JP7141774B2 - Method for preparing purified solution of poplar xylooligosaccharide, purified solution of poplar xylooligosaccharide prepared by the method, solid xylooligosaccharide and use thereof - Google Patents

Description

This application was filed with the Chinese Patent Office on April 22, 2019, and the application number is 201910324716. X, the invention title of which is “Method for Purification and Preparation of Popraxylooligosaccharides by Biological Enzymatic Synergistic Physical and Chemical Method”, the entire content of which is referred to is incorporated into this application by

TECHNICAL FIELD The present invention relates to the technical field of biological purification, in particular, a method for preparing a purified solution of poplar xylooligosaccharides by synergistic physical and chemical methods of biological enzymes, and purification of poplar xylooligosaccharides prepared thereby. It relates to liquids, solids of xylooligosaccharides and uses thereof.

In recent years, the demand for dissolving pulp in the market has increased year by year. As a product during the dissolving pulp manufacturing process, the production of pre-hydrolysis liquor is increasing day by day. In production, people usually concentrate the pre-hydrolyzate and black liquor together and combust them to generate heat. However, due to the high water content in the prehydrolyzate, the content of various hemicellulose sugars is also high, but the calorie value of various hemicellulose sugars is low, so the combustion caused hemicellulose resource wastage. With the introduction of the biorefiner concept, the use of hemicellulose sugars in the prehydrolyzate to produce high value-added products has received increasing attention and become a research hotspot for today's science and technology workers. It's becoming

During the poplar hot water pretreatment process, most of the hemicellulose and some of the lignin are depolymerized and dissolved from the lignocellulosic feedstock to form a prehydrolyzate. The organic components in the prehydrolyzate are complex, mainly xylo-oligosaccharides, xylose and lignin, but also contain small amounts of acetic acid, furfural and so on. Among them, xylo-oligosaccharides have good physical and chemical properties such as selective growth of bifidobacteria, improvement of intestinal function, lowering of blood sugar level, blood lipid level and cholesterol level. is also available. Therefore, xylo-oligosaccharides are widely used in the production of various health care functional oligosaccharide products and have received wide attention in the food and pharmaceutical industries. However, the presence of lignin and furfural in the prehydrolyzate interferes with the production of xylooligosaccharides and reduces the purity of xylooligosaccharides in the product. Therefore, the preparation of xylo-oligosaccharides requires purification of the prehydrolyzate.

At present, the conventional method for preparing xylooligosaccharides using the prehydrolyzate is to carry out the purification of the prehydrolyzate and the preparation of xylooligosaccharides step by step, that is, firstly purify the prehydrolyzate. and then the purified prehydrolyzate is used to prepare xylooligosaccharides. This method has the problems of troublesome operation, long production time and high production cost, and is not suitable for industrial production. In addition, multistage and staged treatments also cause higher sugar losses.

The present invention aims to improve the yield and purity of xylooligosaccharides and to provide a method for the purification and preparation of poplar xylooligosaccharides by bioenzymatic synergistic physical and chemical processes, which is useful for industrialization, The preparation method provided by the present invention can improve the yield and purity of xylo-oligosaccharides, is easy to operate, and is beneficial to industrialization.

To achieve the above objectives, the present invention provides the following technical solutions:
The present invention comprises the step of subjecting poplar hot water pre-hydrolyzate to sequential calcium hydroxide treatment, laccase synergistic xylanase treatment, and activated carbon adsorption treatment to obtain a purified solution of xylooligosaccharides. provided a method for the purification and preparation of poplar xylooligosaccharides by synergistic physical and chemical methods.

Preferably, before the calcium hydroxide treatment, the poplar pre-hydrolyzed hot water solution is centrifuged, the supernatant is taken and calcium hydroxide is treated, and the centrifugation speed is 4000 to 4500 rpm. , the centrifugation time is 4-6 minutes.

Preferably, said poplar hot water pre-hydrolyzate comprises a pre-hydrolyzed liquor produced by hot water pre-treatment during the manufacturing process of kraft dissolving pulp.

Preferably, the amount of calcium hydroxide added is 0.4 to 0.8 wt %, and the calcium hydroxide treatment time is 10 to 30 minutes.

Preferably, the calcium hydroxide treatment includes taking the supernatant after centrifugation, wherein said centrifugation speed is 4000-4500 rpm and said centrifugation time is 5-8 minutes.

Preferably, the specific conditions for the laccase synergistic xylanase treatment are that the amount of laccase is 1 to 2 U/g hydrolyzate, the amount of xylanase is 2 to 5 U/g hydrolyzate, and the pH value of the hydrolyzate is 4.5 to 6.5, the treatment time is 1 to 3 hours, and the treatment temperature is 45 to 55°C.

Preferably, after said laccase-synergistic xylanase treatment, the enzymatically treated material solution is treated in a boiling water bath, and the boiling water bath treatment time is 5-15 minutes.

Preferably, after the laccase-synergistic xylanase treatment, after centrifugation, the supernatant is taken to form the enzymatic hydrolysis solution, the centrifugation speed is 4000-4500 rpm, and the centrifugation time is 5-8 minutes. is.

Preferably, the amount of activated carbon used in the activated carbon adsorption treatment is 0.4-0.8 wt %, and the adsorption treatment time is 5-10 minutes.

Preferably, the adsorption treatment includes taking the supernatant after the centrifugation treatment, that is, obtaining a purified solution of xylooligosaccharides, the centrifugation speed is 4000 to 4500 rpm, and the centrifugation time is 5 ~8 minutes.

The present invention provides a purified liquid of xylo-oligosaccharide prepared by the above technical solution.

The present invention provides a solid xylo-oligosaccharide obtained by separating and purifying the xylo-oligosaccharide purified liquid.

Preferably, said purification includes performing decolorization, desalting, alcohol precipitation and drying.

The present invention further provides the use of said xylo-oligosaccharides in the preparation of solid health care functional oligosaccharide products.

The present invention comprises the step of subjecting poplar hot water pre-hydrolyzate to sequential calcium hydroxide treatment, laccase synergistic xylanase treatment and activated carbon adsorption treatment to obtain a purified solution of xylooligosaccharides. Methods for the purification and preparation of poplar xylooligosaccharides by enzymatic synergistic physical and chemical methods are provided. The present invention uses physical, chemical, and bioenzymatic synergistic methods to prepare xylooligosaccharides using techniques such as calcium hydroxide treatment, laccase synergistic xylanase treatment, and activated carbon adsorption treatment. , The purification process of the prehydrolyzate and the preparation process of xylooligosaccharides are performed at the same time, so the operation is simple, it is beneficial for industrial production, and the soluble organic substances such as lignin and furfural in the prehydrolyzate and impurities are maximized. A high-yield and high-purity xylooligosaccharide solution is prepared and obtained at the same time. The results of the example show that the method for preparing poplar xylooligosaccharide purified liquid by bioenzymatic synergistic physical and chemical methods provided by the present invention can improve the yield and purity of xylooligosaccharides. .

In the present invention, the supernatant after centrifugation of poplar pre-hydrolyzed hot water is subjected to calcium hydroxide treatment, laccase synergistic xylanase treatment, and activated carbon adsorption treatment in order to produce xylooligosaccharides. A method for preparing a purified solution of popraxylooligosaccharides by a bioenzymatic synergistic physical and chemical process was provided, comprising the step of obtaining a purified solution.

In the present invention, a poplar pre-hydrolyzed solution is treated with calcium hydroxide and then centrifuged to obtain a supernatant. In the present invention, before the treatment with calcium hydroxide, in order to remove impurities in the pre-hydrolyzed solution, the pre-hydrolyzed solution of poplar in hot water is subjected to centrifugal separation, and the supernatant is removed to obtain calcium hydroxide. The centrifugation speed is 4000-4500 rpm and the centrifugation time is 4-6 minutes. Said poplar hot water pre-hydrolysis liquid is preferably a pre-hydrolysis liquid produced by hot water pre-treatment in the manufacturing process of kraft dissolving pulp. More preferably, it is a prehydrolyzate produced by hydrothermal pretreatment in the poplar kraft dissolving pulp manufacturing process. In the present invention, the amount of calcium hydroxide to be used is preferably 0.4 to 0.8 wt %. 4-0.8:100, and before the calcium hydroxide treatment, the hot water pre-hydrolyzate of poplar is centrifuged, ie the mass ratio of calcium hydroxide to the supernatant is preferably 0.4-0.8 : 100, and the calcium hydroxide treatment time is preferably 10 to 30 minutes. Poplar, a poplar species growing rapidly in the northern hemisphere, has a short growth cycle, is easy to become a timber, and is abundant. is relatively high, which promotes the decomposition and dissolution of hemicellulose in the hot water pre-hydrolysis process and increases the content of xylose components in the pre-hydrolysis liquid. When the poplar prehydrolyzate is treated with calcium hydroxide, impurities such as lignin and furfural in the prehydrolyzate are effectively removed, and at the same time, the polyxylose main chain in the prehydrolyzate becomes more ordered. and the accessibility of the subsequent xylanase treatment process is improved, and the present invention further enhances the effectiveness of the sodium hydroxide treatment by using and controlling the amount of calcium hydroxide used to reduce complete and effective removal of some lignin and furfural, etc., while at the same time making the polyxylose main chain more ordered in the prehydrolyzate to improve the accessibility of the subsequent xylanase treatment process.

After treatment with calcium hydroxide, a supernatant is obtained by centrifugation, and in the present invention, the obtained supernatant is subjected to laccase synergistic xylanase treatment, and the laccase synergistic xylanase treatment includes the supernatant, It includes mixing laccase and xylanase and subjecting them to enzymatic treatment to obtain an enzyme-treated solution. In the present invention, the specific conditions for the laccase synergistic xylanase treatment are as follows. The pH value is 4.5-6.5, the treatment time is 1-3 hours, and the treatment temperature is 45-55°C. The amount of laccase used is 1 to 2 U/g hydrolyzate, that is, 1 to 2 U of laccase is added per 1 g of hydrolyzate, the hydrolyzate is the supernatant liquid, and the amount of xylanase used is 2 to 2. 5 U/g hydrolyzate, that is, 2-5 U of xylanase is added per 1 g of hydrolyzate, said hydrolyzate being the supernatant.

After said laccase-synergistic xylanase treatment, the present invention preferably further comprises a boiling water bath treatment for the enzyme-treated material solution, said boiling water bath treatment time being preferably 5-15 minutes, most preferably 10 minutes. is. The function of the boiling water bath treatment is to inactivate the laccase and xylanase and then use the inactivated enzymatic treatment solution for the next step. Laccase synergistic xylanase treatment can condense small-molecule lignin into high-molecular-weight lignin, which is difficult to remove even by calcium hydroxide in the prehydrolyzate, while simultaneously reducing the molecular weight of xylose in the prehydrolyzate. , can form smaller molecular weight xylooligosaccharides. Laccase effectively induces the polymerization and precipitation of small molecule lignin in the prehydrolyzate, thus lowering the lignin concentration and promoting the contact and binding of endoxylanase with the main chain of polyxylose to can be efficiently and targetedly degraded to xylooligosaccharides, and the cleaving effect of endoxylanase on polyxylose effectively reduces the molecular weight of polyxylose so that the subsequent adsorption of activated carbon on xylooligosaccharides is weakens and promotes lignin adsorption. Laccase synergistic xylanase treatment can effectively promote lignin removal while greatly increasing the content of xylo-oligosaccharides, greatly improving production efficiency and reducing production costs.

After the laccase synergistic xylanase treatment, in the present invention, preferably, the enzyme-treated material solution is centrifuged to take the supernatant so that the supernatant is subsequently treated as an enzymatic decomposition solution. The speed is preferably 4000-4500 rpm and the centrifugation time is preferably 5-8 minutes.

After obtaining the enzymatic decomposition solution, in the present invention, the enzymatic decomposition solution is subjected to activated carbon adsorption treatment and then to centrifugation to obtain a purified solution of xylo-oligosaccharides. In the present invention, the amount of activated carbon used in the activated carbon adsorption treatment is 0.4 to 0.8 wt %. The duration of the activated carbon adsorption treatment is preferably 5-10 minutes, meaning 4-0.8:100. Activated carbon treatment can further remove residual lignin in the enzymatic decomposition solution, further purify xylooligosaccharides to obtain a purified solution of xylooligosaccharides, and the present invention removes impurities by activated carbon adsorption. It is therefore beneficial to improve the purity of xylo-oligosaccharides.

After the activated carbon adsorption treatment, in the present invention, preferably, the obtained material solution is centrifuged, the supernatant is taken, the supernatant is used as a purified xylooligosaccharide solution, and the centrifugation speed is preferably The centrifugation time is preferably 5-8 minutes at 4000-4500 rpm.

The present invention provides a purified liquid of xylo-oligosaccharide prepared by the above technical solutions. Among them, the content of xylooligosaccharides with a degree of polymerization DP of 2 to 6 is 20.4 g/L. It increases by 40.6% and accounts for 66.5% of the total xylose content of the original prehydrolyzate. The purified liquid of xylo-oligosaccharide is limited to the purified liquid of the hardwood pre-hydrolyzed liquid.

The present invention provides a solid xylo-oligosaccharide obtained by separating and purifying the xylo-oligosaccharide purified liquid described above. In the present invention, the purification step preferably includes decolorization, desalting, alcohol precipitation and drying. , and those well known to those skilled in the art may be used.

The present invention also provides the application of the xylooligosaccharide purified liquid described in the above technical solution or the xylooligosaccharide solid described in the above technical solution to the preparation of health care functional oligosaccharide products.

The method for preparing poplar xylooligosaccharide purified liquid by bioenzymatic synergistic physical and chemical methods provided by the present invention together with the examples below, and the poplarxylooligosaccharide purified liquid prepared thereby, Although solid applications of xylo-oligosaccharides are described in detail, they should not be understood as limiting the scope of protection of the present invention.
Example 1

After centrifuging the poplar hot water pre-hydrolyzate, the supernatant is taken and xylooligosaccharides are prepared according to the following steps.
(1) The supernatant was treated with calcium hydroxide at room temperature. Here, the amount of calcium hydroxide is 0.6 wt%, and specifically, it means that the mass ratio of calcium hydroxide and the treatment liquid to be treated with calcium hydroxide is 0.6:100. , the processing time is 30 minutes.

(2) Centrifuge the supernatant after the treatment with calcium hydroxide, and remove the supernatant. Here, the centrifugation speed is 4500 rpm and the centrifugation time is 5 minutes.

(3) The supernatant obtained in step (2) is treated with laccase synergistic xylanase at a temperature of 55° C. and a pH of 5.5. Here, the amount of laccase used was 1 U/g hydrolyzate, the amount of xylanase used was 2 U/g hydrolyzate, and the treatment time was 2 hours.

(4) Laccase The synergistic xylanase treated solution was placed in a boiling water bath and treated for 10 minutes.

(5) After the boiling water bath treatment, the enzymatically treated solution was centrifuged and the supernatant was removed to obtain an enzymatically decomposed solution, which was treated with activated carbon at room temperature. Here, the amount of activated carbon used in the activated carbon adsorption treatment was 0.6 wt %, and the treatment time was 5 minutes.

(6) Centrifugation of the enzymatic decomposition product after the treatment with activated carbon is performed, and the supernatant is taken to obtain a purified solution of poplar xylooligosaccharide. Here, the centrifugation speed is 4500 rpm and the centrifugation time is 5 minutes.

The above supernatant is tested as follows. Dilute the above supernatant to an appropriate multiple, measure the lignin content in the supernatant by an ultraviolet spectrophotometer, use a high performance liquid chromatograph to measure the content of furfural in the supernatant, An ICS-5000 ion chromatograph is used to determine the content of xylooligosaccharides DP _2-6 and the content of total xylose in the supernatant.

The results were 83.2% lignin removal rate, 94.5% furfural removal rate, xylo-oligo The content of sugars DP _2-6 is 20.4 g/L, compared with the original pre-hydrolyzed liquid, the content of xylooligosaccharides DP _2-6 is increased by 40.6%, and the original pre-hydrolyzed accounted for 66.5% of the total xylose content of the liquor.
Comparative example 1

The difference from Example 1 is that the supernatant obtained in step (2) was treated at a temperature of 55 ° C., a pH of 5.5, a treatment time of 2 hours, and 1 U of laccase per 1 g of the supernatant. Perform a single laccase treatment at . Other steps are the same as in the first embodiment.

The results were 82.4% lignin removal rate, 94.3% furfural removal rate, xylo-oligo The content of sugars DP _{2 to 6} is 14.1 g / L, and the content of xylooligosaccharides with a degree of polymerization DP of 2 to 6 does not increase compared to the original prehydrolyzed solution, and the original prehydrolyzed solution It accounted for 45.6% of the total xylose content of the lysate.
Comparative example 2

The difference from Example 1 is that the supernatant obtained in step (2) was treated at a temperature of 55 ° C., a pH of 5.5, a treatment time of 2 hours, and under the conditions of adding 2 U of xylanase per 1 g of the supernatant. Perform a single xylanase treatment at . Other steps are the same as in the first embodiment.

As a result, according to the test, the lignin removal rate in the prehydrolyzate after being treated by the above steps (1) to (6) was 67.8%, the furfural removal rate was 94.6%, and the xylooligosaccharide DP The content of _2-6 is 20.1 g / L, compared with the original pre-hydrolyzate, the content of xylooligosaccharides DP _2-6 is increased by 38.6%, the content of the original pre-hydrolyzate It accounted for 65.6% of the total xylose content.
Example 2

After centrifuging the poplar hot water pre-hydrolyzate, the supernatant is taken and xylooligosaccharides are prepared according to the following steps.
(1) The supernatant was treated with calcium hydroxide at room temperature. Here, the amount of calcium hydroxide is 0.6 wt%, and specifically, it means that the mass ratio of calcium hydroxide and the treatment liquid to be treated with calcium hydroxide is 0.6:100. , the processing time is 20 minutes.

(2) Centrifuge the supernatant after the treatment with calcium hydroxide, and remove the supernatant. Here, the centrifugation speed is 4500 rpm and the centrifugation time is 5 minutes.

(3) The supernatant obtained in step (2) is treated with laccase synergistic xylanase at a temperature of 50° C. and a pH of 4.5. Here, the amount of laccase used was 2 U/g hydrolyzate, the amount of xylanase used was 3 U/g hydrolyzate, and the treatment time was 3 hours.

(4) Laccase The synergistic xylanase treated solution was placed in a boiling water bath and treated for 10 minutes.

(5) After the boiling water bath treatment, the enzyme-treated solution was subjected to centrifugal separation, and the supernatant was removed to obtain an enzyme-decomposed solution, which was treated with activated carbon at room temperature. Here, the amount of activated carbon used in the activated carbon adsorption treatment is 0.6 wt%, and specifically, the mass ratio of the activated carbon and the enzymatic decomposition solution is 0.6:100. means that the processing time is 10 minutes.

(6) Centrifugation of the enzymatic decomposition product after the treatment with activated carbon is performed, and the supernatant is taken to obtain a purified solution of poplar xylooligosaccharide. Here, the centrifugation speed is 4500 rpm and the centrifugation time is 5 minutes.

The results were 87.6% lignin removal, 94.7% furfural removal, xylo-oligo The content of sugar DP _2-6 is 19.1 g/L, compared with the original pre-hydrolyzate, the content of xylo-oligosaccharide DP _2-6 is increased by 31.4%, and the original pre-hydrolyzate accounted for 62.2% of the total xylose content of
Example 3

After centrifuging the poplar hot water pre-hydrolyzate, the supernatant is taken and xylooligosaccharides are prepared according to the following steps.
(1) The supernatant was treated with calcium hydroxide at room temperature. Here, the amount of calcium hydroxide used is 0.8 wt%, specifically, the mass ratio of calcium hydroxide to the supernatant is 0.8:100, and the treatment time is 10 minutes. is.

(2) Centrifuge the supernatant after the treatment with calcium hydroxide, and remove the supernatant. Here, the centrifugation speed is 4500 rpm and the centrifugation time is 5 minutes.

(3) The supernatant obtained in step (2) is treated with laccase synergistic xylanase at a temperature of 50° C. and a pH of 5.0. Here, the amount of laccase used was 2 U/g hydrolyzate, the amount of xylanase used was 2 U/g hydrolyzate, and the treatment time was 3 hours.

(4) Laccase The synergistic xylanase treated solution was placed in a boiling water bath and treated for 10 minutes.

(5) After the boiling water bath treatment, the enzyme-treated solution was subjected to centrifugal separation, and the supernatant was removed to obtain an enzyme-decomposed solution, which was treated with activated carbon at room temperature. Here, the amount of activated carbon used in the activated carbon adsorption treatment is 0.8 wt%, and specifically, the mass ratio of the activated carbon and the enzymatic decomposition solution is 0.8:100. means that the processing time is 10 minutes.

(6) Centrifugation of the enzymatic decomposition product after the treatment with activated carbon is performed, and the supernatant is taken to obtain a purified solution of poplar xylooligosaccharide. Here, the centrifugation speed is 4500 rpm and the centrifugation time is 5 minutes.

According to the test, the lignin removal rate in the original prehydrolyzate after being treated by the above steps (1) to (6) was 90.3%, the furfural removal rate was 100%, and the xylooligosaccharide DP _2-6 content is 19.5 g / L, compared with the original pre-hydrolyzate, xylooligosaccharide DP _2-6 content is increased by 34.1%, the total of the original pre-hydrolyzate accounted for 63.5% of the xylose content.
Example 4

After centrifuging the poplar hot water pre-hydrolyzate, the supernatant is taken and xylooligosaccharides are prepared according to the following steps.
(1) The supernatant was treated with calcium hydroxide at room temperature. Here, the amount of calcium hydroxide is 0.8 wt%, and specifically, it means that the mass ratio of calcium hydroxide and the treatment liquid to be treated with calcium hydroxide is 0.8:100. , the processing time is 10 minutes.

(2) Centrifuge the supernatant after the treatment with calcium hydroxide, and remove the supernatant. Here, the centrifugation speed is 4500 rpm and the centrifugation time is 5 minutes.

(3) The supernatant obtained in step (2) is treated with laccase synergistic xylanase at a temperature of 65° C. and a pH of 5.5. Here, the amount of laccase used was 2 U/g hydrolyzate, the amount of xylanase used was 1 U/g hydrolyzate, and the treatment time was 3 hours.

(4) Laccase The synergistic xylanase treated solution was placed in a boiling water bath and treated for 10 minutes.

(5) After the boiling water bath treatment, the enzyme-treated solution was subjected to centrifugal separation, and the supernatant was removed to obtain an enzyme-decomposed solution, which was treated with activated carbon at room temperature. Here, the amount of activated carbon used in the activated carbon adsorption treatment is 0.6 wt%, and specifically, the mass ratio of the activated carbon and the enzymatic decomposition solution is 0.6:100. means that the processing time is 5 minutes.

(6) Centrifugation of the enzymatic decomposition product after the treatment with activated carbon is performed, and the supernatant is taken to obtain a purified solution of poplar xylooligosaccharide. Here, the centrifugation speed is 4500 rpm and the centrifugation time is 5 minutes.

The results, according to the tests, were 82.6% lignin removal rate, 100% furfural removal rate, and xylooligosaccharide DP _2-6 content is 18.8 g / L, compared with the original pre-hydrolyzate, xylooligosaccharide DP _2-6 content is increased by 29.3%, the total of the original pre-hydrolyzate accounted for 61.3% of the xylose content.
Example 5

After centrifuging the poplar hot water pre-hydrolyzate, the supernatant is taken and xylooligosaccharides are prepared according to the following steps.
(1) The supernatant was treated with calcium hydroxide at room temperature. Here, the amount of calcium hydroxide used is 0.6 wt%, specifically, it means that the mass ratio of calcium hydroxide and the treatment solution to be treated with calcium hydroxide is 0.6:100. and the processing time is 30 minutes.

(2) Centrifuge the supernatant after the treatment with calcium hydroxide, and remove the supernatant. Here, the centrifugation speed is 4500 rpm and the centrifugation time is 5 minutes.

(3) The supernatant obtained in step (2) is treated with laccase synergistic xylanase at a temperature of 55° C. and a pH of 5.5. Here, the amount of laccase used was 1 U/g hydrolyzate, the amount of xylanase used was 4 U/g hydrolyzate, and the treatment time was 2 hours.

(4) Laccase The synergistic xylanase treated solution was placed in a boiling water bath and treated for 10 minutes.

(5) After the boiling water bath treatment, the enzyme-treated solution was subjected to centrifugal separation, and the supernatant was removed to obtain an enzyme-decomposed solution, which was treated with activated carbon at room temperature. Here, the amount of activated carbon used in the activated carbon adsorption treatment is 0.6 wt%, and specifically, the mass ratio of the activated carbon to the enzymatic decomposition solution is 0.6:100. This means that the processing time is 5 minutes.

(6) Centrifuge the enzymatic decomposition product after the treatment with activated carbon, and collect the supernatant to obtain a purified solution of poplar xylooligosaccharide. Here, the centrifugation speed is 4500 rpm and the centrifugation time is 5 minutes.

The results, according to the tests, were 82% lignin removal, 93% furfural removal, and xylo-oligosaccharides DP _{2 to 6} content was 19.3 g/L, compared with the original prehydrolyzate, xylo-oligosaccharides DP _2-6 content increased by 32.7%, total xylose content of the original prehydrolyzate accounted for 62.9% of the volume.
Example 6

After centrifuging the poplar hot water pre-hydrolyzate, the supernatant is taken and xylooligosaccharides are prepared according to the following steps.
(1) The supernatant was treated with calcium hydroxide at room temperature. Here, the amount of calcium hydroxide used is 0.8 wt%, specifically, the mass ratio of calcium hydroxide and the treatment liquid to be treated with calcium hydroxide is 0.8:100, and the treatment time is 30 minutes.

(2) Centrifuge the supernatant after the treatment with calcium hydroxide, and remove the supernatant. Here, the centrifugation speed is 4500 rpm and the centrifugation time is 5 minutes.

(3) The supernatant obtained in step (2) is treated with laccase synergistic xylanase at a temperature of 55° C. and a pH of 5.5. Here, the amount of laccase used was 1 U/g hydrolyzate, the amount of xylanase used was 5 U/g hydrolyzate, and the treatment time was 2 hours.

(4) Laccase The synergistic xylanase treated solution was placed in a boiling water bath and treated for 10 minutes.

(5) After the boiling water bath treatment, the enzyme-treated solution was subjected to centrifugal separation, and the supernatant was removed to obtain an enzyme-decomposed solution, which was treated with activated carbon at room temperature. Here, the amount of activated carbon used in the activated carbon adsorption treatment is 0.8 wt%, and specifically, the mass ratio of the activated carbon and the enzymatic decomposition solution is 0.8:100. This means that the processing time is 5 minutes.

(6) Centrifuge the enzymatic decomposition product after the treatment with activated carbon, and collect the supernatant to obtain a purified solution of poplar xylooligosaccharide. Here, the centrifugation speed is 4500 rpm and the centrifugation time is 5 minutes.

The results, according to the test, were 84.5% lignin removal rate, 100% furfural removal rate, xylooligosaccharide DP _2-6 content is 20.1 g / L, compared with the original pre-hydrolyzate, the xylooligosaccharide DP _2-6 content is increased by 38.2%, the total of the original pre-hydrolyzate accounted for 65.2% of the xylose content.
Example 7

After centrifuging the poplar hot water pre-hydrolyzate, the supernatant is taken and xylooligosaccharides are prepared according to the following steps.
(1) The supernatant was treated with calcium hydroxide at room temperature. Here, the amount of calcium hydroxide used is 0.8 wt%, specifically, it means that the mass ratio of calcium hydroxide and the treatment solution to be treated with calcium hydroxide is 0.8:100. and the processing time is 30 minutes.

(2) Centrifuge the supernatant after the treatment with calcium hydroxide, and remove the supernatant. Here, the centrifugation speed is 4500 rpm and the centrifugation time is 5 minutes.

(3) The supernatant obtained in step (2) is treated with laccase synergistic xylanase at a temperature of 55° C. and a pH of 5.5. Here, the amount of laccase used was 2 U/g hydrolyzate, the amount of xylanase used was 5 U/g hydrolyzate, and the treatment time was 3 hours.

(4) Laccase The synergistic xylanase treated solution was placed in a boiling water bath and treated for 10 minutes.

(5) After the boiling water bath treatment, the enzyme-treated solution was subjected to centrifugal separation, and the supernatant was removed to obtain an enzyme-decomposed solution, which was treated with activated carbon at room temperature. Here, the amount of activated carbon used in the activated carbon adsorption treatment is 0.8 wt%, and specifically, the mass ratio of the activated carbon and the enzymatic decomposition solution is 0.8:100. This means that the processing time is 5 minutes.

(6) Centrifuge the enzymatic decomposition product after the treatment with activated carbon, and collect the supernatant to obtain a purified solution of poplar xylooligosaccharide. Here, the centrifugation speed is 4500 rpm and the centrifugation time is 5 minutes.

According to the test, the lignin removal rate in the original prehydrolyzate after being treated by the above steps (1) to (6) was 88.7%, the furfural removal rate was 100%, and the xylooligosaccharide DP _2-6 content was 21.1 g/L, compared with the original pre-hydrolyzate, the xylo-oligosaccharide DP _2-6 content increased by 45.1%, the total of the original pre-hydrolyzate accounted for 68.8% of the xylose content.
Example 8

After centrifuging the poplar hot water pre-hydrolyzate, the supernatant is taken and xylooligosaccharides are prepared according to the following steps.
(1) The supernatant was treated with calcium hydroxide at room temperature. Here, the amount of calcium hydroxide used is 0.6 wt%, specifically, it means that the mass ratio of calcium hydroxide and the treatment solution to be treated with calcium hydroxide is 0.6:100. and the processing time is 30 minutes.

(2) Centrifuge the supernatant after the treatment with calcium hydroxide, and remove the supernatant. Here, the centrifugation speed is 4500 rpm and the centrifugation time is 5 minutes.

(3) The supernatant obtained in step (2) is treated with laccase. Here, the amount of laccase used is 1 U/g hydrolyzate, the treatment temperature is 55° C., the treatment time is 3 hours, and the pH value of the treatment solution is 5.5.

(4) The laccase-treated solution after the laccase treatment was placed in a boiling water bath and treated for 10 minutes.

(5) After the boiling water bath treatment, the laccase-treated solution was centrifuged and the supernatant was removed to obtain a laccase-decomposed solution, which was treated with activated carbon at room temperature. Here, the amount of activated carbon used in the activated carbon adsorption treatment is 0.6 wt%, and specifically, the mass ratio of the activated carbon and the laccase decomposition solution is 0.6:100. This means that the processing time is 5 minutes.

(6) Centrifuge the laccase decomposed solution after the activated carbon treatment, and take the supernatant. Here, the centrifugation speed is 4500 rpm and the centrifugation time is 5 minutes.

(7) The supernatant obtained in step (6) is treated with xylanase, wherein the amount of xylanase used is 2 U/g in the supernatant, and the hydrolyzate with the amount of xylanase used is 2 U/g, This means that 2U of xylanase is added per gram of lysate, and the hydrolyzate is the supernatant. The treatment temperature was 55° C., the treatment time was 3 hours, and the pH value of the supernatant was 5.5.

(8) The hydrolyzate after xylanase treatment was placed in a boiling water bath and treated for 10 minutes.

(9) The enzymatic hydrolyzate after the water bath treatment in step (8) is centrifuged and the supernatant is removed to obtain a purified poplar xylooligosaccharide. Here, the centrifugation speed is 4500 rpm and the centrifugation time is 5 minutes.

The results were 82.2% lignin removal rate, 94.2% furfural removal rate, xylo-oligo The content of sugar DP _2-6 is 20.3 g/L, compared with the original pre-hydrolyzate, the content of xylooligosaccharide DP _2-6 is increased by 39.6%, and the original pre-hydrolyzate accounted for 66.1% of the total xylose content of
Example 9

After centrifuging the poplar hot water pre-hydrolyzate, the supernatant is taken and xylooligosaccharides are prepared according to the following steps.
(1) The supernatant was treated with calcium hydroxide at room temperature. Here, the amount of calcium hydroxide used is 0.6 wt%, specifically, it means that the mass ratio of calcium hydroxide and the treatment solution to be treated with calcium hydroxide is 0.6:100. and a processing time of 10 minutes.

(2) Centrifuge the supernatant after the treatment with calcium hydroxide, and remove the supernatant. Here, the centrifugation speed is 4500 rpm and the centrifugation time is 5 minutes.

(3) The supernatant obtained in step (2) is treated with laccase synergistic xylanase at a temperature of 55° C. and a pH of 5.5. Here, the amount of laccase used was 0.5 U/g hydrolyzate, the amount of xylanase used was 1 U/g hydrolyzate, and the treatment time was 2 hours.

(4) Laccase The synergistic xylanase treated solution was placed in a boiling water bath and treated for 10 minutes.

(5) After the boiling water bath treatment, the laccase-treated solution was subjected to centrifugal separation, and the supernatant was removed to obtain an enzyme-decomposed solution, which was treated with activated carbon at room temperature. Here, the amount of activated carbon used in the activated carbon adsorption treatment is 0.6 wt%, and specifically, the mass ratio of the activated carbon and the enzymatic decomposition solution is 0.6:100. means that the processing time is 5 minutes.

(6) Centrifugation of the enzymatic decomposition product after the treatment with activated carbon is performed, and the supernatant is taken to obtain a purified solution of poplar xylooligosaccharides. Here, the centrifugation speed is 4500 rpm and the centrifugation time is 5 minutes.

The results were 76.5% lignin removal, 93.6% furfural removal, xylo-oligo The content of sugar DP _2-6 is 18.3 g/L, compared with the original pre-hydrolyzate, the content of xylooligosaccharide DP _2-6 is increased by 25.9%, and the original pre-hydrolyzate accounted for 59.6% of the total xylose content of

The present invention relates to a method for purifying and preparing poplar xylooligosaccharide purified liquid by bioenzymatic synergistic physical and chemical methods, and poplar xylooligosaccharide purified liquid prepared thereby, xylooligosaccharide solid and its application. According to the present invention, the purification process of poplar prehydrolyzate and the preparation process of xylooligosaccharides are simultaneously completed by comprehensive physical, chemical and biological methods, and the xylooligosaccharides of prehydrolyzate are obtained by conventional methods. Overcoming problems such as complicated manufacturing steps, complicated operations, and high manufacturing costs in the sugar preparation process, the production cycle can be greatly shortened under conditions that do not reduce the yield and purity of xylooligosaccharides. Reduced energy consumption in the process and realized high-value utilization of pre-hydrolyzed poplar hot water. The preparation method provided by the present invention can improve the yield and purity of xylose, is simple to operate, is beneficial to industrial production, and has good practical application value.

The present invention provides a process for purifying and preparing a purified solution of xylo-oligosaccharides from a prehydrolyzed solution, which is environmentally friendly and uses pharmaceuticals such as calcium hydroxide, activated carbon, laccase, and xylanase required for the process. Reagents are less polluting to the environment and there are no special requirements for equipment.

While the above examples describe the present invention in detail, they are only some of the embodiments of the present invention, rather than all of the embodiments. Based on this embodiment, other embodiments can be obtained without creativity, and all such embodiments also belong to the protection scope of the present invention.

Claims (4)

A poplar hot water pre-hydrolyzate is sequentially subjected to calcium hydroxide treatment, laccase synergistic xylanase treatment, and activated carbon adsorption treatment to obtain a purified solution of xylo-oligosaccharides ;
Before the calcium hydroxide treatment, the pre-hydrolyzed poplar hot water solution is centrifuged, and the supernatant is removed and treated with calcium hydroxide.
The centrifugation speed is 4000-4500 rpm, the centrifugation time is 4-6 minutes,
The amount of calcium hydroxide used is 0.4 to 0.8 wt%,
The calcium hydroxide treatment time is 10 to 30 minutes,
After the calcium hydroxide treatment, it includes taking the supernatant after centrifugation, the centrifugation speed is 4000-4500 rpm, the centrifugation time is 5-8 minutes,
The specific conditions for the laccase synergistic xylanase treatment are as follows: laccase used in an amount of 1 to 2 U/g hydrolyzate, xylanase used in an amount of 2 to 5 U/g in the hydrolysate, and the hydrolyzate pH value of 4. .5 to 6.5, the treatment time is 1 to 3 hours, the treatment temperature is 45 to 55 ° C.,
After said laccase synergistic xylanase treatment, the enzymatically treated material solution is subjected to centrifugation treatment and the supernatant is removed, thus obtaining an enzymatic hydrolyzate, wherein said enzymatic hydrolyzate is subjected to activated carbon adsorption treatment. death,
the centrifugation speed is 4000 to 4500 rpm;
Centrifugation time is 5 to 8 minutes,
After the adsorption treatment, the enzymatic hydrolyzate after the activated carbon treatment is centrifuged to remove the supernatant, thereby obtaining a purified xylooligosaccharide solution,
the centrifugation speed is 4000 to 4500 rpm;
The centrifugation time is 5-8 minutes
A method for preparing a purified solution of poplar xylooligosaccharides by synergistic physical and chemical methods of bioenzymes, characterized by: According to the bioenzymatic synergistic physical and chemical process of claim 1, wherein the poplar hot water prehydrolyzate includes prehydrolyzate produced by hot water pretreatment during the production of kraft dissolving pulp. A method for preparing a purified solution of poplar xylooligosaccharides. The amount of activated carbon used in the activated carbon adsorption treatment is 0.4 to 0.8 wt%,
The time of the activated carbon adsorption treatment is 5 to 10 minutes
A method for preparing a purified solution of poplar xylooligosaccharides by the synergistic physical and chemical method of biological enzymes according to claim 1 . after said laccase synergistic xylanase treatment comprising a boiling water bath treatment for the enzymatically treated material solution;
The method for preparing poplarxylooligosaccharide purified liquid by bioenzymatic synergistic physical and chemical method according to claim 1, wherein the boiling water bath treatment time is 5-15 minutes.