阅读说明：本技术 一种耦合酸水解与酶水解制备低聚木糖的方法 (Method for preparing xylo-oligosaccharide by coupling acid hydrolysis and enzyme hydrolysis ) 是由 周鑫 徐勇 荆宇 许超众 埃卡拉姆·哈克 阿里·纳瓦兹 于 2020-05-22 设计创作，主要内容包括：本发明提供了一种一种耦合高温有机酸预处理与酶法制备低聚木糖的方法；其中,一种耦合酸水解与酶水解制备低聚木糖的方法,其包括,将木聚糖原料和酸混合,高温加热搅拌,降温后调节pH；加入内切型糖酶,混合后中温加热搅拌,反应结束立即进行灭酶；分离,得到低聚木糖液；所述高温加热搅拌,其搅拌速率为50～120r/min,温度为130～180℃,时间为5～30min。本发明采用耦合酸水解与酶水解两步法制备低聚木糖,可直接以富含木聚糖的木质纤维为原料直接生产低聚木糖,简化了生产过程工艺；并且低聚木糖得率高且副产品木糖少。(The invention provides a method for preparing xylo-oligosaccharide by coupling high-temperature organic acid pretreatment and an enzymatic method; the method for preparing the xylo-oligosaccharide by coupling acid hydrolysis and enzyme hydrolysis comprises the steps of mixing a xylan raw material with acid, heating and stirring at high temperature, cooling and adjusting the pH value; adding endo-carbohydrase, mixing, heating at medium temperature, stirring, and immediately inactivating enzyme after reaction; separating to obtain xylo-oligosaccharide solution; the high-temperature heating and stirring are carried out, wherein the stirring speed is 50-120 r/min, the temperature is 130-180 ℃, and the time is 5-30 min. The invention adopts a two-step method of coupling acid hydrolysis and enzyme hydrolysis to prepare the xylo-oligosaccharide, can directly produce the xylo-oligosaccharide by taking the wood fiber rich in xylan as the raw material, and simplifies the production process; and the yield of xylo-oligosaccharide is high and the byproduct xylose is less.)

1. A method for preparing xylo-oligosaccharide by coupling acid hydrolysis and enzyme hydrolysis is characterized in that: the method comprises the following steps of,

mixing xylan raw materials with acid, heating and stirring at high temperature, cooling and adjusting pH;

adding endo-carbohydrase, mixing, heating at medium temperature, stirring, and immediately inactivating enzyme after reaction;

and separating to obtain xylo-oligosaccharide solution.

2. The method for preparing xylo-oligosaccharide by coupling acid hydrolysis and enzyme hydrolysis according to claim 1, wherein: the high-temperature heating and stirring are carried out, wherein the stirring speed is 50-120 r/min, the temperature is 130-180 ℃, and the time is 5-30 min.

3. The method for preparing xylo-oligosaccharide by coupling acid hydrolysis and enzyme hydrolysis according to claim 1, wherein: the medium-temperature heating and stirring are carried out, the stirring speed is 50-120 r/min, the temperature is 50-70 ℃, and the time is 3-12 hours.

4. The method for preparing xylo-oligosaccharide by coupling acid hydrolysis and enzyme hydrolysis according to any one of claims 1 to 3, wherein: and the enzyme deactivation is to mix the materials after heating and enzymolysis to 90-100 ℃, and the enzyme deactivation time is 10-30 min.

5. The method for preparing xylo-oligosaccharide by coupling acid hydrolysis and enzyme hydrolysis according to claim 4, wherein: the acid comprises one or more of sulfuric acid, oxalic acid, maleic acid, furoic acid, xylonic acid and gluconic acid-acetic acid; the xylan raw material is a wood fiber raw material containing xylan components, and is preferably one or more of corncobs, bagasse and birch.

6. The method for preparing xylo-oligosaccharide by coupling acid hydrolysis and enzyme hydrolysis according to claim 4, wherein: according to the mass parts, the xylan raw material accounts for 1 part, and the dilute acid solution accounts for 3.5-10 parts; the mass fraction of acid concentration in the dilute acid solution is 0.1-5.0%, the endo-type carbohydrase comprises endo-xylanase, and the amount of the endo-type carbohydrase is 0.0005-0.005 part by mass relative to 1 part of xylan raw material.

7. The method for preparing xylo-oligosaccharide by coupling acid hydrolysis and enzyme hydrolysis according to claim 4, wherein: and cooling to room temperature, adjusting the pH to 4.0-6.0, and using one or more pH regulators selected from calcium carbonate, calcium hydroxide and/or sodium hydroxide.

8. The method for preparing xylo-oligosaccharide by coupling acid hydrolysis and enzyme hydrolysis according to any one of claims 5 to 7, wherein the method comprises the following steps: the heating and stirring reactions are all completed in the same heating reaction hydrolysis tank; the separation method is microfiltration or extrusion filtration.

9. Xylo-oligosaccharides produced by the process according to any one of claims 1 to 8, characterized in that: the xylo-oligosaccharide comprises one or more of xylobiose (X2) and xylotriose (X3); wherein the yield of the xylobiose (X2) and the yield of the xylotriose (X3) are respectively 20-50% and 10-30%.

10. The method for preparing xylo-oligosaccharide by coupling acid hydrolysis and enzyme hydrolysis according to claim 9, wherein: the yields of the xylobiose (X2) and the xylotriose (X3) are respectively 30-50% and 15-30%.

Technical Field

The invention belongs to the technical field of preparation of xylo-oligosaccharide, and particularly relates to a method for preparing xylo-oligosaccharide by coupling acid hydrolysis and enzyme hydrolysis.

Background

The xylo-oligosaccharide is used as a functional food or feed additive, has the characteristic of being incapable of being absorbed by a digestive system (low calorie), has high selective proliferation effect on bifidobacteria in intestinal tracts, and can indirectly activate various immune cell activities; driven by the high-speed development of the industries such as ecological big health, food safety, nonreactive animal breeding and the like, the xylo-oligosaccharide product derived from the agriculture and forestry biomass resources as a 'strongest bifidus factor/superstrong prebiotic' can remarkably promote the development of the recycling, high-valued and high-end processing and utilization industrial system of the agriculture and forestry wastes including the straws, and further promote the implementation of the 'countryside happiness' strategy in China. The current xylo-oligosaccharide production mainly adopts an endo-xylanase preparation to catalyze and hydrolyze alkali-extracted xylan, so that the purity of xylo-oligosaccharide is high, but the alkali extraction treatment process involved in the method is complex, and the wastewater pollution is serious; in addition, the acid hydrolysis method can be adopted to prepare the xylo-oligosaccharide, but mainly faces the problems of the byproduct xylose and low product quality.

Disclosure of Invention

This section is for the purpose of summarizing some aspects of embodiments of the invention and to briefly introduce some preferred embodiments. In this section, as well as in the abstract and the title of the invention of this application, simplifications or omissions may be made to avoid obscuring the purpose of the section, the abstract and the title, and such simplifications or omissions are not intended to limit the scope of the invention.

The present invention has been made in view of the above-mentioned technical drawbacks.

Therefore, as one aspect of the present invention, the present invention overcomes the disadvantages in the prior art, and provides a method for preparing xylooligosaccharide by coupling high temperature organic acid pretreatment and enzymatic method.

In order to solve the technical problems, the invention provides the following technical scheme: a method for preparing xylo-oligosaccharide by coupling acid hydrolysis and enzyme hydrolysis comprises mixing xylan raw material and acid, heating at high temperature under stirring, cooling, and adjusting pH; adding endo-carbohydrase, mixing, heating at medium temperature, stirring, and immediately inactivating enzyme after reaction; and separating to obtain xylo-oligosaccharide solution.

As a preferred embodiment of the method for preparing xylo-oligosaccharide by coupling acid hydrolysis and enzyme hydrolysis, the method comprises the following steps: the high-temperature heating and stirring are carried out, wherein the stirring speed is 50-120 r/min, the temperature is 130-180 ℃, and the time is 5-30 min.

As a preferred embodiment of the method for preparing xylo-oligosaccharide by coupling acid hydrolysis and enzyme hydrolysis, the method comprises the following steps: the medium-temperature heating and stirring are carried out, the stirring speed is 50-120 r/min, the temperature is 50-70 ℃, and the time is 3-12 hours.

As a preferred embodiment of the method for preparing xylo-oligosaccharide by coupling acid hydrolysis and enzyme hydrolysis, the method comprises the following steps: and the enzyme deactivation is to mix the materials after heating and enzymolysis to 90-100 ℃, and the enzyme deactivation time is 10-30 min.

As a preferred embodiment of the method for preparing xylo-oligosaccharide by coupling acid hydrolysis and enzyme hydrolysis, the method comprises the following steps: the acid comprises one or more of sulfuric acid, oxalic acid, maleic acid, furoic acid, xylonic acid and gluconic acid-acetic acid; the xylan raw material is a wood fiber raw material containing xylan components, and is preferably one or more of corncobs, bagasse and birch.

As a preferred embodiment of the method for preparing xylo-oligosaccharide by coupling acid hydrolysis and enzyme hydrolysis, the method comprises the following steps: according to the mass parts, the xylan raw material accounts for 1 part, and the dilute acid solution accounts for 3.5-10 parts; the mass fraction of acid concentration in the dilute acid solution is 0.1-5.0%, the endo-type carbohydrase comprises endo-xylanase, and the amount of the endo-type carbohydrase is 0.0005-0.005 part by mass relative to 1 part of xylan raw material.

As a preferred embodiment of the method for preparing xylo-oligosaccharide by coupling acid hydrolysis and enzyme hydrolysis, the method comprises the following steps: and cooling to room temperature, adjusting the pH to 4.0-6.0, and using one or more pH regulators selected from calcium carbonate, calcium hydroxide and/or sodium hydroxide.

As a preferred embodiment of the method for preparing xylo-oligosaccharide by coupling acid hydrolysis and enzyme hydrolysis, the method comprises the following steps: the heating and stirring reactions are all completed in the same heating reaction hydrolysis tank; the separation method is microfiltration or extrusion filtration.

As another aspect of the present invention, the present invention provides a xylo-oligosaccharide: the xylo-oligosaccharide comprises one or more of xylobiose (X2) and xylotriose (X3); wherein the yield of the xylobiose (X2) and the yield of the xylotriose (X3) are respectively 20-50% and 10-30%.

As a preferred embodiment of the present invention, there is provided a process for preparing xylooligosaccharide, wherein: the yields of the xylobiose (X2) and the xylotriose (X3) are respectively 30-50% and 15-30%.

The invention has the beneficial effects that:

the invention adopts a two-step method of coupling acid hydrolysis and enzyme hydrolysis to prepare the xylo-oligosaccharide, can directly produce the xylo-oligosaccharide by taking the wood fiber rich in xylan as the raw material, and simplifies the production process; and the yield of xylo-oligosaccharide is high and the byproduct xylose is less.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise. Wherein:

FIG. 1 is a flow chart of the production process in example 1.

FIG. 2 is a high performance anion exchange chromatography chromatogram of the feed solution obtained in the two hydrolysis steps of example 1.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with examples are described in detail below.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described and will be readily apparent to those of ordinary skill in the art without departing from the spirit of the present invention, and therefore the present invention is not limited to the specific embodiments disclosed below.

Furthermore, reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one implementation of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.