CN105237647A - Method for preparing high-purity resistant dextrin by improving acidity - Google Patents

Abstract

The invention provides a method for preparing high-purity resistant dextrin by increasing acidity, comprising the following steps: using cornstarch as raw material, treating with acid, performing pyrolysis reaction at high temperature, and obtaining a crude product containing resistant dextrin, The crude product is subjected to enzymatic hydrolysis, decolorization, separation, chromatography, concentration and spray drying to obtain resistant dextrin. The invention adopts the method of increasing the acidity, and obtains high-purity resistant dextrin through high-temperature pyrolysis, which has lower pyrolysis temperature than the traditional preparation method, short reaction time, less side reactants, and saves production cost.

Description

A method for preparing high-purity resistant dextrin by increasing acidity

technical field

The invention relates to the field of starch deep processing, in particular to a preparation method of high-purity resistant dextrin.

Background technique

Dietary fiber is to maintain human health. The "seventh nutrient" that cannot be replaced by other substances. Now many developed countries have realized that the physiological role of dietary fiber is an irreplaceable function for the body, and have developed foods with multiple functions of dietary fiber, which have occupied most of the food market.

Resistant dextrin is processed from starch and belongs to water-soluble dietary fiber. Resistant dextrin has good thermal stability, low calorie value and low glycemic index, and contains glucoside structures linked by α-1,2 and α-1,3 bonds, and contains β-1, 6 structures. Therefore, it is not easy to be decomposed in the body, and can directly enter the large intestine to play its physiological role as dietary fiber.

The traditional method of preparing resistant dextrin is to carry out pyrolysis reaction at low acidity, and then obtain resistant dextrin through enzymatic purification and drying. The disadvantage of this method is that starch needs to be pretreated, the pyrolysis reaction temperature is high, and the reaction time Long, the side reaction products have complex and many components, and the cost is higher. Such as:

Chinese patent document CN104403009A (Application No. 201410671093.0) discloses a method for preparing resistant dextrin, which includes the following steps: (1) Add acid to starch, stir well to obtain acid-treated starch, and pre-dry the acid-treated starch , to obtain pre-dried starch; (2) select sea sand, mix sea sand with pre-dried starch, adjust the temperature at 170-220°C for pyrolysis reaction; (3) obtain crude pyrodextrin after the pyrolysis reaction is completed, and It is refined to obtain resistant dextrin products. The added amount of the acid is 0.02-0.2% of the mass in the starch.

Contents of the invention

The invention aims at the deficiencies of the prior art, and provides a method for preparing high-purity resistant dextrin by increasing the acidity. The technical method saves the starch pretreatment step, reduces the pyrolysis reaction temperature, shortens the pyrolysis reaction time, and reduces the production cost, and the product has a purity greater than 90%, strong thermal stability, low calorie and low glycemic index.

The technical method of the present invention is a method for preparing high-purity resistant dextrin by increasing acidity, comprising the following steps:

(1) Spray an appropriate amount of acid evenly in cornstarch, stir evenly, and let it stand for 30-60min to prepare starch acid-treated samples.

(2) The starch acid-treated sample prepared in step (1) is subjected to pyrolysis reaction at a certain temperature.

(3) After the pyrolysis reaction, the crude resistant dextrin is obtained, which is refined to obtain the pure resistant dextrin.

(4) The acid described in step (1) is preferably one of hydrochloric acid, sulfuric acid and citric acid.

(5) In step (1), the acid concentration is preferably 1-4%.

(6) In step (1), the amount of acid added is preferably 5-15%.

(7) In step (2), the pyrolysis temperature is preferably 110-180°C.

(8) In step (2), the pyrolysis reaction time is preferably 0.5-3h.

(9) During the refining process of step (3): Now dissolve the crude resistant dextrin product in water so that its mass fraction is 20-40%, and then use high-temperature α-amylase, compound glucoamylase (glucoamylase and pullulan enzyme) for enzymolysis, the amount of high temperature resistant α-amylase per ton of dry starch is preferably 2×10 ⁷ -4×10 ⁷ U, the amount of compound glucoamylase is preferably 1×10 ⁷ -2×10 ⁷ U, activated carbon The added amount is preferably 2%-6% of the total dry basis of starch, the decolorization temperature is 60-80°C, and the decolorization time is 30-70min. The ion exchange resin is preferably composed of acidic cation resin D001 and basic anion resin D330 at a ratio of 1:1. The mixed bed resin is then chromatographed, concentrated, and spray dried to obtain the resistant dextrin product.

Excellent effect of the present invention is specifically as follows:

1. On the basis of traditional technology, by increasing the acidity in starch, the pyrolysis reaction temperature is reduced, the pyrolysis reaction time is shortened, and the production cost is reduced;

2. The operation of the present invention saves the starch pretreatment step of the original process, reduces side reaction products, improves the purity of the prepared resistant dextrin product, has strong thermal stability, low calorie and low glycemic index.

detailed description

In order to better understand the content of the present invention, it will be further described below in conjunction with examples.

Enzyme reagent source:

High temperature resistant α-amylase Novozymes company enzyme activity is 20000U/ml

The enzyme activity of compound glucoamylase from Novozymes is 20000U/ml

Example 1

A method for preparing high-purity resistant dextrin by increasing acidity, comprising the following steps:

(1) Spray hydrochloric acid evenly in the cornstarch, the acid concentration is 1%, and the added amount is 15% of the total amount of dry starch, stir evenly, and let it stand for 30 minutes to prepare starch acid treated samples;

(2) The starch acid-treated sample prepared in step (1) was subjected to pyrolysis reaction at 180°C, and the pyrolysis time was 0.5h;

(3) The crude product of resistant dextrin was dissolved in water to make its mass fraction 20%, and then it was hydrolyzed by high-temperature α-amylase and compound glucoamylase (glucoamylase and pullulanase). The added amount of high temperature resistant α-amylase per ton of dry starch is preferably 2×10 ⁷ U, and the added amount of compound glucoamylase is preferably 1×10 ⁷ U. The amount of activated carbon added is preferably 2% of the total dry basis of starch, the decolorization temperature is 60°C, and the decolorization time is 30min. The ion exchange resin is preferably a mixed bed resin composed of acidic cation resin D001 and basic anion resin D330 according to the composition of 1:1. Then chromatographic, concentrated, and spray-dried to obtain a resistant dextrin product, which was detected to have a purity of 91.7%.

Example 2

A method for preparing high-purity resistant dextrin by increasing acidity, comprising the following steps:

(1) Spray sulfuric acid evenly in the cornstarch, the acid concentration is 4%, the added amount is 5% of the total amount of dry starch, stir evenly, and let it stand for 60 minutes to prepare starch acid treated samples;

(2) The starch acid-treated sample prepared in step (1) was subjected to pyrolysis reaction at 110°C, and the pyrolysis reaction time was 3 hours;

(3) The crude product of resistant dextrin was dissolved in water to make its mass fraction 40%, and then it was hydrolyzed by high-temperature α-amylase and compound glucoamylase (glucoamylase and pullulanase). The added amount of high temperature-resistant α-amylase per ton of dry starch is preferably 4×10 ⁷ U, and the added amount of compound glucoamylase is preferably 2×10 ⁷ U. The amount of activated carbon added is preferably 6% of the total dry basis of starch, the decolorization temperature is 80°C, and the decolorization time is 60min. The ion exchange resin is preferably a mixed bed resin composed of acidic cation resin D001 and basic anion resin D330 according to the composition of 1:1. Then carry out chromatography, concentrate, and spray dry to obtain the resistant dextrin product, and the purity of the resistant dextrin product obtained by detection is 96.3%.

Example 3

A method for preparing high-purity resistant dextrin by increasing acidity, comprising the following steps:

(1) Spray citric acid evenly in the cornstarch, the acid concentration is 2.5%, the added amount is 8% of the total amount of dry starch, stir evenly, and let it stand for 45min to prepare starch acid treated samples;

(2) The starch acid-treated sample prepared in step (1) was subjected to a pyrolysis reaction at 140°C, and the pyrolysis reaction time was 2 hours;

(3) The crude resistant dextrin product was dissolved in water to make its mass fraction 30%, and then it was hydrolyzed by high-temperature α-amylase and compound glucoamylase (glucoamylase and pullulanase). The added amount of high temperature-resistant α-amylase per ton of dry starch is preferably 3×10 ⁷ U, and the added amount of compound glucoamylase is preferably 1.5×10 ⁷ U. The amount of activated carbon added is preferably 4% of the total dry basis of starch, the decolorization temperature is 70°C, and the decolorization time is 50min. The ion exchange resin is preferably a mixed bed resin composed of acidic cation resin D001 and basic anion resin D330 according to the composition of 1:1. Then chromatographic, concentrated, and spray-dried to obtain a resistant dextrin product, which was detected to have a purity of 93.1%.

Claims (7)

1. a method for preparing high-purity resistant dextrin by improving acidity, is characterized in that, comprises the steps: (1) Spray an appropriate amount of acid evenly in cornstarch, stir evenly, and let it stand for 30-60min to prepare starch acid treated samples; (2) The starch acid-treated sample prepared in step (1) is subjected to a pyrolysis reaction at a certain temperature; (3) After the pyrolysis reaction, the crude resistant dextrin is obtained, which is refined to obtain the pure resistant dextrin. 2. The method according to claim 1, characterized in that, in the step (1), the acid is one of hydrochloric acid, sulfuric acid and citric acid. 3. The method according to claim 1, characterized in that, in the step (1), the acid concentration is 1-4%. 4. The method according to claim 1, characterized in that, in the step (1), the amount of acid added is 5-15%. 5. The method according to claim 1, characterized in that, in the step (2), the pyrolysis temperature is 110-180°C. 6. The method according to claim 1, characterized in that, in the step (2), the pyrolysis reaction time is 0.5-3h. 7. The method according to claim 1, characterized in that in the step (3), the refining of the resistant dextrin crude product includes enzymatic hydrolysis, decolorization, separation, chromatography, concentration, and finally spray drying to obtain the resistant dextrin Refined products.