Dictyophora rubrovolvata polysaccharide extraction process

Abstract

The invention discloses a dictyophora rubrovolvata polysaccharide extraction process which comprises the following steps: S1, raw material pretreatment: freeze-drying dictyophora rubrovolvata, crushing and sieving to obtain dictyophora rubrovolvata powder; the lactobacillus bulgaricus is subjected to activating treatment; the screening mesh number is 50-70, and the activation condition of the lactobacillus bulgaricus is that the material-liquid ratio is 1: (80-120), and the lactobacillus bulgaricus is subjected to water bath at 35-39 DEG C for 25-35 minutes; s2, fermentation: activated lactobacillus bulgaricus is added for fermentation; s3, sterilization and extraction: sterilizing a fermentation product in a water bath at 95-105 DEG C for 8-12 minutes, then extracting with hot water at 80-90 DEG C for 2-3 hours, and centrifuging after extracting for 1-3 times to take supernate; and S4, purifying and drying: adding low-temperature ethanol into the supernate, centrifugally collecting precipitate, and freeze-drying to obtain the dictyophora rubrovolvata polysaccharide.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polysaccharide extraction process, and particularly relates to a extraction process of Dictyophora rubrovolvata polysaccharide. BACKGROUND

[0002] Dictyophora rubrovolvata, as a precious fungus with both food and medicinal functions in Zhijin, Guizhou, China, is known as the queen of mushrooms. It is rich in polysaccharide components with multiple excellent biological activities such as immune regulation, antioxidant, anti-tumor, liver protection, hypoxia tolerance and anti-fatigue, and has a high development potential in the fields of food, medicine and health care. With the increasing demand for natural functional ingredients, the efficient extraction and quality optimization of Dictyophora rubrovolvata polysaccharide have become a research hotspot in the industry.

[0003] At present, the related researches on Dictyophora rubrovolvata polysaccharide mainly focus on the optimization of traditional extraction process and the verification of basic biological activity, and the research on the improvement of polysaccharide quality by using probiotic fermentation technology has not been fully developed. The existing extraction technology mainly uses traditional methods such as water extraction and alcohol precipitation, and there are many problems to be solved. Firstly, the polysaccharide extraction rate is low. The extraction rate of Dictyophora rubrovolvata polysaccharide under traditional process is usually only about 4.67%, and the main reason is that the cell wall structure of Dictyophora rubrovolvata is dense, and cellulose, hemicellulose and other components wrap the polysaccharide, making it difficult to release. Secondly, the purity of polysaccharide is insufficient. The purity of naturally extracted Dictyophora rubrovolvata polysaccharide is generally about 77.7%, and the impurities mainly include protein, pigment and small molecule organic matter. The existence of these impurities not only affects the functional properties of polysaccharide, but also increases the difficulty and cost of subsequent purification process. Thirdly, the functional properties of polysaccharide are limited. The polysaccharide extracted by traditional method has general performance in water holding capacity, oil holding capacity, swelling capacity and other physical and chemical properties, and the antioxidant activity needs to be further improved, which is difficult to meet the strict requirements of high-end food, medicine on functional ingredients. Fourthly, the process applicability is poor. The utilization rate of Dictyophora rubrovolvata raw material is low under traditional process, and the structure of polysaccharide is easily damaged during extraction, resulting in the loss of biological activity.

[0004] As a new biological processing method, probiotic fermentation technology has shown significant advantages in the field of plant polysaccharide extraction. Probiotics can effectively degrade plant cell wall structure through the metabolism of various hydrolytic enzymes (such as cellulase, amylase, protease, etc.), promote the release of polysaccharide, and the metabolites can also interact with polysaccharide to improve the structure and functional properties of polysaccharide. However, there is no special probiotic fermentation system for the extraction of Dictyophora rubrovolvata polysaccharide in the existing technology, and there is also a lack of a standardized extraction process that takes into account the extraction efficiency, polysaccharide purity and functional activity. Therefore, developing a Dictyophora rubrovolvata polysaccharide extraction process based on probiotic fermentation to solve the many defects of traditional extraction technology is of great significance to promote the high-value utilization of Dictyophora rubrovolvata resources and the innovative development of related industries. SUMMARY

[0005] The present application intends to provide a red-stemmed dictyophora polysaccharide extraction process, which realizes the extraction of red-stemmed dictyophora polysaccharide through probiotic fermentation.

[0006] A red-stemmed dictyophora polysaccharide extraction process, characterized by comprising the following steps: S1, raw material pretreatment: freeze-drying and crushing red-stemmed dictyophora to obtain red-stemmed dictyophora powder; activate the lactobacillus bulgaricus; the mesh number of the screening is 50-70, and the activation conditions of the lactobacillus bulgaricus are a material-to-liquid ratio of 1:80-120 and a water bath at 35-39℃ for 25-35min; S2, fermentation: mix the red-stemmed dictyophora powder with water at a material-to-liquid ratio of 1:20-30, add the activated lactobacillus bulgaricus, and ferment at a fermentation temperature of 40-48℃, a pH of 6.5-7.5, and a shaking table speed of 60-80r / min for 20-28h; the addition amount of the lactobacillus bulgaricus is 8%-12% of the mass of the red-stemmed dictyophora powder; S3, sterilization and extraction: sterilize the fermentation product in a 95-105℃ water bath for 8-12min, then hot water extract at 80-90℃ for 2-3h, centrifuge to obtain the supernatant after 1-3 times of extraction; the centrifugal speed is 3500-4500r / min, and the centrifugal time is 12-18min; S4, purification and drying: add 3-5 times the volume of 90%-98% ethanol to the supernatant, alcoholize at 2-6℃ for 10-14h, centrifuge to collect the precipitate, and freeze-dry to obtain red-stemmed dictyophora polysaccharide; the freeze-drying temperature is -55~-35℃, and the vacuum degree is 5-25Pa.

[0007] As a preferred, in step S1, the red-stemmed dictyophora is crushed and then screened through a 60-mesh sieve; the activation conditions of the lactobacillus bulgaricus are a material-to-liquid ratio of 1:100 and a water bath at 37℃ for 30min.

[0008] As a preferred, in step S2, the material-to-liquid ratio is 1:25, the fermentation temperature is 44℃, the pH is 7, the shaking table speed is 70r / min, the fermentation time is 24h, and the addition amount of the lactobacillus bulgaricus is 10% of the mass of the red-stemmed dictyophora powder.

[0009] As a preferred, in step S3, the sterilization temperature is 100℃, the sterilization time is 10min, the hot water extraction temperature is 85℃, the extraction time is 2.5h, the extraction number is 2, the centrifugal speed is 4000r / min, and the centrifugal time is 15min.

[0010] As a preferred, in step S4, the volume of ethanol added is 4 times the supernatant, the ethanol concentration is 95%, the alcohol precipitation temperature is 4℃, the alcohol precipitation time is 12h, the freeze-drying temperature is-50~-40℃, and the vacuum degree is 10-20Pa.

[0011] A red-stemmed Dictyophora polysaccharide prepared by an extraction process. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 For the scanning result of the low magnification of the electron microscope; Figure 2 For the scanning result of the high magnification of the electron microscope; Figure 3 For the X-ray diffraction analysis chart; Figure 4 For the DPPH free radical scavenging rate chart; Figure 5 For the ABTS scavenging rate chart; Figure 6 For the hydroxyl radical scavenging rate chart; DETAILED DESCRIPTION The following will be further described in detail through specific embodiments: Raw materials: red-stemmed Dictyophora (brand: Shanfuqi food); probiotics including Lactobacillus plantarum (brand: Yangqing Hall), Lactobacillus rhamnosus (brand: DIY), Bacillus subtilis (brand: SHBCC), and Lactobacillus bulgaricus (brand: Biolabor).

[0013] Reagents: sulfuric acid (AR, Shanghai Bomoil Science and Technology Co., Ltd.), sodium hydroxide (AR, Chemical Reagent Co., Ltd. of China National Pharmaceutical Group), 95% ethanol (AR, Chemical Reagent Co., Ltd. of China National Pharmaceutical Group), glucose (AR, Changde Bikeman Biotechnology Co., Ltd.), anhydrous ethanol (AR, Chemical Reagent Co., Ltd. of China National Pharmaceutical Group), DPPH (AR, Tianjin Zhonglian Chemical Reagent Co., Ltd.), ABTS (AR, Chemical Reagent Co., Ltd. of China National Pharmaceutical Group), potassium ferricyanide (AR, Chengdu Jinshan Chemical Reagent Co., Ltd.), trichloroacetic acid (AR, Jiangsu Chemical Industry Co., Ltd.), ferric sulfate (AR, Chengdu Jinshan Chemical Reagent Co., Ltd.), potassium sodium tartrate (AR, Chemical Reagent Co., Ltd. of China National Pharmaceutical Group), sodium dihydrogen phosphate (AR, Chemical Reagent Co., Ltd. of China National Pharmaceutical Group), potassium bromide (AR, Chemical Reagent Co., Ltd. of China National Pharmaceutical Group), phenol solution (AR, Chemical Reagent Co., Ltd. of China National Pharmaceutical Group) (I) Pretreatment The fresh Dictyophora rubrovolvata was frozen into ice cubes in a refrigerator, then moved into a freeze dryer for freeze-drying. The Dictyophora rubrovolvata was crushed by a high-speed pulverizer and passed through a 60-mesh sieve to prepare a Dictyophora rubrovolvata powder sample for use. The Lactobacillus rhamnosus, Lactobacillus bulgaricus, Lactobacillus plantarum and Bacillus subtilis were activated by being immersed in water at 37°C for 30 minutes at a solid-liquid ratio of 1:100.

[0014] (II) Fermentation experiment 50 g of the Dictyophora rubrovolvata powder was weighed and mixed with 5 g of different activated probiotics at a solid-liquid ratio of 1:25. The Lactobacillus rhamnosus was fermented at 30°C and pH 6 with a shaking speed of 70 r / min; the Lactobacillus plantarum was fermented at 30°C and pH 6.5 with a shaking speed of 70 r / min; the Bacillus subtilis was fermented at 25°C and pH 7 with a shaking speed of 70 r / min; the Lactobacillus bulgaricus was fermented at 44°C and pH 7 with a shaking speed of 70 r / min; a control group of the Dictyophora rubrovolvata without probiotics was set, which was fermented at 22°C and pH 5 with a shaking speed of 70 r / min. All the groups were taken out after being fermented for 24 hours.

[0015] (III) Polysaccharide extraction The fermented Dictyophora rubrovolvata was immersed in a water bath at 100°C for 10 minutes to inactivate the probiotics, then immersed in hot water at 85°C for 2.5 hours for continuous extraction twice. The supernatant was obtained by centrifugation, then four times the volume of 95% ethanol was added for alcohol precipitation at low temperature for 12 hours. The Dictyophora rubrovolvata polysaccharide was obtained by freeze-drying.

[0016] According to the above content, the following groups were obtained: Table 1

[0017] According to the above grouping, the following tests were performed: IV. Polysaccharide purity and extraction rate determination Polysaccharide purity determination: 10 mg of anhydrous glucose was accurately weighed, dissolved and diluted to 100 mL to obtain a 0.1 mg / mL mother liquor, which was gradient diluted to 0.2, 0.4, 0.6, 0.8 and 1.0 mg / mL. 1 mL of each concentration standard solution was taken, 0.5 mL of 5% phenol solution was added, 2.5 mL of concentrated sulfuric acid was quickly added, vortex mixed and then placed for 20 minutes. The blank was set to zero, the absorbance was measured at 490 nm, the standard curve was drawn, and the linear equation y=0.0063x+0.0012, R 2 =0.9995 was fitted. Five kinds of polysaccharide samples were dissolved with distilled water to prepare a 1 mg / mL solution, and if necessary, the insoluble substances were removed by centrifugation. 1 mL of the sample solution was operated according to the standard curve procedure to determine the absorbance and calculate the purity.

[0018] Determination of polysaccharide extraction rate: the extracted polysaccharide is ground into powder, the mass is weighed, and the extraction rate is calculated according to (polysaccharide mass x purity / raw material mass) x 100%.

[0019] (Five) Polysaccharide quality analysis Water holding capacity determination: 0.1 g of dried Dictyophora rubrovolvata polysaccharide sample (M) is weighed, 2.5 mL of deionized water is added, and it is shaken in a water bath at room temperature for 30 min, then centrifuged at 4000 r / min for 15 min. The supernatant is removed and the residual water on the wall of the centrifuge tube is wiped off, and the mass (M1) is weighed. The water holding capacity is calculated as (M1-M) / M.

[0020] Oil holding capacity determination: 0.1 g of dried Dictyophora rubrovolvata polysaccharide sample (M) is weighed, 2.5 mL of soybean oil is added, and it is shaken in a water bath at room temperature for 30 min, then centrifuged at 4000 r / min for 15 min. The oil layer is removed and the residual oil on the wall of the centrifuge tube is wiped off, and the mass (M1) is weighed. The oil holding capacity is calculated as (M1-M) / M.

[0021] Swelling power determination: 0.1 g of Dictyophora rubrovolvata polysaccharide powder is weighed in 10 mL of deionized water, vortexed to disperse uniformly, placed in a constant temperature shaking water bath at 70°C for 15 min, then placed in a constant temperature water bath at 95°C for 15 min. After cooling to room temperature, centrifuge at 4000 r / min for 10 min. Pour the supernatant into an aluminum box that has been dried in an oven, and place it in the oven to constant weight. The swelling power is calculated as (centrifuge tube weight after centrifugation - centrifuge tube weight before centrifugation) / powder weight.

[0022] Scanning electron microscopy analysis: The dried sample is attached to the sample stage of the scanning electron microscope with conductive adhesive, gold-coated, and then placed in the scanning electron microscope. Choose appropriate parameters, and observe and record photographs at 800x and 4000x.

[0023] X-ray diffraction analysis: Take an appropriate amount of dried polysaccharide sample and dried potassium bromide powder, mix them in a ratio of 1:100-1:200 in a agate mortar, and press them into transparent slices. Turn on the infrared spectrometer and preheat it for 30 minutes to 1 hour. First, perform a background scan, then place the polysaccharide KBr tablet in the sample cell, and scan 32 times at a scanning range of 4000-400 cm -1 Scanning resolution, 4 cm -1 Scanning resolution.

[0024] (Six) In vitro antioxidant activity determination DPPH radical scavenging rate: VC was used as a positive control, deionized water was used as a blank control, and anhydrous ethanol was used as a sample control. Different concentrations of Dictyophora rubrovolvata polysaccharide solutions (0.02, 0.04, 0.06, 0.08, 1 mg / mL) were prepared with deionized water, 2.0 mL of each was taken in a test tube, 2.0 mL of 0.2 mol / L DPPH solution was added, and it was shaken and mixed, then reacted in the dark for 30 min, the absorbance was measured at 517 nm with a microplate reader, and the scavenging rate was calculated as (experimental group absorbance / blank group absorbance) x 100%.

[0025] ABTS scavenging rate: ABTS stock solution was prepared by mixing 7 mM ABTS and 2.45 potassium persulfate, and then diluted to an absorbance of about 0.7 at 734 nm after standing at room temperature for 12 h to obtain ABTS working solution. VC was used as a positive control, deionized water was used as a blank control, and different concentrations of Dictyophora rubrovolvata polysaccharide solutions (0.25, 0.50, 0.75, 1.0, 1.25 mg / mL) were prepared, 1 mL of each polysaccharide solution was taken in a test tube, 1 mL of ABTS working solution was added and shaken to mix, then reacted at room temperature for 6 min, the absorbance was measured at 734 nm, and the scavenging rate was calculated as (experimental group absorbance / blank group absorbance) x 100%.

[0026] Hydroxyl radical scavenging rate: Vitamin C solution was used as a control group, and different concentrations of Dictyophora rubrovolvata polysaccharide solutions (0.25, 0.50, 0.75, 1.0, 1.25 mg / mL) were accurately taken, 1.0 mL of each sample solution was taken, 0.5 mL of 9 mol / L ferrous sulfate solution, 5.0 mL of H2O2 solution, and 0.5 mL of 9 mmol / L salicylic acid solution were added, and the absorbance was measured at 510 nm after water bath at 37°C for 20 min, and the scavenging rate was calculated as (experimental group absorbance / blank group absorbance) x 100%.

[0027] The following data was obtained: I. Analysis of polysaccharide purity and extraction rate results Table 2 Analysis of polysaccharide purity results

[0028] Table 3 Analysis of polysaccharide extraction rate results

[0029] Purity: The purity of the original Dictyophora rubrovolvata polysaccharide was 77.7 ± 0.4%, the purity of the Lactobacillus plantarum fermented polysaccharide was 83.3 ± 0.5%, the purity of the Bacillus subtilis fermented polysaccharide was 86.1 ± 0.3%, the purity of the Lactobacillus rhamnosus fermented polysaccharide was 79.9 ± 0.4%, and the purity of the Lactobacillus bulgaricus fermented polysaccharide was 82.3 ± 0.5%.

[0030] Extraction rate: The extraction rate of the original polysaccharide of Dictyophora rubrovolvata was 4.67±0.4%, the extraction rate of the fermented polysaccharide by Lactobacillus plantarum was 6.45±0.5%, the extraction rate of the fermented polysaccharide by Bacillus subtilis was 7.38±0.3%, the extraction rate of the fermented polysaccharide by Lactobacillus rhamnosus was 5.15±0.4%, and the extraction rate of the fermented polysaccharide by Lactobacillus bulgaricus was 5.85±0.5% II. Effects of probiotic fermentation on the physicochemical properties of polysaccharides of Dictyophora rubrovolvata Table 4 - Analysis of water holding capacity, oil holding capacity, and swelling capacity

[0031] Water holding capacity: The water holding capacity of the Dictyophora rubrovolvata group was 4.964±0.003 g / g, the water holding capacity of the Lactobacillus plantarum group was 6.772±0.001 g / g, the water holding capacity of the Lactobacillus rhamnosus group was 6.822±0.005 g / g, the water holding capacity of the Bacillus subtilis group was 6.831±0.002 g / g, and the water holding capacity of the Lactobacillus bulgaricus group was 6.884±0.004 g / g.

[0032] Oil holding capacity: The oil holding capacity of the Dictyophora rubrovolvata group was 5.978±0.006 g / g, the oil holding capacity of the Lactobacillus plantarum group was 5.032±0.001 g / g, the oil holding capacity of the Lactobacillus rhamnosus group was 4.986±0.002 g / g, the oil holding capacity of the Bacillus subtilis group was 5.900±0.007 g / g, and the oil holding capacity of the Lactobacillus bulgaricus group was 5.545±0.009 g / g.

[0033] Swelling capacity: The swelling capacity of the Dictyophora rubrovolvata group was 9.956±0.005 g / g, the swelling capacity of the Lactobacillus plantarum group was 9.987±0.004 g / g, the swelling capacity of the Lactobacillus rhamnosus group was 10.003±0.001 g / g, the swelling capacity of the Bacillus subtilis group was 10.173±0.007 g / g, and the swelling capacity of the Lactobacillus bulgaricus group was 10.205±0.002 g / g.

[0034] III. Scanning electron microscope analysis As shown in Figure 1 and Figure 2 , the scanning electron microscope analysis showed that under 800 times magnification, the Dictyophora rubrovolvata group had relatively large and irregular block-like structures with relatively complete structures; the Lactobacillus bulgaricus group had small and dispersed fragments; the Bacillus subtilis group had more fragmented structures with high dispersion; the Lactobacillus rhamnosus group had some fragmentation, but still had some large fragments; and the Lactobacillus plantarum group had small block-like aggregates with moderate dispersion. Under 4000 times magnification, the surface of the Dictyophora rubrovolvata group was relatively smooth with some layered structures; the surface of the Bacillus subtilis group was rough with obvious erosion marks; the surface of the Lactobacillus rhamnosus group was somewhat uneven with slight signs of damage; the surface of the Lactobacillus plantarum group had some pores and texture changes; and the surface of the Lactobacillus bulgaricus group was severely fragmented with loose structures.

[0035] As shown in Figure 3As shown, X-ray diffraction analysis, red to bamboo original polysaccharide has characteristic diffraction peak, after the fermentation of probiotics peak intensity increased significantly. Lactobacillus bulgaricus group at 19.33818° has a relatively high intensity peak, the diffraction peak position and intensity of each fermentation group compared with the control group are different.

[0036] Four, the effect of probiotic fermentation on the in vitro antioxidant activity of red to bamboo polysaccharide As Figures 4-6 shown, DPPH free radical scavenging rate: with the increase of concentration, the clearance rate of each sample showed an upward trend, which was lower than that of VC. The red to bamboo group showed a relatively stable growth trend, the Bacillus subtilis group showed a significant increase in clearance rate at high concentration, and the Lactobacillus rhamnosus group had a lower overall clearance rate than other fermented groups at the same concentration.

[0037] ABTS clearance rate: with the increase of concentration, the clearance rate of each sample showed an upward trend. The red to bamboo group showed a slow upward trend after 0.4 mg / mL, the Bacillus subtilis group showed a relatively stable and high clearance rate at each concentration, and the Lactobacillus rhamnosus group had the lowest initial clearance rate, which significantly improved at high concentration.

[0038] Hydroxyl radical scavenging rate: with the increase of concentration, the clearance rate of each sample showed an upward trend. The red to bamboo group showed a relatively slow upward trend, the Lactobacillus bulgaricus group showed a relatively stable upward trend, and the Lactobacillus rhamnosus group was close to some dominant groups at high concentration.

[0039] From the above analysis, different probiotic fermentation of Dictyophora rubrovolvata polysaccharide basic composition, physicochemical properties and in vitro antioxidant effect. Among them, the polysaccharide purity (86.1±0.3%) and extraction rate (7.38±0.3%) of Bacillus subtilis fermentation extraction are the highest, the water holding capacity (6.884±0.004g / g), oil holding capacity (5.545±0.009g / g) and swelling capacity (10.205±0.002g / g) of polysaccharide extracted from Dictyophora rubrovolvata fermented by Lactobacillus bulgaricus are the best, and the characterization structure is observed by scanning electron microscope. The characterization structure of different samples is different under 800 and 4000 times, among which the characterization structure of Lactobacillus bulgaricus is the most serious, small and dispersed, in addition, the biological activity results show that the DPPH, ABTS and hydroxyl radical scavenging rate of Dictyophora rubrovolvata polysaccharide fermented by probiotics increase with the increase of concentration, among which the DPPH scavenging rate of Dictyophora rubrovolvata is the best, the ABTS scavenging rate of Bacillus subtilis is the best, and the hydroxyl radical scavenging rate of Lactobacillus rhamnosus is the best. The antioxidant activity of polysaccharide is greatly improved, and the X-ray diffraction analysis shows that the polysaccharide extracted by Lactobacillus bulgaricus has a relatively high intensity peak at 19.33818°, which indicates that the atomic arrangement is more regular and the number is more in this crystal face direction, and the X-ray scattering ability is stronger, which makes the structure of polysaccharide produce unique change and affect its functional characteristics.

[0040] Comprehensive analysis shows that the polysaccharide extracted from Dictyophora rubrovolvata fermented by Lactobacillus bulgaricus is the best, and the extraction process is as follows: solid-liquid ratio 1:25, fermentation time 24h, fermentation temperature 44℃, ph7. The purity of polysaccharide extracted under this condition is 86.1±0.3%, and the quality of Dictyophora rubrovolvata polysaccharide is optimized to a certain extent by probiotic fermentation, which makes its application in food and drug field more advantageous, but the effect of different probiotics is different, and the appropriate probiotic fermentation should be selected according to the specific application requirement.

[0041] It should be pointed out that for those skilled in the art, without departing from the technical scheme of the present application, some modifications and improvements can also be made, which should also be regarded as the protection scope of the present application, which will not affect the effect of the present application and the practicality of the patent. The protection scope claimed in the present application should be subject to the content of its claims, and the specific implementation mode and the like recorded in the specification can be used to explain the content of the claims.

Claims

1. A process for extracting polysaccharides from Dictyophora rubrozonata, characterized in that, It comprises the following steps: S1, raw material pretreatment: the dried and frozen Dictyophora rubrovolvata is crushed and sieved to obtain Dictyophora rubrovolvata powder; the Lactobacillus bulgaricus is activated; the sieving mesh number is 50-70, and the activation conditions of the Lactobacillus bulgaricus are that the solid-liquid ratio is 1:80-120, and the water bath temperature is 35-39℃ for 25-35 min; S2, fermentation: the Dictyophora rubrovolvata powder is mixed with water at a solid-liquid ratio of 1:20-30, and the activated Lactobacillus bulgaricus is added, and the fermentation is carried out at a fermentation temperature of 40-48℃, a pH of 6.5-7.5, and a shaking speed of 60-80 r / min for 20-28 h; the addition amount of the Lactobacillus bulgaricus is 8%-12% of the mass of the Dictyophora rubrovolvata powder; S3, sterilization and extraction: the fermentation product is sterilized in a water bath at 95-105℃ for 8-12 min, and then hot water extraction is carried out at 80-90℃ for 2-3 h; after 1-3 times of extraction, the supernatant is obtained by centrifugation at a speed of 3500-4500 r / min for 12-18 min; S4, purification and drying: 3-5 times the volume of 90%-98% ethanol is added to the supernatant, and alcohol precipitation is carried out at 2-6℃ for 10-14 h; the precipitate is collected by centrifugation and dried to obtain Dictyophora rubrovolvata polysaccharide; the freezing drying temperature is-55~-35℃, and the vacuum degree is 5-25 Pa.

2. The method for extracting August melon seed protein polypeptide according to claim 1, characterized in that, In step S1, the Dictyophora rubrovolvata is crushed and sieved through a 60-mesh sieve; the activation conditions of the Lactobacillus bulgaricus are that the solid-liquid ratio is 1:100, and the water bath temperature is 37℃ for 30 min.

3. The method of claim 2, wherein the extraction of the polypeptide from the seed of Gomphrena celosioides is characterized by, In step S2, the solid-liquid ratio is 1:25, the fermentation temperature is 44℃, the pH is 7, the shaking speed is 70 r / min, the fermentation time is 24 h, and the addition amount of the Lactobacillus bulgaricus is 10% of the mass of the Dictyophora rubrovolvata powder.

4. The method of claim 3, wherein the extraction of the polypeptide of the Gynostemma pentaphyllum seed is characterized by, In step S3, the sterilization temperature is 100℃, the sterilization time is 10 min, the hot water extraction temperature is 85℃, the extraction time is 2.5 h, the extraction number is 2, the centrifugation speed is 4000 r / min, and the centrifugation time is 15 min.

5. The method of claim 4, wherein the extraction of the polypeptide of the Gynostemma pentaphyllum seed is characterized by, In step S4, the volume of the added ethanol is 4 times that of the supernatant, the ethanol concentration is 95%, the alcohol precipitation temperature is 4℃, the alcohol precipitation time is 12 h, the freezing drying temperature is-50~-40℃, and the vacuum degree is 10-20 Pa.

6. A Dictyophora rubrovolvata polysaccharide prepared by the extraction process according to any one of claims 1-5.

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