Search

CN-121975882-A - Method for preparing mannooligosaccharide based on subcritical alkaline water pretreatment and biological enzyme

CN121975882ACN 121975882 ACN121975882 ACN 121975882ACN-121975882-A

Abstract

The invention provides a method for preparing mannooligosaccharide based on subcritical alkali water pretreatment and biological enzyme, which comprises the following steps of S1, uniformly mixing palm meal powder and alkali liquor, pretreating under subcritical conditions to obtain a first material, S2, carrying out enzymolysis on the first material to obtain a second material, and S3, separating and purifying the second material to obtain mannooligosaccharide. According to the invention, through subcritical alkali water pretreatment and biological enzyme, glycosidic bond fracture is directionally controlled, the yield of the prepared mannooligosaccharide is improved to 24% -28%, the target mannooligosaccharide accounts for more than or equal to 90%, the purity is up to 90% -93%, the monosaccharide content is less than or equal to 6%, and the method accords with GB/T23747-2020 standard.

Inventors

  • LIU GUOQING
  • XU BING
  • GUO PING
  • Ji Shentian

Assignees

  • 上海纽富莱生物科技有限公司

Dates

Publication Date
20260505
Application Date
20260204

Claims (10)

  1. 1. A method for preparing mannooligosaccharides based on subcritical alkaline water pretreatment and biological enzymes, which is characterized by comprising the following steps: S1, uniformly mixing palm meal powder and alkali liquor, and performing pretreatment under subcritical conditions to obtain a first material; S2, carrying out enzymolysis on the first material to obtain a second material; S3, separating and purifying the second material to obtain the mannooligosaccharide.
  2. 2. The method of claim 1, wherein the subcritical conditions include a temperature rise to 130-150 ℃ and a pressure of 5-7 mpa.
  3. 3. The method of claim 1, wherein the lye comprises any one of aqueous NaOH, aqueous KOH, and aqueous Na 2 CO 3 .
  4. 4. A method according to claim 3, wherein the lye concentration is between 0.3wt% and 0.5wt%.
  5. 5. The method of claim 4, wherein the solid-to-liquid ratio of the palm meal powder to the lye is 1 (8-12).
  6. 6. The method of claim 2, wherein the pretreatment time is 10-20 min and the stirring speed is 150-200 r/min.
  7. 7. The method of claim 1, wherein step S2 further comprises cooling to 45-60 ℃, adjusting pH to 7.0-7.5, and performing enzymolysis on the first material to obtain a second material.
  8. 8. The method of claim 1, wherein the enzymatic hydrolysis comprises adding neutral protease to the first material for a first enzymatic hydrolysis and adding a complex enzyme to the second material for a second enzymatic hydrolysis.
  9. 9. The method of claim 8, wherein the complex enzyme comprises beta-mannanase and further comprises any one of pectinase, xylanase or hemicellulase, and the addition amount of the complex enzyme is 0.8% -1.2% of the dry weight of the palm meal powder.
  10. 10. The method of claim 2, wherein the subcritical conditions further comprise passing an inert atmosphere.

Description

Method for preparing mannooligosaccharide based on subcritical alkaline water pretreatment and biological enzyme Technical Field The invention relates to the technical field of plant extraction, in particular to a method for preparing mannooligosaccharide based on subcritical alkaline water pretreatment and biological enzyme. Background With the implementation of global 'forbidden' technology (such as the full forbidden antibiotics as feed additives in 2006 in European Union, the implementation of 'drug feed additive exit catalogue' in China 2020), the green feed additive replacing antibiotics becomes the core requirement of the livestock and poultry raising industry. The mannooligosaccharides (Mannooligosaccharides, MOS) are taken as typical functional oligosaccharides, and can realize the functions of regulating intestinal microecological balance, improving animal immunity and reducing emission of culture pollutants by competitively combining intestinal pathogens (such as escherichia coli and salmonella) and promoting proliferation of probiotics (such as lactobacillus and bifidobacterium), and the global market demand of 2025 is estimated to reach 58 ten thousand tons, and the annual growth rate is over 18 percent. However, the existing mannooligosaccharide preparation has the bottleneck of high raw material cost, namely, the main stream process takes yeast cell walls (8000-10000 yuan per ton) and konjaku flour (6000-8000 yuan per ton) as raw materials, so that the unit price of the finished product is as high as 2.5-3 ten thousand yuan per ton, which is difficult for medium and small breeding enterprises to bear. Thus, there is a strong need in the industry for low cost, high yield alternatives to raw materials. Palm meal is a byproduct of palm oil processing, annual output of over 4000 ten thousand tons (indonesia, malaysia output of over 80%) worldwide, raw material cost is only 800-1600 yuan/ton, and chemical composition has significant advantages: the content of mannans is high, wherein the mannans in the palm meal account for 35-40 percent (dry basis) of the total amount of carbohydrate, and the linear structure connected by beta-1, 4 glycosidic bonds is taken as the main material, so that the mannans are ideal substrates for preparing mannans, the impurity content is low, the crude fiber content is 18-22 percent, the crude protein content is 14-16 percent, and toxic and harmful components (such as gossypol and trypsin inhibitor) are not needed, and complex detoxification treatment is not needed; the resource utilization rate is low, more than 80 percent of the current palm meal is directly used as coarse fodder, the added value is only 800-1000 yuan/ton, and the problem of serious waste of high-value components exists. However, the structural characteristics of palm meal bring great challenges to the preparation of the mannooligosaccharide, wherein the cell wall of the mannooligosaccharide is of a three-dimensional cross-linked structure of lignin-cellulose-mannooligosaccharide (lignin content is 13.6% -15.2%), fiber particles are of a gravel shape, and the dense structure causes that enzyme preparations and chemical reagents are difficult to permeate, so that the conventional process cannot be efficiently disassembled, and becomes a core bottleneck for restricting the high-value utilization of the mannooligosaccharide. In the prior art, the mannooligosaccharide is prepared from palm meal, and the problems of low efficiency, long production period, high cost, low yield and purity of the prepared mannooligosaccharide, severe excessive degradation, serious pollution in the production process and high post-treatment cost exist. Disclosure of Invention In view of the above, the present invention provides a method for preparing mannooligosaccharides based on subcritical alkaline water pretreatment and biological enzymes. Through subcritical alkali water pretreatment and biological enzyme, cellulose and lignin are destroyed, glycosidic bond breakage is directionally controlled, the yield of the finally prepared mannooligosaccharide is improved to 24% -28%, the target mannooligosaccharide accounts for more than or equal to 90%, the purity is 90% -93%, the monosaccharide content is less than or equal to 6%, and the standard of GB/T23747-2020 is met. The technical scheme of the invention is realized as follows: The invention provides a method for preparing mannooligosaccharide based on subcritical alkali water pretreatment and biological enzyme, which comprises the following steps of S1, uniformly mixing palm meal powder and alkali liquor, and carrying out pretreatment under subcritical conditions to obtain a first material; S2, carrying out enzymolysis on the first material to obtain a second material; S3, separating and purifying the second material to obtain the mannooligosaccharide. In the three-dimensional cross-linked structure of the lignin-cellulose-mannite of the palm meal, lignin exists in a form