A soluble peach gum polysaccharide and its preparation method

Abstract

This application relates to a soluble peach gum polysaccharide and its preparation method, comprising the following steps: S1, water extraction: 0.01%-0.1% (by weight) of lecithin is added to pulverized peach gum powder, mixed, and then water is added and stirred at room temperature for water extraction. The mixture is filtered, and the filtrate is reserved. S2, adsorption: an adsorbent is added to the filtrate, and the mixture is stirred until flocculent matter appears. After settling, the mixture is centrifuged to obtain a precipitate. The adsorbent is tea polyphenols. S3, elution: the precipitate is eluted with alcohol as the eluent to obtain a polysaccharide-containing eluted precipitate. S4, drying: the eluted precipitate is dried and pulverized to obtain soluble peach gum polysaccharide. The preparation method in this application does not use high temperature, acid, alkali, or ultrasonic extraction to prepare soluble peach gum polysaccharide. The preparation conditions are mild, thus avoiding damage to biological activity. The prepared soluble peach gum polysaccharide has good solubility, significantly improving the solubility compared to peach gum polysaccharide prepared by conventional methods.

Description

Technical Field

[0001] This application relates to the field of bio-extraction technology, and in particular to a peach gum polysaccharide and its preparation method. Background Technology

[0002] Peach gum, also known as peach blossom tears or peach resin, is a reddish-brown or yellowish-brown resinous substance secreted from the bark of peach trees such as *Prunus persica* (L.) Batsch or *Prunus davidiana* (Carr.) Franch, belonging to the Rosaceae family. 70%–80% of its composition is peach gum polysaccharide. The viscous liquid or jelly-like colloid harvested from the trunk is commonly called peach tree oil; the solid substance obtained after drying through sun exposure or natural air drying is called peach gum, which is usually smooth and translucent brownish-yellow in color.

[0003] The main component of peach gum is polysaccharide. Current technologies typically process peach gum using methods such as acid, alkali, ultrasound, organic solvents, or high-temperature hydrolysis to break it down into smaller molecules. However, the hydrolyzed peach gum exhibits lower activity of its components, inevitably diminishing its unique functional effects. On one hand, in the commonly used water extraction and alcohol precipitation method, when precipitating the filtrate obtained after water extraction or hydrolysis, some non-water-soluble polysaccharides are also precipitated, affecting the content of truly water-soluble peach gum polysaccharides in the precipitate. This poor solubility severely limits the application of peach gum polysaccharides.

[0004] The literature: Gao Ailing, Jin Weiwei, Chen Gongkai, et al. Discussion on the solubility characteristics of almond gum [J]. Zhejiang Agricultural Sciences, 2014(5):732-733, 739. mentions that the solubility of almond gum is less than 5%; while the literature: Cai Yanqu, Dong Bilian. Study on the changes in polysaccharide content, functional properties and in vitro release rate of peach gum before and after improvement [J]. Chinese Traditional and Herbal Drugs, 2021, 49(20)4809-4810. mentions that the solubility of raw peach gum from different origins is 60.8 mg / g in Xishui, Guizhou, 57.5 mg / g in Xinfeng, Jiangxi, and 51.2 mg / g in Suixian, Hubei, while the improved peach gum is 178.2, 167.3 and 163.8 mg / g respectively. The solubility is less than 20% when converted to percentage. Furthermore, CN116693713A discloses that the solubility of the peach gum polysaccharide product prepared by the method of this invention has been increased from about 5% in existing peach gum polymer products to 30%, which has expanded the application of peach gum polysaccharide to a certain extent.

[0005] Therefore, in the preparation and extraction of peach gum polysaccharides, how to obtain more soluble peach gum polysaccharide components with better solubility and reduce the damage to its biological activity has always been a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0006] One of the objectives of this application is to provide a method for preparing soluble peach gum polysaccharide, which does not use high temperature, acid, alkali, or ultrasound to extract and prepare soluble peach gum polysaccharide. The preparation conditions are mild, thereby avoiding damage to biological activity. The prepared soluble peach gum polysaccharide has good solubility, which is significantly improved compared with peach gum polysaccharide prepared by conventional methods.

[0007] The preparation method of soluble peach gum polysaccharide in this application includes the following steps:

[0008] S1, Water extraction: Take the crushed peach gum powder, add 0.01%-0.1% of lecithin by weight of peach gum powder, mix, add water at room temperature, stir and mix well, perform water extraction, filter, and keep the filtrate for later use;

[0009] S2, Adsorption: Add adsorbent to the filtrate, stir until flocculent matter appears, let it stand to settle, and centrifuge to obtain the precipitate. The adsorbent is tea polyphenol, and the weight ratio of adsorbent to peach gum powder is (1.5-3.5):10.

[0010] S3, Elution: The precipitate is eluted with alcohol as the eluent to obtain a polysaccharide-containing eluted precipitate; using alcohol for elution can also dissolve lecithin and tea polyphenols from the precipitate as much as possible, thereby improving the purity of the final product.

[0011] S4, Drying: The precipitate is washed off, dried, and pulverized to obtain soluble peach gum polysaccharide.

[0012] Furthermore, it also includes the step of preparing conventional peach gum polysaccharide, specifically: adding the adsorption and filtration liquid described in S2 to alcohol for alcohol precipitation to obtain alcohol-precipitated peach gum polysaccharide; using alcohol as an eluent to elute impurities from the alcohol-precipitated peach gum polysaccharide to obtain alcohol-precipitated peach gum polysaccharide precipitate; drying and pulverizing the alcohol-precipitated peach gum polysaccharide precipitate to obtain conventional peach gum polysaccharide.

[0013] Furthermore, in S1, the peach gum powder has a purity of over 95% that passes through a 40-mesh sieve.

[0014] Furthermore, in step S1, the amount of water used during water extraction is 30-40 times the weight of the gum powder; the water extraction time is more than 120 minutes.

[0015] Furthermore, the amount of lecithin added in S1 is 0.06% of the weight of the peach gum powder.

[0016] Furthermore, the amount of tea polyphenol adsorbent added in S2 is 3% of the weight of peach gum powder.

[0017] Furthermore, in S3, the ethanol concentration in the eluent is ≥90%, and the amount of alcohol used in the eluent is 20 times the weight of the peach gum powder;

[0018] Furthermore, the purity of the tea polyphenols in S2 is ≥95%, and the content of flavonoid tea polyphenols in the tea polyphenols is ≥50%.

[0019] The second objective of this application is to provide a soluble peach gum polysaccharide prepared by the above-described preparation method.

[0020] The inventive mechanism of this application:

[0021] In the process of water extraction of peach gum powder, this application adds lecithin to prevent the aggregation and precipitation of linear polysaccharides in the aqueous solution, thereby dispersing them and reducing the loss of soluble polysaccharides caused by aggregation and precipitation, thus improving the yield of soluble peach gum polysaccharides.

[0022] Simultaneously, this application adds a certain amount of tea polyphenols to the soluble peach gum polysaccharide filtrate obtained after water extraction. The mechanism of action of adding tea polyphenols is as follows: on the one hand, the hydroxyl groups on the surface of the polysaccharide form a rigid structure with water, thus forming binding cavities or gaps inside the polysaccharide. Then, tea polyphenols enter the binding cavities or gaps, which is more conducive to the formation of flocculent precipitates. On the other hand, tea polyphenols containing aromatic rings and hydroxyl structures are more likely to bind with polysaccharides to form flocculent precipitates than tea polyphenols with a single aromatic ring. This application can promote the aggregation of soluble peach gum polysaccharides into clusters and thus form precipitates by adding an appropriate amount of tea polyphenols to the soluble peach gum polysaccharide filtrate. In particular, experimental data show that the soluble peach gum polysaccharide prepared by adding lecithin and tea polyphenols has excellent solubility, which is much higher than the water solubility of peach gum polysaccharides prepared by existing methods.

[0023] The beneficial effects of this application are:

[0024] 1. The method for preparing peach gum polysaccharide in this application involves adding lecithin during water extraction and tea polyphenols to the polysaccharide filtrate. On one hand, the added lecithin reduces polysaccharide aggregation during water extraction, allowing for more thorough contact between the dispersed polysaccharides and water, thus increasing the extraction rate of soluble polysaccharides. On the other hand, the tea polyphenols adsorb and precipitate the polysaccharides instead of alcohol precipitation, preventing the less soluble polysaccharide portion from entering the final product, thereby obtaining highly pure soluble peach gum polysaccharide. The soluble peach gum polysaccharide prepared in this application has a soluble polysaccharide content ≥90%, and its solubility is significantly improved. Due to its excellent solubility, its applications are effectively expanded.

[0025] 2. The preparation method in this application uses mild conditions throughout the entire preparation process, avoiding the damage to the bioactivity of peach gum polysaccharides caused by traditional high temperature, acid, alkali and ultrasonic extraction.

[0026] 3. The lecithin and tea polyphenols added in this application have wide applications in food, cosmetics and pharmaceuticals, and are highly safe with no toxic side effects.

[0027] 4. In this application, while preparing soluble peach gum polysaccharide, the adsorption and filtration liquid is added to alcohol for alcohol precipitation to obtain alcohol-precipitated peach gum polysaccharide and finally prepare conventional peach gum polysaccharide. Although the water solubility of conventional peach gum polysaccharide is far less than that of soluble peach gum polysaccharide, it can still meet some common application needs. Moreover, through this preparation method, both highly soluble soluble peach gum polysaccharide and moderately soluble conventional soluble peach gum polysaccharide can be recovered, thus making full use of resources and meeting the needs of different application scenarios. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the process flow of the present invention. Detailed Implementation

[0029] The implementation of this application will now be described in more detail with reference to the embodiments.

[0030] Example 1

[0031] A method for preparing soluble peach gum polysaccharide, the process flow is as follows: Figure 1 As shown, it includes the following steps:

[0032] S1, Water extraction: Take the pulverized peach gum powder that has passed through a 40-mesh sieve, add 0.05% lecithin by weight of the peach gum powder, mix, add water at a ratio of 40 times the weight of the peach gum powder at room temperature, stir for 120 minutes, let stand for 20 minutes, filter through a 300-mesh sieve, and keep the filtrate for later use.

[0033] S2, Adsorption: Add 2.5% by weight of peach gum powder and tea polyphenols to the filtrate, stir until flocculent matter appears, let stand and settle for 1 hour, and centrifuge to obtain the precipitate;

[0034] S3, Elution: The precipitate was eluted with alcohol containing 20 times the weight of the gum powder (92% ethanol) to remove impurities, yielding a polysaccharide precipitate.

[0035] S4, Drying: The precipitate is dried in an oven and pulverized to obtain soluble peach gum polysaccharide.

[0036] This embodiment also involves adding the adsorption and filtration liquid described in S2 to alcohol for alcohol precipitation for 4 hours to obtain alcohol-precipitated peach gum polysaccharide; specifically, during alcohol precipitation, the volume ratio of alcohol to adsorption and filtration liquid is 4:1.

[0037] The impurities in the precipitated peach gum polysaccharide were eluted using alcohol as the eluent to obtain the precipitated peach gum polysaccharide precipitate. The precipitated peach gum polysaccharide precipitate was dried and pulverized to obtain conventional peach gum polysaccharide.

[0038] Example 2

[0039] A method for preparing soluble peach gum polysaccharide includes the following steps:

[0040] S1, Water extraction: Take the pulverized peach gum powder that has passed through a 40-mesh sieve, add 0.08% lecithin by weight of the peach gum powder, mix, add water at a ratio of 35 times the weight of the peach gum powder at room temperature, stir for 240 minutes, let stand for 30 minutes, filter through a 300-mesh sieve, and keep the filtrate for later use.

[0041] S2, Adsorption: Add 3.5% by weight of peach gum powder and tea polyphenols to the filtrate, stir until flocculent matter appears, let stand and settle for 1 hour, and centrifuge to obtain the precipitate;

[0042] S3, Elution: The precipitate was eluted with alcohol containing 20 times the weight of the gum powder (92% ethanol) to remove impurities, yielding a polysaccharide precipitate.

[0043] S4, Drying: The precipitate was freeze-dried and pulverized to obtain soluble peach gum polysaccharide.

[0044] This embodiment also involves adding the adsorption and filtration liquid described in S2 to alcohol for alcohol precipitation for 4 hours to obtain alcohol-precipitated peach gum polysaccharide; specifically, during alcohol precipitation, the volume ratio of alcohol to adsorption and filtration liquid is 4:1.

[0045] The impurities in the precipitated peach gum polysaccharide were eluted using alcohol as the eluent to obtain the precipitated peach gum polysaccharide precipitate. The precipitated peach gum polysaccharide precipitate was dried and pulverized to obtain conventional peach gum polysaccharide.

[0046] Example 3

[0047] A method for preparing soluble peach gum polysaccharide includes the following steps:

[0048] S1, Water extraction: Take the pulverized peach gum powder that has passed through a 40-mesh sieve, add 0.03% lecithin by weight of the peach gum powder, mix, add water at a ratio of 30 times the weight of the peach gum powder at room temperature, stir for 480 minutes, let stand for 30 minutes, filter through a 300-mesh sieve, and keep the filtrate for later use.

[0049] S2, Adsorption: Add 1.5% by weight of peach gum powder and tea polyphenols to the filtrate, stir until flocculent matter appears, let stand and settle for 1 hour, and centrifuge to obtain the precipitate;

[0050] S3, Elution: The precipitate was eluted with alcohol containing 20 times the weight of the gum powder (92% ethanol) to remove impurities, yielding a polysaccharide precipitate.

[0051] S4, Drying: The precipitate is dried in an oven and pulverized to obtain soluble peach gum polysaccharide.

[0052] This embodiment also involves adding the adsorption and filtration liquid described in S2 to alcohol for alcohol precipitation for 4 hours to obtain alcohol-precipitated peach gum polysaccharide; specifically, during alcohol precipitation, the volume ratio of alcohol to adsorption and filtration liquid is 4:1.

[0053] The impurities in the precipitated peach gum polysaccharide were eluted using alcohol as the eluent to obtain the precipitated peach gum polysaccharide precipitate. The precipitated peach gum polysaccharide precipitate was dried and pulverized to obtain conventional peach gum polysaccharide.

[0054] Example 4

[0055] A method for preparing soluble peach gum polysaccharide includes the following steps:

[0056] S1, Water extraction: Take the pulverized peach gum powder that has passed through a 40-mesh sieve, add 0.06% lecithin by weight of the peach gum powder and mix. Then add water at room temperature at a ratio of 40 times the weight of the peach gum powder, stir for 360 minutes, let stand for 60 minutes, filter through a 300-mesh sieve, and keep the filtrate for later use.

[0057] S2, Adsorption: Add 3% by weight of peach gum powder and tea polyphenols to the filtrate, stir until flocculent matter appears, let stand and settle for 1 hour, and centrifuge to obtain the precipitate;

[0058] S3, Elution: The precipitate was eluted with alcohol containing 20 times the weight of the gum powder (92% ethanol) to remove impurities, yielding a polysaccharide precipitate.

[0059] S4, Drying: The precipitate is dried in an oven and pulverized to obtain soluble peach gum polysaccharide.

[0060] This embodiment also involves adding the adsorption and filtration liquid described in S2 to alcohol for alcohol precipitation for 4 hours to obtain alcohol-precipitated peach gum polysaccharide; specifically, during alcohol precipitation, the volume ratio of alcohol to adsorption and filtration liquid is 4:1.

[0061] The impurities in the precipitated peach gum polysaccharide were eluted using alcohol as the eluent to obtain the precipitated peach gum polysaccharide precipitate. The precipitated peach gum polysaccharide precipitate was dried and pulverized to obtain conventional peach gum polysaccharide.

[0062] Comparative Example 1

[0063] The difference between Comparative Example 1 and Example 1 is that lecithin was not added in S1, while the rest were the same (water extraction + tea polyphenols).

[0064] The yield, purity, and water solubility of the soluble peach gum polysaccharides obtained in Examples 1-4 and the comparative examples were statistically analyzed and tested. The results are shown in Table 1.

[0065] It should be noted that the detection method for the prepared soluble peach gum polysaccharide in this application adopts the 3,5-dinitrosalicylic acid DNS colorimetric method, which is well known in the art, and xylose is used as a standard for determination.

[0066] Of course, the test methods disclosed in the literature: Cai Yanqu, Dong Bilian. Study on changes in polysaccharide content, functional properties and in vitro release rate of peach gum before and after improvement [J]. Chinese Traditional and Herbal Drugs. 2021, 49(20)4809-4810. can also be used for testing.

[0067] Specifically, the solubility test method in this application is as follows: Weigh 1g of each of the soluble peach gum polysaccharides prepared in Examples 1-4 and the comparative example, place them in beakers, add 100g of pure water, heat to dissolve at (37±1)℃, centrifuge at 3500r / min for 15min, take the supernatant, vacuum dry, weigh, and calculate the solubility using the following formula (solubility% = A / W × 100, where A is the mass of the sample dissolved in water, and W is the original mass of the sample).

[0068] Table 1. Comparison of soluble polysaccharide yield, purity, and water solubility between the examples and comparative examples.

[0069]

[0070] As can be seen from the table above, the extraction of peach gum polysaccharide using the preparation method in this application can be divided into two parts. One part is to use water extraction with the addition of lecithin, followed by adsorption and precipitation with tea polyphenols to prepare highly water-soluble peach gum polysaccharide. The solubility of this soluble peach gum polysaccharide in water is extremely high, averaging over 90%, which is significantly higher than the solubility of peach gum polysaccharide prepared by the preparation method used in the prior art. As for the conventional peach gum polysaccharide prepared by adding alcohol to the adsorption liquid for alcohol precipitation, the solubility is relatively average, around 12%, but it is still higher than the solubility of almond gum mentioned in the prior art: Gao Ailing, Jin Weiwei, Chen Gongkai, et al. Discussion on the solubility characteristics of almond gum [J]. Zhejiang Agricultural Sciences, 2014(5):732-733, 739. The solubility in that literature is less than 5%. The possible reason is that the water extraction conditions in this application are relatively mild, and the extracted part has better solubility. Unlike the prior art, which uses high temperature and alkali for extraction, the poorly soluble part is not extracted as well.

[0071] Because this application divides the extraction and preparation of peach gum polysaccharides into two parts with significantly different solubility, either soluble peach gum polysaccharides or conventional peach gum polysaccharides can be selected according to specific needs. For example, when applied in the pharmaceutical or cosmetic fields, where absorption and dissolution requirements are extremely high, soluble peach gum polysaccharides with better solubility are suitable; while when used as an additive in general food products, conventional peach gum polysaccharides with moderate solubility can be selected.

[0072] The preparation method described in this application yields soluble gum polysaccharide with a high yield and high purity. In particular, the soluble gum polysaccharide prepared in this application exhibits extremely high solubility in water, averaging over 90%, significantly higher than the solubility of gum polysaccharide prepared by existing methods.

Claims

1. A method for preparing soluble peach gum polysaccharide, characterized in that, Includes the following steps: S1, Water extraction: Take the crushed peach gum powder, add 0.01%-0.1% of lecithin by weight of peach gum powder, mix, add water at room temperature, stir and mix well, perform water extraction, filter, and keep the filtrate for later use; S2, Adsorption: Add adsorbent to the filtrate, stir until flocculent matter appears, let it stand to settle, filter, and obtain precipitate and adsorption filtrate. The adsorbent is tea polyphenol. The amount of tea polyphenols added as adsorbent is 1.5%, 2.5%, 3%, or 3.5% of the weight of peach gum powder; S3, Elution: The precipitate is eluted with alcohol as the eluent to obtain a polysaccharide-containing eluted precipitate; S4, Drying: The precipitate is washed off, dried, and pulverized to obtain soluble peach gum polysaccharide.

2. The method for preparing soluble peach gum polysaccharide according to claim 1, characterized in that, It also includes the step of preparing conventional peach gum polysaccharide, specifically: adding the adsorption and filtration liquid described in S2 to alcohol for alcohol precipitation to obtain alcohol-precipitated peach gum polysaccharide; using alcohol as an eluent to elute impurities from the alcohol-precipitated peach gum polysaccharide to obtain alcohol-precipitated peach gum polysaccharide precipitate; drying and pulverizing the alcohol-precipitated peach gum polysaccharide precipitate to obtain conventional peach gum polysaccharide.

3. The method for preparing soluble peach gum polysaccharide according to claim 1, characterized in that, The peach gum powder in S1 has a purity of over 95% that passes through a 40-mesh sieve.

4. The method for preparing soluble peach gum polysaccharide according to claim 1, characterized in that, In step S1, the amount of water used during water extraction is 30-40 times the weight of the gum powder; the water extraction time is more than 120 minutes.

5. The method for preparing soluble peach gum polysaccharide according to claim 1, characterized in that, The amount of lecithin added in S1 is 0.06% of the weight of the peach gum powder.

6. The method for preparing soluble peach gum polysaccharide according to claim 1, characterized in that, In S3, the ethanol concentration of the eluent alcohol is ≥90%, and the amount of eluent alcohol used is 20 times the weight of the peach gum powder.

7. The method for preparing soluble peach gum polysaccharide according to claim 1, characterized in that, The purity of tea polyphenols in S2 is ≥95%, and the content of flavonoid tea polyphenols in the tea polyphenols is ≥50%.

8. A soluble peach gum polysaccharide prepared by the method according to any one of claims 1-7.

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