Atractylodes macrocephalaon polysaccharide BZ-3 as well as preparation method and application thereof

Abstract

The invention relates to the technical field of feed additives, and provides an oligomeric atractylodes macrocephala polysaccharide BZ-3 as well as a preparation method and application thereof. The oligomeric atractylodes macrocephala polysaccharide BZ-3 is glucosan oligosaccharide composed of 14 monosaccharides, and specifically comprises the following components: 10 beta-furanfructose are connected through beta-1, 2 glucosidic bonds, then alpha-glucopyranose is connected through the beta-1, 2 glucosidic bonds, the tail end of the glucosan oligosaccharide is connected with 3 alpha-glucopyranose through alpha-1, 4 glucosidic bonds, and the molecular formula of the glucosan oligosaccharide is C72H144O72. According to the technical scheme, the problem that the application of the atractylodes macrocephala polysaccharide is limited due to the fact that the atractylodes macrocephala polysaccharide is insufficient in structural analysis and poor in quality controllability in the prior art is solved.

Description

Technical Field

[0001] This invention relates to the field of feed additive technology, specifically to an oligosaccharide BZ-3, its preparation method, and its application. Background Technology

[0002] Against the backdrop of strict controls on the use of antibiotics in livestock farming, feed additives such as plant extracts, probiotics, polysaccharides and oligosaccharides, and enzyme preparations have gradually replaced traditional feed antibiotics and become a hot topic in the industry. Existing studies have confirmed that plant polysaccharides have functional uses in farmed animals, including immune regulation, enhancing antioxidant capacity, reducing stress, and improving production performance.

[0003] Among the many raw materials that can be used to extract plant polysaccharides, Atractylodes macrocephala is a highly promising choice. Atractylodes macrocephala is a plant belonging to the Asteraceae family (Atractylodes macrocephala). Atractylodes macrocephala The rhizome of *Atractylodes macrocephala* (Koidz.) is cultivated in most parts of my country and has high economic value. It is used both as food and medicine, and is also a feed ingredient. In addition to volatile oils and flavonoids, the rhizome of *Atractylodes macrocephala* contains a high content of active polysaccharides, which can act on multiple aspects of the body, mainly concentrated in the immune and gastrointestinal systems. It has various pharmacological effects such as immune regulation, liver protection, gastric mucosal repair, and anti-inflammation, making it an ideal raw material for preparing feed additives.

[0004] However, the structural analysis of existing Atractylodes macrocephala polysaccharides is insufficient. Most existing polysaccharides are randomly polymerized from monosaccharides such as glucose and galactose, with molecular weights ranging from 5kDa to 500kDa, lacking precise analysis of glycosidic bond types and branched structures. Furthermore, the preparation process has flaws; polysaccharides obtained by traditional water extraction contain 20%–35% protein residue, directly leading to decreased feed palatability. Additionally, the larger molecular weight polysaccharides cannot be absorbed through intestinal epithelial cells and are directly excreted in feces, resulting in a high fecal detection rate. Moreover, due to the unclear structure of Atractylodes macrocephala polysaccharides, relying solely on "total sugar content" as an indicator leads to poor quality control, hindering its large-scale application in the feed industry.

[0005] In conclusion, the research and development of new plant polysaccharide feed additives using Atractylodes macrocephala has important practical and long-term significance for promoting the healthy development of my country's aquaculture industry. Summary of the Invention

[0006] This invention proposes an oligosaccharide BZ-3, its preparation method, and its application, which solves the problems of insufficient structural analysis and poor quality control of oligosaccharides in related technologies, thus limiting their application.

[0007] The technical solution of the present invention is as follows: This invention proposes an oligosaccharide BZ-3, which is an oligofructose composed of 14 monosaccharides, with the following specific structure: .

[0008] As a further technical solution, the molecular weight of the oligosaccharide BZ-3 is 2200 Da.

[0009] This invention also proposes a method for preparing Atractylodes macrocephala oligosaccharide BZ-3, which includes the following steps: S1. Atractylodes macrocephala is extracted with water for the first time and filtered to obtain a first filtrate and a first residue. The first residue is extracted with water for the second time and filtered to obtain a second filtrate and a second residue. The second residue is extracted with water for the third time and filtered to obtain a third filtrate and a third residue. The first filtrate, the second filtrate, and the third filtrate are combined and concentrated to obtain a concentrated solution. S2. Decolorize the concentrated solution to obtain a supernatant; S3. The supernatant is subjected to ultrafiltration separation to obtain ultrafiltration concentrate; S4. The ultrafiltration concentrate is dried to obtain the oligosaccharide BZ-3.

[0010] In the preparation method of Atractylodes macrocephala oligosaccharide BZ-3 of the present invention, Atractylodes macrocephala oligosaccharide BZ-3 is obtained by water extraction of Atractylodes macrocephala, activated carbon treatment, ultrafiltration membrane separation and vacuum concentration.

[0011] As a further technical solution, in step S1, during the first extraction, the mass ratio of Atractylodes macrocephala to water is 1:8~12; During the second extraction, the mass ratio of the first filter residue to water is 1:8~12; During the third extraction, the mass ratio of the second filter residue to water is 1:8~12.

[0012] As a further technical solution, the temperature for the first extraction, the second extraction, and the third extraction is independently 98~100℃, for example, 98℃, 99℃, and 100℃, preferably 98℃.

[0013] As a further technical solution, the relative density of the concentrate is 1.02~1.05 at 20°C.

[0014] In this invention, the relative density of the concentrate is the ratio of the solution density to the water density measured at 20°C.

[0015] As a further technical solution, a decolorizing agent is added during the decolorization process, and the decolorizing agent includes activated carbon; The mass-to-volume ratio of the decolorizing agent to the concentrated solution is 0.005~0.01 g / mL.

[0016] As a further technical solution, the boiling time is 20-30 minutes.

[0017] As a further technical solution, the pore size of the ultrafiltration membrane is 1000 Da during ultrafiltration.

[0018] The present invention also proposes the application of the aforementioned Atractylodes macrocephala polysaccharide BZ-3 or the preparation method thereof for Atractylodes macrocephala polysaccharide BZ-3 in feed.

[0019] As a further technical solution, the amount of Atractylodes macrocephala polysaccharide BZ-3 added to the feed is 75~900mg / kg, that is, the amount of Atractylodes macrocephala polysaccharide BZ-3 added per kilogram of feed is 75~900mg.

[0020] The working principle and beneficial effects of this invention are as follows: The present invention provides Atractylodes macrocephala polysaccharide BZ-3, which is an oligofructose with a molecular weight of 2200 Da. Atractylodes macrocephala polysaccharide BZ-3 can improve the weight gain rate and reduce the feed conversion ratio of largemouth bass. In terms of physiological improvement, Atractylodes macrocephala polysaccharide BZ-3 can reduce plasma aspartate aminotransferase (AST) and creatinine (Cr) levels. Regarding antioxidant stress capacity, Atractylodes macrocephala polysaccharide BZ-3 can enhance the total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) activity in the liver of largemouth bass, while reducing inducible nitric oxide synthase (iNOS), malondialdehyde (MDA), and nitric oxide (NO) levels, thus enhancing the body's antioxidant stress capacity. In terms of digestive function regulation, Atractylodes macrocephala polysaccharide BZ-3 can increase the activity of intestinal amylase and lipase, promoting digestion. Furthermore, Atractylodes macrocephala polysaccharide BZ-3 can increase the length of intestinal microvilli in largemouth bass, optimize intestinal structure, and facilitate nutrient absorption.

[0021] In summary, the oligosaccharide BZ-3 of the present invention has significant application value in the field of largemouth bass feed additives. It can effectively improve the growth, health and digestion of largemouth bass, and has low preparation cost and simple method, thus possessing good industrialization prospects. Attached Figure Description

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0023] Figure 1 The molecular structural formula of Atractylodes macrocephala oligosaccharide BZ-3; Figure 2 The infrared spectrum of the oligosaccharide BZ-3 obtained in Example 3 of this invention; Figure 3 The infrared spectrum of the oligosaccharide BZ-3 obtained in Example 4 of this invention; Figure 4 The infrared spectrum of the oligosaccharide BZ-3 prepared in Example 5 of this invention; Figure 5 These are scanning electron microscope images of the six largemouth bass experimental groups in Experiment Example 3 of this invention; Among them, A0, A75, A150, A300, A450, and A900 are the six experimental groups for largemouth bass, and the numbers are represented by XYn, which represents group-replication-sample number: each group was repeated 6 times in the experiment, and the sample size of each replication was 30 fish; where X represents the group: 1 to 6 represent groups A0, A75, A150, A300, A450, and A900 respectively; Y represents the number of the replication in each group; and n represents the sample number in that replication. Figure 6 This is a diagram showing the intestinal microvilli length test results of the six largemouth bass experimental groups in Experiment Example 3 of this invention; Figure 7 A photograph of the filtrate after ultrafiltration in Example 1; Figure 8 This is a photograph of the filtrate after ultrafiltration in Example 3; Figure 9 A photograph of the Atractylodes macrocephala extract prepared in Example 1; Figure 10 A photograph of the oligosaccharide BZ-3 prepared in Example 3; Figure 11 The high-performance liquid chromatogram of the Atractylodes macrocephala extract prepared in Example 1; Figure 12 The high-performance liquid chromatogram of the Atractylodes macrocephala extract prepared in Example 2; Figure 13 The high-performance liquid chromatogram of the oligosaccharide BZ-3 prepared in Example 3 is shown below. Figure 14 The high-performance liquid chromatogram of the oligosaccharide BZ-3 prepared in Example 4 is shown below. Figure 15 The high-performance liquid chromatogram of the oligosaccharide BZ-3 prepared in Example 5 is shown below. Figures 11-15 In the figure, the horizontal axis represents minutes, and the vertical axis represents the micro-refractive index; Figure 16 This is a statistical chart showing the average initial weight and average final weight of sea bass in different experimental groups in Experiment Example 3; Figure 17 The chart shows the weight gain rate of bass in different experimental groups in Experiment Example 3. Figure 18 This is a statistical graph showing the feed conversion ratio of sea bass in different experimental groups in Experiment Example 3; Figure 19This is a statistical chart showing the aspartate aminotransferase (AST) content in different experimental groups of bass in Experiment Example 3. Figure 20 This is a statistical graph showing the creatinine content of sea bass in different experimental groups in Experiment Example 3; Figure 21 This is a statistical chart showing the lipase and amylase content in different experimental groups of bass in Experiment Example 3; Figure 22 This is a statistical chart showing the total cholesterol and triglyceride content of sea bass in different experimental groups in Experiment Example 3; Figure 23 This is a statistical chart showing the superoxide dismutase content in different experimental groups of sea bass in Experiment Example 3; Figure 24 This is a statistical chart showing the malondialdehyde (MDA) content in sea bass from different experimental groups in Experiment Example 3. Figure 25 This is a statistical chart showing the content of antioxidant capacity indicators in different experimental groups of sea bass in Experiment Example 3; in Figures 16-25 In the diagram, the letters indicate the comparison results with A0: those with the same letters as group A0 indicate no statistically significant difference. P >0.05), indicating a statistically significant difference compared to group A0, where no two letters are the same. P <0.05). Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] In the following examples and comparative examples, Atractylodes macrocephala was purchased from Anguo Longda Chinese Herbal Pieces Co., Ltd.

[0026] Example 1 Take 1 kg of Atractylodes macrocephala, add 12 times the amount of water, and extract at 98℃ for 2 hours. Filter to obtain the first filtrate and the first residue. Extract the first residue with 10 times the amount of water at 98℃ for 2 hours, and filter to obtain the second filtrate and the second residue. Extract the second residue with 8 times the amount of water at 98℃ for 2 hours, and filter to obtain the third filtrate and the third residue. Combine the first, second, and third filtrates, and concentrate under reduced pressure to a relative density of 1.03 (the ratio of the solution density to the water density measured at 20℃). Let stand overnight, filter, and separate the supernatant using an ultrafiltration membrane with a pore size of 1000 Da. Collect the ultrafiltrate, and then concentrate under reduced pressure to a relative density of 1.13 to obtain the concentrate (see image of the concentrate). Figure 7 (As shown), after drying, Atractylodes macrocephala extract was obtained (image of Atractylodes macrocephala extract as shown). Figure 9 (As shown).

[0027] Example 2 Take 1 kg of Atractylodes macrocephala, add 12 times the amount of water and extract at 98℃ for 2 hours, filter to obtain the first filtrate and the first residue. Extract the first residue with 10 times the amount of water at 98℃ for 2 hours, filter to obtain the second filtrate and the second residue. Extract the second residue with 8 times the amount of water at 98℃ for 2 hours, filter to obtain the third filtrate and the third residue. Combine the first, second, and third filtrates, concentrate under reduced pressure to a relative density of 1.03 (the ratio of solution density to water density measured at 20℃), add 0.5% (w / v) activated carbon, heat and maintain a gentle boil for 20 minutes, let stand overnight, filter, concentrate the filtrate under reduced pressure to a relative density of 1.11, dry to obtain the Atractylodes macrocephala extract.

[0028] Example 3 Take 1 kg of Atractylodes macrocephala, add 12 times the amount of water and extract at 98℃ for 2 hours, filter to obtain the first filtrate and the first residue. Extract the first residue with 10 times the amount of water at 98℃ for 2 hours, filter to obtain the second filtrate and the second residue. Extract the second residue with 8 times the amount of water at 98℃ for 2 hours, filter to obtain the third filtrate and the third residue. Combine the first, second, and third filtrates, concentrate under reduced pressure to a relative density of 1.03 (the ratio of solution density to water density measured at 20℃), add 1% (w / v) activated carbon, heat and maintain a gentle boil for 30 minutes, let stand overnight, filter, collect the supernatant, separate by ultrafiltration membrane, collect the ultrafiltrate, and then concentrate under reduced pressure to a relative density of 1.12 (see photo). Figure 8 After drying, oligosaccharide BZ-3 was obtained (see photo). Figure 10 ).

[0029] Example 4 Take 1 kg of Atractylodes macrocephala, add 8 times the amount of water and extract at 98℃ for 2 hours, filter to obtain the first filtrate and the first residue. Extract the first residue with 8 times the amount of water at 98℃ for 2 hours, filter to obtain the second filtrate and the second residue. Extract the second residue with 8 times the amount of water at 98℃ for 2 hours, filter to obtain the third filtrate and the third residue. Combine the first, second, and third filtrates, concentrate under reduced pressure to a relative density of 1.02 (the ratio of the solution density to the water density at 20℃), add 0.5% (w / v) activated carbon, heat and maintain a gentle boil for 20 minutes, let stand overnight, filter, take the supernatant, separate by ultrafiltration membrane, collect the ultrafiltrate, concentrate under reduced pressure to a relative density of 1.10, dry to obtain oligosaccharide Atractylodes macrocephala polysaccharide BZ-3.

[0030] Example 5 Take 1 kg of Atractylodes macrocephala, add 12 times the amount of water and extract at 98℃ for 2 hours, filter to obtain the first filtrate and the first residue. Extract the first residue with 12 times the amount of water at 98℃ for 2 hours, filter to obtain the second filtrate and the second residue. Extract the second residue with 12 times the amount of water at 98℃ for 2 hours, filter to obtain the third filtrate and the third residue. Combine the first, second, and third filtrates, concentrate under reduced pressure to a relative density of 1.05 (the ratio of the solution density to the water density at 20℃), add 1% (w / v) activated carbon, heat and maintain a gentle boil for 30 minutes, let stand overnight, filter, take the supernatant, separate by ultrafiltration membrane, collect the ultrafiltrate, concentrate under reduced pressure to a relative density of 1.15, dry to obtain oligosaccharide Atractylodes macrocephala polysaccharide BZ-3.

[0031] Experimental Example 1 Using a Fourier transform infrared spectrometer (FTIR7600), potassium bromide pellets were prepared at 4000 cm⁻¹. -1 ~400cm -1 The infrared spectra of the oligosaccharide BZ-3 prepared in Examples 3-5 were tested for wavenumber range. The infrared spectra are as follows: Figures 2-4 .

[0032] Infrared spectrum of Atractylodes macrocephala oligosaccharide BZ-3 in Example 3 ( Figure 2 This indicates that at 3297cm -1 The strong, broad peak at 2928 cm⁻¹ is the absorption peak of the stretching vibration of OH. -1 It is the absorption peak of the CH stretching vibration of -CH2-, and it is also a characteristic peak of carbohydrates. 1641 cm⁻¹ -1 The absorption peak is the stretching vibration of the carbonyl C=O group, at 1163 cm⁻¹. -1 The absorption peak for the angular vibration of OH is 1027 cm⁻¹. -1 The absorption peak for the stretching vibration of COC is 935 cm⁻¹. -1 and 819cm -1 The characteristic absorption peak of furanose is 874 cm⁻¹. -1 and 596cm -1 The characteristic absorption peak is pyranose, indicating that the oligosaccharide BZ-3 is composed of both furanose and pyranose.

[0033] The infrared spectra of the oligosaccharide BZ-3 prepared in Examples 4 and 5 are consistent with the absorption peaks of the oligosaccharide BZ-3 prepared in Example 3, indicating that their compositions are consistent.

[0034] Experimental Example 2 The content of oligosaccharide BZ-3 prepared in Examples 1-5 was determined by high performance liquid chromatography (Waters 2695 HPLC system). The test results are shown in Table 2.

[0035] Chromatographic conditions and system suitability tests were conducted using hydrophilic spherical polymethyl methacrylate particles as the packing material (TSKgel GMPW column). XL (Dimensions 300mm × 7.8mm, purchased from Tosoh Corp.); Watson's water was used as the mobile phase; flow rate was 0.8mL / min; column temperature was 30℃; flow cell temperature was 30℃. The theoretical plate number, calculated based on the BZ-3 peak of Atractylodes macrocephala oligosaccharide, should be no less than 500.

[0036] Preparation of reference solution: Take 25 mg of Atractylodes macrocephala oligosaccharide BZ-3 reference standard (provided by the Institute of Analysis and Testing, Beijing Academy of Science and Technology (Beijing Physical and Chemical Analysis and Testing Center)), accurately weigh it, add water to make a solution containing 1 mg per 1 mL.

[0037] Preparation of the test solution: Weigh 0.1g of this product accurately, place it in a 50mL volumetric flask, add 45mL of water at about 80℃, shake to disperse, sonicate for 20min, shake well, cool, and then add water to make up to the mark, filter, and the solution is obtained.

[0038] Determination method: Accurately pipette 20 μL of the reference solution and the test solution into the high performance liquid chromatograph, record the chromatogram, and calculate the results by peak area according to the external standard method.

[0039] The test results are shown in Table 2; The high-performance liquid chromatogram of the Atractylodes macrocephala extract obtained in Example 1 is shown below. Figure 11 As shown; The high-performance liquid chromatogram of the Atractylodes macrocephala extract obtained in Example 2 is shown below. Figure 12 As shown; The high-performance liquid chromatogram of the oligosaccharide BZ-3 prepared in Example 3 is shown below. Figure 13 As shown; The high-performance liquid chromatogram of the oligosaccharide BZ-3 prepared in Example 4 is shown below. Figure 14 As shown; The high-performance liquid chromatogram of the oligosaccharide BZ-3 prepared in Example 5 is shown below. Figure 15 As shown.

[0040] Table 2. Results of the test for the content of Atractylodes macrocephala oligosaccharide BZ-3

[0041] Experimental Example 3 The experiment used the oligosaccharide BZ-3 prepared in Example 3 as the research object and largemouth bass as the experimental animal.

[0042] One hundred and eighty healthy, uniformly sized largemouth bass were selected for the experiment and divided into six groups of 180 fish each. They were fed experimental diets supplemented with 0 mg / kg, 75 mg / kg, 150 mg / kg, 300 mg / kg, 450 mg / kg, and 900 mg / kg of atractylodes oligosaccharide BZ-3, respectively, and named A0, A75, A150, A300, A450, and A900 groups. Feeding and mortality were observed and recorded daily. After 10 weeks of rearing, the fish in each experimental group were counted and weighed to determine the weight gain rate and feed conversion ratio. The test results are shown below. Figures 16-18 As shown, where, Figure 16 Statistical graphs showing the average initial weight and average final weight of sea bass in different experimental groups; Figure 17 A statistical chart showing the weight gain rate of bass in different experimental groups; Figure 18 The chart shows the feed conversion ratio (FCR) of bass in different experimental groups. Twelve bass were randomly selected from each group, numbered, and blood was collected. Liver and intestinal tissues were removed on ice, flash-frozen in liquid nitrogen, and stored at -80°C for testing blood parameters, liver antioxidant levels, and intestinal digestive enzymes. The test results are shown below. Figures 19-25 As shown, where, Figure 19 A statistical chart showing the aspartate aminotransferase content in sea bass from different experimental groups; Figure 20 Statistical graph of creatinine content in sea bass from different experimental groups; Figure 21 Statistical graph showing the content of lipase and amylase in sea bass from different experimental groups; Figure 22 Statistical chart of total cholesterol and triglyceride content in sea bass from different experimental groups; Figure 23 A statistical chart showing the superoxide dismutase content in sea bass from different experimental groups; Figure 24 A statistical chart showing the malondialdehyde (MDA) content in sea bass from different experimental groups; Figure 25 Statistical chart of antioxidant capacity index content in sea bass from different experimental groups ( Figures 16-25 In the diagram, the letters indicate the comparison results with A0: those with the same letters as group A0 indicate no statistically significant difference. P >0.05), indicating a statistically significant difference compared to group A0, where no two letters are the same. P <0.05). In addition, 12 fish were randomly selected from each group and numbered. Intestinal tissue was removed on ice and fixed in 2% glutaraldehyde fixative for ultrathin section preparation and scanning electron microscopy.

[0043] The scanning electron microscope (SEM) test results are shown below. Figure 5 The experimental results show that: 1. Compared with group A0, the average final weight of largemouth bass in groups A150, A300, A450 and A900 was significantly higher. P <0.05)( Figure 16 ), among which the A300 group showed a significantly increased weight gain rate ( P <0.05)( Figure 17 ), feed conversion ratio significantly reduced ( P <0.05)( Figure 18 The above results indicate that the addition of appropriate amounts of Atractylodes macrocephala extract can promote the growth of largemouth bass and improve feed utilization efficiency.

[0044] 2. The AST activity in the A150, A300, and A450 groups was significantly lower than that in other groups. P <0.05)( Figure 19 The TC content of largemouth bass in group A150 was significantly lower than that in other groups. P <0.05); the TG content in group A150 was significantly lower than that in groups A75, A300, and A450 ( P <0.05)( Figure 22 Meanwhile, the Cr content of largemouth bass in groups A150 and A300 was significantly lower than that in group A0. P <0.05)( Figure 20 ).

[0045] 3. From Figure 21 As can be seen, compared with group A0, group A150 significantly increased amylase activity ( P <0.05); the A300 group significantly increased lipase and amylase activities ( P <0.05); the A450 group significantly increased lipase activity ( P <0.05).

[0046] 4. Compared with the absence of Atractylodes oligosaccharide BZ-3, the addition of Atractylodes oligosaccharide BZ-3 to the feed at concentrations of 75 mg / kg, 150 mg / kg, 300 mg / kg, 450 mg / kg, and 900 mg / kg enhanced the antioxidant stress resistance of largemouth bass to varying degrees. Figures 23-25 It can be seen that the liver SOD activity was significantly increased and the MDA content was decreased in the A75 group. P <0.05); The A150 group showed significantly increased T-AOC and SOD activities in the liver of largemouth bass, and decreased iNOS and NO levels ( P <0.05); SOD activity was significantly increased and MDA level was significantly decreased in the A300 group ( P <0.05); SOD activity was significantly enhanced in the A450 group, while iNOS and NO levels were significantly reduced ( P <0.05); the levels of iNOS and NO in the A900 group were significantly reduced ( P <0.05). The above results indicate that the addition of Atractylodes oligosaccharide BZ-3 can improve the antioxidant capacity of largemouth bass.

[0047] 5. Compared with group A0, the addition of 75 mg / kg, 150 mg / kg, 300 mg / kg, 450 mg / kg and 900 mg / kg of Atractylodes oligosaccharide BZ-3 to the feed significantly increased the length of intestinal microvilli, such as... Figure 6 As shown, the microvilli in groups A150 and A300 are more neatly and densely arranged, and the cells are more tightly connected.

[0048] In summary, adding an appropriate amount of Atractylodes oligosaccharide BZ-3 to the basal diet can effectively improve the weight gain rate and feed efficiency of largemouth bass; it can significantly reduce plasma aspartate aminotransferase (AST) and creatinine (Cr) levels; it can enhance the antioxidant stress capacity of largemouth bass, significantly increase the total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) activity in the liver, and significantly reduce the levels of inducible nitric oxide synthase (iNOS), malondialdehyde (MDA), and nitric oxide (NO); at the same time, it can also increase the activity of intestinal amylase and lipase, and significantly increase the length of intestinal microvilli in largemouth bass.

[0049] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An oligosaccharide BZ-3, characterized in that, The oligofructose, composed of 14 monosaccharides, has the following structure: 。 2. The oligosaccharide BZ-3 of Atractylodes macrocephala according to claim 1, characterized in that, The molecular weight of the oligosaccharide BZ-3 is 2200 Da.

3. A method for preparing Atractylodes macrocephala oligosaccharide BZ-3, used to prepare the Atractylodes macrocephala oligosaccharide BZ-3 as described in any one of claims 1 to 2, characterized in that, Includes the following steps: S1. Atractylodes macrocephala is extracted with water for the first time and filtered to obtain a first filtrate and a first residue. The first residue is extracted with water for the second time and filtered to obtain a second filtrate and a second residue. The second residue is extracted with water for the third time and filtered to obtain a third filtrate and a third residue. The first filtrate, the second filtrate, and the third filtrate are combined and concentrated to obtain a concentrated solution. S2. Decolorize the concentrated solution to obtain a supernatant; S3. The supernatant is subjected to ultrafiltration separation to obtain ultrafiltration concentrate; S4. The ultrafiltration concentrate is dried to obtain the oligosaccharide BZ-3.

4. The method for preparing oligosaccharide BZ-3 of Atractylodes macrocephala according to claim 3, characterized in that, In step S1, during the first extraction, the mass ratio of Atractylodes macrocephala to water is 1:8~12; During the second extraction, the mass ratio of the first filter residue to water is 1:8~12; During the third extraction, the mass ratio of the second filter residue to water is 1:8~12.

5. The method for preparing oligosaccharide BZ-3 according to claim 3, characterized in that, At 20°C, the relative density of the concentrate is 1.02~1.

05.

6. The method for preparing oligosaccharide BZ-3 according to claim 2, characterized in that, A decolorizing agent, including activated carbon, is added during the decolorization process. The mass-to-volume ratio of the decolorizing agent to the concentrated solution is 0.005~0.01 g / mL.

7. The method for preparing oligosaccharide BZ-3 according to claim 3, characterized in that, The boiling time is 20-30 minutes.

8. The method for preparing oligosaccharide BZ-3 according to claim 3, characterized in that, The ultrafiltration separation process uses an ultrafiltration membrane; The ultrafiltration membrane has a pore size of 1000 Da.

9. The application of an oligosaccharide BZ-3 prepared according to any one of claims 1 to 2 or the preparation method of an oligosaccharide BZ-3 according to any one of claims 2 to 8 in feed.

10. The application according to claim 10, characterized in that, The amount of the oligosaccharide BZ-3 added to the feed is 75~900mg / kg.

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