Salt-reducing and salty-increasing salt-carrying particles as well as preparation method and application thereof

Abstract

The invention provides salt-reducing and salty-increasing salt-carrying particles as well as a preparation method and application thereof, and belongs to the technical field of food salt reduction. The salt-reducing and salt-increasing salt-loading particle provided by the invention comprises negatively charged nano-particles and Na < + > loaded on the negatively charged nano-particles, wherein the nano-particles are formed by sequentially performing enzymolysis and self-assembly on amphiphilic protein. Nanoparticles are obtained through enzymolysis and self-assembly of amphiphilic protein and loaded with sodium ions, the nanoparticles can serve as an adhesion component to adjust sensory perception and modify sensory characteristics, the nanoparticles serve as a carrier to load the sodium ions, and the obtained salt-loaded particles have the excellent mucus penetrating property and can be used for preparing the salt-loaded particles. The product can deeply permeate into oral mucus and stay for a long time, so that the salty taste perception effect is enhanced. The salt-reducing and salt-increasing salt-carrying particle provided by the invention can effectively solve the problem of reducing salt but not reducing salt, and is low in cost and suitable for large-scale production and application.

Description

Technical Field

[0001] The present invention relates to the technical field of food salt reduction, and in particular to a salt-reducing and salt-increasing salt-carrying granule, and a preparation method and application thereof. Background Art

[0002] Excessive intake of salt in the diet can directly lead to high blood pressure and increase the risk of stroke and cardiovascular disease. Excessive salt intake has become the second largest dietary risk factor for disease and death worldwide. Therefore, it is necessary to consider reducing the public's daily salt intake by reducing salt. At present, salt reduction strategies mainly include the use of salt substitutes, the use of flavor or saltiness enhancers, and the change of the physical form of salt particles. However, the above methods have certain defects. The use of salt substitutes such as potassium chloride is often accompanied by bitterness and metallic taste, and may disrupt the body's ion balance; the use of flavor or saltiness enhancers such as yeast extract and monosodium glutamate may have adverse effects on health, such as causing hyperactivity and migraines; the disadvantage of changing the physical form of salt particles is the high production cost, which limits its commercial application. Summary of the invention

[0003] The purpose of the present invention is to provide a salt-reducing and salt-increasing salt-carrying particle and a preparation method and application thereof. The salt-reducing and salt-increasing salt-carrying particle provided by the present invention can effectively solve the problem of reducing salt without reducing salt, and has low cost and is suitable for large-scale production and application.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The invention provides a salt-reducing and salt-increasing salt-carrying particle, comprising a negatively charged nanoparticle and Na loaded on the negatively charged nanoparticle. + The nanoparticles are formed by enzymatic hydrolysis and self-assembly of amphiphilic proteins.

[0006] Preferably, the Na in the salt-reducing and salt-increasing salt-carrying particles is + The mass of the nanoparticles is 40-45% of the mass of the nanoparticles.

[0007] Preferably, the amphiphilic protein comprises one or more of β-lactoglobulin, soy protein isolate and pea protein isolate.

[0008] Preferably, the nanoparticles include one or more of long rod-shaped nanoparticles, short rod-shaped nanoparticles and spherical nanoparticles; the long rod-shaped nanoparticles have a length of 500 to 1500 nm and a diameter of 9 to 11 nm; the short rod-shaped nanoparticles have a length of 50 to 250 nm and a diameter of 9 to 11 nm; the spherical nanoparticles have a particle size of 50 to 300 nm.

[0009] Preferably, the method for preparing the long rod-shaped nanoparticles comprises the following steps:

[0010] The amphiphilic protein, the first protease and water are mixed for a first enzymatic hydrolysis, the pH value of the obtained first enzymatic hydrolysis solution is adjusted to 1.8-2.2, and a first self-assembly is performed under stirring conditions to obtain the long rod-shaped nanoparticles;

[0011] The method for preparing the short rod-shaped nanoparticles comprises the following steps:

[0012] Ultrasonic treatment is performed on the liquid containing the long rod-shaped nanoparticles to obtain the short rod-shaped nanoparticles;

[0013] The preparation method of the spherical nanoparticles comprises the following steps:

[0014] The amphiphilic protein, the second protease and the buffer solution are mixed to perform a second enzymatic hydrolysis, and the obtained second enzymatic hydrolysis solution is subjected to a second self-assembly under ultrasonic conditions to obtain the spherical nanoparticles.

[0015] Preferably, the first protease and the second protease are independently selected from Bacillus licheniformis protease, pepsin or papain;

[0016] The temperature of the first enzymatic hydrolysis is 45-55°C, and the time is 50-70 min; the conditions of the first self-assembly include: the temperature is 85-95°C, the stirring rate is 130-170 rpm, and the time is 1.5-14 h;

[0017] The number of ultrasonic treatments is 2 to 4 times; the temperature of each ultrasonic treatment is independently -2 to 2°C, the time is independently 25 to 35 seconds, and the power is independently 140 to 160W; the interval between two adjacent ultrasonic treatments is 4 to 6 minutes;

[0018] The temperature of the second enzymatic hydrolysis is 45-55° C., and the time is 20-40 min. The conditions of the second self-assembly include: the temperature is -2-2° C., the ultrasonic power is 140-160 W, and the time is 25-35 s.

[0019] The present invention provides a method for preparing the salt-reducing and salt-increasing salt-carrying particles described in the above technical solution, comprising the following steps:

[0020] The nanoparticles and sodium chloride are loaded in a dispersant to obtain the salt-reducing and salt-increasing salt-loaded particles; the nanoparticles are formed by enzymatic hydrolysis and self-assembly of amphiphilic proteins in sequence.

[0021] Preferably, the load treatment conditions include: temperature of 15-35° C. and time of 25-35 min.

[0022] The present invention provides the use of the salt-reducing and salt-increasing salt-carrying particles described in the above technical solution or the salt-reducing and salt-increasing salt-carrying particles prepared by the preparation method described in the above technical solution in food seasonings.

[0023] Preferably, the food condiment comprises hot pot base or dipping sauce.

[0024] The invention provides a salt-reducing and salt-increasing salt-carrying particle, comprising a negatively charged nanoparticle and Na loaded on the negatively charged nanoparticle. + , the nanoparticles are formed by enzymatic hydrolysis and self-assembly of amphiphilic proteins in sequence. The present invention utilizes the enzymatic hydrolysis and self-assembly of amphiphilic proteins to obtain nanoparticles and load sodium ions, wherein the nanoparticles can be used as adhesion components to regulate sensory perception and modify sensory properties, and are used as carriers to load sodium ions. The resulting salt-loaded particles have excellent mucus penetration properties, can penetrate deeply into oral mucus and stay for a long time, thereby enhancing the salty taste perception effect, and provide a new technical means for reducing salt and increasing saltiness. At the same time, the salt-reducing and salt-increasing salt-loaded particles provided by the present invention have low cost, are suitable for large-scale production and application, and can be used as food flavorings in various foods, such as hot pot base or dipping sauce, etc., which can achieve the purpose of reducing salt and increasing saltiness, and are conducive to reducing the public's daily salt intake and reducing the health risks caused by excessive salt intake.

[0025] Furthermore, the present invention can prepare nanoparticles of different shapes, such as long rod-shaped nanoparticles, short rod-shaped nanoparticles or spherical nanoparticles, based on amphiphilic proteins such as β-lactoglobulin, soy protein isolate and pea protein isolate by controlling enzymatic hydrolysis and self-assembly conditions, which is conducive to meeting the particle size requirements of different foods for salt particles; and the present invention studies the effect of the mucus penetration properties of nanoparticles of different shapes on the perception of saltiness. The results show that compared with spherical nanoparticles and long rod-shaped nanoparticles of the same chemical properties, short rod-shaped nanoparticles have more excellent adhesion and penetration properties, can penetrate deeper into the mucus, and stay in the mucus longer, so that more sodium ions are retained on the tongue, which helps to improve the salty perception effect. Based on this, the goal of reducing salt and increasing saltiness in liquid and semi-solid foods (such as hot pot base or dipping sauce) can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 TEM images of the long rod-shaped nanoparticles prepared in Example 1 and the short rod-shaped nanoparticles prepared in Example 2;

[0027] Figure 2 TEM image of spherical nanoparticles prepared in Example 3;

[0028] Figure 3 A comparison of the salty taste of salt solutions containing different types of nanoparticles;

[0029] Figure 4 are salinity-concentration curves of table salt in water and in feed solutions containing long-rod-shaped nanoparticles, short-rod-shaped nanoparticles or spherical nanoparticles respectively;

[0030] Figure 5 This is a saltiness evaluation chart for different types of hot pot base products;

[0031] Figure 6 This is a test diagram of the adhesion of different types of salt-loaded particles on pig tongue in vitro;

[0032] Figure 7 This is a test diagram of the dynamic diffusion of sodium ions through the mucin layer in different types of salt-loaded particles. DETAILED DESCRIPTION

[0033] The invention provides a salt-reducing and salt-increasing salt-carrying particle, comprising a negatively charged nanoparticle and Na loaded on the negatively charged nanoparticle. + The nanoparticles are formed by enzymatic hydrolysis and self-assembly of amphiphilic proteins.

[0034] In the present invention, unless otherwise specified, the raw materials used are commercially available products well known to those skilled in the art or are prepared by methods well known to those skilled in the art; and unless otherwise specified, the sodium chloride described in the present invention specifically refers to table salt.

[0035] The salt-reducing and salt-increasing salt-carrying particles of the present invention include negatively charged nanoparticles and Na loaded on the negatively charged nanoparticles. + As an embodiment of the present invention, the Na + The mass of the nanoparticles is 40-45% (i.e., Na on each gram of nanoparticles). + The loading amount can be 400-450 mg), specifically 40%, 40.5%, 41%, 41.5%, 42%, 42.5%, 43%, 43.5%, 44%, 44.5% or 45%.

[0036] The nanoparticles of the present invention are formed by enzymatic hydrolysis and self-assembly of amphiphilic proteins. As an embodiment of the present invention, the amphiphilic protein may include one or more of β-lactoglobulin, soy protein isolate and pea protein isolate, specifically β-lactoglobulin, soy protein isolate or pea protein isolate.

[0037] As an embodiment of the present invention, the nanoparticles may include one or more of long rod-shaped nanoparticles, short rod-shaped nanoparticles and spherical nanoparticles, and may specifically be long rod-shaped nanoparticles, short rod-shaped nanoparticles or spherical nanoparticles. As an embodiment of the present invention, the length of the long rod-shaped nanoparticles may be 500-1500nm, further may be 700-1400nm, specifically may be 800-1200nm; the diameter may be 9-11nm, specifically may be 10nm. As an embodiment of the present invention, the length of the short rod-shaped nanoparticles may be 50-250nm, further may be 80-220nm, specifically may be 100-200nm; the diameter may be 9-11nm, specifically may be 10nm. As an embodiment of the present invention, the particle size of the spherical nanoparticles may be 50-300nm, further may be 50-200nm, specifically may be 50-150nm.

[0038] As an embodiment of the present invention, the preparation method of the long rod-shaped nanoparticles includes the following steps: mixing an amphiphilic protein, a first protease and water for a first enzymatic hydrolysis, adjusting the pH value of the obtained first enzymatic hydrolysis solution to 1.8-2.2, and performing a first self-assembly under stirring conditions to obtain the long rod-shaped nanoparticles.

[0039] As an embodiment of the present invention, the first protease may be Bacillus licheniformis protease, pepsin or papain, specifically Bacillus licheniformis protease; the enzymatic activity of the first protease may be 13-14U / mg, specifically 13.7U / mg; the mass of the first protease may be 1.8-2.2% of the mass of the amphiphilic protein, specifically 2%; the dosage ratio of the amphiphilic protein to water may be 60mg:1.5-2.5mL, specifically 60mg:2mL. As an embodiment of the present invention, the temperature of the first enzymolysis may be 45-55°C, specifically 50°C; the time may be 50-70min, specifically 60min. In the embodiment of the present invention, the first enzymolysis is carried out under the above conditions, so that the amphiphilic protein can be hydrolyzed into peptide segments, which is conducive to rapid self-assembly into long rod-shaped nanoparticles.

[0040] As an embodiment of the present invention, after the first enzymolysis, no post-treatment is required, and the pH value of the obtained first enzymolysis liquid is directly adjusted to 1.8-2.2 (specifically 2.0), and the first self-assembly is performed under stirring conditions; the reagent used to adjust the pH value can be hydrochloric acid, and the concentration of the hydrochloric acid can be 1M. As an embodiment of the present invention, the conditions for the first self-assembly include: the temperature can be 85-95°C, specifically 90°C; the stirring rate can be 130-170rpm, specifically 150rpm; the time can be 1.5-14h, wherein when the amphiphilic protein is β-lactoglobulin, the time of the first self-assembly can be 1.5-2.5h, specifically 2h; when the amphiphilic protein is soy protein isolate or pea protein isolate, the time of the first self-assembly can be 10-14h. In the embodiment of the present invention, the first self-assembly is performed under the above conditions, which can induce the amphiphilic protein hydrolysate to self-assemble into long rod-shaped nanoparticles. As an embodiment of the present invention, the slurry containing long rod-shaped nanoparticles obtained after the first self-assembly can be separated as needed (the separation method can be, for example, ultrafiltration) to obtain the long rod-shaped nanoparticles, or the slurry containing long rod-shaped nanoparticles can be directly used for subsequent related treatments (such as preparing short rod-shaped nanoparticles or loading sodium ions to prepare salt-reducing and salt-increasing salt-loaded particles), and the present invention has no special limitations on this.

[0041] As an embodiment of the present invention, the method for preparing the short rod-shaped nanoparticles comprises the following steps: subjecting a liquid containing the long rod-shaped nanoparticles to ultrasonic treatment to obtain the short rod-shaped nanoparticles.

[0042] As an embodiment of the present invention, the liquid containing long rod-shaped nanoparticles obtained after the first self-assembly of the above technical solution can be subjected to ultrasonic treatment. As an embodiment of the present invention, the number of ultrasonic treatments can be 2 to 4 times, specifically 3 times; the temperature of each ultrasonic treatment can be independently -2 to 2°C, specifically 0°C; the time can be independently 25 to 35s, specifically 30s; the power can be independently 140 to 160W, specifically 150W; the interval between two adjacent ultrasonic treatments can be 4 to 6min, specifically 5min. In the embodiment of the present invention, ultrasonic treatment is carried out under the above conditions, which can shorten the long rod-shaped nanoparticles, which is conducive to the rapid preparation of short rod-shaped nanoparticles. As an embodiment of the present invention, the liquid containing short rod-shaped nanoparticles obtained after the ultrasonic treatment can be separated as needed (the separation method can be, for example, ultrafiltration) to obtain the short rod-shaped nanoparticles, or the liquid containing short rod-shaped nanoparticles can be directly used for subsequent related treatments (such as loading sodium ions to prepare salt-reducing and salt-increasing salt-carrying particles), and the present invention is not particularly limited to this.

[0043] As an embodiment of the present invention, the method for preparing the spherical nanoparticles comprises the following steps: mixing the amphiphilic protein, the second protease and the buffer solution for a second enzymatic hydrolysis, and subjecting the obtained second enzymatic hydrolysis solution to a second self-assembly under ultrasonic conditions to obtain the spherical nanoparticles.

[0044] As an embodiment of the present invention, the second protease may be Bacillus licheniformis protease, pepsin or papain, specifically Bacillus licheniformis protease; the enzymatic activity of the second protease may be 13-14U / mg, specifically 13.7U / mg; the mass of the second protease may be 1.8-2.2% of the mass of the amphiphilic protein, specifically 2%; the buffer solution may be a PBS buffer solution, the pH value of the PBS buffer solution may be 7.3-7.7, specifically 7.5 (the concentration may be 10mM); the dosage ratio of the amphiphilic protein to the buffer solution may be 6mg:5-7mL, specifically 6mg:6mL. As an embodiment of the present invention, the temperature of the second enzymolysis may be 45-55°C, specifically 50°C; the time may be 20-40min, specifically 30min. In the embodiment of the present invention, the second enzymolysis is carried out under the above conditions, so that the amphiphilic protein can be hydrolyzed into peptide segments, which is conducive to rapid self-assembly into spherical nanoparticles.

[0045] As an embodiment of the present invention, no post-treatment is required after the second enzymatic hydrolysis, and the obtained second enzymatic hydrolysis liquid is directly subjected to the second self-assembly under ultrasonic conditions. As an embodiment of the present invention, the conditions for the second self-assembly include: the temperature can be -2 to 2°C, specifically 0°C; the ultrasonic power is 140 to 160W, specifically 150W; the time can be 25 to 35s, specifically 30s. In the embodiment of the present invention, the second self-assembly is carried out under the above conditions, so that the peptide segments produced by the second enzymatic hydrolysis can self-assemble into spherical nanoparticles. As an embodiment of the present invention, the liquid containing spherical nanoparticles is obtained after the second self-assembly, and can be separated as needed (the separation method can be, for example, ultrafiltration) to obtain the spherical nanoparticles, or the liquid containing spherical nanoparticles can be directly used for subsequent related treatments (such as loading sodium ions to prepare salt-reducing and salt-increasing salt-carrying particles), and the present invention has no special restrictions on this.

[0046] The present invention provides a method for preparing the salt-reducing and salt-increasing salt-carrying particles described in the above technical solution, comprising the following steps:

[0047] The nanoparticles and sodium chloride are loaded in a dispersant to obtain the salt-reducing and salt-increasing salt-loaded particles; the nanoparticles are formed by enzymatic hydrolysis and self-assembly of amphiphilic proteins in sequence.

[0048] The preparation method of the nanoparticles of the present invention can refer to the above technical solution and will not be repeated here. As one embodiment of the present invention, the dispersant can be water; in the embodiment of the present invention, the sodium chloride can be mixed with the dispersant to obtain a sodium chloride solution; the nanoparticles are mixed with the sodium chloride solution, and the resulting mixed liquid is subjected to a loading treatment; the concentration of the sodium chloride solution can be 40 to 60 mmol / L, further can be 45 to 55 mmol / L, and specifically can be 50 mmol / L; the concentration of the nanoparticles in the mixed liquid can be 0.15 to 0.25 wt%, further can be 0.18 to 0.22 wt%, and specifically can be 0.2 wt%. As one embodiment of the present invention, the loading treatment conditions include: the temperature can be 15 to 35 ° C, specifically can be 25 ° C; the time can be 25 to 35 min, specifically can be 30 min. In the embodiment of the present invention, loading treatment is carried out under the above conditions, and the electrostatic interaction mechanism can be utilized to make Na + Loaded on the surface of negatively charged nanoparticles. As an embodiment of the present invention, after the loading treatment, a slurry containing salt-reducing and salt-increasing salt-carrying particles is obtained, which can be separated as needed (separation method can be, for example, ultrafiltration) to obtain the salt-reducing and salt-increasing salt-carrying particles, or the slurry containing salt-reducing and salt-increasing salt-carrying particles can be directly used for subsequent related treatment (such as for preparing food seasonings), and the present invention has no special limitation on this.

[0049] The present invention provides the use of the salt-reducing and salt-increasing salt-carrying particles described in the above technical solution or the salt-reducing and salt-increasing salt-carrying particles prepared by the preparation method described in the above technical solution in food seasonings. As an embodiment of the present invention, the food seasoning may include hot pot base or dipping sauce.

[0050] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] Example 1

[0052] 60 mg of β-lactoglobulin (purchased from Aladdin, CAS No.: 9045-23-2) was dissolved in 2 mL of deionized water to obtain a β-lactoglobulin solution; Bacillus licheniformis protease (purchased from Sigma-Aldrich, CAS No.: 9014-01-1) with an enzyme activity of 13.7 U / mg was added to the β-lactoglobulin solution, and the mass of the Bacillus licheniformis protease was 2% of the mass of β-lactoglobulin, and then an enzymatic hydrolysis reaction was performed at 50° C. for 1 hour to obtain a feed solution containing β-lactoglobulin hydrolysate;

[0053] The pH value of the β-lactoglobulin hydrolysate-containing solution is adjusted to 2.0 with 1M hydrochloric acid, and then incubated for 2 hours at a temperature of 90°C and a magnetic stirring speed of 150 rpm to induce the β-lactoglobulin hydrolysate to self-assemble into long rod-shaped nanoparticles (LNF), thereby obtaining a slurry containing long rod-shaped nanoparticles, and then subjected to ultrafiltration treatment to separate the long rod-shaped nanoparticles;

[0054] The long rod-shaped nanoparticles were mixed with a 50 mM salt (NaCl) solution, and the concentration of the long rod-shaped nanoparticles in the obtained mixed solution was 0.2 wt %, and then the loading treatment was carried out at 25° C. for 30 min to allow NaCl to + The salt-loaded particles (Na in the salt-loaded particles) are then separated by ultrafiltration. + The mass of the nanoparticles is 42.5 wt% of the mass of the long rod-shaped nanoparticles).

[0055] Example 2

[0056] A feed solution containing long rod-shaped nanoparticles was prepared according to the method of Example 1;

[0057] The feed solution containing long rod-shaped nanoparticles is subjected to ultrasonic treatment for 3 times in an ice bath (0° C.) at a power of 150 W, with each ultrasonic treatment lasting 30 seconds and an interval of 5 minutes between two adjacent ultrasonic treatments, to obtain a feed solution containing short rod-shaped nanoparticles (SNF), and then subjected to ultrafiltration treatment to separate the short rod-shaped nanoparticles;

[0058] The short rod-shaped nanoparticles were mixed with a 50 mM salt solution, and the concentration of the short rod-shaped nanoparticles in the obtained mixed solution was 0.2 wt %, and then the loading treatment was carried out at 25° C. for 30 min to allow Na + The salt-loaded particles (Na in the salt-loaded particles) are then separated by ultrafiltration. + The mass of the short rod-shaped nanoparticles is 42.5 wt %).

[0059] Figure 1TEM images of the long rod-shaped nanoparticles prepared in Example 1 and the short rod-shaped nanoparticles prepared in Example 2, wherein A is the TEM image of the long rod-shaped nanoparticles, and B is the TEM image of the short rod-shaped nanoparticles; the results show that the rod-shaped nanoparticles prepared in Example 1 have good dispersibility in water, and the length of the long rod-shaped nanoparticles is 800-1200nm and the diameter is 10nm; the length of the short rod-shaped nanoparticles is 100-200nm and the diameter is 10nm.

[0060] Example 3

[0061] 6 mg of β-lactoglobulin was dissolved in 6 mL of PBS buffer solution (pH 7.5, concentration 10 mM) to obtain a β-lactoglobulin solution; Bacillus licheniformis protease with an enzyme activity of 13.7 U / mg was added to the β-lactoglobulin solution, and the amount of the Bacillus licheniformis protease was 2% of the mass of β-lactoglobulin; then, an enzymolysis reaction was performed at 50° C. for 30 min to obtain a feed solution containing β-lactoglobulin protease hydrolysate;

[0062] The feed liquid containing β-lactoglobulin hydrolysate is subjected to ultrasonic treatment for 30 seconds at a temperature of 0° C. and a power of 150 W to allow the β-lactoglobulin hydrolysate to self-assemble into spherical nanoparticles (BNS), thereby obtaining a feed liquid containing spherical nanoparticles, and then subjected to ultrafiltration treatment to separate and obtain the spherical nanoparticles;

[0063] The spherical nanoparticles were mixed with a 50 mM salt solution, and the concentration of the spherical nanoparticles in the obtained mixed solution was 0.2 wt %, and then the loading treatment was carried out at 25° C. for 30 min to allow Na + The loaded particles are loaded on the surface of spherical nanoparticles, and then separated by ultrafiltration to obtain salt-loaded particles (Na + The mass of the spherical nanoparticles is 42.5wt%).

[0064] Figure 2 This is a TEM image of the spherical nanoparticles prepared in Example 3. The results show that the spherical nanoparticles prepared in Example 3 have good dispersibility in water, and the particle size of the spherical nanoparticles is 50-150 nm.

[0065] Test Example 1 Sensory Evaluation

[0066] All sensory evaluations of this test case were conducted in a sensory evaluation room, and each experiment was repeated three times, including saltiness comparison evaluation and quantitative saltiness analysis, which are described in detail below.

[0067] 1. Saltiness comparison evaluation: In the saltiness comparison evaluation, the panelists were not trained, but were informed of the purpose of the test. The panelists consisted of 12 student volunteers, including 6 girls and 6 boys, aged between 20 and 30 years old. The volunteers had no history of taste or smell disorders and agreed to the standard sample evaluation procedure (ISO 8586) before participating. The volunteers participated in the saltiness comparison evaluation test of salt solutions containing different types of nanoparticles. The test steps are as follows:

[0068] The long rod-shaped nanoparticles, short rod-shaped nanoparticles and spherical nanoparticles prepared in Examples 1 to 3 were mixed with a 50 mM salt solution, respectively, so that the concentration of the nanoparticles in the resulting mixed solution was 0.1 wt%, and an experimental sample was obtained. The researchers gave each volunteer 5 mL of a 50 mM salt solution as a control sample, and asked each volunteer to hold it in the mouth for 10 seconds and then spit it out. The volunteers then held the experimental sample in the mouth for 10 seconds and then spit it out. The relative saltiness of the test sample was evaluated based on the control sample, and between two consecutive sample tastings, the volunteers rinsed their mouths thoroughly with water for 2 minutes. The relative saltiness of the sample in this test example is expressed as: "none" means that there is no difference in saltiness; "+" means that it feels slightly salty; "++" means that it feels saltier; "+++" means that it feels very salty.

[0069] Figure 3 Figure 1 is a comparison of the saltiness of salt solutions containing different types of nanoparticles, wherein A is a saltiness test result diagram of a salt solution containing long rod-shaped nanoparticles, B is a saltiness test result diagram of a salt solution containing short rod-shaped nanoparticles, and C is a saltiness test result diagram of a salt solution containing spherical nanoparticles; Figure 3 The middle horizontal axis represents the relative saltiness intensity of the salt solution with a comparison concentration of 50mM. The results show that the volunteers felt that the saltiness of the samples with the addition of nanoparticles was enhanced, especially the experimental samples with the addition of short rod-shaped nanoparticles, whose saltiness intensity was significantly higher and all group members felt the enhanced saltiness.

[0070] 2. Quantitative saltiness analysis: In the quantitative saltiness analysis, the team members were trained to standardize the saltiness of different standard salt solution concentrations and assign values ​​of 10mM (0.0), 20mM (0.5), 30mM (1.0), 40mM (1.5), 60mM (3.0), 70mM (4.0), 80mM (6.0) and 100mM (10.0). The specific test steps are as follows:

[0071] The long rod-shaped nanoparticles, short rod-shaped nanoparticles and spherical nanoparticles prepared in Examples 1 to 3 were mixed with salt solutions of different concentrations (10 to 100 mM) respectively, so that the concentration of nanoparticles in the resulting mixed solution was 0.1 wt%, to obtain experimental samples. The researchers gave each volunteer 5 mL of salt solutions of different concentrations (10 to 100 mM) as a control sample, and asked each volunteer to hold it in the mouth for 10 seconds and then spit it out. The volunteers then held the experimental sample in the mouth for 10 seconds and then spit it out. The panelists need to judge the saltiness score of the experimental sample by repeatedly checking the control salt solution to determine the saltiness intensity. Each time, the panelists take the average saltiness of the 10-second tasting to score the experimental sample, and the time interval between two adjacent scores is 30 seconds. Then the panelists rinse their mouths thoroughly with water for 2 minutes to evaluate the next sample.

[0072] Figure 4 The saltiness-concentration curves of salt in water and in liquids containing long-rod-shaped nanoparticles, short-rod-shaped nanoparticles or spherical nanoparticles respectively. The results show that compared with the control salt solution, under different salt concentration conditions, the addition of different types of nanoparticles has a saltiness enhancement effect. Among them, under different salt concentration conditions, the saltiness perception of the liquid containing short-rod-shaped nanoparticles is significantly improved, followed by spherical nanoparticles, and then long-rod-shaped nanoparticles, indicating that the shape of the nanoparticles will affect their saltiness enhancement effect.

[0073] Test Example 2 Preparation and Saltiness Evaluation of Low-Salt Hot Pot Base

[0074] According to the recipe (composition includes butter, bean paste, chili, fermented black beans, green onion, ginger, monosodium glutamate, garlic, edible salt, spices, single crystal rock sugar, pepper, yeast extract and 5'-flavor ribonucleotide disodium), 0.3wt% salt (normal), 0.2wt% salt (33% salt reduction), 0.2wt% salt plus 0.2wt% nanoparticles of different shapes of hot pot soup base were prepared; the obtained hot pot soup base was dried and sterilized to obtain hot pot soup base products with normal salt content, reduced salt hot pot soup base products and reduced salt and increased saltiness hot pot soup base products respectively; the 12 trained team members in Test Example 1 were used to evaluate the saltiness of each hot pot soup base product.

[0075] Figure 5The saltiness evaluation chart of different types of hot pot soup base products shows that the addition of nanoparticles under the condition of reducing salt can achieve the effect of increasing saltiness. Among them, the saltiness of the reduced-salt hot pot soup base products containing short-rod-shaped nanoparticles or spherical nanoparticles is not significantly different from that of the hot pot soup base products with normal salt content. In other words, the addition of short-rod-shaped nanoparticles and spherical nanoparticles enhances the perception of saltiness, reducing the salt content of the hot pot soup base by 33% without losing saltiness. In particular, when short-rod-shaped nanoparticles are added, the saltiness of the reduced-salt hot pot soup base products is even slightly higher than that of the hot pot soup base products with normal salt content, indicating that it is expected to further reduce the salt content in food.

[0076] Test Example 3 Adhesion of Sodium on Pig Tongue in Vitro

[0077] This test case preliminarily explores the mechanism of different shapes of nanoparticles in enhancing saltiness in food. In the perception of saltiness in the mouth, the adhesion behavior of nanoparticles to enhance sodium ion retention will be a very important factor. This test case explored the retention of long rod-shaped nanoparticles, short rod-shaped nanoparticles, spherical nanoparticles and salt solution in water on pig tongues in vitro.

[0078] The pig tongue used in this test example was purchased from a local supermarket. The front, back and side parts of the pig tongue were cut into blocks of length × width × thickness = 1 cm × 1 cm × 2 mm; a mixture containing 0.005 wt% sodium fluorescein and 0.3 wt% nanoparticles of different shapes was added to the pig tongue, and then the pig tongue was placed on a glass slide at a 45° angle and rinsed with artificial saliva controlled by a precision injection pump (flow rate of 6 mL / min); after rinsing with different volumes of artificial saliva, the pig tongue was photographed with a fluorescence microscope. The fluorescent photo of the pig tongue that was not rinsed with artificial saliva was used as a reference (100%), and the obtained fluorescence image was analyzed using ImageJ software to quantify the fluorescence intensity. The artificial saliva after rinsing was collected, and the increase in the sodium content in the artificial saliva after rinsing was determined using an atomic absorption spectrophotometer.

[0079] Figure 6 The following is a test chart of the adhesion of different types of salt-loaded particles on pig tongue in vitro. Figure 6 A in the figure is a schematic diagram of a flushing retention experiment for measuring adhesion. The adhesion analysis specifically uses artificial saliva to flush the pig tongue mucosal tissue to detect the retention of sodium under different artificial saliva flushing volume conditions. Figure 6 B in the figure is the relative fluorescence intensity of sodium retained on the pig tongue in vitro, which can explain the relative retention of sodium in four samples: long rod-shaped nanoparticles, short rod-shaped nanoparticles, spherical nanoparticles and water. After statistical analysis, it was found that the sodium retention rate of short rod-shaped nanoparticles was the highest. In order to accurately quantify the sodium retention, this test example measured the sodium content in the flushing solution obtained after each flushing test, such as Figure 6As shown in C, it can be seen that, consistent with the results of fluorescence intensity, short rod-shaped nanoparticles exhibit the best ability to retain sodium.

[0080] Test Example 4 Dynamic Diffusion of Sodium Ions Penetrating the Mucin Layer

[0081] In this test example, polycarbonate (Snapwell) was used to make the diffusion chamber, which has an area of ​​1.12 cm 2 ; A 50 μL mucin (1.0 wt%) layer was spread in the Snapwell diffusion chamber, and then 0.5 mL of 5 mM salt solution was carefully added to the mucin layer donor cavity; 1.5 mL of PBS buffer solution (pH 7.5, concentration 10 mM) was then placed in the receptor cavity, and after standing, the sample was taken out from the receptor cavity and diluted, and its sodium content was determined using an atomic absorption spectrophotometer.

[0082] Figure 7 The figure shows the dynamic diffusion test of sodium ions through the mucin layer in different types of salt-loaded particles, where A is a schematic diagram of the dynamic diffusion of sodium ions through the mucin layer, and B is a diagram showing the dynamic diffusion results of sodium ions through the mucin layer in the presence of different types of nanoparticles. Figure 7 It can be seen that sodium ions diffuse fastest in the short rod-shaped nanoparticle sample. This result confirms that short rod-shaped nanoparticles are mucus-penetrating protein particles that can serve as nanocarriers for loading sodium and can penetrate the mucin network. The function of mucin is to allow small molecules such as water, electrolytes, and nutrients to diffuse while resisting the invasion of pathogens. However, mucin has a variety of interactions, including physical entanglements and chemical interactions. These interactions can delay the free diffusion of water, electrolytes, and nutrients. The embedding of mucin significantly reduces the diffusion coefficient of sodium ions, which is related to the free diffusion of sodium ions in the mucin layer. Short rod-shaped nanoparticles can promote the entry of sodium ions into oral taste receptors by reducing the barrier effect with the mucin network, ultimately enhancing the perception of salty taste.

[0083] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A salt-reducing and salt-increasing salt-carrying particle, comprising a negatively charged nanoparticle and Na loaded on the negatively charged nanoparticle + The nanoparticles are formed by enzymatic hydrolysis and self-assembly of amphiphilic proteins.

2. The salt-reducing and salt-increasing salt-carrying granules according to claim 1, characterized in that: The Na + The mass of the nanoparticles is 40-45% of the mass of the nanoparticles.

3. The salt-reducing and salt-increasing salt-carrying granules according to claim 1, characterized in that: The amphiphilic protein includes one or more of beta-lactoglobulin, soy protein isolate and pea protein isolate.

4. The salt-reducing and salt-increasing salt-carrying granules according to any one of claims 1 to 3, characterized in that: The nanoparticles include one or more of long rod-shaped nanoparticles, short rod-shaped nanoparticles and spherical nanoparticles; the long rod-shaped nanoparticles have a length of 500 to 1500 nm and a diameter of 9 to 11 nm; the short rod-shaped nanoparticles have a length of 50 to 250 nm and a diameter of 9 to 11 nm; and the spherical nanoparticles have a particle size of 50 to 300 nm.

5. The salt-reducing and salt-increasing salt-carrying granules according to claim 4, characterized in that: The method for preparing the long rod-shaped nanoparticles comprises the following steps: The amphiphilic protein, the first protease and water are mixed for a first enzymatic hydrolysis, the pH value of the obtained first enzymatic hydrolysis solution is adjusted to 1.8-2.2, and a first self-assembly is performed under stirring conditions to obtain the long rod-shaped nanoparticles; The method for preparing the short rod-shaped nanoparticles comprises the following steps: Ultrasonic treatment is performed on the liquid containing the long rod-shaped nanoparticles to obtain the short rod-shaped nanoparticles; The preparation method of the spherical nanoparticles comprises the following steps: The amphiphilic protein, the second protease and the buffer solution are mixed to perform a second enzymatic hydrolysis, and the obtained second enzymatic hydrolysis solution is subjected to a second self-assembly under ultrasonic conditions to obtain the spherical nanoparticles.

6. The salt-reducing and salt-increasing salt-carrying granules according to claim 5, characterized in that: The first protease and the second protease are independently selected from Bacillus licheniformis protease, pepsin or papain; The temperature of the first enzymatic hydrolysis is 45-55°C, and the time is 50-70 min; the conditions of the first self-assembly include: the temperature is 85-95°C, the stirring rate is 130-170 rpm, and the time is 1.5-14 h; The number of ultrasonic treatments is 2 to 4 times; the temperature of each ultrasonic treatment is independently -2 to 2°C, the time is independently 25 to 35 seconds, and the power is independently 140 to 160W; the interval between two adjacent ultrasonic treatments is 4 to 6 minutes; The temperature of the second enzymatic hydrolysis is 45-55° C., and the time is 20-40 min. The conditions of the second self-assembly include: the temperature is -2-2° C., the ultrasonic power is 140-160 W, and the time is 25-35 s.

7. The method for preparing the salt-reducing and salt-increasing salt-carrying granules according to any one of claims 1 to 6, comprising the following steps: The nanoparticles and sodium chloride are loaded in a dispersant to obtain the salt-reducing and salt-increasing salt-loaded particles; the nanoparticles are formed by enzymatic hydrolysis and self-assembly of amphiphilic proteins in sequence.

8. The preparation method according to claim 7, characterized in that: The load treatment conditions include: temperature of 15-35° C. and time of 25-35 min.

9. Use of the salt-reducing and salt-increasing salt-carrying granules according to any one of claims 1 to 6 or the salt-reducing and salt-increasing salt-carrying granules prepared by the preparation method according to claim 7 or 8 in food seasonings.

10. The use according to claim 9, characterized in that: The food seasoning includes hot pot base or dipping sauce.

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