Fermented jujube selenium protein microcapsule tablet and preparation method and application thereof

Abstract

This invention discloses a fermented jujube selenoprotein microcapsule tablet, its preparation method, and its application, belonging to the field of functional food processing technology. Using jujube as raw material, the invention utilizes lactic acid bacteria fermentation to significantly increase the polyphenol content. Then, selenoprotein powder is added, and a double emulsification microcapsule technology is used to encapsulate the lactic acid bacteria-fermented jujube juice and selenoprotein powder. Simultaneously, spray drying and direct compression techniques are combined to prepare fermented jujube selenoprotein microcapsule tablets, significantly improving the bioavailability of jujube polyphenols and organic selenium. Furthermore, the preparation method is simple, suitable for industrial production, and the tableting process does not require the addition of any excipients, meeting consumer demand for clean product labels and possessing excellent market prospects. This fermented jujube selenoprotein microcapsule tablet integrates multiple nutrients such as polyphenols and organic selenium, and is easy to carry and store, making it suitable for busy office workers, travelers, or the elderly as a convenient nutritional supplement.

Description

Technical Field

[0001] This invention belongs to the field of functional food processing technology, specifically relating to a fermented jujube selenium protein microcapsule tablet, its preparation method, and its application. Background Technology

[0002] According to the Pharmacopoeia of the People's Republic of China, jujubes are associated with the spleen, stomach, and heart meridians. They are sweet and warm in nature, possessing the effects of nourishing qi and blood, and calming the nerves. Modern nutritional research shows that jujubes are rich in polyphenols and polysaccharides, which have antioxidant, immune-enhancing, intestinal function-regulating, anti-aging, and memory-improving effects. Polyphenols in jujubes exist in both free and bound forms, with the free form being predominant. However, the bound form accounts for 1 / 5 to 1 / 10 of the total phenol content. Compared to free phenols, bound phenols are often bound to polysaccharides such as pectin and cellulose via ester bonds, making them difficult for the human body to absorb. Furthermore, polyphenols have poor solubility and poor tolerance to temperature and pH, limiting their bioavailability in the gastrointestinal tract and affecting their biological activity.

[0003] Selenium is an essential trace element for the human body. Selenium deficiency can lead to Kashin-Beck disease and Keshan disease. Studies have shown that appropriate selenium supplementation plays an important role in preventing cardiovascular disease and improving human immunity. Compared to inorganic selenium, organic selenium in food mainly exists in the form of selenoproteins, which is safer. However, the absorption and utilization of organic selenium is also affected by the gastrointestinal environment, resulting in low bioavailability.

[0004] In view of this, it is necessary to provide a new fermented jujube selenium protein microcapsule tablet to overcome the shortcomings of the existing technology. Summary of the Invention

[0005] The purpose of this invention is to provide a fermented jujube selenium protein microcapsule tablet, its preparation method, and its application. This addresses the problem of low bioavailability in existing polyphenol and organic selenium products.

[0006] In a first aspect, the present invention provides a method for preparing fermented jujube selenoprotein microcapsule tablets, comprising the following steps: providing lactic acid bacteria fermented jujube juice; mixing the lactic acid bacteria fermented jujube juice and selenoprotein powder to obtain a first aqueous phase solution; mixing the first aqueous phase solution with an oil phase and performing a first homogenization treatment to obtain a water-in-oil emulsion; further mixing the water-in-oil emulsion with a second aqueous phase solution and performing a second homogenization treatment to obtain a water-in-oil emulsion; adjusting the pH of the water-in-oil emulsion to acidic; and refrigerating to obtain wet microcapsules; mixing the wet microcapsules with a drying agent and spray drying to obtain fermented jujube selenoprotein microcapsule powder; and compressing the fermented jujube selenoprotein microcapsule powder to obtain fermented jujube selenoprotein microcapsule tablets.

[0007] In this invention, the inventors discovered that by using jujubes as raw material and fully utilizing the functional factors within them, lactic acid bacteria fermentation significantly increases the polyphenol content. Then, selenoprotein powder is added to fully utilize its abundant organic selenium. A dual emulsification microencapsulation technology is used to encapsulate the lactic acid bacteria-fermented jujube juice and selenoprotein powder. Combined with spray drying and direct tableting techniques, fermented jujube selenoprotein microcapsule tablets are prepared, significantly improving the bioavailability of jujube polyphenols and organic selenium. Furthermore, this preparation method is simple, suitable for industrial production, and the tableting process does not require the addition of any excipients, meeting consumer demand for clean product labels and possessing excellent market potential. Simultaneously, these fermented jujube selenoprotein microcapsule tablets integrate multiple nutrients such as polyphenols and organic selenium, are easy to carry and store, and are suitable for busy office workers, travelers, or the elderly as a convenient nutritional supplement, especially suitable for those needing comprehensive health maintenance, fatigue relief, and improved physical fitness.

[0008] In some embodiments, the preparation of lactic acid bacteria fermented jujube juice includes: mixing jujubes and water and grinding them to obtain a grinding liquid; sterilizing the grinding liquid and inoculating it with *Lactobacillus plantarum* powder under aseptic conditions, followed by constant temperature culture, homogenization, and concentration to obtain lactic acid bacteria fermented jujube juice; wherein the mass ratio of jujubes to water is 1:(2-5); sterilization includes sterilization at 115-130℃ for 10-20 min; the inoculation amount of *Lactobacillus plantarum* powder is 0.1-0.5 mg / mL; constant temperature culture includes culture at 32-42℃ for 24-48 h; homogenization includes homogenization at 5000-8000 rpm for 3-8 min; and the soluble solids content in the lactic acid bacteria fermented jujube juice is 20-35%.

[0009] In some embodiments, in the step of obtaining wet microcapsules, the volume-to-mass ratio of lactic acid bacteria fermented jujube juice to selenoprotein powder is (50-100):1, and the selenoprotein powder includes violet leaf selenoprotein powder; the volume ratio of the first aqueous phase solution to the oil phase is (1-4):(6-9), and the oil phase includes corn oil and polyglycerol polyricinoleate; wherein the volume ratio of corn oil to polyglycerol polyricinoleate is (93-99):(1-7).

[0010] In some embodiments, in the step of obtaining wet microcapsules, the volume ratio of the second aqueous solution to the water-in-oil emulsion is (6-9):(1-4); the mass concentration of the second aqueous solution is 0.5-2%, and the second aqueous solution is obtained by dissolving rice bran albumin and sodium carboxymethyl cellulose in water; wherein the mass ratio of rice bran albumin to sodium carboxymethyl cellulose is (0.5-3):1.

[0011] In some embodiments, in the step of obtaining wet microcapsules, the first homogenization process includes: homogenizing for 1-5 min at a rotation speed of 6000-10000 rpm; and / or, the second homogenization process includes: homogenizing for 1-5 min at a rotation speed of 8000-12000 rpm.

[0012] In some implementations, in the step of obtaining the wet microcapsules, the pH of the water-in-oil-in-water emulsion is 1.5-4; refrigeration includes: refrigerating at a temperature of 4-10°C for 12-48 hours.

[0013] In some embodiments, in the step of mixing the wet microcapsules with the drying aid and then spray drying, the volume-to-mass ratio of the wet microcapsules to the drying aid is (8-12):1, and the drying aid includes resistant dextrin; the spray drying includes spray drying under the following conditions: a feed flow rate of 0.5-1.2 mL / min, a feed temperature of 130-160°C, a discharge temperature of 50-80°C, and a compressed air pressure of 0.25-1 MPa.

[0014] In some implementations, the tableting process of fermented jujube selenium protein microcapsule powder includes tableting under a pressure of 10-20 kN.

[0015] In a second aspect, the present invention provides a fermented jujube selenium protein microcapsule tablet, which is prepared by any of the above preparation methods.

[0016] In a third aspect, the present invention provides the application of fermented jujube selenium protein microcapsule tablets as described above in food.

[0017] The beneficial effects of this invention are as follows: Unlike existing technologies, this invention uses jujubes as raw material, fully exploring and utilizing the functional factors in jujubes. Lactic acid bacteria fermentation significantly increases the polyphenol content. Then, selenoprotein powder is added to fully utilize its rich organic selenium. A dual emulsification microencapsulation technology is used to encapsulate the lactic acid bacteria-fermented jujube juice and selenoprotein powder. Simultaneously, spray drying and direct tableting technologies are combined to prepare fermented jujube selenoprotein microcapsule tablets, significantly improving the bioavailability of jujube polyphenols and organic selenium. Furthermore, this preparation method is simple, suitable for industrial production, and the tableting process does not require the addition of any excipients, meeting consumer demand for clean product labels and possessing excellent market prospects. At the same time, these fermented jujube selenoprotein microcapsule tablets integrate multiple nutrients such as polyphenols and organic selenium, and are easy to carry and store, making them suitable for busy office workers, travelers, or the elderly as a convenient nutritional supplement, especially suitable for those who need comprehensive health maintenance, fatigue relief, and improved physical fitness. Attached Figure Description

[0018] Figure 1This is a flowchart of the preparation method of fermented jujube selenium protein microcapsule tablets in this invention. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] Experimental methods not specified in the examples are generally performed under conventional conditions and as described in the manual, or as recommended by the manufacturer. Unless otherwise specified, the general equipment, materials, reagents, etc. used are commercially available.

[0021] Currently, existing polyphenol and organic selenium products suffer from problems such as low bioavailability.

[0022] To address the issues of low bioavailability in existing polyphenol and organic selenium products, this invention provides a fermented jujube selenium protein microcapsule tablet, its preparation method, and its application.

[0023] In a first aspect, the present invention provides a method for preparing fermented jujube selenoprotein microcapsule tablets, comprising the following steps: providing lactic acid bacteria fermented jujube juice; mixing the lactic acid bacteria fermented jujube juice and selenoprotein powder to obtain a first aqueous phase solution; mixing the first aqueous phase solution with an oil phase and performing a first homogenization treatment to obtain a water-in-oil emulsion; further mixing the water-in-oil emulsion with a second aqueous phase solution and performing a second homogenization treatment to obtain a water-in-oil emulsion; adjusting the pH of the water-in-oil emulsion to acidic; and refrigerating to obtain wet microcapsules; mixing the wet microcapsules with a drying agent and spray drying to obtain fermented jujube selenoprotein microcapsule powder; and compressing the fermented jujube selenoprotein microcapsule powder to obtain fermented jujube selenoprotein microcapsule tablets.

[0024] The preparation method provided by this invention employs a dual emulsification microencapsulation technology to encapsulate lactic acid bacteria-fermented jujube juice and selenoprotein powder. Combined with spray drying and direct tableting techniques, the resulting fermented jujube selenoprotein microcapsule tablets effectively protect the polyphenols produced by lactic acid bacteria fermentation of jujubes and the exogenous organic selenium fortification, significantly improving the bioavailability of polyphenols and selenium. Furthermore, the related technologies used in this preparation process are mature and easily promoted, suitable for industrialized production. In addition, the tableting process does not require the addition of any excipients, meeting consumers' needs for clean product labels. The tablets are also easy to carry and store, making them suitable for busy office workers, travelers, or the elderly as a convenient nutritional supplement, especially for those seeking comprehensive health maintenance, fatigue relief, and improved physical fitness.

[0025] In some embodiments, the preparation of lactic acid bacteria fermented jujube juice includes: mixing jujubes and water and grinding them to obtain a grinding liquid; sterilizing the grinding liquid and inoculating it with *Lactobacillus plantarum* powder under aseptic conditions, followed by constant temperature culture, homogenization, and concentration to obtain lactic acid bacteria fermented jujube juice; wherein the mass ratio of jujubes to water is 1:(2-5); sterilization includes sterilization at 115-130℃ for 10-20 min; the inoculation amount of *Lactobacillus plantarum* powder is 0.1-0.5 mg / mL; constant temperature culture includes culture at 32-42℃ for 24-48 h; homogenization includes homogenization at 5000-8000 rpm for 3-8 min; and the soluble solids content in the lactic acid bacteria fermented jujube juice is 20-35%.

[0026] In this invention, fermentation of jujubes with Lactobacillus plantarum not only promotes the conversion of bound polyphenols in jujubes into free polyphenols, but also increases the total polyphenol content in jujubes, significantly improving the nutritional and functional activity of jujube juice.

[0027] In some embodiments, in the step of obtaining wet microcapsules, the volume-to-mass ratio of lactic acid bacteria fermented jujube juice to selenoprotein powder is (50-100):1, and the selenoprotein powder includes violet leaf selenoprotein powder; the volume ratio of the first aqueous phase solution to the oil phase is (1-4):(6-9), and the oil phase includes corn oil and polyglycerol polyricinoleate; wherein the volume ratio of corn oil to polyglycerol polyricinoleate is (93-99):(1-7).

[0028] In this invention, by adding polyglycerol polyricinoleate to the oil phase, the interfacial tension can be reduced through moderate emulsification, thereby promoting the formation of an interfacial film and stabilizing the water-in-oil emulsion structure.

[0029] In some embodiments, in the step of obtaining wet microcapsules, the volume ratio of the second aqueous solution to the water-in-oil emulsion is (6-9):(1-4); the mass concentration of the second aqueous solution is 0.5-2%, and the second aqueous solution is obtained by dissolving rice bran albumin and sodium carboxymethyl cellulose in water; wherein the mass ratio of rice bran albumin to sodium carboxymethyl cellulose is (0.5-3):1.

[0030] In this invention, rice bran albumin (RBA) possesses excellent emulsifying activity and foam stability, making it a superior delivery carrier for bioactive ingredients. However, its resistance to mechanical stress is insufficient, making it difficult to protect the stability of active ingredients during drying and extrusion processes. Sodium carboxymethyl cellulose (CMC) is an excellent thickener, and CMC at a suitable viscosity exhibits heat retention and high mechanical strength. Therefore, adding sodium carboxymethyl cellulose (CMC) to the second aqueous phase solution promotes the formation of hydrogen bonds and electrostatic bonds between CMC and RBA, overcoming the shortcomings of using RBA alone as a sustained-release substrate.

[0031] In some embodiments, in the step of obtaining wet microcapsules, the first homogenization process includes: homogenizing for 1-5 min at a rotation speed of 6000-10000 rpm; and / or, the second homogenization process includes: homogenizing for 1-5 min at a rotation speed of 8000-12000 rpm.

[0032] In this invention, by controlling the parameters of the first homogenization treatment and the second homogenization treatment within a specific range, microcapsules with a "two-phase three-layer" emulsion structure can be made more stable, thereby significantly improving the bioavailability of polyphenols and organic selenium.

[0033] In some implementations, in the step of obtaining the wet microcapsules, the pH of the water-in-oil-in-water emulsion is 1.5-4; refrigeration includes: refrigerating at a temperature of 4-10°C for 12-48 hours.

[0034] In this invention, by adjusting the pH of the water-in-oil-in-water emulsion and then subjecting it to cold-condensation, pH-responsive characteristics are acquired, enabling it to remain stable under low pH conditions. Through microencapsulation technology involving dual emulsification and condensation, the resulting "two-phase, three-layer" emulsion structure not only blocks oxygen in the oil phase, reducing polyphenol oxidation, but also possesses pH-responsive and gastrointestinal controlled-release properties. This allows the two unstable active ingredients, polyphenols and organoselenium, to maintain their structural integrity in the acidic environment of the stomach and trigger release in the neutral environment of the intestine, significantly improving the bioavailability of polyphenols and organoselenium.

[0035] In some embodiments, in the step of mixing the wet microcapsules with the drying aid and then spray drying, the volume-to-mass ratio of the wet microcapsules to the drying aid is (8-12):1, and the drying aid includes resistant dextrin; the spray drying includes spray drying under the following conditions: a feed flow rate of 0.5-1.2 mL / min, a feed temperature of 130-160°C, a discharge temperature of 50-80°C, and a compressed air pressure of 0.25-1 MPa.

[0036] In this invention, resistant dextrin has the characteristics of high solubility, low viscosity, and good film-forming properties, which can greatly improve the flowability, dispersibility, and yield of powder. Adding resistant dextrin as a drying aid in spray drying not only improves the flowability and dispersibility of the prepared lactic acid bacteria fermented jujube juice and selenium protein microcapsule powder, effectively preventing clumping, but also, as a water-soluble dietary fiber, is beneficial to intestinal health and avoids the sugar burden caused by the commonly used drying aid maltodextrin.

[0037] In some implementations, the tableting process of fermented jujube selenium protein microcapsule powder includes tableting under a pressure of 10-20 kN.

[0038] In this invention, tablets can be directly compressed without the use of excipients such as microcrystalline cellulose, magnesium stearate, and silica during the tableting process. This results in tablets with high hardness and low brittleness, which also meets consumers' demand for clean product labels and has excellent market prospects.

[0039] In a second aspect, the present invention provides a fermented jujube selenium protein microcapsule tablet, which is prepared by any of the above preparation methods.

[0040] In a third aspect, the present invention provides the application of fermented jujube selenium protein microcapsule tablets as described above in food.

[0041] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0042] Please see Figure 1 This is a flowchart illustrating the preparation method of fermented jujube selenoprotein microcapsule tablets according to the present invention. Specifically, the preparation method includes the following steps: providing lactic acid bacteria fermented jujube juice; mixing the lactic acid bacteria fermented jujube juice and selenoprotein powder to obtain a first aqueous phase solution; mixing the first aqueous phase solution with an oil phase and performing a first homogenization treatment to obtain a water-in-oil emulsion; further mixing the water-in-oil emulsion with a second aqueous phase solution and performing a second homogenization treatment to obtain a water-in-oil emulsion; adjusting the pH of the water-in-oil emulsion to acidic; and obtaining wet microcapsules after refrigeration; mixing the wet microcapsules with a drying aid and spray drying to obtain fermented jujube selenoprotein microcapsule powder; and compressing the fermented jujube selenoprotein microcapsule powder to obtain fermented jujube selenoprotein microcapsule tablets.

[0043] Example 1 A method for preparing fermented jujube selenium protein microcapsule tablets includes the following steps: S1. Preparation of lactic acid bacteria fermented jujube juice: Jujubes and water are mixed at a mass ratio of 1:2 and then ground to obtain a grinding liquid; the grinding liquid is sterilized at 121℃ for 15 min; under aseptic conditions, 0.1 mg / mL of Lactobacillus plantarum powder is inoculated and cultured at 32℃ for 48 h; homogenization is continued at 5000 rpm for 8 min; finally, it is concentrated to a soluble solids content of 35% to obtain lactic acid bacteria fermented jujube juice. S2. Lactic acid bacteria fermented jujube juice and selenoprotein undergo double emulsification and coagulation: The suspension formed by mixing the lactic acid bacteria fermented jujube juice and violet leaf crushed rice selenoprotein powder prepared in step S1 at a volume-to-mass ratio of 50:1 is used as the inner aqueous phase W1; the solution of corn oil and polyglycerol polyricinoleate at a volume ratio of 99:1 is used as the oil phase O. The above inner aqueous phase W1 and oil phase O are mixed at a volume ratio of 1:9 and homogenized for 5 minutes at a rotation speed of 6000 rpm to form a water-in-oil (W1 / O) emulsion. The external aqueous phase W2 was prepared by mixing rice bran albumin (RBA) and sodium carboxymethyl cellulose (CMC) at a mass ratio of 3:1 to form a 2% aqueous solution. The external aqueous phase W2 was then mixed with the above W1 / O emulsion at a volume ratio of 9:1 and homogenized for 5 min at 8000 rpm to form a water-in-oil-in-water (W1 / O / W2) emulsion. The pH of the W1 / O / W2 emulsion was adjusted to 1.5 with 0.1M acetic acid and then re-coagulated at 10℃ for 48 h to obtain wet microcapsules. S3. Spray drying of wet microcapsules: The wet microcapsules prepared in step S2 are mixed with resistant dextrin at a volume-to-mass ratio of 12:1. The spray drying feed flow rate is set to 0.5 mL / min, the feed temperature is 130℃, the discharge temperature is 50℃, and the compressed air pressure is 0.25 MPa to obtain a free-flowing fermented jujube juice selenoprotein microcapsule powder. S4. The fermented jujube selenoprotein microcapsule powder prepared in step S3 is directly compressed into tablets using a continuous tablet press with a pressure of 10kN to obtain fermented jujube selenoprotein microcapsule tablets.

[0044] Example 2 A method for preparing fermented jujube selenium protein microcapsule tablets includes the following steps: S1. Preparation of lactic acid bacteria fermented jujube juice: Jujubes and water are mixed at a mass ratio of 1:4 and then ground to obtain a grinding liquid; the grinding liquid is sterilized at 121℃ for 15 min; under aseptic conditions, 0.3 mg / mL of Lactobacillus plantarum powder is inoculated and cultured at 37℃ for 36 h; homogenization is continued at 6000 rpm for 8 min; finally, it is concentrated to a soluble solids content of 30% to obtain lactic acid bacteria fermented jujube juice. S2. Lactic acid bacteria fermented jujube juice and selenoprotein undergo double emulsification and coagulation: The suspension formed by mixing the lactic acid bacteria fermented jujube juice and violet leaf spore selenoprotein powder prepared in step S1 at a volume-to-mass ratio of 80:1 is used as the inner aqueous phase W1; the solution of corn oil and polyglycerol polyricinoleate at a volume ratio of 95:5 is used as the oil phase O. The above inner aqueous phase W1 and oil phase O are mixed at a volume ratio of 3:7 and homogenized for 3 minutes at a rotation speed of 8000 rpm to form a water-in-oil (W1 / O) emulsion. The external aqueous phase W2 was prepared by mixing rice bran albumin (RBA) and sodium carboxymethyl cellulose (CMC) at a mass ratio of 1:1 to form an aqueous solution with a mass concentration of 1%. The external aqueous phase W2 was mixed with the above W1 / O emulsion at a volume ratio of 8:2 and homogenized for 3 min at a speed of 10000 rpm to form a water-in-oil-in-water (W1 / O / W2) emulsion. The pH of the W1 / O / W2 emulsion was adjusted to 2.5 with 0.1M acetic acid and re-coagulated at 6℃ for 24 h to obtain wet microcapsules. S3. Spray drying of wet microcapsules: The wet microcapsules prepared in step S2 are mixed with resistant dextrin at a volume-to-mass ratio of 10:1. The spray drying feed flow rate is set to 0.8 mL / min, the feed temperature is 140℃, the discharge temperature is 60℃, and the compressed air pressure is 0.5 MPa to obtain a free-flowing fermented jujube juice selenoprotein microcapsule powder. S4. The fermented jujube selenoprotein microcapsule powder prepared in step S3 is directly compressed into tablets using a continuous tablet press with a pressure of 15kN to obtain fermented jujube selenoprotein microcapsule tablets.

[0045] Example 3 A method for preparing fermented jujube selenium protein microcapsule tablets includes the following steps: S1. Preparation of lactic acid bacteria fermented jujube juice: Jujubes and water are mixed at a mass ratio of 1:5 and then ground to obtain a grinding liquid; the grinding liquid is sterilized at 121℃ for 15 min; under aseptic conditions, 0.5 mg / mL of Lactobacillus plantarum powder is inoculated and cultured at 42℃ for 24 h; homogenization is continued at 8000 rpm for 3 min; finally, it is concentrated to a soluble solids content of 20% to obtain lactic acid bacteria fermented jujube juice. S2. Lactic acid bacteria fermented jujube juice and selenoprotein undergo double emulsification and coagulation: The suspension formed by mixing the lactic acid bacteria fermented jujube juice and violet leaf crushed rice selenoprotein powder prepared in step S1 at a volume-to-mass ratio of 100:1 is used as the inner aqueous phase W1; the solution of corn oil and polyglycerol polyricinoleate at a volume ratio of 93:7 is used as the oil phase O; the above inner aqueous phase W1 and oil phase O are mixed at a volume ratio of 4:6, and homogenized for 1 min at a rotation speed of 10000 rpm to form a water-in-oil (W1 / O) emulsion. The external aqueous phase W2 was prepared by mixing rice bran albumin (RBA) and sodium carboxymethyl cellulose (CMC) at a mass ratio of 0.5:1 to form an aqueous solution with a mass concentration of 0.5%. The external aqueous phase W2 was mixed with the above W1 / O emulsion at a volume ratio of 6:4 and homogenized for 1 min at a speed of 12000 rpm to form a water-in-oil-in-water (W1 / O / W2) emulsion. The pH of the W1 / O / W2 emulsion was adjusted to 4 with 0.1M acetic acid and re-coagulated at 4℃ for 12 h to obtain wet microcapsules. S3. Spray drying of wet microcapsules: The wet microcapsules prepared in step S2 are mixed with resistant dextrin at a volume-to-mass ratio of 8:1. The spray drying feed flow rate is set to 1.2 mL / min, the feed temperature is 160℃, the discharge temperature is 80℃, and the compressed air pressure is 1 MPa to obtain a free-flowing fermented jujube juice selenoprotein microcapsule powder. S4. The fermented jujube selenoprotein microcapsule powder prepared in step S3 is directly compressed into tablets using a continuous tablet press with a pressure of 20kN to obtain fermented jujube selenoprotein microcapsule tablets.

[0046] Comparative Example 1 In this comparative example, the preparation method of fermented jujube selenium protein microcapsule tablets is basically the same as that in Example 2, except that in step S1, the amount of Lactobacillus plantarum powder added is 1.0 mg / mL.

[0047] Comparative Example 2 In this comparative example, the preparation method of fermented jujube selenium protein microcapsule tablets is basically the same as that in Example 2, except that in step S1, the constant temperature incubation is set to 45°C.

[0048] Comparative Example 3 In this comparative example, the preparation method of fermented jujube selenium protein microcapsule tablets is basically the same as that in Example 2. The difference is that in step S2, polyglycerol polyricinoleate is not added to the oil phase.

[0049] Comparative Example 4 In this comparative example, the preparation method of fermented jujube selenium protein microcapsule tablets is basically the same as that in Example 2. The difference is that in step S2, rice bran albumin (RBA) and sodium carboxymethyl cellulose (CMC) are prepared into an aqueous solution with a mass concentration of 1% at a mass ratio of 5:1.

[0050] Comparative Example 5 In this comparative example, the preparation method of fermented jujube selenium protein microcapsule tablets is basically the same as that in Example 2. The difference is that in step S2, rice bran albumin (RBA) and sodium carboxymethyl cellulose (CMC) are prepared into an aqueous solution with a mass concentration of 1% at a mass ratio of 0.2:1.

[0051] Comparative Example 6 In this comparative example, the preparation method of fermented jujube selenium protein microcapsule tablets is basically the same as that in Example 2. The difference is that in step S3, resistant dextrin is not added, and the wet microcapsules are directly spray-dried.

[0052] Comparative Example 7 In this comparative example, the preparation method of fermented jujube selenoprotein microcapsule tablets is basically the same as that in Example 2. The difference is that in step S4, the fermented jujube juice selenoprotein microcapsule powder, microcrystalline cellulose, and magnesium stearate are mixed in a mass ratio of 90:8:2 and then compressed into tablets by a continuous tablet press.

[0053] Comparative Example 8 In this comparative example, the preparation method of fermented jujube selenium protein microcapsule tablets is basically the same as that in Example 2. The difference is that in step S1, Lactobacillus plantarum powder is not inoculated; in step S2, only the lactic acid bacteria fermented jujube juice and Viola yedoensis selenium protein powder are mixed to form a suspension, without subsequent double emulsification and coagulation treatment.

[0054] Performance testing The polyphenol content in the lactic acid bacteria fermented jujube juice prepared in Examples 1-3 and Comparative Examples 1, 2, and 8 was determined to evaluate the polyphenol enrichment effect under different fermentation conditions. The total phenol content was determined using the Folin-Ciocalteu colorimetric method, with gallic acid standard as a reference. The contents of free phenol, bound phenol, and total phenol were calculated, and the results are shown in Table 1.

[0055] Table 1. Total phenolic content (mg / mL) of jujube juice fermented with lactic acid bacteria under different conditions.

[0056] Note: Different letters in each column indicate significant differences (p<0.05); "-" indicates not detected.

[0057] As shown in Table 1, Comparative Example 8, the unfermented jujube juice had the lowest content of free phenols and total polyphenols, while the bound phenol content was the highest. In Examples 1-3, the jujube juice prepared by lactic acid bacteria fermentation showed significantly increased contents of free phenols and total polyphenols (p<0.05), and significantly decreased contents of bound phenols (p<0.05). Furthermore, the jujube juice prepared in Example 2 had the highest contents of free phenols and total polyphenols, reaching 4.05 mg / mL and 4.20 mg / mL respectively, while the bound phenol content was the lowest. This is because fermentation with *Lactobacillus plantarum* not only promoted the conversion of bound polyphenols in jujubes to free polyphenols but also increased the contents of both free and total polyphenols. Compared to Comparative Example 1, the higher amount of bacteria added resulted in insufficient substrate for microbial utilization, accelerating the accumulation of alcohol and acids. Similarly, the higher culture temperature in Comparative Example 2 also accelerated the accumulation of alcohol and acids, inhibiting the production of polyphenols and other active substances. The conditions in Example 2 are more conducive to the preservation of lactic acid bacteria activity and promote the accumulation of jujube polyphenols.

[0058] The encapsulation rates of polyphenols and organic selenium in the fermented jujube selenoprotein microcapsules prepared in Examples 1-3 and Comparative Examples 1-8 were determined. At the same time, the bioavailability of polyphenols and organic selenium in the fermented jujube selenoprotein microcapsule tablets after in vitro simulated gastrointestinal digestion was determined. The results are shown in Table 2.

[0059] The polyphenol content was determined using the Folin-Ciocalteu colorimetric method, and the organic selenium content was determined using the inductively coupled plasma mass spectrometry method in GB 5009.93-2017 "National Food Safety Standard - Determination of Selenium in Food". The Agilent standard internal standard solution was used as a reference. The encapsulation efficiency was recorded as the ratio of polyphenols and organic selenium in the microcapsules to that before the reaction, and the bioavailability was recorded as the ratio of polyphenols and organic selenium in the simulated gastrointestinal tract in vitro to that before the reaction.

[0060] Table 2 Encapsulation efficiency of polyphenols and organic selenium in fermented jujube selenium protein microcapsules and their bioavailability (%)

[0061] Note: Different letters in each column indicate significant differences (p<0.05).

[0062] As shown in Table 2, in Comparative Example 8, the jujube selenoprotein microcapsule tablets exhibited the highest release of polyphenols and organic selenium in the stomach, while having the lowest bioavailability in the small intestine. Compared to Comparative Examples 1-7, the jujube selenoprotein microcapsule tablets in Examples 1-3 showed significantly reduced release of polyphenols and organic selenium in the stomach (p<0.05), while significantly increased bioavailability in the small intestine (p<0.05). In Example 2, the jujube selenoprotein microcapsule tablets showed the lowest release of polyphenols and organic selenium in the stomach, both less than 5%, while exhibiting the highest bioavailability in the small intestine, both exceeding 85%. This is because the "two-phase, three-layer" emulsion structure formed through dual emulsification and re-coagulation microencapsulation technology not only blocks oxygen in the oil phase, reducing polyphenol oxidation and improving the encapsulation efficiency of polyphenols and organic selenium, but also possesses pH-responsive and gastrointestinal controlled-release characteristics. This allows the two unstable active ingredients, polyphenols and organic selenium, to maintain structural integrity in the acidic environment of the stomach and trigger release in the neutral environment of the intestine, significantly improving the bioavailability of polyphenols and organic selenium. In Comparative Example 3, the absence of polyglycerol polyricinoleate, and in Comparative Examples 4 and 5, the unsuitable ratio of rice bran albumin and sodium carboxymethyl cellulose, both resulted in instability of the double emulsion structure, weakened encapsulation of polyphenols and organoselenium, leading to excessive product release in the stomach and reduced bioavailability during intestinal digestion. Example 2, by adding polyglycerol polyricinoleate to the oil phase, achieved moderate emulsification, reducing interfacial tension, promoting interfacial film formation, and stabilizing the W1 / O emulsion structure. Adding an appropriate ratio of rice bran albumin and sodium carboxymethyl cellulose to the external aqueous phase W2 promoted hydrogen bonding and electrostatic binding, resulting in both sustained-release and anti-compression properties. Comparative Example 7 used conventional tableting with excipients such as microcrystalline cellulose and magnesium stearate. While this protected against excessive release during gastric digestion, it also reduced release and bioavailability during intestinal digestion.

[0063] In summary, the fermented jujube selenium protein microcapsule tablets prepared by this invention effectively protect the polyphenols produced by lactic acid bacteria fermentation of jujubes and the exogenous organic selenium fortification, significantly improving the bioavailability of polyphenols and selenium. Furthermore, the related technologies used in this preparation process are mature and easily promoted, suitable for industrialized production. In addition, the tableting process does not require the addition of any excipients, meeting consumers' needs for clean product labels. The tablets are also easy to carry and store, making them suitable for busy office workers, travelers, or the elderly as a convenient nutritional supplement, especially for those requiring comprehensive health maintenance, fatigue relief, and improved physical fitness.

[0064] It should be noted that all the above embodiments belong to the same inventive concept, and the descriptions of each embodiment have different focuses. Where the description in a particular embodiment is not detailed, please refer to the description in other embodiments.

[0065] The embodiments described above are merely illustrative of implementation methods of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for preparing fermented jujube selenium protein microcapsule tablets, characterized in that, Includes the following steps: Provides lactic acid bacteria fermented jujube juice; The lactic acid bacteria fermented jujube juice and selenium protein powder were mixed to obtain a first aqueous solution. The first aqueous solution was mixed with an oil phase and homogenized to obtain a water-in-oil emulsion. The water-in-oil emulsion was then mixed with a second aqueous solution and homogenized to obtain a water-in-oil emulsion. The pH of the water-in-oil emulsion was adjusted to acidic and then refrigerated to obtain wet microcapsules. The wet microcapsules were mixed with a drying aid and then spray-dried to obtain fermented jujube selenium protein microcapsule powder. The fermented jujube selenoprotein microcapsule powder was compressed into tablets to obtain fermented jujube selenoprotein microcapsule tablets.

2. The preparation method according to claim 1, characterized in that, In the step of providing lactic acid bacteria fermented jujube juice, the preparation of the lactic acid bacteria fermented jujube juice includes: mixing jujubes and water and then grinding them to obtain a grinding liquid; sterilizing the grinding liquid and then inoculating it with Lactobacillus plantarum powder under aseptic conditions, followed by constant temperature culture, homogenization, and concentration to obtain lactic acid bacteria fermented jujube juice; The mass ratio of jujubes to water is 1:(2-5); the sterilization process includes sterilization at 115-130℃ for 10-20 minutes; the inoculation amount of *Lactobacillus plantarum* powder is 0.1-0.5 mg / mL; the isothermal culture includes culture at 32-42℃ for 24-48 hours; the homogenization process includes homogenization at 5000-8000 rpm for 3-8 minutes; and the soluble solids content in the lactic acid bacteria fermented jujube juice is 20-35%.

3. The preparation method according to claim 1, characterized in that, In the step of obtaining wet microcapsules, the volume-to-mass ratio of the lactic acid bacteria fermented jujube juice to the selenium protein powder is (50-100):1, and the selenium protein powder includes violet leaf broken rice selenophora selenium protein powder. The volume ratio of the first aqueous phase solution to the oil phase is (1-4):(6-9), and the oil phase comprises corn oil and polyglycerol polyricinoleate; The volume ratio of the corn oil to the polyglycerol polyricinoleate is (93-99):(1-7).

4. The preparation method according to claim 1, characterized in that, In the step of obtaining wet microcapsules, the volume ratio of the second aqueous solution to the water-in-oil emulsion is (6-9):(1-4). The second aqueous solution has a mass concentration of 0.5-2%, and is obtained by dissolving rice bran albumin and sodium carboxymethyl cellulose in water. The mass ratio of the rice bran albumin to the sodium carboxymethyl cellulose is (0.5-3):

1.

5. The preparation method according to claim 1, characterized in that, In the step of obtaining wet microcapsules, the first homogenization process includes: homogenizing for 1-5 minutes at a rotation speed of 6000-10000 rpm; and / or, The second homogenization process includes homogenizing for 1-5 minutes at a rotation speed of 8000-12000 rpm.

6. The preparation method according to claim 1, characterized in that, In the step of obtaining wet microcapsules, the pH of the water-in-oil-in-water emulsion is 1.5-4; The refrigeration includes: refrigerating for 12-48 hours at a temperature of 4-10℃.

7. The preparation method according to claim 1, characterized in that, In the step of mixing the wet microcapsules with the drying aid and then spray drying, the volume-to-mass ratio of the wet microcapsules to the drying aid is (8-12):1, and the drying aid includes resistant dextrin. The spray drying process includes spray drying under the following conditions: feed flow rate of 0.5-1.2 mL / min, feed temperature of 130-160℃, discharge temperature of 50-80℃, and compressed air pressure of 0.25-1 MPa.

8. The preparation method according to claim 1, characterized in that, In the step of compressing the fermented jujube selenium protein microcapsule powder into tablets, the tableting process includes compressing the tablets under a pressure of 10-20 kN.

9. A fermented jujube selenium protein microcapsule tablet, characterized in that, It is prepared by the preparation method according to any one of claims 1-8.

10. The application of the fermented jujube selenium protein microcapsule tablets as described in claim 9 in food.

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