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CN-121975885-A - Method for preparing starch-based alpha-glucan by high-concentration starch conversion

CN121975885ACN 121975885 ACN121975885 ACN 121975885ACN-121975885-A

Abstract

The invention discloses a method for preparing starch-based alpha-glucan by converting high-concentration starch, belonging to the technical field of food industry. The invention provides a high substrate concentration conversion method of starch-based anti-digestion alpha-glucan. Aims at realizing the efficient preparation of various different starch-based anti-digestion alpha-glucans so as to promote the industrialization of products. The method comprises a starch liquefying process, a debranching process and a transglycosylation process, solves the problems of high starch viscosity and complex components under high-concentration reaction conditions, and is convenient for glycosyltransferase to efficiently modify starch so as to synthesize starch-based anti-digestion alpha-glucan with different structures and properties.

Inventors

  • BAI YUXIANG
  • LI XIAOXIAO
  • FAN RUI

Assignees

  • 江南大学

Dates

Publication Date
20260505
Application Date
20260211

Claims (10)

  1. 1. A method of preparing starch-based α -glucan, the method comprising the steps of: (1) Adding 2U/g Dry starch ~4 U/g Dry starch beta-cyclodextrin glucosyltransferase into a starch suspension for liquefaction reaction, wherein the reaction conditions are that the temperature is raised to 100 ℃ within 50-70 min, and then the temperature is kept for 30-50 min, the mass fraction (w/w) of starch in the starch suspension is 1-30%, and the temperature is reduced to 60 ℃ after the liquefaction reaction; (2) Adding pullulanase into the reaction system obtained in the step (1) for enzymolysis, wherein the addition amount of the pullulanase is 15U/g Dry starch ~25 U/g Dry starch or 45U/g Dry starch ~55 U/g Dry starch , the enzymolysis conditions are that the enzymolysis is carried out for 20-24 hours at 55-65 ℃, and the enzyme is deactivated after the enzymolysis and is cooled to 50 ℃; (3) Adding 4, 6-alpha-glucosyltransferase into the system obtained in the step (2) for reaction, wherein the addition amount of the 4, 6-alpha-glucosyltransferase is 30U/g Dry starch ~40 U/g Dry starch , the enzymolysis condition is that the enzymolysis is carried out for 20-30 hours at 45-50 ℃, the enzyme is inactivated after the enzymolysis to obtain a reactant, centrifuging the reactant, collecting supernatant, dialyzing the supernatant, and drying to obtain the starch-based alpha-glucan.
  2. 2. The method of claim 1, wherein the mass fraction of starch in the starch suspension is 20% -21%, 21% -22%, 22% -23%, 23% -24%, 24% -25%, 25% -26%, 26% -27%, 27% -28%, 28% -29% or 29% -30%.
  3. 3. The method according to claim 1 or 2, wherein in step (1), the β -cyclodextrin glucosyltransferase is derived from Alkalophilic Bacillus sp.1011; Preferably, the beta-cyclodextrin glucosyltransferase is added in an amount of 2.1 U/g Dry starch 、2.2 U/g Dry starch 、2.3 U/g Dry starch 、2.4 U/g Dry starch 、2.5 U/g Dry starch 、2.6 U/g Dry starch 、2.7 U/g Dry starch 、2.8 U/g Dry starch 、2.9 U/g Dry starch 、3.0 U/g Dry starch 、3.1 U/g Dry starch 、3.2 U/g Dry starch 、3.3 U/g Dry starch 、3.4 U/g Dry starch 、3.5 U/g Dry starch 、3.6 U/g Dry starch 、3.7 U/g Dry starch 、3.8 U/g Dry starch 、3.9 U/g Dry starch or 4.0U/g Dry starch ; Preferably, the reaction condition in the step (1) is that after heating to 50 ℃, the solution is heated from 50 ℃ to 100 ℃ in 1h, then the temperature is kept for 30min, and the temperature is reduced to 60 ℃ after the liquefaction is finished.
  4. 4. The method according to any one of claims 1 to 3, wherein in the step (2), the pullulanase is derived from Bacillus thermoleovorans US.
  5. 5. The method according to any one of claims 1 to 4, wherein in the step (2), the pullulanase is added in an amount of 15 U/g Dry starch 、16 U/g Dry starch 、17 U/g Dry starch 、18 U/g Dry starch 、19 U/g Dry starch 、20 U/g Dry starch 、21 U/g Dry starch 、22 U/g Dry starch 、23 U/g Dry starch 、24 U/g Dry starch or 25U/g Dry starch ; Preferably, in the step (2), the pullulanase is added in an amount of 45 U/g Dry starch 、46 U/g Dry starch 、47 U/g Dry starch 、48 U/g Dry starch 、49 U/g Dry starch 、40 U/g Dry starch 、41 U/g Dry starch 、42 U/g Dry starch 、43 U/g Dry starch 、44 U/g Dry starch or 45U/g Dry starch .
  6. 6. The method according to any one of claims 1 to 4, wherein the enzyme deactivation method comprises high-temperature enzyme deactivation, acid-base enzyme deactivation and ethanol enzyme deactivation; Preferably, the dialysis cut-off molecular weight is above 1000 Da; Preferably, the drying method comprises freeze drying, atmospheric drying, spray drying, drum drying or microwave drying.
  7. 7. The method according to any one of claims 1 to 6, wherein in the step (2), the enzymolysis condition is that the enzymolysis is performed at 60 ℃ and is performed at 24 h, and the boiling water bath is performed at 15 to min after the reaction is finished and the temperature is cooled to 50 ℃.
  8. 8. The method according to any one of claims 1 to 7, wherein in step (3), the 4,6- α -glucosyltransferase is derived from Limosilacto bacillus mucosae L-B or Lactobacillus reuteri 121; preferably, in the step (3), the 4, 6-alpha-glucosyltransferase is added in an amount of 30 U/g Dry starch 、31 U/g Dry starch 、32 U/g Dry starch 、33 U/g Dry starch 、34 U/g Dry starch 、35 U/g Dry starch 、36 U/g Dry starch 、37 U/g Dry starch 、38 U/g Dry starch 、39 U/g Dry starch 、40 U/g Dry starch .
  9. 9. The method according to any one of claims 1 to 8, wherein in the step (3), the condition of the enzymolysis is that the reaction is carried out at 50 ℃ 24h, and the boiling water bath is 15min after the reaction is finished.
  10. 10. The method according to any one of claims 1 to 9 or the use of starch-based α -glucan prepared by the method according to any one of claims 1 to 9 in the preparation of food, biologicals, pharmaceuticals.

Description

Method for preparing starch-based alpha-glucan by high-concentration starch conversion Technical Field The invention relates to a method for preparing starch-based alpha-glucan by converting high-concentration starch, belonging to the technical field of food industry. Background Alpha-glucan is a homotype polysaccharide formed by connecting glucose units through alpha-glycosidic bonds, and is widely found in nature. The starch-based anti-digestion alpha-glucan is a type of alpha-glucan with anti-digestion characteristics, which is synthesized by taking starch as a substrate through a specific process. Such polysaccharides have received wide attention in recent years in the fields of food science and nutrition because of their unique physiological functions and nutritional values. The digestion-resistant property of the compound can resist enzymolysis in the human digestive tract, so that the release and absorption of glucose are delayed, the prebiotic effect is exerted, the proliferation of beneficial intestinal flora is promoted, and various health benefits such as reducing blood sugar and improving lipid metabolism are possibly brought. The alpha-glucan shows rich physicochemical properties due to the structural diversity, has excellent dietary fiber and prebiotic potential, and is a functional polysaccharide with great development prospect. However, the current research on starch-based anti-digestion alpha-glucan is mainly focused on a laboratory stage, and is mostly carried out in a low-concentration starch system, and has a significant difference from a high-concentration condition in actual industrial production, so that the existing research result is difficult to directly apply to large-scale production. Therefore, there is an urgent need for a process for preparing high-yield α -glucan by efficiently converting starch, which converts starch into a deep processed product with higher nutritional value and application efficacy, so as to realize high-valued and diversified applications of starch. The invention lays a good foundation for realizing the large-scale industrialized production of the starch-based anti-digestion alpha-glucan. Disclosure of Invention In order to overcome the defects, the invention provides a high substrate concentration conversion method of starch-based anti-digestion alpha-glucan. Aims at realizing the efficient conversion of various different starch-based anti-digestion alpha-glucans so as to promote the industrialization of products. The method comprises a starch liquefying process, a debranching process and a transglycosylation process, solves the problems of high starch viscosity and complex components, and is convenient for glycosyltransferase to efficiently modify starch so as to synthesize starch-based digestion-resistant alpha-glucan with different structures and properties. The invention provides a method for preparing starch-based anti-digestion alpha-glucan by using a high-concentration substrate, which comprises the steps of liquefying starch by using liquefying enzyme, inactivating enzyme after liquefying, debranching and transglycosylating reactions are carried out on the starch step by using debranching enzyme and glycosyltransferase, inactivating enzyme and centrifuging after the reaction is finished, and obtaining a target product of starch-based anti-digestion alpha-glucan after supernatant is dialyzed and dried. The present invention also provides a method for preparing starch-based α -glucan, the method comprising the steps of: (1) And adding liquefying enzyme into the starch suspension to carry out liquefaction reaction, wherein the mass fraction (w/w) of starch in the starch suspension is 1-30%. (2) Adding debranching enzyme into the starch obtained in the step (1) to carry out debranching reaction, and then adding transglycosylase to carry out reaction to obtain the starch-based anti-digestion alpha-glucan. The present invention also provides a method for preparing starch-based alpha-glucan (starch-based anti-digestive alpha-glucan), the method comprising the steps of: (1) Adding 2U/g Dry starch ~4 U/g Dry starch beta-cyclodextrin glucosyltransferase into a starch suspension for liquefaction reaction, wherein the reaction conditions are that the temperature is raised to 100 ℃ within 50-70 min, and then the temperature is kept for 30-50 min, wherein the mass fraction (w/w) of starch in the starch suspension is 1-30%, and the temperature is reduced to 60 ℃ after the liquefaction reaction; (2) Adding pullulanase into the reaction system obtained in the step (1) for enzymolysis, wherein the addition amount of the pullulanase is 15U/g Dry starch ~25 U/g Dry starch or 45U/g Dry starch ~55 U/g Dry starch , the enzymolysis conditions are that the enzymolysis is carried out for 20-24 hours at 55-65 ℃, and the enzyme is deactivated after the enzymolysis and is cooled to 50 ℃; (3) Adding 4, 6-alpha-glucosyltransferase into the system obtained in the step (2)