water with a hardness of about 300 mg / L, respectively. The test temperature was 25℃, and the results are shown in Table 7.

[0069] Table 7 As shown in Table 7, the solubility of Comparative Example 1 decreased to only 58.2% under hard water conditions; while Example 1 still maintained a high solubility of 97.5% under hard water conditions. This indicates that the protective layer formed by the self-assembled micelle structure of the present invention effectively avoids protein precipitation induced by calcium and magnesium ions, ensuring the applicability of the formulation under different water quality conditions, without the need to add additional metal ion chelating agents.

[0070] The sample from Example 1 was selected, and the wetting time and solubility were measured at 5℃, 25℃, and 50℃ respectively. The results are shown in Table 8.

[0071] Table 8 As can be seen from Table 8, the formulation of the present invention can still maintain a short wetting time and a high solubility at a low temperature of 5°C, indicating that it does not depend on high-temperature hot water and has a good rapid solubility effect in ice water as well.

[0072] The sample from Example 1 was subjected to an accelerated test at 40°C and 75%RH for 6 months to measure the change in its instant dissolution effect. The results are shown in Table 9.

[0073] Table 9 As shown in Table 9, after 6 months of accelerated testing, there were no significant changes in the wetting time and solubility of the samples, indicating that the formulation of the present invention has good stability. The product's instant solubility and stability did not change significantly under accelerated storage conditions, demonstrating good storage stability.

[0074] The conventional storage conditions for the instant protein powder prepared by this invention are: below 25℃, relative humidity ≤60%, sealed, protected from light and moisture. After an accelerated stability test at 40℃ and 75%RH for 6 months, the key performance indicators of the product, such as wetting time, solubility, and stratification rate, showed no significant changes (see Table 9). According to the general rules of accelerated stability testing, the aging rate of the product increases approximately twice for every 10℃ increase in temperature. Therefore, it is estimated that a 6-month accelerated test at 40℃ is equivalent to 18 months of conventional storage at 25℃, indicating that the shelf life of the product under conventional storage conditions is 18 months.

[0075] The technical scope of this invention is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this invention, and all such modifications and variations should fall within the protection scope of this invention.

Claims

1. A type of instant protein powder, characterized in that, By weight, it comprises: 70-100 parts protein base, 2-10 parts hydrophilic protective agent, 0.5-3 parts plasticizer, and 0.1-1 parts anti-caking agent; the hydrophilic protective agent and plasticizer work synergistically with the protein base that has undergone controlled enzymatic hydrolysis, so that the enzymatically hydrolyzed peptides of the protein base form nanoparticles and construct a protective layer for the protein particles, and the anti-caking agent improves the dispersibility of the powder, thereby achieving rapid dissolution and stable suspension of the protein powder in multiple media.

2. The instant protein powder according to claim 1, characterized in that: The hydrophilic protective agent is trehalose, the plasticizer is triethyl citrate, and the anti-caking agent is silicon dioxide.

3. The instant protein powder according to claim 1, characterized in that: The protein base is selected from one or more of whey protein, soy protein, pea protein, rice protein, wheat protein, and casein; the whey protein is whey protein concentrate or whey protein isolate, and the soy protein is soy protein isolate.

4. The instant protein powder according to claim 3, characterized in that: The whey protein has a protein content of ≥80%, the soy protein isolate has a protein content of ≥90%, the pea protein and rice protein have a protein content of ≥80%, the wheat protein has a protein content of ≥75%, and the casein has a protein content of ≥90%.

5. The instant protein powder according to claim 1, characterized in that: By weight, it includes: 70-100 parts protein base, 5-8 parts hydrophilic protective agent, 1.2-1.8 parts plasticizer, and 0.3-0.5 parts anti-caking agent.

6. The instant protein powder according to claim 1, characterized in that: The protein base material is subjected to controlled enzymatic hydrolysis, and the degree of hydrolysis after enzymatic hydrolysis is 7-10%. The enzymatically hydrolyzed protein base material forms nanoparticles of enzymatically hydrolyzed peptides with a particle size of 50-110 nm.

7. A method for preparing the instant protein powder as described in claims 1-6, characterized in that: Includes the following steps: S1: Prepare a protein base material into a solution with a mass percentage concentration of 10-15%, add protease for controlled enzymatic hydrolysis, control the enzymatic hydrolysis conditions to make the degree of hydrolysis of the protein base material reach 7-10%, and inactivate the enzyme after enzymatic hydrolysis. S2: Cool the enzyme hydrolysate after enzyme inactivation to 40-45℃, add hydrophilic protective agent and plasticizer, stir and let stand for 30-60 minutes to form nanoparticles from the enzyme hydrolysate peptides; S3: The nanoparticles are subjected to three-stage temperature-controlled spray drying, which successively goes through high-temperature shelling, medium-temperature drying and low-temperature cooling stages to obtain protein powder particles; S4: Add an anti-caking agent to the protein powder granules, mix, sieve, and package to obtain instant protein powder.

8. The method for preparing an instant protein powder according to claim 7, characterized in that: The protease mentioned in step S1 is an alkaline protease with an enzyme-substrate ratio of 1:100-1:200, an enzymatic hydrolysis temperature of 50-55℃, a pH of 7.5-8.0, and a stirring speed of 150-250 rpm; the enzyme inactivation condition is incubation at 80-90℃ for 8-12 minutes; the cooling rate in step S2 is 5-10℃ / min, the stirring speed is 50-80 rpm, and the particle size of the nanoparticles is 50-110 nm.

9. The method for preparing an instant protein powder according to claim 7, characterized in that: The process parameters for the three-stage temperature-controlled spray drying in step S3 are as follows: inlet air temperature 180-190℃ and outlet air temperature 80-90℃ in the high-temperature shell-forming stage; inlet air temperature 150-160℃ and outlet air temperature 75-85℃ in the medium-temperature drying stage; and inlet air temperature 70-80℃ and outlet air temperature 45-55℃ in the low-temperature cooling stage. The spray drying feed flow rate is 40-60L / h, the atomization pressure is 0.15MPa-0.20MPa, and the negative pressure at the top of the tower is -150Pa to -250Pa.

10. The method for preparing an instant protein powder according to claim 7, characterized in that: In step S4, the mixing speed is 10-20 rpm, the mixing time is 15-25 minutes, and the mixture is passed through a 40-60 mesh sieve.

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