Dietary composition helpful for enhancing immunity and preparation method thereof

Abstract

The present invention discloses a dietary composition that helps enhance immunity and a preparation method thereof. The dietary composition comprises the following components, by weight: 40-50 parts of astragalus extract, 30-40 parts of kudzu root extract, 20-30 parts of polygonatum extract, and 5-10 parts of rhodiola rosea extract. By scientifically combining four immunomodulatory Chinese herbal extracts—astragalus, kudzu root, polygonatum, and rhodiola rosea—in specific proportions, this dietary composition integrates the positive effects of each component in different immune pathways, producing a synergistic or multi-targeted modulation effect. This achieves a more comprehensive and effective overall immunity-enhancing effect than a single component alone, providing a safe and effective dietary supplement option for improving immune function.

Description

Technical Field

[0001] The present invention belongs to the technical field of functional foods, and in particular relates to a dietary composition that helps to enhance immunity and a preparation method thereof. Background Art

[0002] Immunity is the body's own defense mechanism, enabling it to identify and eliminate any invading foreign bodies (viruses, bacteria, etc.), manage aging, damaged, dying, and degenerating cells, and identify and treat mutated and virus-infected cells. When the body's nutrient intake (protein, vitamins, amino acids, and some trace elements) is insufficient, immunity declines, increasing the risk of contracting diseases such as bacterial and viral infections and cancer. However, an immune system that exceeds normal levels can also cause damage, such as triggering allergic reactions.

[0003] The main factors affecting low immunity are: (1) Age: There are two stages of low immunity in life, namely childhood and old age. Children's immune systems are not yet mature, their functions are not perfect, and their immunity is low; while the elderly's organ functions decline, their ability to obtain nutrition decreases, and their immune organs gradually shrink and decline, leading to a decline in immunity. Correspondingly, children and the elderly are also two stages with a high incidence of diseases. (2) Unhealthy lifestyles and habits: Mental stress, malnutrition, lack of exercise or lack of sleep, abuse of alcohol and smoking, etc., may suppress the immune system and reduce the body's immunity. (3) Other factors: Toxic substances in the environment, certain drugs, radiotherapy, and excessive use of antibiotics can also suppress the immune system.

[0004] In recent years, with the continuous improvement of people's health awareness, more and more people hope to enhance their immunity and improve their health through health foods. Although there are many types of health foods used to enhance immunity, these products generally suffer from complex ingredients and lack of obvious effects. In addition, due to the complex ingredients, health foods are expensive and cannot be taken for a long time, and they cannot achieve the effect of sustained and systematic immune enhancement.

[0005] Chinese patent application CN110237118A discloses a composition containing nicotinamide mononucleotide for use in anti-aging medicines / health products. The raw materials of the composition, measured in parts by mass, include: 1-10 parts of nicotinamide mononucleotide, 1-10 parts of astragalus, 1-10 parts of ginseng, 1-10 parts of ginsenoside Rb1, 1-10 parts of coenzyme Q10, 1-10 parts of puerarin, 1-10 parts of eucommia leaves, and 1-10 parts of huangmao polysaccharide. In this invention, NMN can activate the body's energy metabolism and improve the body's oxidative stress response. At the same time, in combination with the synergistic effect of the other components, it has a good anti-aging effect. In addition, the components in the composition have a stable structure, and the corresponding products are not easily deteriorated or damaged after being prepared. At the same time, the components are safe and have basically no adverse reactions to the human body. This solves the technical defects of the prior art that anti-aging products have difficulty in balancing good anti-aging effects, harmlessness to the human body, and stable product quality. Chinese patent application CN104544437A discloses a health drink with anti-fatigue and immune regulation, which is made of the following raw materials in parts by weight: honeysuckle 12, golden buckwheat 8, dandelion 8, andrographis paniculata 8, herba ecliptae 10, raspberry 8, white lentils 6, chicken's gizzard 9, yiqi 8, ebony 8, purple quartz 6, linseed 9, rush 8, loofah 8, codonopsis pilosula 10, papaya 12, calamus 8, malt 10, reed root 10, bamboo leaf 8, julibrissin bark 10, clove 6, honey 15. The present invention adopts natural Chinese medicine as raw material, and each Chinese medicine has a synergistic effect, and jointly plays the effect of replenishing qi and nourishing blood, tonifying yang and promoting body fluid, can effectively improve human fatigue state, can effectively improve human immunity and lasting effect. However, the above-mentioned composition and health drink are mostly based on Chinese medicine as raw material, and the component mainly plays a single effect in the composition, and there is still room for improvement in bioavailability and improving immunity.

[0006] Therefore, it is of great significance to develop a dietary composition for enhancing immunity that has simple ingredients, is effective, and can be taken for a long time. Summary of the Invention

[0007] In view of the deficiencies of the prior art, the present invention aims to provide a dietary composition that helps to enhance immunity and a preparation method thereof.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A dietary composition that helps enhance immunity, comprising the following components by weight:

[0010] 40-50 parts of Astragalus root extract, 30-40 parts of Pueraria root extract, 20-30 parts of Polygonatum odoratum extract, and 5-10 parts of Rhodiola rosea extract.

[0011] Astragalus, a traditional Chinese tonic herb, boasts high medicinal and nutritional value. Its sweet flavor and mild nature have benefits such as tonifying the spleen and strengthening the exterior, as well as promoting diuresis and promoting salivation. Its active ingredients, including astragalus polysaccharides, saponins, and flavonoids, possess anti-inflammatory, antibacterial, and antioxidant properties. Studies have shown that its active ingredients can effectively regulate growth, development, and immune function in animals.

[0012] Pueraria root is the root or tuberous stem of Pueraria lobata, a perennial deciduous vine of the Leguminosae family. It is rich in polysaccharides, flavonoids, saponins, organic acids, alkaloids, vitamins, phenols and other active ingredients. Modern pharmacological experiments have shown that Pueraria root also has antioxidant, circulatory system regulation, blood pressure regulation, blood sugar lowering, tumor inhibition, immunity enhancement, memory improvement and other functions. It also has special therapeutic effects on cerebrovascular diseases, sudden deafness, eye diseases, alcoholism and diabetes.

[0013] Polygonatum odoratum is a herbaceous plant in the genus Polygonatum of the Liliaceae family. Its dried rhizome is a traditional Chinese medicine with both medicinal and edible properties, known for its nourishing yin, moistening dryness, promoting fluid production, and quenching thirst. Modern pharmacological research has shown that Polygonatum odoratum has multiple pharmacological effects, including hypoglycemic, antioxidant, vascular protection, and immune enhancement. This is primarily attributed to its rich content of polysaccharides, flavonoids, and saponins, with polysaccharides being the primary active ingredient.

[0014] Rhodiola rosea is the dried root and rhizome of the Rhodiola genus of the Crassulaceae family. Rhodiola rosea plants contain a variety of biologically active substances such as flavonoids, amino acids, polyphenols, etc., and have multiple physiological functions such as anti-aging, anti-hypoxia, anti-fatigue, anti-radiation, anti-tumor, immunity enhancement, and regulation of the endocrine system and nervous system. It is a traditional Chinese medicine with multiple active ingredients and rich pharmacological activities.

[0015] In the present invention, four plant extracts are compounded in a certain proportion, among which astragalus polysaccharides and polygonatum polysaccharides activate different pattern recognition receptors or act on different immune cells, initiating and enhancing immune responses from multiple links. Small molecule components such as astragaloside and salidroside focus on regulating the functional state of immune cells, complementing the direct activation effect of polysaccharides in the dietary composition. This combination helps maintain the homeostasis of the immune system under stress. Astragalus flavonoids, kudzu isoflavones, and salidroside phenolic compounds all have antioxidant capacity and can jointly scavenge excessive free radicals in the body and protect immune cells from oxidative damage. At the same time, puerarin and other ingredients also have certain anti-inflammatory activity, which can help regulate the inflammatory balance in the immune response. By integrating the characteristics of different extracts, this composition is rich in different types of active ingredients such as polysaccharides, saponins, flavonoids, phenols, etc., and exerts synergistic effects at multiple levels such as immune activation, immunomodulation, anti-oxidation, and anti-stress, thereby achieving a more comprehensive and effective immune enhancement effect than a single ingredient.

[0016] Preferably, a dietary composition that helps enhance immunity comprises the following components by weight: 45-50 parts of astragalus extract, 30-35 parts of kudzu root extract, 25-30 parts of polygonatum extract, and 7-10 parts of rhodiola rosea extract.

[0017] Preferably, the preparation method of the astragalus extract is as follows:

[0018] The astragalus root is dried, crushed with a liquid nitrogen grinder, and passed through a 60-mesh sieve to obtain astragalus root powder; the astragalus root powder is then added to deionized water, and phosphate buffer is added to adjust the pH to 4-5, followed by the addition of cellulase, pectinase, and sodium phytate for enzymatic hydrolysis, and after the treatment is completed, the enzyme is inactivated by boiling water, and ultrasonic extraction is performed. After the extraction is completed, the extraction is filtered to obtain a filtrate and a filter residue, and the filtrate is rotary evaporated to obtain an aqueous extract; the filter residue is added to anhydrous ethanol, and then xylitol anhydride monostearate is added for reflux extraction. After the extraction is completed, the extraction is filtered, and the filtrate is rotary evaporated to obtain an alcohol extract, and the aqueous extract and the alcohol extract are uniformly mixed to obtain the astragalus root extract.

[0019] Preferably, the solid-liquid ratio of the astragalus powder to deionized water is 1:20-25, the amount of the cellulase added is 2-3% of the mass of the astragalus powder, the amount of the pectinase added is 1-2% of the mass of the astragalus powder, the amount of the sodium phytate added is 0.3-0.5% of the mass of the astragalus powder, the temperature of the enzymatic hydrolysis treatment is 45-55°C, the time is 40-60min, the temperature of the ultrasonic extraction is 60-70°C, the power is 400-500W, and the time is 30-40min.

[0020] In the present invention, a two-step method combining enzyme-assisted water extraction and alcohol extraction of the water extraction residue is used to extract the Astragalus root extract. First, the Astragalus root extract is extracted in a weakly acidic environment (pH 4-5) and an appropriate temperature (45-55°C), cellulase and pectinase were used to synergistically hydrolyze the Astragalus cell wall, supplemented by ultrasound to enhance mass transfer, effectively dissolving the water-soluble active ingredients in the Astragalus cell wall, especially the key immunoactive polysaccharides. At the same time, sodium phytate was innovatively added to the water extraction process to utilize its strong chelating ability for metal ions to inhibit potential metal-catalyzed oxidation reactions, thereby effectively protecting the structural integrity of easily oxidized components such as Astragalus polysaccharides during the extraction process and enhancing the biological activity of the Astragalus extract. Subsequently, the filter residue after water extraction was further extracted with anhydrous ethanol reflux to extract alcohol-soluble active components (such as some saponins and flavonoids). Xylitol monostearate was added to improve wettability or solubilize certain alcohol-soluble components (such as some saponins) to act as an extraction aid. This specific extraction method better ensures the quality and stability of the Astragalus polysaccharide component, provides the dietary composition with stronger immunomodulatory potential, and produces a better synergistic effect with other herbal extracts, thereby enhancing the immune-enhancing effect of the entire dietary composition.

[0021] Preferably, the material-liquid ratio of the filter residue to anhydrous ethanol is 1:15-20, the added amount of xylitol anhydride monostearate is 0.4-0.6% of the mass of the astragalus powder, and the reflux time is 1-1.5h.

[0022] Preferably, the preparation method of the Polygonatum odoratum extract is as follows:

[0023] The polygonatum odoratum is crushed and passed through a 60-mesh sieve, then added into deionized water, followed by adding cellulase and soaking for 1-2 hours, followed by adding xylanase and soaking for 0.5-1 hour, and ultrasonic extraction is performed after the enzyme is inactivated. After the extraction is completed, the filtrate is filtered and concentrated to 1 / 4 of the original volume, and 4 times the volume of anhydrous ethanol is added for precipitation. After filtering, freeze-drying is performed to obtain the polygonatum odoratum extract.

[0024] Preferably, the solid-liquid ratio of the polygonatum to deionized water is 1:18-22, the amount of the cellulase added is 1.5-2% of the mass of the polygonatum, the amount of the xylanase added is 1-1.5% of the mass of the polygonatum, the immersion temperature is 45-55°C, the ultrasonic extraction temperature is 60-70°C, the power is 400-450W, and the time is 30-40min.

[0025] In the present invention, an enzymatic pretreatment technology is adopted in the preparation method of the Polygonatum odoratum extract, that is, before the main extraction step (ultrasonic extraction), the Polygonatum odoratum powder is subjected to a mild enzymatic hydrolysis treatment using cellulase and xylanase in sequence or simultaneously. Cellulase acts on cellulose, the main skeleton component of the cell wall, while xylanase degrades the hemicellulose component, which is also relatively abundant in the cell wall. The synergistic action of these two enzymes can effectively destroy the structural integrity of the Polygonatum odoratum cell wall and improve its permeability, thereby greatly promoting the release and dissolution of active ingredients such as polysaccharides in the cell during the subsequent ultrasonic extraction process. Compared with traditional simple water extraction or acid-base treatment that may cause polysaccharide degradation, this enzymatic pretreatment not only has mild conditions, helps to maintain the natural structure and biological activity of polysaccharides, but also has higher efficiency.

[0026] Preferably, the preparation method of the Rhodiola rosea extract is as follows:

[0027] The Rhodiola rosea was crushed and passed through a 60-mesh sieve, then added to an ethanol aqueous solution and heated for extraction. The extraction was repeated twice, and the filtrates were combined and rotary evaporated to obtain the Rhodiola rosea extract.

[0028] Preferably, the solid-liquid ratio of Rhodiola rosea to ethanol water is 1:25-30, the mass fraction of ethanol in the ethanol water solution is 50-60%, the temperature of the heating extraction is 60-70°C, the time is 1.5-2h, and the solid-liquid ratio during the second extraction is 1:8-10.

[0029] The present invention also protects a method for preparing the dietary composition that helps enhance immunity as described above, comprising the following steps:

[0030] The raw materials are weighed according to the formula, and the astragalus extract, kudzu root extract, polygonatum extract and rhodiola rosea extract are evenly mixed to obtain the product.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] (1) The dietary composition provided by the present invention is helpful for enhancing immunity. By scientifically combining the extracts of four Chinese herbal medicines with immunomodulatory activity, namely, astragalus, kudzu root, polygonatum and rhodiola, in a specific proportion, it can integrate the positive effects of each component in different immune links, produce synergistic enhancement or multi-target regulation effects, thereby achieving a more comprehensive and effective overall immunity enhancement effect than a single component, and providing a safe and effective dietary supplement option for improving the body's immune function.

[0033] (2) The dietary composition provided by the present invention is helpful for enhancing immunity. First, an enzymatic method (cellulase and pectinase) is used to assist water extraction, and the extraction is carried out at a pH of 4-5 and a temperature of 45-55°C, which can gently and efficiently destroy the cell wall structure of Astragalus membranaceus and significantly improve the dissolution rate of water-soluble active ingredients (especially polysaccharides). Second, sodium phytate is added as a metal ion chelating agent during the enzymatic hydrolysis process, which effectively inhibits the catalytic oxidation degradation of active ingredients such as polysaccharides by trace metal ions that may exist during the extraction process, thereby protecting the structural integrity and biological activity of the active substances. Third, a two-step extraction method of first water extraction and then alcohol extraction of the water extraction residue is used, and combined with ultrasonic assistance, a comprehensive and efficient extraction of water-soluble and alcohol-soluble active ingredients (such as polysaccharides, saponins, flavonoids, etc.) in Astragalus membranaceus is achieved, thereby obtaining extracts of more active components and maximizing the use of medicinal resources.

[0034] (3) The dietary composition provided by the present invention that helps to enhance immunity adopts an enzymatic pretreatment technology that combines cellulase and xylanase. These two enzymes act on the main components of the cell wall of Polygonatum odoratum, namely cellulose and hemicellulose, respectively. Through synergistic hydrolysis, they can significantly improve the permeability and even the degree of damage of the cell wall, thereby greatly improving the extraction efficiency and yield of the target active ingredient, Polygonatum odoratum polysaccharide, under subsequent mild ultrasonic extraction conditions. This method avoids the use of strong acids, strong bases or extreme high temperatures that may cause degradation or structural damage of polysaccharides, thereby ensuring the natural structure and potential biological activity of the obtained Polygonatum odoratum polysaccharide, and obtaining a high-quality extract rich in polysaccharides. DETAILED DESCRIPTION

[0035] The technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0036] In the present invention, the Pueraria root extract was purchased from Xi'an Yourui Biotechnology Co., Ltd., and the puerarin content was 40%. Example 1

[0037] A dietary composition that helps enhance immunity, comprising the following components by weight:

[0038] 45 parts of Astragalus root extract, 35 parts of Pueraria root extract, 25 parts of Polygonatum odoratum extract, and 8 parts of Rhodiola rosea extract.

[0039] Wherein, the preparation method of the astragalus extract is as follows:

[0040] The astragalus root is dried, crushed with a liquid nitrogen grinder, and passed through a 60-mesh sieve to obtain an astragalus root powder; the astragalus root powder is then added to deionized water with a solid-liquid ratio of astragalus root powder to deionized water of 1:22, phosphate buffer is added to adjust the pH to 4.5, and then 2.5% of cellulase by weight of the astragalus root powder, 1.5% of pectinase by weight of the astragalus root powder, and 0.4% of sodium phytate by weight of the astragalus root powder are added. The mixture is enzymatically hydrolyzed at 50° C. for 50 minutes, and after the treatment, the enzyme is inactivated by boiling water. The mixture is ultrasonically extracted at a temperature of 65° C. and a power of 450 W for 35 minutes. After the extraction is completed, the mixture is filtered to obtain a filtrate and a filter residue. The filtrate is rotary evaporated to obtain an aqueous extract. The filter residue is added to anhydrous ethanol with a solid-liquid ratio of the filter residue to anhydrous ethanol of 1:18, and then 0.5% of xylitol monostearate by weight of the astragalus root powder is added. The mixture is refluxed for 1.5 hours. After the extraction is completed, the mixture is filtered and the filtrate is rotary evaporated to obtain an alcohol extract. The aqueous extract and the alcohol extract are uniformly mixed to obtain the astragalus root extract.

[0041] The preparation method of the polygonatum extract is as follows:

[0042] The polygonatum was crushed and passed through a 60-mesh sieve, and then added into deionized water with a solid-liquid ratio of polygonatum to deionized water of 1:20. Then, 1.8% cellulase by weight of the polygonatum was added and soaked at 50°C for 1.5 hours. Then, 1.5% xylanase by weight of the polygonatum was added and soaked at 50°C for 1 hour. After the enzyme was inactivated by boiling water, ultrasonic extraction was performed at a temperature of 65°C, a power of 430W, and a time of 35 minutes. After the extraction was completed, the filtrate was filtered and concentrated to 1 / 4 of the original volume. Four times the volume of anhydrous ethanol was added for precipitation, and the mixture was filtered and freeze-dried to obtain the polygonatum extract.

[0043] The preparation method of the Rhodiola rosea extract is as follows:

[0044] Rhodiola rosea was crushed and passed through a 60-mesh sieve. It was then added to an ethanol-water solution (the mass fraction of ethanol was 55%) at a solid-liquid ratio of 1:28. The mixture was heated and extracted at 65°C for 2 h. After the extraction was completed, it was filtered. An ethanol-water solution was added to the filter residue at a solid-liquid ratio of 1:9. The mixture was extracted again at 65°C for 1 h. The mixture was filtered and the filtrate was combined and rotary evaporated to obtain the Rhodiola rosea extract. Example 2

[0045] A dietary composition that helps enhance immunity, comprising the following components by weight:

[0046] 40 parts of Astragalus root extract, 30 parts of Pueraria root extract, 20 parts of Polygonatum odoratum extract, and 5-10 parts of Rhodiola rosea extract.

[0047] Wherein, the preparation method of the astragalus extract is as follows:

[0048] The astragalus root is dried, crushed with a liquid nitrogen grinder, and then passed through a 60-mesh sieve to obtain an astragalus root powder; the astragalus root powder is then added to deionized water with a solid-liquid ratio of astragalus root powder to deionized water of 1:20, phosphate buffer is added to adjust the pH to 5, and then 2% of cellulase by weight of the astragalus root powder, 1% of pectinase by weight of the astragalus root powder, and 0.3% of sodium phytate by weight of the astragalus root powder are added, and enzymatic hydrolysis is carried out at 45° C. for 60 minutes. After the treatment is completed, the enzyme is inactivated by boiling water, and ultrasonic extraction is performed at a temperature of 60° C. and a power of 400 W for 40 minutes. After the extraction is completed, the extract is filtered to obtain a filtrate and a filter residue, and the filtrate is rotary evaporated to obtain an aqueous extract; the filter residue is added to anhydrous ethanol with a solid-liquid ratio of the filter residue to anhydrous ethanol of 1:15, and then 0.4% of xylitol monostearate by weight of the astragalus root powder is added, and the extract is refluxed for 1.5 hours. After the extraction is completed, the extract is filtered, and the filtrate is rotary evaporated to obtain an alcohol extract. The aqueous extract and the alcohol extract are evenly mixed to obtain the astragalus root extract.

[0049] The preparation method of the polygonatum extract is as follows:

[0050] The Polygonatum odoratum was crushed and passed through a 60-mesh sieve, and then added into deionized water with a solid-liquid ratio of Polygonatum odoratum to deionized water of 1:18. Then, 1.5% cellulase by weight of Polygonatum odoratum was added and soaked at 45°C for 2 h. Then, 1.5% xylanase by weight of Polygonatum odoratum was added and soaked at 45°C for 1 h. After the enzyme was inactivated by boiling water, ultrasonic extraction was performed at a temperature of 60°C, a power of 400 W, and a time of 40 min. After the extraction was completed, the filtrate was filtered and concentrated to 1 / 4 of the original volume. Four times the volume of anhydrous ethanol was added for precipitation, and the mixture was filtered and freeze-dried to obtain the Polygonatum odoratum extract.

[0051] The preparation method of the Rhodiola rosea extract is as follows:

[0052] Rhodiola rosea was crushed and passed through a 60-mesh sieve. It was then added to an ethanol-water solution (the mass fraction of ethanol was 50%) at a solid-liquid ratio of 1:25. The mixture was heated and extracted at 60°C for 2 h. After the extraction was completed, it was filtered. Ethanol-water solution was added to the residue at a solid-liquid ratio of 1:8. The mixture was extracted again at 60°C for 1.5 h. The mixture was filtered and the filtrate was combined and rotary evaporated to obtain the Rhodiola rosea extract. Example 3

[0053] A dietary composition that helps enhance immunity, comprising the following components by weight:

[0054] 50 parts of Astragalus extract, 40 parts of Pueraria root extract, 30 parts of Polygonatum odoratum extract, and 10 parts of Rhodiola rosea extract.

[0055] Wherein, the preparation method of the astragalus extract is as follows:

[0056] The astragalus root is dried, crushed with a liquid nitrogen grinder, and then passed through a 60-mesh sieve to obtain an astragalus root powder; the astragalus root powder is then added to deionized water with a solid-liquid ratio of astragalus root powder to deionized water of 1:25, phosphate buffer is added to adjust the pH to 4, and then 3% of cellulase by weight of the astragalus root powder, 2% of pectinase by weight of the astragalus root powder, and 0.5% of sodium phytate by weight of the astragalus root powder are added, and enzymatic hydrolysis is carried out at 55° C. for 40 minutes. After the treatment is completed, the enzyme is inactivated by boiling water, and ultrasonic extraction is performed at a temperature of 70° C. and a power of 500 W for 30 minutes. After the extraction is completed, the filtrate is filtered to obtain a filtrate and a filter residue, and the filtrate is rotary evaporated to obtain an aqueous extract; the filter residue is added to anhydrous ethanol with a solid-liquid ratio of the filter residue to anhydrous ethanol of 1:20, and then 0.6% of xylitol anhydride monostearate by weight of the astragalus root powder is added, and reflux extraction is carried out for 1 hour. After the extraction is completed, the filter is filtered, and the filtrate is rotary evaporated to obtain an alcohol extract. The aqueous extract and the alcohol extract are evenly mixed to obtain the astragalus root extract.

[0057] The preparation method of the polygonatum extract is as follows:

[0058] The polygonatum was crushed and passed through a 60-mesh sieve, and then added into deionized water, with a solid-liquid ratio of polygonatum to deionized water of 1:22, and then 2% cellulase by weight of the polygonatum was added, and the mixture was immersed at 55°C for 1 hour, and then 1% xylanase by weight of the polygonatum was added, and the mixture was immersed at 55°C for 0.5 hour. After the enzyme was inactivated by boiling water, ultrasonic extraction was performed, and the ultrasonic extraction temperature was 70°C, the power was 450W, and the time was 30 minutes. After the extraction was completed, the filtrate was filtered, and the filtrate was concentrated to 1 / 4 of the original volume, and 4 times the volume of anhydrous ethanol was added for precipitation. After filtration, the mixture was freeze-dried to obtain the polygonatum extract.

[0059] The preparation method of the Rhodiola rosea extract is as follows:

[0060] Rhodiola rosea was crushed and passed through a 60-mesh sieve. It was then added to an ethanol-water solution (the mass fraction of ethanol was 60%) at a solid-liquid ratio of 1:30. The mixture was heated and extracted at 70°C for 1.5 hours. After the extraction was completed, it was filtered. An ethanol-water solution was added to the residue at a solid-liquid ratio of 1:10. The mixture was extracted again at 70°C for 1 hour. The mixture was filtered and the filtrate was combined and rotary evaporated to obtain the Rhodiola rosea extract. Comparative Example 1

[0061] A dietary composition that helps enhance immunity, comprising the following components by weight:

[0062] 45 parts of Astragalus root extract, 35 parts of Pueraria root extract, 25 parts of Polygonatum odoratum extract, and 8 parts of Rhodiola rosea extract.

[0063] Wherein, the preparation method of the astragalus extract is as follows:

[0064] The astragalus root is dried, crushed with a liquid nitrogen grinder, and then passed through a 60-mesh sieve to obtain astragalus root powder; the astragalus root powder is then added to deionized water with a solid-liquid ratio of astragalus root powder to deionized water of 1:22, phosphate buffer is added to adjust the pH to 4.5, and then 2.5% of cellulase by weight of the astragalus root powder and 1.5% of pectinase by weight of the astragalus root powder are added, and enzymatic hydrolysis is carried out at 50° C. for 50 minutes. After the treatment is completed, the enzyme is inactivated by boiling water, and ultrasonic extraction is carried out at a temperature of 65° C. and a power of 450 W for 35 minutes. After the extraction is completed, the filtrate is filtered to obtain a filtrate and a filter residue, and the filtrate is rotary evaporated to obtain a water extract; the filter residue is added to anhydrous ethanol with a solid-liquid ratio of the filter residue to anhydrous ethanol of 1:18, and reflux extraction is carried out for 1.5 hours. After the extraction is completed, the filter is filtered, and the filtrate is rotary evaporated to obtain an alcohol extract. The water extract and the alcohol extract are evenly mixed to obtain the astragalus root extract.

[0065] The preparation method of the polygonatum extract is as follows:

[0066] The polygonatum was crushed and passed through a 60-mesh sieve, and then added into deionized water with a solid-liquid ratio of polygonatum to deionized water of 1:20. Then, 1.8% cellulase by weight of the polygonatum was added and soaked at 50°C for 1.5 hours. Then, 1.5% xylanase by weight of the polygonatum was added and soaked at 50°C for 1 hour. After the enzyme was inactivated by boiling water, ultrasonic extraction was performed at a temperature of 65°C, a power of 430W, and a time of 35 minutes. After the extraction was completed, the filtrate was filtered and concentrated to 1 / 4 of the original volume. Four times the volume of anhydrous ethanol was added for precipitation, and the mixture was filtered and freeze-dried to obtain the polygonatum extract.

[0067] The preparation method of the Rhodiola rosea extract is as follows:

[0068] Rhodiola rosea was crushed and passed through a 60-mesh sieve. It was then added to an ethanol-water solution (the mass fraction of ethanol was 55%) at a solid-liquid ratio of 1:28. The mixture was heated and extracted at 65°C for 2 h. After the extraction was completed, it was filtered. An ethanol-water solution was added to the filter residue at a solid-liquid ratio of 1:9. The mixture was extracted again at 65°C for 1 h. The mixture was filtered and the filtrate was combined and rotary evaporated to obtain the Rhodiola rosea extract.

[0069] Compared with Example 1, in this comparative example, sodium phytate and xylitol monostearate were not added when preparing the astragalus extract. Comparative Example 2

[0070] A dietary composition that helps enhance immunity, comprising the following components by weight:

[0071] 45 parts of Astragalus root extract, 25 parts of Polygonatum odoratum extract, and 8 parts of Rhodiola rosea extract.

[0072] Wherein, the preparation method of the astragalus extract is as follows:

[0073] The astragalus root is dried, crushed with a liquid nitrogen grinder, and passed through a 60-mesh sieve to obtain an astragalus root powder; the astragalus root powder is then added to deionized water with a solid-liquid ratio of astragalus root powder to deionized water of 1:22, phosphate buffer is added to adjust the pH to 4.5, and then 2.5% of cellulase by weight of the astragalus root powder, 1.5% of pectinase by weight of the astragalus root powder, and 0.4% of sodium phytate by weight of the astragalus root powder are added. The mixture is enzymatically hydrolyzed at 50° C. for 50 minutes, and after the treatment, the enzyme is inactivated by boiling water. The mixture is ultrasonically extracted at a temperature of 65° C. and a power of 450 W for 35 minutes. After the extraction is completed, the mixture is filtered to obtain a filtrate and a filter residue. The filtrate is rotary evaporated to obtain an aqueous extract. The filter residue is added to anhydrous ethanol with a solid-liquid ratio of the filter residue to anhydrous ethanol of 1:18, and then 0.5% of xylitol monostearate by weight of the astragalus root powder is added. The mixture is refluxed for 1.5 hours. After the extraction is completed, the mixture is filtered and the filtrate is rotary evaporated to obtain an alcohol extract. The aqueous extract and the alcohol extract are uniformly mixed to obtain the astragalus root extract.

[0074] The preparation method of the polygonatum extract is as follows:

[0075] The polygonatum was crushed and passed through a 60-mesh sieve, and then added into deionized water with a solid-liquid ratio of polygonatum to deionized water of 1:20. Then, 1.8% cellulase by weight of the polygonatum was added and soaked at 50°C for 1.5 hours. Then, 1.5% xylanase by weight of the polygonatum was added and soaked at 50°C for 1 hour. After the enzyme was inactivated by boiling water, ultrasonic extraction was performed at a temperature of 65°C, a power of 430W, and a time of 35 minutes. After the extraction was completed, the filtrate was filtered and concentrated to 1 / 4 of the original volume. Four times the volume of anhydrous ethanol was added for precipitation, and the mixture was filtered and freeze-dried to obtain the polygonatum extract.

[0076] The preparation method of the Rhodiola rosea extract is as follows:

[0077] Rhodiola rosea was crushed and passed through a 60-mesh sieve. It was then added to an ethanol-water solution (the mass fraction of ethanol was 55%) at a solid-liquid ratio of 1:28. The mixture was heated and extracted at 65°C for 2 h. After the extraction was completed, it was filtered. An ethanol-water solution was added to the filter residue at a solid-liquid ratio of 1:9. The mixture was extracted again at 65°C for 1 h. The mixture was filtered and the filtrate was combined and rotary evaporated to obtain the Rhodiola rosea extract.

[0078] Compared with Example 1, this comparative example does not add Pueraria root extract. Comparative Example 3

[0079] A dietary composition that helps enhance immunity, comprising the following components by weight:

[0080] 45 parts of Astragalus root extract, 35 parts of Pueraria root extract, and 8 parts of Rhodiola rosea extract.

[0081] Wherein, the preparation method of the astragalus extract is as follows:

[0082] The astragalus root is dried, crushed with a liquid nitrogen grinder, and passed through a 60-mesh sieve to obtain an astragalus root powder; the astragalus root powder is then added to deionized water with a solid-liquid ratio of astragalus root powder to deionized water of 1:22, phosphate buffer is added to adjust the pH to 4.5, and then 2.5% of cellulase by weight of the astragalus root powder, 1.5% of pectinase by weight of the astragalus root powder, and 0.4% of sodium phytate by weight of the astragalus root powder are added. The mixture is enzymatically hydrolyzed at 50° C. for 50 minutes, and after the treatment, the enzyme is inactivated by boiling water. The mixture is ultrasonically extracted at a temperature of 65° C. and a power of 450 W for 35 minutes. After the extraction is completed, the mixture is filtered to obtain a filtrate and a filter residue. The filtrate is rotary evaporated to obtain an aqueous extract. The filter residue is added to anhydrous ethanol with a solid-liquid ratio of the filter residue to anhydrous ethanol of 1:18, and then 0.5% of xylitol monostearate by weight of the astragalus root powder is added. The mixture is refluxed for 1.5 hours. After the extraction is completed, the mixture is filtered and the filtrate is rotary evaporated to obtain an alcohol extract. The aqueous extract and the alcohol extract are uniformly mixed to obtain the astragalus root extract.

[0083] The preparation method of the Rhodiola rosea extract is as follows:

[0084] Rhodiola rosea was crushed and passed through a 60-mesh sieve. It was then added to an ethanol-water solution (the mass fraction of ethanol was 55%) at a solid-liquid ratio of 1:28. The mixture was heated and extracted at 65°C for 2 h. After the extraction was completed, it was filtered. An ethanol-water solution was added to the filter residue at a solid-liquid ratio of 1:9. The mixture was extracted again at 65°C for 1 h. The mixture was filtered and the filtrate was combined and rotary evaporated to obtain the Rhodiola rosea extract.

[0085] Compared with Example 1, this comparative example does not add the Polygonatum odoratum extract. Comparative Example 4

[0086] A dietary composition that helps enhance immunity, comprising the following components by weight:

[0087] 45 parts of Astragalus root extract, 35 parts of Pueraria root extract, and 25 parts of Polygonatum odoratum extract.

[0088] Wherein, the preparation method of the astragalus extract is as follows:

[0089] The astragalus root is dried, crushed with a liquid nitrogen grinder, and passed through a 60-mesh sieve to obtain an astragalus root powder; the astragalus root powder is then added to deionized water with a solid-liquid ratio of astragalus root powder to deionized water of 1:22, phosphate buffer is added to adjust the pH to 4.5, and then 2.5% of cellulase by weight of the astragalus root powder, 1.5% of pectinase by weight of the astragalus root powder, and 0.4% of sodium phytate by weight of the astragalus root powder are added. The mixture is enzymatically hydrolyzed at 50° C. for 50 minutes, and after the treatment, the enzyme is inactivated by boiling water. The mixture is ultrasonically extracted at a temperature of 65° C. and a power of 450 W for 35 minutes. After the extraction is completed, the mixture is filtered to obtain a filtrate and a filter residue. The filtrate is rotary evaporated to obtain an aqueous extract. The filter residue is added to anhydrous ethanol with a solid-liquid ratio of the filter residue to anhydrous ethanol of 1:18, and then 0.5% of xylitol monostearate by weight of the astragalus root powder is added. The mixture is refluxed for 1.5 hours. After the extraction is completed, the mixture is filtered and the filtrate is rotary evaporated to obtain an alcohol extract. The aqueous extract and the alcohol extract are uniformly mixed to obtain the astragalus root extract.

[0090] The preparation method of the polygonatum extract is as follows:

[0091] The polygonatum was crushed and passed through a 60-mesh sieve, and then added into deionized water with a solid-liquid ratio of polygonatum to deionized water of 1:20. Then, 1.8% cellulase by weight of the polygonatum was added and soaked at 50°C for 1.5 hours. Then, 1.5% xylanase by weight of the polygonatum was added and soaked at 50°C for 1 hour. After the enzyme was inactivated by boiling water, ultrasonic extraction was performed at a temperature of 65°C, a power of 430W, and a time of 35 minutes. After the extraction was completed, the filtrate was filtered and concentrated to 1 / 4 of the original volume. Four times the volume of anhydrous ethanol was added for precipitation, and the mixture was filtered and freeze-dried to obtain the polygonatum extract.

[0092] Compared with Example 1, this comparative example did not add Rhodiola rosea extract.

[0093] The dietary compositions prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to mouse tests, as follows:

[0094] One hundred and eighty female BALB / c mice were randomly divided into 20 groups, with nine mice in each group. The BALB / c mice were 6-8 weeks old and weighed 18-22 g. Grouping is shown in Table 1. The experimental animals were housed in a barrier animal room at a temperature of 22°C, a humidity of 40-70%, and a 12-hour light-dark cycle. They were fed a standard diet and adapted for one week with free access to water. The blank and model groups were gavage-administered with normal saline for 30 consecutive days. The Example 1 group was gavage-administered with the dietary composition of Example 1, the Example 2 group was gavage-administered with the dietary composition of Example 2, and the Example 3 group was gavage-administered with the dietary composition of Example 3. The Comparative Example 1 group was gavage-administered with the dietary composition of Comparative Example 1, the Comparative Example 2 group was gavage-administered with the dietary composition of Comparative Example 2, the Comparative Example 3 group was gavage-administered with the dietary composition of Comparative Example 3, and the Comparative Example 4 group was gavage-administered with the dietary composition of Comparative Example 4 for 30 consecutive days. On days 1-3, except for the blank group, mice in all other groups received intraperitoneal injections of normal saline, with 100 μL of cyclophosphamide (40 mg / kg) to establish immunocompromised mouse models. Twelve hours after the last oral administration, the mice were killed by cervical dislocation after recording their body weights, and their thymus and spleen were removed aseptically and their weights were recorded.

[0095] Table 1 Experimental classification

[0096] Grouping Number of animals Feed amount Oral dose (based on animal daily intake) control group 20 Free access to food Same weight of normal saline Model Group 20 Free access to food Subcutaneous injection of cyclophosphamide + equal weight of normal saline Example 1 group 20 Free access to food Subcutaneous injection of cyclophosphamide + the composition of Example 1 (200 mg / kg) Example 2 group 20 Free access to food Subcutaneous injection of cyclophosphamide + composition of Example 2 (200 mg / kg) Example 3 group 20 Free access to food Subcutaneous injection of cyclophosphamide + composition of Example 3 (200 mg / kg) Comparative Example 1 20 Free access to food Subcutaneous injection of cyclophosphamide + the composition of comparative example 1 (200 mg / kg) Comparative Example 2 20 Free access to food Subcutaneous injection of cyclophosphamide + the composition of comparative example 2 (200 mg / kg) Comparative Example 3 20 Free access to food Subcutaneous injection of cyclophosphamide + the composition of comparative example 3 (200 mg / kg) Comparative Example 4 20 Free access to food Subcutaneous injection of cyclophosphamide + the composition of comparative example 4 (200 mg / kg)

[0097] Immune function index measurement

[0098] Immune function indicators were determined according to the "Technical Specifications for Inspection and Evaluation of Health Foods" (2003 edition). Immune function assessment primarily encompasses cellular immunity, humoral immunity, monocyte-macrophage function, and natural killer cell (NK cell) activity. The following method was used to assess immune function in mice.

[0099] The effects of different treatments on the body weight of mice are shown in Table 2:

[0100] Table 2 Body weight changes of mice

[0101] Group Initial body weight / g Final body weight / g Weight gain Blank group 19.72±1.45 31.88±1.68 12.05 Model Group 20.15±1.52 25.06±1.39** 4.91 Example 1 group 19.64±1.37 <![CDATA[28.76±1.51 ## ]]> 9.12 Example 2 group 20.78±1.33 <![CDATA[29.26±1.25 ## ]]> 8.47 Example 3 group 20.41±1.18 <![CDATA[29.37±1.62 ## ]]> 8.96 Comparative Example 1 19.85±1.24 <![CDATA[27.02±1.17 # ]]> 7.17 Comparative Example 2 20.62±1.39 <![CDATA[26.9±1.44 # ]]> 6.28 Comparative Example 3 20.28±1.25 <![CDATA[27.01±1.35 # ]]> 6.73 Comparative Example 4 21.03±1.57 <![CDATA[27.49±1.22 # ]]> 6.46

[0102] Note: *P<0.05, **P<0.01, compared with the blank group; #P<0.05, ##P<0.01, compared with the model group

[0103] As can be seen from Table 2 above, the weight gain of the model group was significantly lower than that of the blank group, indicating that the immunocompromised mice were modeled, and the weight gain of the Example 1-3 groups was significantly higher than that of the model group (P<0.05), and was extremely significant (P<0.01), indicating that the dietary composition prepared by the present invention has a good effect on weight recovery and growth of immunocompromised mice, and is better than that of the comparative examples 1-4, indicating that the dietary compositions in the present application have a synergistic effect.

[0104] 1. Splenic Lymphocyte Transformation Assay: On day 31 of the experiment, five mice were randomly selected from each group, their weights recorded, and they were sacrificed by cervical dislocation. The thymus and spleen were aseptically removed and their weights recorded. Splenic lymphocyte transformation was then measured using the MTT assay, and NK cell activity was measured using the lactate dehydrogenase (LDH) assay. The results are shown in Table 3:

[0105] Table 3 Lymphoid organ / body weight ratio, optical density difference, and NK cell activity test results of mice in each group

[0106] Group Thymus / body weight ratio (mg / g) Spleen / body weight ratio (mg / g) Optical density difference NK cell activity% Blank group 2.63±0.59 4.25±1.41 0.296±0.058 46.1.3±8.2 Model Group 1.18±0.31** 3.08±0.62** 0.214±0.033** 32.9±6.1** Example 1 group <![CDATA[2.41±0.46 ## ]]> <![CDATA[4.09±1.25 ## ]]> <![CDATA[0.277±0.039 ## ]]> <![CDATA[42.6±7.5 ## ]]> Example 2 group <![CDATA[2.25±0.53 ## ]]> <![CDATA[3.96±1.31 ## ]]> <![CDATA[0.263±0.041 ## ]]> <![CDATA[41.7±7.2 ## ]]> Example 3 group <![CDATA[2.39±0.42 ## ]]> <![CDATA[4.05±1.36 ## ]]> <![CDATA[0.272±0.044 ## ]]> <![CDATA[42.3±6.5 ## ]]> Comparative Example 1 <![CDATA[2.02±0.38 ## ]]> <![CDATA[3.71±1.28 ## ]]> <![CDATA[0.256±0.035 ## ]]> <![CDATA[39.5±7.3 ## ]]> Comparative Example 2 <![CDATA[1.88±0.31 # ]]> <![CDATA[3.56±1.21 # ]]> <![CDATA[0.252±0.031 # ]]> <![CDATA[37.7±6.1 # ]]> Comparative Example 3 <![CDATA[1.91±0.29 # ]]> <![CDATA[3.59±1.29 # ]]> <![CDATA[0.257±0.037 # ]]> <![CDATA[36.8±5.9 # ]]> Comparative Example 4 <![CDATA[1.82±0.31 # ]]> <![CDATA[3.67±1.14 # ]]> <![CDATA[0.261±0.049 ## ]]> <![CDATA[37.5±6.2 # ]]>

[0107] Note: Compared with the blank group, *P<0.05, **P<0.01; compared with the model group, #P<0.05, ##P<0.01

[0108] As can be seen from Table 3, compared with the normal control group, the thymus and spleen indexes of the model group mice were significantly reduced, with extremely significant ( P <0.01, indicating a decline in immune function. The thymus and spleen indices of Example 1-3 and Comparative Examples 1-4 were higher than those of the model group, especially those of Example 1-3, which were significantly higher than those of the model group ( P <0.01). This demonstrates that the dietary composition prepared by the present invention can promote the development of the thymus and spleen in immunocompromised mice, increase the quality of immune organs, and thus improve the body's immune status. Furthermore, the performance of Example 1-3 groups was superior to that of Comparative Examples 1-4 groups, demonstrating a synergistic effect between the ingredients in the dietary composition. Compared with the blank group, the optical density differences of mice in Example 1-3 and Comparative Examples 1-4 groups were significantly higher than those in the model group, demonstrating that the dietary composition can enhance cellular immune function. The differences in optical density between Example 1-3 groups and Comparative Examples 1-4 groups were significantly higher than those in the model group, indicating that the dietary composition can enhance cellular immune function. Furthermore, the differences in optical density between Example 1-3 groups were extremely significant, demonstrating a synergistic effect between the ingredients in the dietary composition prepared by the present invention. NK cell activity in the model group was extremely significantly reduced (P < 0.01), indicating that immunocompromised mice were well-established. Compared with the model group, the differences in optical density between Example 1-3 groups were extremely significant (P < 0.01), demonstrating that the dietary composition of the present invention significantly enhanced NK cell activity in mice. Furthermore, the effects of Example 1-3 groups were superior to those of Comparative Examples 1-4 groups, demonstrating a synergistic effect between the ingredients in the dietary composition of the present invention.

[0109] (2) Delayed hypersensitivity reaction experiment: On the 31st day of the experiment, 5 mice were randomly selected from each group and each mouse was intraperitoneally injected with 0.2 mL of 2% (v / v) packed sheep red blood cell (SRBC) suspension for immunization. 4 days after immunization, the thickness of the left hind paw was measured, and then 20% (v / v) SRBC was subcutaneously injected at the measurement site, 20 μL (about 1×10 8SRBC) and the thickness of the left hind foot plantar was measured 24 hours after injection. The same part was measured three times and the average value was taken. The results are shown in Table 4:

[0110] Table 4 Test results of thickness difference of the left hind paw of mice in each group

[0111] Group Number of animals Thickness difference of left hindfoot plantar part (mm) Blank group 5 0.81±0.21 Model Group 5 0.46±0.08** Example 1 group 5 <![CDATA[0.77±0.15 ## ]]> Example 2 group 5 <![CDATA[0.71±0.16 ## ]]> Example 3 group 5 <![CDATA[0.73±0.12 ## ]]> Comparative Example 1 5 <![CDATA[0.64±0.18 # ]]> Comparative Example 2 5 <![CDATA[0.59±0.14 # ]]> Comparative Example 3 5 <![CDATA[0.57±0.13 # ]]> Comparative Example 4 5 <![CDATA[0.62±0.18 # ]]>

[0112] Note: Compared with the blank group, *P<0.05, **P<0.01; compared with the model group, #P<0.05, ##P<0.01

[0113] As can be seen from Table 4, compared with the blank group, the thickness difference of the left hind paw plantar of the model group was significantly decreased, and the difference was extremely significant, indicating that the immunocompromised mouse model was successfully established. The thickness difference of the left hind paw plantar of the mice in the Example 1-3 groups was significantly increased compared with the model group, and the difference was extremely significant, indicating that the dietary composition prepared by the present invention has an enhancing effect on delayed-type hypersensitivity in mice.

[0114] (3) Humoral immune function assay: On the 31st day of the experiment, 5 mice were randomly selected from each group and immunized by intraperitoneal injection of 0.2 mL of 2% (v / v) SRBC suspension. Four days later, the mice were sacrificed by cervical dislocation. Serum hemolysin levels were determined by hemagglutination assay; the ability of mice to produce antibodies against SRBC was determined by Jerne's modified slide method. The results are shown in Table 5:

[0115] Table 5 Humoral immunity test results of mice in each group

[0116] Group Number of animals Number of hemolytic plaques Anti-volume number Blank group 5 34.2±6.8 133±24 Model Group 5 21.8±3.5** 81±12** Example 1 group 5 <![CDATA[31.3±4.5 ## ]]> <![CDATA[116±21 ## ]]> Example 2 group 5 <![CDATA[30.2±4.8 ## ]]> <![CDATA[107±19 ## ]]> Example 3 group 5 <![CDATA[31.1±4.2 ## ]]> <![CDATA[114±28 ## ]]> Comparative Example 1 5 <![CDATA[27.8±4.6 # ]]> <![CDATA[97±16 ## ]]> Comparative Example 2 5 <![CDATA[26.4±3.1 # ]]> <![CDATA[89±17 # ]]> Comparative Example 3 5 <![CDATA[27.5±5.4 # ]]> <![CDATA[84±25 # ]]> Comparative Example 4 5 <![CDATA[28.2±4.7 ## ]]> <![CDATA[86±13 # ]]>

[0117] Note: Compared with the blank group, *P<0.05, **P<0.01; compared with the model group, #P<0.05, ##P<0.01

[0118] As can be seen from Table 5, compared with the blank group, the number of hemolytic plaques in the model group mice was significantly lower than that in the normal control group, while the absorbance values ​​of spleen lymphocytes in the Example 1-3 and Comparative Example 1-3 groups were significantly higher than those in the model group, with significant differences, indicating that the dietary composition can increase the number of hemolytic plaques and enhance humoral immune function, and the Example 1-3 groups showed extremely significant differences, indicating that the raw materials of the dietary composition prepared by the present invention have a synergistic effect. The number of antibody cells in the model group mice was significantly lower than that in the normal control group, while the absorbance values ​​of spleen lymphocytes in the Example 1-3 and Comparative Example 2-4 groups were significantly higher than those in the model group, with significant differences, indicating that the dietary composition can increase the number of antibody cells and enhance humoral immune function, and the Example 1-3 groups showed extremely significant differences, indicating that the raw materials of the dietary composition prepared by the present invention have a synergistic effect.

[0119] (4) Peritoneal macrophage phagocytosis experiment: On the 31st day of the experiment, 5 mice were randomly selected from each group, and 1 mL of 20% (v / v) chicken red blood cell suspension was injected into the peritoneal cavity of each mouse. The mice were killed by cervical dislocation at intervals of 1 h. The peritoneal fluid droplets were taken and incubated in a 38°C incubator for 30 min. The cells were fixed, stained, and examined under a microscope. 100 macrophages were counted, and the phagocytic rate and phagocytic index were calculated.

[0120] Phagocytosis percentage (%) =

[0121] Phagocytic index =

[0122] The results are shown in Table 6:

[0123] Table 6 Test results of phagocytic rate and phagocytic index of mice in each group

[0124] Group Number of animals Phagocytosis rate (%) Phagocytic index Blank group 5 28.1±4.7 0.61±0.12 Model Group 5 17.4±2.5** 0.34±0.06** Example 1 group 5 <![CDATA[26.3±3.5 ## ]]> <![CDATA[0.53±0.16 ## ]]> Example 2 group 5 <![CDATA[25.2±3.8 ## ]]> <![CDATA[0.47±0.18 ## ]]> Example 3 group 5 <![CDATA[25.8±3.6 ## ]]> <![CDATA[0.51±0.15 ## ]]> Comparative Example 1 5 <![CDATA[23.9±2.7 # ]]> <![CDATA[0.45±0.18 # ]]> Comparative Example 2 5 <![CDATA[22.3±3.2 # ]]> <![CDATA[0.43±0.21 # ]]> Comparative Example 3 5 <![CDATA[21.6±2.4 # ]]> <![CDATA[0.41±0.14 # ]]> Comparative Example 4 5 <![CDATA[21.8±3.1 # ]]> <![CDATA[0.42±0.13 # ]]>

[0125] Note: Compared with the blank group, *P<0.05, **P<0.01; compared with the model group, #P<0.05, ##P<0.01

[0126] As can be seen from Table 6, the phagocytic percentage of the model group mice was significantly lower than that of the normal control group, indicating that the immunocompromised mouse model was successfully established. The phagocytic rate and phagocytic index of the Example 1-3 groups were both higher than those of the model group, with extremely significant differences (P < 0.01), indicating that the dietary composition prepared by the present invention has a certain effect of enhancing the nonspecific immunity of mice.

[0127] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A dietary composition that helps enhance immunity, characterized in that: The dietary composition comprises the following components by weight: 40-50 parts of Astragalus root extract, 30-40 parts of Pueraria root extract, 20-30 parts of Polygonatum odoratum extract, and 5-10 parts of Rhodiola rosea extract; Wherein, the preparation method of the astragalus extract is as follows: The astragalus root is dried, crushed with a liquid nitrogen grinder, and passed through a 60-mesh sieve to obtain astragalus root powder; the astragalus root powder is then added to deionized water, and phosphate buffer is added to adjust the pH to 4-5, followed by the addition of cellulase, pectinase, and sodium phytate for enzymatic hydrolysis, and after the treatment is completed, the enzyme is inactivated by boiling water, and ultrasonic extraction is performed. After the extraction is completed, the extraction is filtered to obtain a filtrate and a filter residue, and the filtrate is rotary evaporated to obtain an aqueous extract; the filter residue is added to anhydrous ethanol, and then xylitol anhydride monostearate is added for reflux extraction. After the extraction is completed, the extraction is filtered, and the filtrate is rotary evaporated to obtain an alcohol extract, and the aqueous extract and the alcohol extract are uniformly mixed to obtain the astragalus root extract.

2. The dietary composition for enhancing immunity according to claim 1, characterized in that: The dietary composition comprises the following components by weight: 45-50 parts of astragalus extract, 30-35 parts of kudzu root extract, 25-30 parts of polygonatum extract, and 7-10 parts of rhodiola rosea extract.

3. The dietary composition for enhancing immunity according to claim 1, characterized in that: The material-liquid ratio of the astragalus powder to deionized water is 1:20-25, the amount of the cellulase added is 2-3% of the mass of the astragalus powder, the amount of the pectinase added is 1-2% of the mass of the astragalus powder, and the amount of the sodium phytate added is 0.3-0.5% of the mass of the astragalus powder. The temperature of the enzymatic hydrolysis treatment is 45-55°C, the time is 40-60 minutes, the temperature of the ultrasonic extraction is 60-70°C, the power is 400-500W, and the time is 30-40 minutes.

4. The dietary composition for enhancing immunity according to claim 1, characterized in that: The material-liquid ratio of the filter residue to anhydrous ethanol is 1:15-20, the added amount of xylitol anhydride monostearate is 0.4-0.6% of the mass of the astragalus powder, and the reflux time is 1-1.5 hours.

5. The dietary composition for enhancing immunity according to claim 1, characterized in that: The preparation method of the polygonatum extract is as follows: The polygonatum odoratum is crushed and passed through a 60-mesh sieve, then added into deionized water, followed by adding cellulase and soaking for 1-2 hours, followed by adding xylanase and soaking for 0.5-1 hour, and ultrasonic extraction is performed after the enzyme is inactivated. After the extraction is completed, the filtrate is filtered and concentrated to 1 / 4 of the original volume, and 4 times the volume of anhydrous ethanol is added for precipitation. After filtering, freeze-drying is performed to obtain the polygonatum odoratum extract.

6. The dietary composition for enhancing immunity according to claim 5, characterized in that: The material-liquid ratio of the polygonatum to deionized water is 1:18-22, the amount of the cellulase added is 1.5-2% of the mass of the polygonatum, the amount of the xylanase added is 1-1.5% of the mass of the polygonatum, the immersion temperature is 45-55°C, the ultrasonic extraction temperature is 60-70°C, the power is 400-450W, and the time is 30-40min.

7. The dietary composition for enhancing immunity according to claim 1, characterized in that: The preparation method of the Rhodiola rosea extract is as follows: The Rhodiola rosea was crushed and passed through a 60-mesh sieve, then added to an ethanol aqueous solution and heated for extraction. The extraction was repeated twice, and the filtrates were combined and rotary evaporated to obtain the Rhodiola rosea extract.

8. The dietary composition for enhancing immunity according to claim 7, characterized in that: The solid-liquid ratio of Rhodiola rosea to ethanol water is 1:25-30, the mass fraction of ethanol in the ethanol water solution is 50-60%, the temperature of the heating extraction is 60-70°C, the time is 1.5-2h, and the solid-liquid ratio during the second extraction is 1:8-10.

9. A method for preparing the dietary composition for enhancing immunity according to any one of claims 1 to 8, characterized in that: The following steps are involved: The raw materials are weighed according to the formula, and the astragalus extract, kudzu root extract, polygonatum extract and rhodiola rosea extract are evenly mixed to obtain the product.