Method for extracting polysaccharide from pomace of sorbus pomace

Abstract

The invention discloses a method for extracting polysaccharide from pomace of sorbus pomace, and belongs to the technical field of separation of active ingredients of natural products. The method comprises the following steps: drying, crushing and sieving sorbus pomace, putting the sorbus pomace into an extraction kettle, pumping water into the extraction kettle, carrying out subcritical extraction for 10-50 minutes, cooling, carrying out solid-liquid separation, deproteinizing with trichloroacetic acid, centrifuging, precipitating supernate with ethanol, collecting the precipitate, and freeze-drying to obtain the sorbus pomace polysaccharide. The extraction yield of the sorbus pomace polysaccharide is high, the energy consumption is low, the process is clean and environment-friendly, the process is simple, and the structure and function research of the sorbus pomace polysaccharide and the development of high-added-value products of the sorbus pomace polysaccharide are more convenient.

Description

Technical Field

[0001] The invention relates to the technical field of separation of active components of natural products, and more particularly to a method for extracting polysaccharides from Sorbus sylvestris pomace. Background Art

[0002] The mountain ash tree (Sorbus pohuashanensis) is a deciduous small tree of the genus Sorbus, subfamily Maloideae, Rosaceae. It is also known as the hundred-flower mountain ash and is a native tree species unique to my country. It is distributed in Heilongjiang, Jilin, Liaoning, Inner Mongolia, Hebei, Shanxi, Gansu, Shandong and other places in my country. It has been planted as a street tree in Northeast my country and shows good adaptability. It is an important ornamental foliage, flowering and fruiting tree species with extremely high garden and ecological value.

[0003] The fruit of the mountain ash tree is called "mountain ash fruit", which contains a variety of vitamins, sugars, citric acid, etc. Eating it in moderation can help the body supplement nutrition and promote the body's metabolism. Mountain ash fruit can be eaten raw, but because fresh fruit is not easy to preserve and store, it is often made into jam, fruit vinegar, fruit wine, fruit cake, jelly, juice, candied fruit or dry powder. Mountain ash pomace is the remaining solid part of mountain ash fruit after processing, including pulp, peel and seeds, which still contain more active ingredients such as polysaccharides and anthocyanins. Improving the comprehensive utilization of mountain ash pomace can not only obtain effective active ingredients, but also avoid waste of resources and unnecessary pollution. Therefore, research on the utilization of mountain ash pomace has important practical application significance.

[0004] The existing extraction processes of polysaccharides from mountain ash fruit mainly include: traditional hot water extraction, dilute acid (alkali) extraction, enzymatic extraction, ultrasonic-assisted extraction, enzyme method, etc. However, the above methods have the disadvantages of long cycle, low extraction rate, and large loss of effective ingredients. Summary of the invention

[0005] In view of the above problems, the present invention provides a method for extracting polysaccharides from shandong ...

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A method for extracting polysaccharides from Sorbus sylvestris pomace comprises the following steps:

[0008] (1) drying the ash pomace, crushing and sieving it, and then placing it into an extraction kettle, pumping water with a pH of 6.0 into it according to the water-to-material ratio, performing subcritical water extraction for 10-50 minutes, and cooling it to room temperature to obtain an extract containing ash pomace polysaccharides;

[0009] (2) After solid-liquid separation of the extract obtained in step (1), the supernatant was concentrated under reduced pressure to 10% of the original volume, trichloroacetic acid was added to a final concentration of 8%-12% (w / v), and the protein precipitate was removed by centrifugation. The protein removal operation was repeated 3 times;

[0010] (3) adding anhydrous ethanol to a final concentration of 60%-80% (v / v) to the supernatant after protein removal in step (2) for alcohol precipitation, collecting the precipitate by filtration, and freeze-drying to obtain the shanya pomace polysaccharide.

[0011] Using weakly acidic water with a pH value of 6 as an extraction solvent to extract polysaccharides from Sorbus australis pomace can help maintain the macromolecular properties and extraction yield of the polysaccharides while having little effect on the biological activity of the polysaccharides.

[0012] Preferably, the moisture content of the drying in step (1) is less than 5%; the size of the crushing is 60-70 mesh. Coarse powder will affect its contact with the extraction solvent, and finer powder is conducive to extraction, such as powder with a fineness of 60-70 mesh; but finer powder reduces the ease of operation during solid-liquid separation.

[0013] Preferably, the solid-liquid ratio in step (1) is 1g:7-10ml. The solid-liquid ratio of the extract has a significant impact on the extraction efficiency. Too high a water content may dilute the extract, reducing the polysaccharide concentration, thereby affecting the extraction efficiency and increasing the energy consumption and time of the subsequent concentration step; too low a water content may cause the polysaccharides in the pomace to be tightly bound to the solid matter, limiting the release of the polysaccharides and making it difficult to effectively extract them.

[0014] Preferably, the conditions of the subcritical extraction in step (1) are: pressure of 5-20 MPa, extraction temperature of 100-150° C., and extraction time of 10-50 min.

[0015] By controlling the temperature and pressure of water, the polarity, surface tension and viscosity of water can be changed, thereby increasing its solubility in moderately acute or non-polar substances, and then selectively classifying and extracting them. The subcritical water obtained by high temperature and high pressure treatment in the above-mentioned specific range has better dissolution performance for mountain ash pomace polysaccharides.

[0016] Preferably, the solid-liquid separation in step (2) is carried out by filtration or centrifugation, which does not affect the extraction rate of polysaccharides.

[0017] Preferably, the centrifugation in step (2) is: centrifugation at 3500-4000 g / min for 8-10 min.

[0018] Preferably, the alcohol precipitation condition in step (3) is: standing at 4-10°C for 8-12h. A high alcohol precipitation temperature may increase the extraction yield, but it may affect the structure and moisture content of the polysaccharide, and thus may affect its biological activity. The antioxidant activity of the polysaccharide extracted from the fruit residue of Sorbus arborescens is highly sensitive to the alcohol precipitation temperature, so it is set to 4-10°C.

[0019] Preferably, the freeze drying in step (3) is: drying at -30°C for 8-10 hours. Freeze drying is beneficial to maintaining the activity and antioxidant properties of the polysaccharide.

[0020] Another object of the present invention is to provide the Sorbus australis pomace polysaccharide obtained by the above method.

[0021] Another object of the present invention is to provide the use of the above-mentioned Sorbus elata pomace polysaccharide in the preparation of food or medicine.

[0022] Through the above technical scheme, it can be known that the present invention discloses a method for extracting polysaccharides from Sorbus affine pomace. The extraction rate of polysaccharides from Sorbus affine pomace is >5%, which is much higher than the extraction rate of traditional hot water extraction method and ultrasonic method; subcritical water obtained by high temperature and high pressure treatment within a specific range has better dissolution performance for Sorbus affine pomace polysaccharides, and the extraction time is generally 10-50 minutes; subcritical water extraction uses water as the extraction solvent, which will not pollute the environment; the process is simple, the energy consumption is low, and it is suitable for large-scale promotion. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] The reagents involved in the embodiments of the present invention are all purchased from commercial channels, and the methods not mentioned are conventional experimental methods and will not be described in detail here.

[0025] Example 1

[0026] The fruit pomace of Sorbus affine is dried to a moisture content of less than 5%, crushed and passed through a 60-mesh sieve, and then 100 g is put into an extraction kettle, and 700 ml of water with a pH of 6.0 is pumped into the extraction kettle. The pressure in the extraction kettle is controlled to be 5 MPa and the temperature is 150° C. After extraction for 50 min, the mixture is cooled to room temperature; centrifuged at 3500 g / min for 8 min, the supernatant is collected and concentrated under reduced pressure to 1 / 8 of the original volume, trichloroacetic acid is added to a final concentration of 8% (w / v), and the protein precipitate is removed by centrifugation at 4000 g / min for 10 min. After the supernatant is deproteinized 3 times, anhydrous ethanol is added to the supernatant to a final concentration of 60% (v / v), the mixture is allowed to stand at 4° C. for 12 h, the precipitate is collected by filtration, and freeze-dried at -30° C. for 8 h to obtain a polysaccharide powder of Sorbus affine. The calculated extraction yield is 5.1%.

[0027] Example 2

[0028] The fruit pomace of Sorbus affine is dried to a moisture content of less than 5%, crushed and passed through a 70-mesh sieve, and then 100 g is put into an extraction kettle, and 800 ml of water with a pH of 6.0 is pumped into the extraction kettle. The pressure in the extraction kettle is controlled to be 8 MPa and the temperature is 160° C. After extraction for 40 minutes, the mixture is cooled to room temperature; centrifuged at 3500 g / min for 8 minutes, the supernatant is collected and concentrated under reduced pressure to 1 / 8 of the original volume, trichloroacetic acid is added to a final concentration of 9% (w / v), and the protein precipitate is removed by centrifugation at 4000 g / min for 10 minutes. After the supernatant is deproteinized 3 times, anhydrous ethanol is added to a final concentration of 60% (v / v), the mixture is allowed to stand at 6° C. for 10 hours, the precipitate is collected by filtration, and freeze-dried at -30° C. for 9 hours to obtain a polysaccharide powder of Sorbus affine. The calculated extraction yield is 5.6%.

[0029] Example 3

[0030] The ash pomace is dried to a moisture content of less than 5%, crushed and passed through a 70-mesh sieve, and then 100 g is put into an extraction kettle, and 900 ml of water with a pH of 6.0 is pumped into the extraction kettle. The pressure in the extraction kettle is controlled to be 10 MPa and the temperature is 170° C. After extraction for 30 minutes, the mixture is cooled to room temperature; centrifuged at 3500 g / min for 8 minutes, the supernatant is collected and concentrated under reduced pressure to 1 / 8 of the original volume, trichloroacetic acid is added to a final concentration of 10% (w / v), and the protein precipitate is removed by centrifugation at 4000 g / min for 10 minutes. After the supernatant is deproteinized 3 times, anhydrous ethanol is added to a final concentration of 70% (v / v), the mixture is allowed to stand at 8° C. for 8 hours, the precipitate is collected by filtration, and freeze-dried at -30° C. for 8 hours to obtain ash pomace polysaccharide powder, and the calculated extraction yield is 5.8%.

[0031] Example 4

[0032] The fruit pomace of Sorbus affine is dried to a moisture content of less than 5%, crushed and passed through a 70-mesh sieve, and then 100 g is put into an extraction kettle, and 1000 ml of water with a pH value of 6.0 is pumped into the extraction kettle. The pressure in the extraction kettle is controlled to be 12 MPa and the temperature is 180° C. After extraction for 20 min, the mixture is cooled to room temperature; centrifuged at 3500 g / min for 8 min, the supernatant is collected and concentrated under reduced pressure to 1 / 8 of the original volume, trichloroacetic acid is added to a final concentration of 12% (m / v), and the protein precipitate is removed by centrifugation at 4000 g / min for 10 min. After the supernatant is deproteinized 3 times, anhydrous ethanol is added to a final concentration of 65% (v / v), the mixture is allowed to stand at 10° C. for 8 h, the precipitate is collected by filtration, and freeze-dried at -30° C. for 10 h to obtain a polysaccharide powder of Sorbus affine. The calculated extraction yield is 5.3%.

[0033] Example 5

[0034] Comparison of extraction rates of different extraction processes

[0035] 1. Subcritical water extraction of polysaccharides from Sorbus oleifera pomace

[0036] The fruit pomace of Sorbus affine is dried to a moisture content of less than 5%, crushed and passed through a 70-mesh sieve, and then 100 g is put into an extraction kettle, and 900 ml of water with a pH value of 6.0 is pumped into the extraction kettle. The pressure in the extraction kettle is controlled to be 10 MPa and the temperature is 170° C. After extraction for 40 min, the mixture is cooled to room temperature; centrifuged at 3500 g / min for 8 min, the supernatant is collected and concentrated under reduced pressure to 1 / 8 of the original volume, trichloroacetic acid is added to a final concentration of 10% (m / v), and the protein precipitate is removed by centrifugation at 4000 g / min for 10 min. After the supernatant is deproteinized 3 times, anhydrous ethanol is added to a final concentration of 70% (v / v), the mixture is allowed to stand at 6° C. for 10 h, the precipitate is collected by filtration, and freeze-dried at -30° C. for 10 h to obtain a polysaccharide powder of Sorbus affine. The calculated extraction yield is 5.7%.

[0037] 2. Extraction of polysaccharides from Sorbus sylvestris pomace by hot water extraction

[0038] The fruit pomace of Sorbus ovata is dried to a moisture content of <5%, crushed and passed through a 70-mesh sieve, 100 g is taken and added to 900 ml of distilled water with a pH of 6.0, extracted at 90° C. for 6 hours, and then cooled to room temperature; centrifuged at 3500 g / min for 8 minutes, the supernatant is collected and concentrated under reduced pressure to 1 / 8 of the original volume, trichloroacetic acid is added to its final concentration of 10% (m / v), and the protein precipitate is removed by centrifugation at 4000 g / min for 10 minutes. After the supernatant is deproteinized 3 times, anhydrous ethanol is added to its final concentration of 70% (v / v), and the supernatant is allowed to stand at 6° C. for 10 hours, the precipitate is collected by filtration, and freeze-dried at -30° C. for 10 hours to obtain the polysaccharide powder of Sorbus ovata fruit pomace, and the calculated extraction yield is 2.5%.

[0039] 3. Ultrasonic extraction of polysaccharides from Sorbus sylvestris fruit residue

[0040] The fruit pomace of Sorbus ovata is dried to a moisture content of <5%, crushed and passed through a 70-mesh sieve, 100 g is added to 900 ml of distilled water with a pH of 6.0, and ultrasonic-assisted extraction is performed at 500 W and 60° C. for 40 min, and then cooled to room temperature; centrifuged at 3500 g / min for 8 min, the supernatant is collected and concentrated under reduced pressure to 1 / 8 of the original volume, trichloroacetic acid is added to a final concentration of 10% (m / v), and the protein precipitate is removed by centrifugation at 4000 g / min for 10 min. After the supernatant is deproteinized 3 times, anhydrous ethanol is added to a final concentration of 70% (v / v), and the supernatant is allowed to stand at 6° C. for 10 h, the precipitate is collected by filtration, and freeze-dried at -30° C. for 10 h to obtain the polysaccharide powder of Sorbus ovata fruit pomace, and the calculated extraction yield is 3.3%.

[0041]

[0042] As shown in Table 1, the extraction rate of polysaccharides from Sorbus affine pomace obtained by the subcritical water extraction process of the present invention is higher than the extraction rate of polysaccharides from Sorbus affine pomace obtained by the hot water extraction method and the ultrasonic method.

[0043] Example 6 Comparison of antioxidant properties of polysaccharides from Sorbus serrata pomace obtained by different extraction processes

[0044] A certain amount of DPPH was weighed and prepared into a 0.04 mg / mL DPPH solution with anhydrous ethanol. 10 g of the polysaccharide powder obtained by the three extraction processes in Example 5 was added to 1000 mL of anhydrous ethanol to obtain a 10 mg / mL diluted sample solution. 2 mL of each was added to 2 mL of DPPH solution, mixed evenly, reacted at room temperature for 30 minutes, and the absorbance value A was measured at 517 nm. i .

[0045] Simultaneously measure the absorbance A of 2mL DPPH solution + 2mL anhydrous ethanol 0 Absorbance A after mixing with 2mL sample solution + 2mL anhydrous ethanol j The measurement was repeated twice. The scavenging rate of the sample for DPPH free radicals was calculated using the following formula: The experimental results are shown in Table 2.

[0046] DPPH free radical scavenging rate = (A 0 -A j +A i ) / A 0 ×100%.

[0047] The higher the DPPH free radical scavenging rate, the stronger the antioxidant capacity, and vice versa.

[0048]

[0049] As can be seen from Table 2, the DPPH radical scavenging rate of the Sorbus elata pomace polysaccharide obtained by the subcritical water extraction process of the present invention is higher than the DPPH radical scavenging rate of the Sorbus elata pomace polysaccharide extracted by hot water extraction and ultrasonic extraction, indicating that the extraction method of the present invention can better protect the antioxidant activity of the Sorbus elata pomace polysaccharide.

[0050] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the embodiments can be referred to each other. The above description of the disclosed embodiments enables professionals and technicians in this field to implement or use the present invention. Various modifications to these embodiments will be obvious to professionals and technicians in this field, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown in this article, but will comply with the widest range consistent with the principles and novel features disclosed herein.

Claims

1. A method for extracting polysaccharides from Sorbus sylvestris pomace, characterized in that: The following steps are involved: (1) drying the ash pomace, crushing and sieving it, and then placing it into an extraction kettle, pumping water with a pH of 6.0 into it according to the solid-liquid ratio, performing subcritical water extraction, and cooling it to room temperature to obtain an extract containing ash pomace polysaccharide; (2) After solid-liquid separation of the extract obtained in step (1), the supernatant was concentrated under reduced pressure to 1 / 8 of the original volume, trichloroacetic acid was added to a final concentration of 8%-12% (w / v), and the protein precipitate was removed by centrifugation. The protein removal operation was repeated 3 times; (3) adding anhydrous ethanol to a final concentration of 60%-80% (v / v) to the supernatant after protein removal in step (2) for alcohol precipitation, collecting the precipitate by filtration, and freeze-drying to obtain the Sorbus elata pomace polysaccharide.

2. The method for extracting polysaccharides from Sorbus sylvestris pomace according to claim 1, characterized in that: The moisture content of the drying in step (1) is less than 5%; The size of the crushed powder is 60-70 mesh.

3. The method for extracting polysaccharides from Sorbus affine pomace according to claim 1 or 2, characterized in that: In step (1), the solid-liquid ratio is 1g:7-10ml.

4. The method for extracting polysaccharides from Sorbus affine pomace according to claim 3, characterized in that: The conditions of the subcritical extraction in step (1) are: pressure of 5-12 MPa, extraction temperature of 150-180° C., and extraction time of 10-50 min.

5. The method for extracting polysaccharides from Sorbus affine pomace according to claim 1, characterized in that: The solid-liquid separation method in step (2) is filtration or centrifugation.

6. The method for extracting polysaccharides from Sorbus affine pomace according to claim 1 or 5, characterized in that: The centrifugation in step (2) is: centrifugation at 3500-4000 g / min for 8-10 min.

7. The method for extracting polysaccharides from Sorbus affine pomace according to claim 1, characterized in that: The conditions for the alcohol precipitation in step (3) are: standing at 4-10°C for 8-12 hours.

8. The method for extracting polysaccharides from Sorbus affine pomace according to claim 1 or 7, characterized in that: The freeze drying in step (3) is: drying at -30°C for 8-10 hours.

9. A polysaccharide from Sorbus elata pomace obtained by the method according to any one of claims 1 to 8.

10. Use of the Sorbus elata pomace polysaccharide according to claim 9 in preparing food or medicine.

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