A method for treating rhizoma polygonati culm by steam explosion technology and extracting total flavonoids and xylo-oligosaccharides and application thereof

Abstract

The application discloses a method for treating rhizoma polygonati culm and simultaneously extracting total flavones and xylo-oligosaccharides by adopting a steam explosion technology and application, and comprises the following steps: after the rhizoma polygonati culm is crushed and pre-impregnated, the rhizoma polygonati culm is placed into a steam explosion storage tank to be exploded, and after the treatment, alcohol extraction and acid hydrolysis are used to extract alcohol-soluble total flavones and xylo-oligosaccharide crude extract respectively. The application generates strong shearing force by instant pressure release of high-temperature and high-pressure steam, effectively destroys the crystal structure of lignocellulose, promotes the glycosidic bond breakage of the main chain of hemicellulose, reduces the polymerization degree of xylan, generates xylo-oligosaccharides, and forms a loose porous structure and increases the surface area by explosion, thereby promoting the dissolution of flavonoids, avoiding the tediousness of repeated extraction in the traditional method, and being green, efficient and pollution-free. Through the technology, the xylo-oligosaccharides and alcohol-soluble total flavones can reach 47.7 g / kg and 45.4 mg / g respectively; compared with the content of alcohol-soluble total flavones of 0.366% of the rhizoma polygonati culm raw material, the technology is increased by about 10 times.

Description

Technical Field

[0001] This invention relates to the field of recycling waste Polygonatum sibiricum stems, specifically to a method and application of using steam explosion technology to process Polygonatum sibiricum stems and simultaneously extract total flavonoids and xylooligosaccharides. Background Technology

[0002] As a major province for the cultivation of Chinese medicinal herbs, Henan Province has 35,000 mu (approximately 2,333 hectares) of Polygonatum cultivation, yielding over 12,000 tons of Polygonatum and over 4,000 tons of stems and leaves. The active components of Polygonatum include polysaccharides, flavonoids, saponins, alkaloids, amino acids, and trace elements. The rhizome of Polygonatum is its medicinal part, possessing functions such as nourishing yin and moistening the lungs, tonifying the spleen and replenishing qi, and nourishing the kidneys and replenishing essence. The non-medicinal part—the stem—mainly consists of cellulose, hemicellulose, and active substances from traditional Chinese medicine. The cellulose and hemicellulose contents are 33.18% and 20.43%, respectively. These components in natural Chinese medicinal plants are characterized by complex structures, strong resistance to degradation, and difficulty in extracting active components. Traditional extraction methods such as reflux extraction, ultrasound-assisted extraction, microwave extraction, and ethanol ultrasound-assisted extraction were used to extract total flavonoids from Polygonatum stems, with extraction rates of 0.007%, 0.124%, 0.110%, and 0.366%, respectively. Therefore, finding a new, efficient, and green method for extracting inactive parts is an urgent problem to be solved in the Chinese medicinal materials industry today.

[0003] Instant Catapult Steam Explosion (ICSE), as an innovative physicochemical treatment method, has demonstrated significant application value in multiple fields. Our team, after more than ten years of effort, has developed ICSE technology and equipment, possessing multiple independent intellectual property rights and constructing various pretreatment technology systems for natural biomass. This technology can efficiently break down the natural anti-degradation barriers of these substances, improve the extraction of effective components from traditional Chinese medicine, and effectively convert hemicellulose into xylooligosaccharides. Xylooligosaccharides, which cannot be absorbed by the host and are known as "super bifidus factors," can effectively promote the growth of beneficial bacteria in the intestines, inhibit the proliferation of harmful bacteria, improve the animal's digestive barrier and immune function, and achieve disease prevention and growth promotion effects. Therefore, ICSE technology can be used to process Polygonatum sibiricum stems to produce feed additives rich in Polygonatum flavonoids and xylooligosaccharides. Xylooligosaccharides used as feed additives can promote the reproduction of beneficial bacteria in the animal's digestive tract, inhibit the growth of harmful bacteria, improve the balance of the microbial community, stimulate the animal's immune system, and enhance immunity.

[0004] This application utilizes steam explosion technology in conjunction with a catalyst to treat Polygonatum sibiricum stems, thereby disrupting the lignocellulose structure, promoting the dissolution of flavonoids in the stems, and facilitating the more efficient degradation of hemicellulose into xylooligosaccharides. This process is then used to produce feed additives with high xylooligosaccharide and high total flavonoid content, providing a practical basis for the probiotic effects of steam-exploded Polygonatum sibiricum stem feed additives. Summary of the Invention

[0005] The purpose of this invention is to provide a method and application for processing Polygonatum stems using steam explosion technology to simultaneously extract total flavonoids and xylooligosaccharides. The method involves pre-treating the waste, non-medicinal parts of Polygonatum stems with steam explosion, which destroys the lignocellulose structure, degrades hemicellulose to obtain xylooligosaccharides, and promotes the dissolution of the active ingredient, total flavonoids, thereby improving the utilization rate of Polygonatum stems.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for simultaneously extracting total flavonoids and xylooligosaccharides from Polygonatum sibiricum stems using steam explosion technology includes the following steps: S1 Soaking: After crushing the Polygonatum stems, soak them in a citric acid aqueous solution for later use. The concentration of the citric acid aqueous solution is 0.05~0.2 mol / L, the solid-liquid mass ratio during pre-soaking is 1:(0.5~0.7), and the pre-soaking time is 10~15 h.

[0007] S2 Steam Explosion Pretreatment: The Polygonatum stems soaked in S1 are placed into the steam explosion storage tank, the pressure and holding time are set, and the pressure relief program is started to obtain the exploded Polygonatum stem material A.

[0008] The steam explosion pretreatment adopts instantaneous ejection steam explosion technology, which uses instantaneous pressure relief to drive the sliding cover to move back and forth at high speed to trigger the explosion conditions. The material release time is compressed to 0.0875 s, which is shorter and can be scaled up and produced on a large scale.

[0009] The conditions for steam explosion are set with an explosion pressure of 1.2~2.0 MPa and a pressure holding time of 60~540 s.

[0010] S3. Ethanol extraction of total flavonoids from explosive Polygonatum sibiricum stem material A: The solvent used for ethanol extraction was 50-70 v% ethanol, with a solid-liquid mass ratio of 1:(15-25). The extraction was performed under ultrasonication at 30-50 W and 200-300 kHz at 30-50℃ for 20-60 min. The extract was then filtered through filter paper to obtain extract B. The total flavonoid content in extract B was determined using the NaNO2-Al(NO3)3 colorimetric method.

[0011] S4 acid-extracted xylooligosaccharides: Sample preparation before hydrolysis: Weigh 1-2 g (accurate to 0.0001 g) of the blasted Polygonatum sibiricum stem material A, dissolve it in 80-150 mL of 0.005-0.010 mol / L sulfuric acid solution, sonicate for 5-20 min, then separate the solid and liquid using medium-speed qualitative filter paper. Take the filtrate and filter it again through a 0.22 μm nylon membrane with water to obtain the sample solution before hydrolysis, and perform HPLC analysis.

[0012] Sample preparation after hydrolysis: A certain amount of the sample solution before hydrolysis was pipetted into a 100 mL colorimetric tube, 3-6 mol / L sulfuric acid solution was added, and the mixture was shaken well. The tube was then placed in a boiling water bath for 80-120 min to hydrolyze. After cooling, the volume was adjusted to 100 mL, and the sample was shaken well and filtered through a 0.22 μm nylon membrane before HPLC analysis. The xylose content in the solutions before and after hydrolysis was determined using liquid chromatography. The xylooligosaccharide content was calculated using the following formula: Xylooligosaccharide content (g / 100g) = (Xylose content after hydrolysis - Xylose content before hydrolysis) × 1.1 (average correction factor for xylooligosaccharides and xylose).

[0013] The total flavonoids and xylooligosaccharides prepared by the above method are used as feed additives for livestock and poultry. The total flavonoids and xylooligosaccharides refer to the explosive Polygonatum sibiricum stem material A containing total flavonoids and xylooligosaccharides obtained in step (1).

[0014] Furthermore, the amount of explosive Polygonatum sibiricum stem material A added is 0.025%~0.075% of the mass of the base material.

[0015] Furthermore, the livestock and poultry mentioned are cattle, pigs, or chickens. Beneficial effects

[0016] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention achieves simultaneous degradation of hemicellulose to generate xylooligosaccharides and disruption of the cell structure of Polygonatum sibiricum stems to promote the dissolution of flavonoids through steam explosion treatment. The optimal extraction yield of the target product is screened by changing the concentration of the treatment reagent, the explosion pressure, and the holding time. Through this technology, the content of xylooligosaccharides and total alcohol-soluble flavonoids can reach 47.7 g / kg and 45.4 mg / g, respectively; compared to the 0.366% content of total alcohol-soluble flavonoids in Polygonatum sibiricum stem raw materials, this technology improves the content by approximately 10 times.

[0017] The ICSE pretreatment of Polygonatum sibiricum stems used in this invention disrupts the lignocellulose structure of the stems, promoting the breakage of β-1,4 glycosidic bonds in the hemicellulose backbone to generate xylooligosaccharides. The resulting loose, porous structure and increased surface area facilitate the dissolution of active ingredients. This invention provides a new approach and feasible method for the efficient utilization of Polygonatum sibiricum stems, applicable to industries such as feed additives, offering high efficiency, environmental friendliness, and controllable economic costs. Attached Figure Description

[0018] Figure 1 FT-IR spectra of Polygonatum stems under different steam explosion conditions; Figure 2 Scanning electron microscope images of Polygonatum stems under different steam explosion conditions; Figure 3 Analysis of specific surface area and porosity of Polygonatum stems under different steam explosion conditions; Figure 4 The changes in daily cumulative milk production of dairy cows (A), a magnified view of cumulative milk production (B, C), and the daily increase in milk production in the 0.075% popped Polygonatum stalks experimental group over the last two weeks (D). Figure 5 Changes in somatic cell count in milk; Figure 6 This refers to changes in the content of milk fat, milk protein, lactose, and nonfat milk solids in milk; Figure 7 This refers to changes in the levels of immunoglobulins IgG, IgA, and IgM in the blood. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto. Example 1

[0020] The stems of Polygonatum sibiricum were crushed and passed through a 40-mesh sieve, then soaked in deionized water at a solid-liquid mass ratio of 1:0.6 for 12 h or overnight. The material was then placed in a material silo, and saturated steam at a pressure of 2.0 MPa was introduced. After maintaining the pressure for 540 s, the material was released into a collection silo via a momentary ejection. After collection and drying, the exploded material A was obtained. Flavonoids were extracted by alcohol extraction. The exploded material A was soaked in 60 v% ethanol at a solid-liquid mass ratio of 1:20, and sonicated for 40 min at 40 W, 250 kHz, and 40 °C. The extract was then filtered through filter paper to obtain extract B. The total flavonoid content in extract B was determined using the NaNO2-Al(NO3)3 colorimetric method.

[0021] Xylooligosaccharides were extracted using acid hydrolysis. Sample preparation before hydrolysis: 1 g (accurate to 0.0001 g) of material A was weighed and dissolved in an Erlenmeyer flask containing 100 mL of 0.005 mol / L sulfuric acid solution. After sonication for 10 min, the mixture was shaken well and subjected to solid-liquid separation using medium-speed qualitative filter paper. The filtrate was then filtered again through a 0.22 μm nylon membrane to obtain the sample solution before hydrolysis, which was then analyzed by HPLC.

[0022] Sample preparation after hydrolysis: Pipette 10 mL of the unhydrolyzed sample solution into a 100 mL colorimetric tube, add 1.2 mL of 4 mol / L sulfuric acid solution, shake well, and hydrolyze in a boiling water bath for 100 min. After cooling, bring the volume to 100 mL, shake well, and sample. Filter the solution through a 0.22 μm nylon membrane and perform HPLC analysis. The xylose content in the solutions before and after hydrolysis was determined using liquid chromatography. The xylooligosaccharide content was calculated using the following formula: Xylooligosaccharide content (g / 100g) = (Xylose content after hydrolysis - Xylose content before hydrolysis) × 1.1 (average correction factor for xylooligosaccharides and xylose).

[0023] Tests showed that the yield of xylooligosaccharides in material A after blasting was approximately 29.4 g / kg, and the content of alcohol-soluble total flavonoids was 38.7 mg / g. Example 2

[0024] The stems of Polygonatum sibiricum were crushed and passed through a 40-mesh sieve, then soaked in 0.1 mol / L citric acid aqueous solution at a solid-liquid mass ratio of 1:0.6 for 12 h or overnight. The material was then placed in a material silo, and saturated steam at a pressure of 2.0 MPa was introduced. After maintaining the pressure for 540 s, the material was released into a collection silo via a momentary ejection. After collection and drying, the exploded material A was obtained. Flavonoids were extracted by alcohol extraction. The exploded material A was soaked in 60 v% ethanol at a solid-liquid mass ratio of 1:20, and sonicated for 40 min at 40 W, 250 kHz, and 40 °C. The extract was then filtered through filter paper to obtain extract B. The total flavonoid content in extract B was determined using the NaNO2-Al(NO3)3 colorimetric method.

[0025] Xylooligosaccharides were extracted using acid hydrolysis. Sample preparation before hydrolysis: 1 g (accurate to 0.0001 g) of material A was weighed and dissolved in an Erlenmeyer flask containing 100 mL of 0.005 mol / L sulfuric acid solution. After sonication for 10 min, the mixture was shaken well and subjected to solid-liquid separation using medium-speed qualitative filter paper. The filtrate was then filtered again through a 0.22 μm nylon membrane to obtain the sample solution before hydrolysis, which was then analyzed by HPLC.

[0026] Sample preparation after hydrolysis: Pipette 10 mL of the unhydrolyzed sample solution into a 100 mL colorimetric tube, add 1.2 mL of 4 mol / L sulfuric acid solution, shake well, and hydrolyze in a boiling water bath for 100 min. After cooling, bring the volume to 100 mL, shake well, and sample. Filter the solution through a 0.22 μm nylon membrane and perform HPLC analysis. The xylose content in the solutions before and after hydrolysis was determined using liquid chromatography. The xylooligosaccharide content was calculated using the following formula: Xylooligosaccharide content (g / 100g) = (Xylose content after hydrolysis - Xylose content before hydrolysis) × 1.1 (average correction factor for xylooligosaccharides and xylose).

[0027] Tests showed that the yield of xylooligosaccharides in material A after blasting was approximately 35.9 g / kg, and the content of alcohol-soluble total flavonoids was 45.4 mg / g. Example 3

[0028] The stems of Polygonatum sibiricum were crushed and passed through a 40-mesh sieve, then soaked in 0.1 mol / L citric acid aqueous solution at a solid-liquid mass ratio of 1:0.6 for 12 h or overnight. The material was then placed in a material silo, and saturated steam at a pressure of 1.4 MPa was introduced. After maintaining the pressure for 540 s, the material was released into a collection silo via a momentary ejection. After collection and drying, the exploded material A was obtained. Flavonoids were extracted by alcohol extraction. The exploded material A was soaked in 60 v% ethanol at a solid-liquid mass ratio of 1:20, and sonicated at 40 W, 250 kHz, and 40 °C for 40 min. The extract was then filtered through filter paper to obtain extract B. The total flavonoid content in extract B was determined using the NaNO2-Al(NO3)3 colorimetric method.

[0029] Xylooligosaccharides were extracted using acid hydrolysis. Sample preparation before hydrolysis: 1 g (accurate to 0.0001 g) of material A was weighed and dissolved in an Erlenmeyer flask containing 100 mL of 0.005 mol / L sulfuric acid solution. After sonication for 10 min, the mixture was shaken well and subjected to solid-liquid separation using medium-speed qualitative filter paper. The filtrate was then filtered again through a 0.22 μm nylon membrane to obtain the sample solution before hydrolysis, which was then analyzed by HPLC.

[0030] Sample preparation after hydrolysis: Pipette 10 mL of the unhydrolyzed sample solution into a 100 mL colorimetric tube, add 1.2 mL of 4 mol / L sulfuric acid solution, shake well, and hydrolyze in a boiling water bath for 100 min. After cooling, bring the volume to 100 mL, shake well, and sample. Filter the solution through a 0.22 μm nylon membrane and perform HPLC analysis. The xylose content in the solutions before and after hydrolysis was determined using liquid chromatography. The xylooligosaccharide content was calculated using the following formula: Xylooligosaccharide content (g / 100g) = (Xylose content after hydrolysis - Xylose content before hydrolysis) × 1.1 (average correction factor for xylooligosaccharides and xylose).

[0031] Tests showed that the yield of xylooligosaccharides in material A after blasting was approximately 47.7 g / kg, and the content of alcohol-soluble total flavonoids was 31.40 mg / g.

[0032] Table 1. Specific surface area and porosity analysis of Polygonatum rhizome stems before and after treatment.

[0033] Note: A: Polygonatum rhizome stem; B: 0.1 mol / L citric acid - 2.0 MPa - 540 s Table 1 shows that compared to group A, group B has a decreased specific surface area and an increased average pore size, which is beneficial for the dissolution rate and amount of medium or large molecules such as flavonoids. Simultaneously, citric acid can promote the degradation of hemicellulose in Polygonatum stems, making the embedded flavonoids easier to dissolve. The increased pore size indicates that steam explosion hydrolyzes the hemicellulose, loosening the internal structure of the material; consequently, some micropores or small pores merge or collapse under high pressure and the action of citric acid, resulting in a decrease in specific surface area.

[0034] Figure 1 FT-IR spectra of Polygonatum stems under different steam explosion conditions: High-pressure water explosion mainly achieved deacetylation of hemicellulose (the peak at ~1730 cm⁻¹ weakened). High-pressure explosion with 0.1 mol / L citric acid further disrupted the lignin structure on the basis of deacetylation, resulting in a stronger destructive effect on the cell walls of Polygonatum stems. Therefore, the addition of citric acid is of positive significance for subsequent flavonoid extraction.

[0035] Figure 2 Scanning electron microscope images of Polygonatum stems under different steam explosion conditions: High-pressure explosion with 0.1 mol / L citric acid is a violent physicochemical treatment of Polygonatum stems, which achieves the dissociation of lignocellulose structure by destroying its natural porous structure.

[0036] Figure 3 Analysis of specific surface area and porosity of Polygonatum odoratum stems under different steam explosion conditions: High-pressure explosion with 0.1 mol / L citric acid greatly optimized the mesoporous structure, creating a large number of new and smaller mesopores. After the explosion treatment, the macropores collapsed, but the cell walls were filled with nanoscale pores. The newly generated large number of mesopores provided abundant permeation paths and contact areas for the solvent, enabling efficient extraction of embedded flavonoids.

[0037] Determination of total alcohol-soluble flavonoids in the stems of Polygonatum sibiricum Weigh 1 g (accurate to 0.0001 g) of the blasted Polygonatum sibiricum stem powder, and soak it in a 60 v% ethanol solution at a solid-liquid mass ratio of 1:20. Use ultrasonic treatment at 40 W, 250 kHz and 40℃ for 40 min. Filter with filter paper to obtain the total flavonoid extract. Dilute the extract 10 times and use it for later use. The total flavonoid content in extract B was determined using the NaNO2-Al(NO3)3 colorimetric method. Using a 0.2 mg / mL rutin standard stock solution, 0.00, 1.00, 2.00, 3.00, 4.00, 5.00, and 6.00 mL of the rutin standard solution were transferred to 25 mL volumetric flasks, and the NaNO2-Al(NO3)3 colorimetric method was used. The absorbance was measured at 510 nm. A standard curve was plotted with the concentration of the standard solution on the x-axis and the absorbance on the y-axis. The regression equation was Y = 12.085X - 0.0088 (R² / 2π)² / 2π.2 =0.9994).

[0038] Total alcohol-soluble flavonoids content (mg / g) = (X * extraction volume * dilution factor) / mass Determination of xylooligosaccharide content in Polygonatum stems Xylose was analyzed using a high-performance liquid chromatography (Shimadzu LC-20A) equipped with a differential detector (RID-10A) and an Aminex HPX-87H ion-exclusion column. The mobile phase was 0.005 mol / L sulfuric acid solution, the column temperature was 65℃, the flow rate was 0.6 mL / min, and the injection volume was 10 μL.

[0039] The post-explosion material A obtained under the conditions of Example 3 was used as a feed additive in Holstein dairy cows. The specific results of the experiment are as follows: (1) This experiment involved 16 dairy cows of similar weight from a centralized ranch. The cows were randomly divided into 4 treatments, with 4 cows in each treatment. The control group was fed a basal feed, while the experimental groups were fed the basal feed with 0.025 wt%, 0.05 wt%, and 0.075 wt% of the experimental product, respectively, mixed evenly. The formal experimental period was 4 weeks, during June and July when heat stress was more severe. The cows had free access to feed and were given sufficient water. The basal feed for dairy cows was Tianfeng milk concentrate; the self-prepared feed consisted of corn, soybean meal, soybean residue, brewer's grains, yellow silage, and silage (with corn kernels). The main observations were on milk yield, milk quality, changes in somatic cells, and immune cells.

[0040] Table 2 Test Protocol

[0041] (2) Changes in milk production: After 28 days of feeding, the cumulative changes in daily milk production (the second day is the sum of the milk production of the previous two days, the third day is the sum of the milk production of the previous three days, etc.), such as Figure 4 As shown in Figure A. Compared with the control, the milk production of the 0.075% popped Polygonatum stalk experimental group was significantly increased, and the difference gradually widened with the increase of feeding days. At 28 days, the total milk production was 70 kg more than the control, an increase of 3.54%; the milk production difference between the 0.025% popped Polygonatum stalk experimental group and the control group decreased in the fourth week (days 21-28) (e.g., Figure 4 (B) indicates that it also has good potential in milk production. In the 0.075% *Polygonatum sibiricum* stem experimental group, starting from the third week, the average daily milk production of the 0.075% *Polygonatum sibiricum* stem experimental group was higher than that of the control group (e.g., ...). Figure 4 (C) Starting from the third week, the daily milk production change of the 0.075% explosive Polygonatum stalk test group compared to the control group was calculated, and it was generally able to increase by 0.25-3.25 kg per day (e.g., Figure 4(D) can significantly increase milk production in dairy cows.

[0042] (3) Changes in the content of somatic cells, lactose, milk protein, milk fat, and non-fat milk solids: like Figure 5 As shown, the somatic cell count in the control group gradually increased from day 0 to day 21, indicating that the inflammation and other conditions of the dairy cow's mammary glands were not improved, and the somatic cell content increased. The somatic cell counts in the 0.025% and 0.075% explosive Polygonatum stalk experimental groups showed an initial increase followed by a decrease, remaining stable at a low level. The somatic cell count in the 0.050% explosive Polygonatum stalk experimental group remained at a low level throughout the experiment with minimal fluctuations, indicating that the Polygonatum stalk feed additive can effectively improve the inflammation of the dairy cow's mammary glands, enhance resistance, and thus reduce the somatic cell content in milk.

[0043] Figure 6 Milk fat content (A): The milk fat content in milk decreased slightly in the first two weeks, but increased significantly from the third week onwards, and gradually stabilized in the fourth week; and the experimental group showed a significant increase compared to the control group. Figure 6 Medium B (milk protein content): In the second week, due to the lack of soybean residue in the feed, the protein intake decreased and the milk protein content dropped significantly. In the third week, with normal feeding, it began to rise again, but due to weather and late lactation, it could not reach the higher level of day 0. Figure 6 C (non-fat milk solids content): Non-fat milk solids in milk show a slow decrease in the first three weeks, and a significant increase in the fourth week. This may be because the cow is in the late lactation stage, the water content in the milk is relatively reduced, and the non-fat milk solids content is relatively increased. Figure 6 Lactose content (D): In the later stages of lactation, the mammary glands' ability to synthesize lactose weakens, resulting in a certain degree of decrease in the control group; while the experimental group showed a slight increase compared to day 0. It is speculated that the flavonoids and xylooligosaccharides in the additives of the experimental group are beneficial for promoting digestion and absorption and regulating metabolism, thereby promoting lactose synthesis.

[0044] (3) Changes in immunoglobulin levels: such as Figure 7 As shown, the changes in the concentrations of immunoglobulins IgG, IgA, and IgM in the serum of dairy cows were measured on day 0 and day 28. It was found that after 28 days of feeding, compared with the control group, the concentrations of immunoglobulins in the blood of dairy cows in each treatment group changed significantly: all three immunoglobulins showed significant increases in the 0.025% and 0.075% *Polygonatum sibiricum* stem test groups. The IgG, IgA, and IgM concentrations in the 0.025% *Polygonatum sibiricum* stem test group increased by 84.96%, 72.00%, and 85.45%, respectively, compared to the CK group; the 0.075% *Polygonatum sibiricum* stem test group also showed increases of 81.59%, 38.67%, and 71.82%, respectively.

[0045] Obviously, the above examples of the present invention are merely illustrative of the present invention and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A method for simultaneously extracting total flavonoids and xylooligosaccharides from Polygonatum odoratum stems using steam explosion technology, characterized in that, Includes the following steps: (1) After crushing the Polygonatum stems and soaking them, they were put into a steam explosion storage tank for steam explosion. After collecting the material, they were dried to obtain the exploded Polygonatum stem material A. (2) The alcohol-soluble total flavonoids in the explosive Polygonatum stem material A in step (1) were extracted by alcohol extraction and xylooligosaccharides were extracted by acid hydrolysis.

2. The method according to claim 1, characterized in that, In step (1), the solvent used for pre-soaking is an aqueous solution of citric acid with a concentration of 0.05~0.2 mol / L, the solid-liquid mass ratio during pre-soaking is 1:(0.5~0.7), and the pre-soaking time is 10~15 h.

3. The method according to claim 1, characterized in that, In step (1), the steam explosion pressure is 1.2~2.0 MPa and the pressure holding time is 60~540 s.

4. The method according to claim 1, characterized in that, In step (1), the temperature of the dried material shall not exceed 60°C.

5. The method according to claim 1, characterized in that, In step (2), the solvent used for alcohol extraction is 50-70 v% ethanol, with a solid-liquid mass ratio of 1:(15-25). The extract is ultrasonicated at 30-50℃ for 20-60 min under conditions of 30-50W and 200-300 kHz, and then filtered through filter paper to obtain extract B.

6. The method according to claim 1, characterized in that, In step (2), the process of extracting xylooligosaccharides by acid hydrolysis is as follows: Sample preparation before hydrolysis: Weigh 1-2 g of the blasted Polygonatum sibiricum stem material A, dissolve it in 80-150 mL of 0.005-0.01 mol / L sulfuric acid solution, sonicate for 5-20 min, then separate the solid and liquid using medium-speed qualitative filter paper. Take the filtrate and filter it again through a 0.22 μm nylon membrane with water to obtain the sample solution before hydrolysis, for later use. Sample preparation after hydrolysis: Pipette the sample solution before hydrolysis into a 100 mL colorimetric tube, add 3-6 mol / L sulfuric acid solution, shake well, place in a boiling water bath for 80-120 min, remove and cool, then dilute to 100 mL with deionized water, shake well, take the sample, and filter through a 0.22 μm nylon membrane with water to obtain the final sample.

7. The method according to claim 6, characterized in that, The volume ratio of the sample solution before hydrolysis to the sulfuric acid solution is (8~10):1, and the volume of the sample solution before hydrolysis is 5~20 mL.

8. The application of the total flavonoids and xylooligosaccharides prepared according to any one of claims 1 to 4 as feed additives for livestock and poultry, characterized in that, Total flavonoids and xylooligosaccharides refer to the explosive Polygonatum sibiricum stem material A containing total flavonoids and xylooligosaccharides obtained in step (1).

9. The application according to claim 8, characterized in that, The amount of explosive Polygonatum sibiricum stem material A added is 0.025%~0.075% of the base material mass.

10. The application according to claim 8, characterized in that, The livestock and poultry mentioned are cattle, pigs, or chickens.

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