Lutein-loaded functional hollow salt and preparation method thereof

Abstract

The invention discloses a lutein-loaded functional hollow salt and a preparation method thereof, the functional hollow salt is prepared by taking a Maillard reaction product of whey protein isolate and maltodextrin as a salt carrier, mixing the salt carrier with lutein-loaded vegetable oil and carrying out spray drying, the weight percentage of sodium chloride in the functional hollow salt is greater than 50% and less than or equal to 85%. The particle size of the hollow salt is 1 / 10 of that of common salt. The reduction of the particle size generally shows that a denser particle structure is formed in the spray drying process, so that the exposure of active ingredients can be reduced, the possibility of oxidation or photolysis is further reduced, and the stability of the ingredients is improved; through comparison of sensory evaluation, it is found that when the same salty taste feeling is achieved, 20-30% of salt can be reduced in the hollow salt; the lutein-loaded hollow salt prepared by the invention is relatively dispersed, has no adhesion phenomenon, and can be stored for a long time under a certain condition.

Description

Technical Field

[0001] The invention belongs to the field of food technology, relates to edible salt, and specifically relates to a functional hollow salt loaded with lutein and a preparation method thereof. Background Art

[0002] Salt is a condiment widely used in the food industry and in the daily lives of residents. Its main ingredient is sodium chloride. The appropriate intake of salt plays an important role in the normal physiological and biochemical activities of the body. Generally, 3g of salt per day is enough for adults to meet basic physiological needs, while excessive intake will increase the risk of diseases such as hypertension, gastric cancer, and stroke. Therefore, with the improvement of people's health awareness, it is a general trend to study salt reduction technology to control sodium intake and increase the production of low-sodium products while ensuring the quality of food flavor.

[0003] With the advancement of science and technology, many methods to reduce salt intake have appeared on the market. The most commonly used ones include the use of non-sodium elements (such as potassium, calcium, etc.) as substitutes; the use of salty peptides; and changing the crystal structure of salt. However, these methods all have some disadvantages to a greater or lesser extent. For example, when using non-sodium salts as substitutes, the introduced elements such as K and Ca are prone to introduce unpleasant odors; the production cost of salty peptides is very high, almost 50 times that of traditional salt, which is difficult for consumers to accept and difficult to mass produce. One of the methods that is currently more accepted is to change the crystal structure of salt, such as making hollow structured salt. A large number of reports have shown that without introducing factors that change the flavor, the manufacture of hollow structured salt particles with a large specific surface area significantly improves the saltiness efficiency in food. Hollow salt, such as Tate & Lyle's commercial SODA- Take salt microspheres as an example. They maintain saltiness while reducing sodium content and exhibit free-flowing properties. These salt microspheres are composed of sodium chloride and solid organic materials at ambient temperature. They present a shell structure with sodium chloride crystals with a size of less than 100 μm. Although the hollow salt microspheres launched by Tate & Lyle can reduce the salt content by 25-50%, and produce greater salty stimulation due to their larger surface area, they lack product characteristics such as nutritional functions. Patent CN114568681 A describes a hollow sodium chloride microsphere with a small particle size, low volume density, fast dissolution rate, good diffusion ability and a salt reduction effect of 30-50%, which is suitable for cold salads and dry sprinkles. However, this product uses non-food source raw materials in the manufacturing process, which limits its application to a certain extent. Therefore, under the premise of "reducing salt without reducing saltiness", it is an urgent problem to make the hollow structure edible salt have good powder properties and functional activity.

[0004] Lutein is a terpene compound of the xanthophyll class. It participates in the synthesis of vitamin A in the body and is also the main pigment in the macular region of the human retina. Studies have shown that adequate intake of lutein is essential for eye health. Lutein can effectively prevent retinal pigment epithelial cells from being damaged by blue light and prevent diseases such as macular degeneration. However, the human body cannot synthesize lutein on its own. Most of the lutein in the body comes from dietary intake. The poor water solubility and low bioavailability of lutein itself limit its application in food.

[0005] Patent CN117337961A discloses that a hollow salt loaded with lutein is prepared by mixing whey protein isolate and gum arabic as emulsifiers with vegetable oil loaded with lutein and spray drying. Although this method obtains a hollow salt with a good salt reduction effect, the loading amount of lutein in the hollow salt is low, and gum arabic as a wall material for spray drying has disadvantages such as high viscosity, and the prepared hollow salt is prone to adhesion and adhesion, which increases the difficulty of processing on the one hand, and on the other hand, the prepared hollow salt cannot be stored for a long time.

[0006] Therefore, preparing a functional salt that can achieve the purpose of salt reduction while achieving a high lutein content and improving its bioavailability in the human body has become the focus of current research. Summary of the invention

[0007] In view of the above problems, the purpose of the present invention is to provide a method for preparing a functional hollow salt loaded with lutein, using the Maillard reaction product of whey protein isolate and maltodextrin as a salt carrier, mixing it with a vegetable oil loaded with lutein, and preparing a hollow salt containing lutein by a spray drying method, so as to solve the problems that the existing hollow salt cannot load lutein or the loaded lutein content is low, and the processing is difficult.

[0008] To achieve the above-mentioned purpose, the present invention first provides a functional hollow salt loaded with lutein. The functional hollow salt is prepared by using a Maillard reaction product of whey protein isolate and maltodextrin as a salt carrier, mixing the salt with a vegetable oil loaded with lutein, and spray drying. The weight percentage of sodium chloride in the functional hollow salt is greater than 50% and less than or equal to 85%.

[0009] In one embodiment of the present invention, the Maillard reaction product is prepared by heating a mixed solution of whey protein isolate and maltodextrin in a water bath at 90° C. and pH 8.0 for 1 to 5 hours.

[0010] In one embodiment of the present invention, in the mixed solution, the mass ratio of whey protein isolate to maltodextrin is 1:1 to 1.5:1.

[0011] In one embodiment of the present invention, the vegetable oil includes at least one of soybean oil, corn oil, rapeseed oil and peanut oil, and the loading amount of lutein in the vegetable oil is 1 to 1.5 mg / mL.

[0012] The present invention also discloses a method for preparing the functional hollow salt loaded with lutein, comprising the following steps:

[0013] (1) adding a mixture of whey protein isolate and maltodextrin to water, stirring at room temperature overnight, then adjusting the pH to 8.0 with a 1 mol / L NaOH solution, stirring at 90° C. and heating in a water bath for 1 to 5 minutes to induce a Maillard reaction, and freeze-drying the obtained Maillard reaction product to obtain a powdered Maillard reaction product;

[0014] (2) mixing the powdered Maillard reaction product in step (1) with a salt solution, and mixing it with a vegetable oil loaded with lutein, and high-pressure homogenizing to obtain an emulsion loaded with salt and lutein;

[0015] (3) connecting the emulsion of step (2) to the feed pump of a pressure spray drying tower, collecting the product after spray drying, and drying it to prepare a functional hollow salt loaded with lutein.

[0016] In one embodiment of the present invention, in step (1), the mass ratio of the mixture of whey protein isolate and maltodextrin to water is 1:9 to 1.5:9.

[0017] In one embodiment of the present invention, in step (1), the freeze-drying conditions are freeze-drying at 0.1 mBar and -80°C for 48 hours.

[0018] In one embodiment of the present invention, in step (2), the concentration of the saline solution is 20-22%.

[0019] In one embodiment of the present invention, in step (2), the mass concentration of the powdered Maillard reaction product in the saline solution is 1 to 1.5%.

[0020] In one embodiment of the present invention, in step (2), the loading amount of lutein in the vegetable oil is 1 to 1.5 mg / mL.

[0021] In one embodiment of the present invention, in step (2), the volume ratio of the mixture of the Maillard reaction product and the saline solution to the vegetable oil loaded with lutein is 2:8 to 2.2:8.

[0022] In one embodiment of the present invention, in step (2), the pressure of high-pressure homogenization is 500-550 Bar, and the high-pressure homogenization time is 4-6 min.

[0023] In one embodiment of the present invention, in step (3), the feeding frequency is 25 to 35 Hz; the pressure of the pressure spray drying tower is set to 1 to 10 kg, the tower inlet air temperature is 150 to 200° C., the air supply frequency is 18 to 25 Hz, the induced air frequency is 25 to 40 Hz, and the pressure inside the tower is 130 to 180 Pa.

[0024] In one embodiment of the present invention, in step (3), the outlet air temperature of the spray drying tower is 100-140°C.

[0025] In one embodiment of the present invention, in step (3), the drying process is carried out in a hot air drying oven, the drying temperature is 50-55° C., the drying time is 10-12 min, and the moisture content in the material is controlled to be below 2%.

[0026] Beneficial effects of the present invention:

[0027] (1) The present invention uses maltodextrin and whey protein isolate to carry out the Maillard reaction. On the one hand, maltodextrin can form a protective film to coat oil droplets or active substances, increase the stability of the emulsion, reduce the risk of oil phase separation, mutual aggregation or oil droplet rupture, and reduce the loss of active ingredients during spray drying. Under high temperature environment, it can also play a certain protective role on the active ingredients, reduce the degradation or oxidation of ingredients, and help to improve the shelf life of the product and the stability of the ingredients; on the other hand, the solution viscosity of maltodextrin is low, and it will not significantly increase the overall viscosity of the emulsion, making the emulsion easier to spray dry. This also helps to avoid nozzle clogging and improve the efficiency of spray drying and product quality. In addition, using maltodextrin as a raw material for the Maillard reaction can improve the solubility of the Maillard reaction product in a saline solution, help improve the fluidity of the powder after spray drying, reduce agglomeration, and maltodextrin will not have a significant effect on the flavor and taste of the product.

[0028] (2) The hollow salt particle size of the present invention is 1 / 10 of that of common table salt. The reduction in particle size generally indicates that a denser particle structure is formed during the spray drying process, which can reduce the exposure of active ingredients and further reduce the possibility of oxidation or photolysis, thereby improving the stability of the ingredients; through comparative sensory evaluation, it was found that when achieving the same salty taste as common table salt, the hollow salt of the present invention can achieve the effect of adding 20-30% less salt.

[0029] (3) The hollow salt loaded with lutein prepared by the present invention is relatively dispersed and has no adhesion phenomenon, and can be stored for a long time under certain conditions.

[0030] (4) The hollow salt prepared by the method of the present invention has a high content of lutein. In every 100 mg of hollow salt, the lutein loading amount is as high as 356.95±34.25 mg, and the lutein encapsulation rate is as high as 78.41%.

[0031] (5) Due to the hollow structure of this product, it is easy to be destroyed during high-temperature cooking or dissolving. Therefore, it is particularly suitable for reducing salt in dry sprinkle foods and can effectively reduce the amount of edible salt added.

[0032] (6) The hollow structure edible salt of the present invention is also suitable for hypertensive patients taking antihypertensive drugs because it does not contain potassium chloride, and is also suitable for gout patients because it does not contain purine. Therefore, it is applicable to a wider range of people than ordinary reduced sodium salt and has a better commercial prospect;

[0033] (7) The hollow structure edible salt of the present invention has low cost and high output rate; and the diameter of the hollow salt particles is 7 to 10 μm. Generally, small-particle salt can significantly increase the specific surface area of ​​the hollow salt, greatly increase the dissolution rate of the hollow salt, make the salt evenly distributed, and directly increase the sensory saltiness of the salt.

[0034] (8) The preparation method of the present invention is energy-saving and environmentally friendly, has low cost, is easy to use, has a short cycle, can be used for large-scale production, and is easy to industrialize. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a scanning electron microscope effect diagram of the hollow salt prepared in Example 1-5.

[0036] Figure 2 These are scanning electron microscope renderings of common salt and the common salt prepared in Comparative Examples 1-3.

[0037] Figure 3 Comparison of the finished appearance of the hollow salt prepared in Examples 2 and 3. DETAILED DESCRIPTION

[0038] The preferred embodiments of the present invention are described below. It should be understood that the embodiments are for better explaining the present invention and are not used to limit the present invention.

[0039] The raw materials used in the examples, unless otherwise specified, are commercially available.

[0040] Whey protein isolate (WPI), maltodextrin (MD) and gum arabic (GA) were purchased from Shanghai Yuanye Biotechnology Co., Ltd.; lutein (purity>90%) was purchased from Shanghai McLean Biochemical Co., Ltd.; soybean oil was purchased from Shandong Jinlongyu Industry Co., Ltd.

[0041] In the examples, all percentages without specific indication of % are by mass, and all solvents without specific indication of solvent are water.

[0042] Test Method

[0043] 1. Microstructure determination:

[0044] SU8010 / PP3010T scanning electron microscope cryotransfer system (Hitachi / Quorum); a small amount of product was evenly dispersed on the sample stage with conductive glue, and then the excess product was blown away with an ear bulb, and then the sample stage was placed in an ion sputtering instrument for gold spraying. The operating voltage of the scanning electron microscope was 10kV.

[0045] 2. Determination of hollow salt fluidity

[0046] The flowability analysis was performed by measuring the angle of repose of the hollow salt. In order to determine the bulk density and tap density, 3 g of the hollow salt was placed in a 10 ml graduated glass cylinder and the volume of the hollow salt in the loose state and in the compacted state was recorded. The volume and tap density were calculated by dividing the mass of the salt by the respective volume.

[0047] 3. Determination of lutein content and embedding rate

[0048] Weigh 100 mg of hollow salt, add 10 mL of dichloromethane, stir evenly, and ultrasonically treat for 30 minutes to fully extract lutein. Centrifuge the extract (such as 5000 rpm, 10 minutes) and take the supernatant. Repeat the above extraction 2-3 times on the residue and combine the supernatant. Filter the supernatant with a filter membrane (such as 0.45 μm) to remove suspended particles and obtain a clear lutein extract. Weigh an appropriate amount of extract and measure the absorbance at a wavelength of 445 nm using a spectrophotometer. Use the lutein standard solution to draw a standard curve and calculate the lutein content in the sample.

[0049] Weigh 100 mg of hollow salt loaded with lutein, first treat with 10 mL of organic mixed solvent (cyclohexane: dichloromethane, 1:1) to remove surface lutein (unencapsulated lutein), centrifuge at 10,000 g for 5 min, collect complete microcapsule particles, add 1 mL of water to the precipitate, mix, and ultrasonically treat to fully dissolve the wall material and release the inner lutein (encapsulated lutein), then dilute with 90% ethanol, use an ultraviolet split-tube photometer to detect at 450 nm, and calculate the encapsulated lutein content through the standard curve. And use the following formula to calculate the lutein encapsulation rate:

[0050] Encapsulation rate (%) = inner layer lutein / total lutein × 100%

[0051] 4. Particle size determination

[0052] 10 mg of hollow salt was weighed and dissolved in 10 mL of Milli Q water (final concentration 1 mg / mL), and the particle size of the hollow salt microspheres was measured using a Malvern laser particle size analyzer.

[0053] 5. Salinity determination

[0054] Weigh the same mass (1.0 g) of hollow salt and dissolve it in 5 mL of water, and use a salinity meter to measure the salinity value.

[0055] 6. Hollow salt sensory evaluation test

[0056] Cut the grilled steak into equal-sized pieces and sprinkle equal volumes of hollow salt and table salt evenly on the food. Prepare three parallel samples on white plates and provide them to a total of 40 assessors, who are required to clean their mouths with water before taking each sample. By scoring the sensory evaluation index of saltiness (1 = very dislike, 5 = neither dislike nor dislike, 10 = very like), the judges can score within the range of 1-10 according to their own sensory level.

[0057] Example 1

[0058] A method for preparing a functional hollow salt loaded with lutein comprises the following steps:

[0059] The whey protein isolate and maltodextrin mixture was added to water in a mass ratio of 1:1 (solid-water ratio of 1:9, w / w). Stirred overnight at room temperature. The pH was then adjusted to 8.0 with 1 mol / L NaOH solution. The solution was stirred at 90°C and heated in a water bath for 1 h to induce the Maillard reaction. Freeze-dried at 0.1 mBar and -80°C for 48 h to prepare a powder product, i.e., the Maillard product. Salt was dissolved in water to prepare a saline solution with a final concentration of 20%; the Maillard product was mixed with a NaCl solution at a concentration of 1% to obtain a saline solution of the Maillard product, and lutein was added to soybean oil at a concentration of 1 mg / mL and mixed with the saline solution of the Maillard product (oil-water ratio 2:8). High-pressure homogenization obtains an emulsion loaded with salt and lutein; the emulsion is connected to a feed pump of a pressure spray drying tower, and the feeding frequency is 25-35Hz; the spray drying pressure is set to 1-10kg, the tower inlet air temperature is 150-200℃, the air supply frequency is 18-25Hz, the induced air frequency is 25-40Hz, and the pressure in the tower is 130-180Pa; after spray drying, the material is discharged, and the product is collected at the lower end of the drying tower and the cyclone separator, and dried in a hot air drying oven, the drying temperature is 50-55℃, and the drying time is 10-12min. The moisture content in the material is controlled to be below 2%.

[0060] Example 2

[0061] The difference between Example 2 and Example 1 is that the time of the Maillard reaction is 2 hours.

[0062] Example 3

[0063] The difference between Example 3 and Example 1 is that the time of the Maillard reaction is 3 hours.

[0064] Example 4

[0065] The difference between Example 4 and Example 1 is that the time of the Maillard reaction is 4 hours.

[0066] Example 5

[0067] The difference between Example 5 and Example 1 is that the time of the Maillard reaction is 5 hours.

[0068] Comparative Example 1

[0069] A method for preparing common salt comprises the following steps:

[0070] Sodium chloride is mixed with water (NaCl: 40 g; water: 150 mL) to obtain a saturated sodium chloride aqueous solution; the saturated sodium chloride aqueous solution is then sent to a spray dryer for spraying through a peristaltic pump, the inlet temperature of the peristaltic pump is 110° C., the outlet temperature is 75° C., and the peristaltic pump rate is 10 mL / min to obtain the common table salt.

[0071] Comparative Example 2

[0072] The whey protein isolate is added to a 20% NaCl solution at a concentration of 1%, and lutein is added to soybean oil at a concentration of 1 mg / mL, and mixed with the above solution (oil-water ratio 2:8). High-pressure homogenization is performed to obtain an emulsion loaded with salt and lutein; the emulsion is connected to a feed pump of a pressure spray drying tower, and the feeding frequency is 25-35 Hz; the spray drying pressure is set to 1-10 kg, the tower inlet air temperature is 150-200° C., the air supply frequency is 18-25 Hz, the induced air frequency is 25-40 Hz, and the pressure in the tower is 130-180 Pa; after spray drying, the material is discharged, and the product is collected at the lower end of the drying tower and the cyclone separator, and the sample is placed in a 50-55° C. constant temperature hot air drying oven for 10-12 minutes to control the moisture content in the material to be below 2%.

[0073] Comparative Example 3

[0074] The difference between Comparative Example 3 and Example 1 is that the maltodextrin in Example 1 is replaced with gum arabic;

[0075] Figure 1 The scanning electron microscope effect diagram of the hollow salt prepared in Examples 1 to 5. Figure 1It can be seen that the hollow salts prepared in Examples 1 to 5 have a hollow structure. Figure 2 The scanning electron microscope effect diagram of the common salt prepared in Comparative Examples 1-3. Figure 2 It can be seen that ordinary table salt does not have a hollow structure. Comparative Examples 2 and 3 also form a hollow structure. However, compared with Examples 1-5, it can be observed from the microstructure that strong adhesion and adhesion occurred between the powders in Comparative Example 3, which indicates that the hollow salt prepared from the whey protein isolate-gum arabic complex has poor storage and transportation stability.

[0076] Table 1 shows the particle size data of the hollow salt in common salt, Examples 1 to 5 and Comparative Examples 1 to 3. It can be seen from Table 1 that the particle size of common salt is significantly larger than that of all other experimental groups, indicating that the spray drying method significantly reduces the particle size. The average particle size of Examples 1-5 is significantly smaller than that of the comparative example. It shows that the addition of maltodextrin can effectively reduce the particle size of the hollow salt. Smaller particle sizes have higher specific surface areas and can significantly increase the dissolution rate of hollow salt. Rapid dissolution helps to release active substances more efficiently, thereby enhancing their bioavailability. At the same time, the accelerated dissolution rate can also cause the salt to form a "sudden release" phenomenon on the surface of the human tongue. Thereby increasing the saltiness. In addition, a reduction in particle size generally indicates that a denser particle structure is formed during the spray drying process, which can reduce the exposure of active ingredients and further reduce the possibility of oxidation or photolysis, thereby improving the stability of the ingredients.

[0077] Table 1 Particle size data of common salt, hollow salt in Examples 1 to 5 and Comparative Examples 1 to 3

[0078] example Particle size (μm) Ordinary salt 490.12±37.41 Example 1 7.91±1.26 Example 2 6.88±1.01 Example 3 8.79±1.41 Example 4 9.17±1.29 Example 5 9.59±2.01 Comparative Example 1 15.26±1.47 Comparative Example 2 13.26±1.89 Comparative Example 3 14.45±2.56

[0079] Table 2 Bulk density data of hollow salts in Examples 1 to 5 and Comparative Examples 1 to 3

[0080] example <![CDATA[Bulk density (g / cm 3 )]]> Example 1 27.15±2.65 Example 2 25.66±2.51 Example 3 23.12±1.25 Example 4 21.78±2.17 Example 5 22.38±1.49 Comparative Example 1 31.21±2.45 Comparative Example 2 34.56±7.51 Comparative Example 3 35.62±4.21

[0081] Table 3 Tap density data of hollow salts in Examples 1 to 5 and Comparative Examples 1 to 3

[0082]

[0083]

[0084] Tables 2 and 3 show the bulk density and tap density data of Examples 1-5 and Comparative Examples 1-3. The bulk density reflects that for salt particles of the same mass, as the volume of the salt particles increases, the specific surface area increases, the range of contact with the oral cavity increases, and the perception of saltiness increases. It can be seen that the bulk density of the examples (21.78–27.15 g / cm 3 ) and tap density (34.56–40.12 g / cm3 ) is lower than that of the comparative example, which indicates that the particle structure of the embodiment is looser and the inter-particle gaps are larger, which may be related to its unique hollow structure. This low-density property gives the embodiment an advantage in lightweight products, especially in reducing the amount of salt, improving the flavor release efficiency or improving the solubility performance. In addition, the density data of the embodiment fluctuates less and has a lower standard deviation, indicating that its preparation process is more stable and has higher repeatability, which provides support for its reliability in practical applications.

[0085] Table 4 Sensory evaluation scores of samples prepared in Examples 1-5 and Comparative Examples 1-3

[0086] example Saltiness Rating Saltiness (mg / 100mg) Ordinary salt 10.0 416.00±0.02 Example 1 9.6±0.3 356.12±15.62 Example 2 9.4±0.6 314.25±12.36 Example 3 9.5±0.2 326.25±11.01 Example 4 9.8±0.4 365.51±17.41 Example 5 9.5±0.4 332.24±10.14 Comparative Example 1 9.0±0.4 400.21±16.23 Comparative Example 2 8.5±0.5 289.41±12.14 Comparative Example 3 8.4±0.1 256.54±8.24

[0087] Table 4 shows the sensory evaluation scores of the samples prepared in Examples 1-5 and Comparative Examples 1-3. It can be seen from the saltiness score data that the saltiness score of the embodiment (9.4-9.8) is close to the highest score of ordinary table salt (10.0), and is significantly higher than the comparative example (8.4-9.0). This shows that the embodiment performs well in maintaining the intensity of saltiness, and at the same time, it may improve the flavor release efficiency of salt due to its hollow structure or optimized particle design. In contrast, the comparative example scored lower, which may be because the particle structure or preparation method limits its saltiness perception. On the whole, the embodiment can effectively approach the saltiness of ordinary table salt while reducing the amount of salt used, has good application potential, and is particularly suitable for the development of healthy low-salt foods.

[0088] Table 5 Lutein content and lutein encapsulation efficiency in samples prepared in Examples 1-5 and Comparative Examples 1-3

[0089]

[0090]

[0091] Table 5 shows the lutein content of Examples 1-5 and Comparative Examples 1-3, as well as the encapsulation efficiency of lutein. The lutein content in the examples ranges from 306.58±19.21mg to 356.95±34.25mg, which is significantly higher than 259.42±12.31mg and 241.22±15.32mg of the comparative examples. The highest content appears in Example 3 (356.95mg), indicating that its process has the strongest loading capacity for lutein. In the examples, the addition of maltodextrin significantly improves the loading capacity and encapsulation efficiency of lutein, indicating that the hollow salt process used can better protect lutein, reduce losses, and improve utilization.

[0092] Figure 3The appearance diagrams of Example 2 and Example 3. The hollow salt loaded with lutein has a uniform yellow appearance, indicating that the product has uniform and stable characteristics. The granular structure on the surface of the hollow salt is clear and delicate, which indicates that the spray drying process can form salt particles with good appearance and morphology. This structure may help to improve the solubility and release efficiency of lutein. Example 2 and Example 3 have the volume advantage brought by low density, better fluidity and dispersibility, stronger active substance loading capacity, possible sustained release performance and potential taste improvement. These advantages can improve the functionality and user experience of the product in practical applications.

[0093] The embodiments provided above are not intended to limit the scope of the present invention, and the steps described are not intended to limit the execution order thereof. Those skilled in the art may make obvious improvements to the present invention in combination with existing common knowledge, which also fall within the scope of protection defined by the claims of the present invention.

Claims

1. A functional hollow salt loaded with lutein, characterized in that: The functional hollow salt is prepared by using the Maillard reaction product of whey protein isolate and maltodextrin as the salt carrier, mixing it with the vegetable oil loaded with lutein, and spray drying. The weight percentage of sodium chloride in the functional hollow salt is greater than 50% and less than or equal to 85%.

2. The functional hollow salt according to claim 1, characterized in that: In the mixed solution, the mass ratio of whey protein isolate to maltodextrin is 1:1 to 1.5:

1.

3. The functional hollow salt according to claim 1, characterized in that: The vegetable oil includes at least one of soybean oil, corn oil, rapeseed oil and peanut oil, and the loading amount of lutein in the vegetable oil is 1-1.5 mg / mL.

4. A method for preparing a functional hollow salt loaded with lutein according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) adding a mixture of whey protein isolate and maltodextrin to water, stirring at room temperature overnight, then adjusting the pH to 8.0 with a 1 mol / L NaOH solution, stirring at 90° C. and heating in a water bath for 1 to 5 minutes to induce a Maillard reaction, and freeze-drying the obtained Maillard reaction product to obtain a powdered Maillard reaction product; (2) mixing the powdered Maillard reaction product in step (1) with a salt solution, and mixing it with a vegetable oil loaded with lutein, and high-pressure homogenizing to obtain an emulsion loaded with salt and lutein; (3) connecting the emulsion of step (2) to the feed pump of a pressure spray drying tower, collecting the product after spray drying, and drying it to prepare a functional hollow salt loaded with lutein.

5. The preparation method according to claim 4, characterized in that: In step (1), the mass ratio of the mixture of whey protein isolate and maltodextrin to water is 1:9 to 1.5:9, and the freeze-drying conditions are freeze-drying at 0.1 mBar and -80°C for 48 hours.

6. The preparation method according to claim 4, characterized in that: In step (2), the concentration of the saline solution is 20-22%, and the mass concentration of the powdered Maillard reaction product in the saline solution is 1-1.5%.

7. The preparation method according to claim 4, characterized in that: In step (2), the loading amount of lutein in the vegetable oil is 1-1.5 mg / mL, and the volume ratio of the mixture of the Maillard reaction product and the saline solution to the vegetable oil loaded with lutein is 2:8-2.2:

8.

8. The preparation method according to claim 4, characterized in that: In step (2), the pressure of high-pressure homogenization is 500-550 Bar, and the high-pressure homogenization time is 4-6 minutes.

9. The preparation method according to claim 4, characterized in that: In step (3), the feeding frequency is 25-35 Hz; the pressure of the pressure-type spray drying tower is set to 1-10 kg, the air inlet temperature at the tower mouth is 150-200° C., the air supply frequency is 18-25 Hz, the induced air frequency is 25-40 Hz, the pressure in the tower is 130-180 Pa, and the air outlet temperature of the spray drying tower is 100-140° C.

10. The preparation method according to claim 4, characterized in that: In step (3), the drying process is carried out in a hot air drying oven, the drying temperature is 50-55° C., the drying time is 10-12 minutes, and the moisture content in the material is controlled to be below 2%.

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