Method for green and efficient extraction of beta-glucan in barley

Abstract

The invention relates to the technical field of deep processing of plants, in particular to a method for green and efficient extraction of beta-glucan in barley. The method comprises the following steps: grinding barley into powder, adding the powder into an ethanol solution, soaking, separating and drying to obtain barley powder; performing steam explosion treatment on the barley flour, and then performing hot water extraction; after the extraction is finished, sequentially carrying out enzymolysis, enzyme deactivation and centrifugation to obtain a supernatant, and carrying out alcohol precipitation on the supernatant to obtain a precipitate; washing the precipitate, adding water for redissolving, and then carrying out rotary evaporation and freeze drying to obtain the barley beta-glucan extract; the pressure of the steam explosion treatment is 0.6 MPa, 1.2 MPa and 1.8 MPa respectively, and the explosion time is 60 seconds; the extraction temperature is 60 DEG C, and the extraction time is 120 minutes. The invention provides a method for extracting barley beta-glucan from barley, and the extraction process is efficient, green and environment-friendly.

Description

Technical Field

[0001] This invention relates to the field of plant deep processing technology, and in particular to a green and efficient method for extracting β-glucan from barley. Background Technology

[0002] Barley is a widely cultivated grain crop worldwide. In recent years, with increasing attention to dietary nutrition and health, barley has gradually become a new research hotspot in food therapy and health, and is widely used in food, animal feed, and other fields. Barley is rich in soluble dietary fiber β-glucan and is one of the important sources of β-glucan.

[0003] Barley β-glucan is mainly distributed in the endosperm and bran of barley. It is a linear polysaccharide with D-glucose linked by β-(1,3)- and β-(1,4)-glycosidic bonds and has no branched structure. Barley β-glucan has a variety of important physiological functions and health benefits, such as lowering blood lipids and controlling blood sugar, preventing cardiovascular and cerebrovascular diseases, preventing colon cancer, improving the intestinal microenvironment, and enhancing human immunity. Therefore, it is widely used in the fields of medicine and health food.

[0004] Traditional extraction methods for barley β-glucan include hot water extraction, acid-base extraction, and enzymatic hydrolysis. These methods suffer from low extraction rates and purity, as well as environmental problems. Therefore, there is a need for an extraction method for barley β-glucan that offers both high extraction rates and high purity. Summary of the Invention

[0005] Based on the above, this invention provides a green and efficient method for extracting β-glucan from barley. The method of this invention features high extraction rate, high purity, and is environmentally friendly.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] One of the technical solutions of this invention is a method for extracting β-glucan from barley, comprising the following steps:

[0008] Barley flour is obtained by grinding barley into powder, soaking it in an ethanol solution, separating and drying it.

[0009] The barley flour was subjected to steam explosion treatment, followed by hot water extraction; after the extraction was completed, the supernatant obtained by centrifugation was subjected to enzymatic hydrolysis, enzyme inactivation, and alcohol precipitation to obtain a precipitate.

[0010] The precipitate was washed, dissolved in water, then rotary evaporated and freeze-dried to obtain barley β-glucan extract.

[0011] The steam explosion treatments were performed at pressures of 0.6 MPa, 1.2 MPa, and 1.8 MPa, for a duration of 60 seconds.

[0012] The extraction temperature was 60℃ and the time was 120 min.

[0013] The second technical solution of the present invention is a barley β-glucan extract prepared according to the above method.

[0014] The present invention discloses the following technical effects:

[0015] (1) This invention provides a method for extracting barley β-glucan from barley. The extraction process is efficient, green and environmentally friendly.

[0016] (2) The yield of barley β-glucan extracted from barley using the method of the present invention is as high as 6.22%, and the extracted sugar content reaches 95%. The method of the present invention can promote the high-quality and high-efficiency production of functional polysaccharides. Detailed Implementation

[0017] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0018] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0019] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0020] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0021] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0022] Different extraction methods and conditions affect the extraction rate and purity of glucan. Current extraction methods suffer from problems such as insufficient pretreatment and pulverization, low polysaccharide release and extraction rates, unfriendly extraction solvent environments, and difficulties in separation and impurity removal. Therefore, to obtain barley β-glucan with high extraction rate and purity, a new technical solution is needed to address these issues from the aspects of pretreatment and extraction, and to establish a suitable, green, and efficient extraction method.

[0023] The first aspect of this invention provides a method for extracting β-glucan from barley, comprising the following steps:

[0024] Barley flour is obtained by soaking it in an ethanol solution, then separating and drying it.

[0025] The barley flour was subjected to steam explosion treatment, followed by hot water extraction; after the extraction was completed, the supernatant obtained by centrifugation was subjected to enzymatic hydrolysis, enzyme inactivation, and alcohol precipitation to obtain a precipitate.

[0026] The precipitate was washed, dissolved in water, then rotary evaporated and freeze-dried to obtain barley β-glucan extract.

[0027] The steam explosion treatment was carried out at pressures of 0.6 MPa, 1.2 MPa and 1.8 MPa for 60 seconds. Excessive steam explosion pressure would cause the glycosidic bonds in the dextran to break, degrading the polysaccharide molecules into small molecule sugars, reducing the molecular weight and bioactivity of the polysaccharide. When the pressure was too low, the thermodynamic effect of steam explosion was insufficient, which would shorten the extraction time and reduce the extraction efficiency.

[0028] The extraction temperature is 60℃ and the time is 120min. Too high a temperature will cause the degradation of active ingredients and increase energy consumption, while too low a temperature will reduce the molecular motion rate, reduce the contact between solvent and material, and reduce extraction efficiency.

[0029] Steam explosion has advantages such as low energy consumption, no pollution, and high efficiency. This technology is beneficial to the release of β-glucan in barley, and the release rate of β-glucan can be improved by optimizing the steam explosion conditions.

[0030] Enzymatic hydrolysis-assisted hot water extraction is beneficial for the separation and purification of polysaccharides, with high extraction efficiency and is more environmentally friendly.

[0031] The barley powder is obtained by grinding barley; in this embodiment of the invention, the particle size of the barley powder is 80 μm.

[0032] In a preferred embodiment of the present invention, the volume concentration of the ethanol solution is 80%; the ratio of barley powder to the ethanol solution is 1g:10mL; and the soaking time is 24h.

[0033] In this invention, the drying temperature is 80°C until the product is completely dried into powder.

[0034] In a preferred embodiment of the present invention, the steam explosion treatment is carried out in a steam explosion apparatus.

[0035] In a preferred embodiment of the present invention, the material-to-liquid ratio during hot water extraction is 1g:10mL.

[0036] In a preferred embodiment of the present invention, the enzymatic hydrolysis specifically involves first adding 15 μL / g of thermostable α-amylase and hydrolyzing at 95°C for 2 hours, then adding 1 μL / g of saccharifying enzyme and hydrolyzing at 60°C for 0.5 hours, and finally adding 15 mg / g of papain and hydrolyzing at 60°C for 1 hour.

[0037] The enzyme inactivation method is boiling water bath inactivation.

[0038] In a preferred embodiment of the present invention, the alcohol precipitation uses an ethanol solution with a volume concentration of 80%.

[0039] The washing process uses anhydrous ethanol.

[0040] In a preferred embodiment of the present invention, the freeze-drying temperature is -50°C, the time is 72 hours, and the vacuum value is 10-12 Pa.

[0041] The method of this invention is characterized by being green, efficient, and low-energy, and is of great significance to the development of the functional polysaccharide industry.

[0042] A second aspect of the present invention provides a barley β-glucan extract prepared according to the above method.

[0043] Unless otherwise specified, the technical solutions described in this invention are all conventional solutions in the field, and the reagents or raw materials used are all purchased from commercial channels or are publicly available unless otherwise specified.

[0044] The heat-resistant α-amylase used in the embodiments of the present invention was purchased from Shanghai Yuanye Biotechnology Co., Ltd., with an enzyme activity of 20,000 U / ml; the saccharifying enzyme was purchased from Shanghai Yuanye Biotechnology Co., Ltd., with an enzyme activity of 100,000 U / g; and the papain was purchased from Shanghai Yuanye Biotechnology Co., Ltd., with an enzyme activity of 800 U / mg.

[0045] In this invention, the extraction rate of barley β-glucan is calculated using the following formula: yield (%) = [mass of extracted glucan (g) / mass of raw material (g)] × 100%; the sugar content is determined using the phenol-sulfuric acid method.

[0046] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0047] Example 1

[0048] First, barley was ground into powder using a traditional Chinese medicine pulverizer. Then, 95% ethanol (volume fraction) was added to achieve a concentration of 80%, and the powder was soaked in alcohol for 24 hours at a material-to-liquid ratio of 1:10 (g / mL). The powder was then separated and dried completely at 80℃. The dried powder was then placed in a steam explosion apparatus and treated at a pressure of 1.2 MPa for 60 seconds before drying. Following this, hot water extraction was performed at 60℃ for 120 minutes at a material-to-liquid ratio of 1:10 (g / mL). Next, enzymatic hydrolysis was performed (the following enzymes were added sequentially: thermostable α-amylase, saccharifying enzyme, and papain; the hydrolysis conditions were set at 95℃ for 2 hours, 60℃ for 0.5 hours, and 60℃ for 1 hour, respectively). The enzymes were then inactivated by boiling water bath, and the supernatant was collected by centrifugation. 95% ethanol (volume fraction) was added to achieve an ethanol concentration of 80%, and the powder was precipitated for 12 hours. After centrifugation, the precipitate was collected, washed with anhydrous ethanol, stirred thoroughly, and then reconstituted with water. Rotary evaporation was then performed, and the extract was collected in centrifuge tubes and stored at -80°C for at least 2 hours. Following this, it was freeze-dried at -50°C for 72 hours under a vacuum of 10⁻¹² Pa. The final product was barley β-glucan extract.

[0049] In this embodiment, the yield of barley β-glucan was 6.22%, and the sugar content was 96.87%.

[0050] Comparative Example 1

[0051] The only difference from Example 1 is that the barley flour was not obtained by steam explosion; all other steps and parameters are the same as in Example 1.

[0052] In this comparative example, the extraction rate of barley β-glucan was 3.55%, and the purity was 83.11%.

[0053] Comparative Example 2

[0054] The only difference from Example 1 is that the steam explosion pressure in the steam explosion device is 0.6 MPa, while the other steps and parameters are the same as in Example 1.

[0055] In this comparative example, the extraction rate of barley β-glucan was 4.66%, and the purity was 94.84%.

[0056] Comparative Example 3

[0057] The only difference from Example 1 is that the steam explosion pressure in the steam explosion device is 1.8 MPa; all other steps and parameters are the same as in Example 1.

[0058] In this comparative example, the extraction rate of barley β-glucan was 5.02%, and the purity was 89.17%.

[0059] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for extracting β-glucan from barley, characterized in that, Includes the following steps: Barley flour is obtained by soaking it in an ethanol solution, then separating and drying it. The barley flour was subjected to steam explosion treatment, followed by hot water extraction; after the extraction was completed, the supernatant was subjected to enzymatic hydrolysis, enzyme inactivation, and centrifugation, and then precipitated with alcohol to obtain a precipitate. The precipitate was washed, dissolved in water, then rotary evaporated and freeze-dried to obtain barley β-glucan extract. The steam explosion treatments were performed at pressures of 0.6 MPa, 1.2 MPa, and 1.8 MPa, for a duration of 60 seconds. The extraction temperature was 60℃ and the time was 120 min.

2. The method for extracting β-glucan from barley according to claim 1, characterized in that, The volume concentration of the ethanol solution is 80%; the ratio of barley powder to the ethanol solution is 1g:10mL; and the soaking time is 24h.

3. The method for extracting β-glucan from barley according to claim 1, characterized in that, The steam explosion process is carried out in a steam explosion apparatus.

4. The method for extracting β-glucan from barley according to claim 1, characterized in that, The material-to-liquid ratio for hot water extraction is 1g:10mL.

5. The method for extracting β-glucan from barley according to claim 1, characterized in that, The enzymatic hydrolysis specifically involves first adding 15 μL / g of thermostable α-amylase and hydrolyzing at 95°C for 2 hours, then adding 1 μL / g of saccharifying enzyme and hydrolyzing at 60°C for 0.5 hours, followed by adding 15 mg / g of papain and hydrolyzing at 60°C for 1 hour.

6. The method for extracting β-glucan from barley according to claim 1, characterized in that, The alcohol precipitation uses an ethanol solution with a volume concentration of 80%.

7. The method for extracting β-glucan from barley according to claim 1, characterized in that, After reconstitution, the volume is reduced to 25-30 ml by rotary evaporation.

8. The method for extracting β-glucan from barley according to claim 1, characterized in that, The freeze-drying temperature is -50℃, the time is 72h, and the vacuum value is 10-12pa.

9. The barley β-glucan extract prepared by the method according to any one of claims 1-8.