阅读说明：本技术 一种利用微波制备抗性糊精的方法 (Method for preparing resistant dextrin by using microwaves ) 是由 李克文 栾庆民 黄慧娜 熊小兰 张莉 冯涛 李新华 徐虹 尹郑 于 2019-12-02 设计创作，主要内容包括：本发明涉及一种利用微波制备抗性糊精的方法,包括如下步骤：(1)向淀粉干粉中加入酸溶液,搅拌均匀,制得淀粉酸处理样品；(2)淀粉酸处理样品在微波装置中进行处理,制得抗性糊精粗品；(3)将抗性糊精粗品溶解于水中,经α-耐高温淀粉酶和复合糖化酶酶解,然后经脱色、离交、纳滤、喷雾干燥制得抗性糊精糖。本发明通过采用微波法制备抗性糊精,改善了传统酸热法前处理产品受热不均的问题,提高了产品品质。同时在抗性糊精脱色工艺中采用颗粒碳柱脱色方法,摆脱了粉末活性碳仅能一次性使用、脱色后废炭中残留的物料无法回收、物料损失较大、收率降低、劳动强度大等缺点。该脱色方法使生产过程中能耗降低,从而节约了生产成本。(The invention relates to a method for preparing resistant dextrin by using microwaves, which comprises the following steps: (1) adding an acid solution into the starch dry powder, and uniformly stirring to prepare a starch acid treatment sample; (2) treating the starch acid treatment sample in a microwave device to obtain a resistant dextrin crude product; (3) dissolving the resistant dextrin crude product in water, performing enzymolysis by alpha-high temperature resistant amylase and composite saccharifying enzyme, and then performing decoloration, ion exchange, nanofiltration and spray drying to obtain the resistant dextrin sugar. The invention adopts the microwave method to prepare the resistant dextrin, thereby improving the problem that the product is heated unevenly before the traditional acid-heat method, and improving the product quality. Meanwhile, a granular carbon column decoloring method is adopted in the resistant dextrin decoloring process, so that the defects that the powdered activated carbon can be used only once, residual materials in the decolored waste carbon cannot be recovered, the material loss is large, the yield is reduced, the labor intensity is high and the like are overcome. The decoloring method reduces energy consumption in the production process, thereby saving production cost.)

1. A method for preparing resistant dextrin by using microwaves comprises the following steps:

(1) adding an acid solution with the mass of 8-15% of that of the corn starch into the corn starch, and uniformly stirring to obtain a starch acid treatment sample;

(2) adding CaCl accounting for 0.2-0.8% of the mass of the sample into the starch acid treatment sample prepared in the step (1)₂Magnetically stirring for 15-25 min, and performing microwave heating treatment to obtain a resistant dextrin crude product;

(3) dissolving the resistant dextrin crude product obtained in the step (2) in water to prepare a solution with the mass concentration of 20-40%, adjusting the pH value of the solution to 5.5-6.5, performing enzymolysis by alpha-high temperature resistant amylase and composite saccharifying enzyme, then performing decolorization, ion exchange and nanofiltration, and finally performing spray drying to obtain the resistant dextrin.

2. The method for preparing resistant dextrin by using microwave as claimed in claim 1, characterized in that the moisture content of the corn starch in the step (1) is 12-14%.

3. The method for preparing resistant dextrin by using microwave as claimed in claim 1, characterized in that the acid solution in step (1) has a mass fraction of 1-2%, and the acid is hydrochloric acid.

4. The method for preparing resistant dextrin by using microwave as claimed in claim 1, wherein the microwave heating treatment in the step (2) is performed by using NJL07-3 type microwave oven for experiment.

5. The method for preparing resistant dextrin by using microwave as claimed in claim 1, characterized in that the microwave heating treatment parameters in the step (2) are: the processing power is 200-600 w, and the heating time is 5-10 min.

6. The method for preparing resistant dextrin by using microwave as claimed in claim 1, characterized in that the addition amount of the alpha-high temperature resistant amylase in the step (3) is 1-2L per ton of corn starch.

7. The method for preparing resistant dextrin by using microwave according to claim 1, wherein the complex diastase in the step (3) is a mixture of glucoamylase and pullulanase, and the addition amount of the complex diastase is 0.5-1L per ton of corn starch.

8. The method for preparing resistant dextrin by using microwave as claimed in claim 1, wherein the reaction condition of the alpha-high temperature resistant amylase in the step (3) is 90-100 ℃, the enzyme reaction is 30-50 min, and the pH is 5.8-6.0; the reaction conditions of the composite saccharifying enzyme are 55-60 ℃, the enzyme reaction lasts for 36-48 h, and the pH value is 4.2-4.5.

9. The method for preparing resistant dextrin by using microwave as claimed in claim 1, wherein the decolorization in the step (3) is implemented by using granular carbon at 75-80 ℃, the feeding speed is 0.3-0.6 BV/h, and the concentration of the feed liquid is 30-50%; the ion exchange conditions in the step (3) are that the feeding temperature is 30-50 ℃, the conductance of the discharged material liquid is less than 100 mu s/cm, the light transmittance T440nm is more than 95%, and the pH value is 4.0-6.0.

10. The method for preparing resistant dextrin by using microwave as claimed in claim 1, characterized in that the nanofiltration is performed by a nanofiltration membrane with a molecular weight cut-off of 150-250, and the feed sugar is concentrated by 2-8%; the spray drying conditions are as follows: the inlet air temperature is 120-150 ℃, and the feeding concentration is 30-50%.

Technical Field

The invention relates to a method for preparing resistant dextrin by using microwaves, and belongs to the technical field of deep processing of starch.

Background

The resistant dextrin is also called indigestible dextrin or resistant maltodextrin, and an important product of starch deep processing is low-calorie glucan, belongs to low-molecular soluble dietary fiber, is called as the seventh major nutrient necessary for human health, and is an important auxiliary material in modern food industry. Compared with other dietary fiber products, the resistant dextrin has the excellent characteristics of good acid, heat stability, high digestion tolerance, low glycemic index, low insulin index, low calorie, caries prevention and the like.

The existing production process generally adopts various starches to be heated and decomposed at high temperature in the presence of hydrochloric acid to become pyrodextrin, the pyrodextrin is dissolved in water, and the pyrodextrin is prepared by processes of alpha-amylase hydrolysis, glucoamylase hydrolysis, decoloration, desalination, refining and the like.

Chinese patent document CN104403009A discloses a method for preparing resistant dextrin, comprising the following steps: (1) adding acid into starch, stirring to obtain acid-treated starch, and pre-drying the acid-treated starch to obtain pre-dried starch; (2) selecting sea sand, uniformly mixing the sea sand with pre-dried starch, and adjusting the temperature to 170-220 ℃ to perform pyrolysis reaction; (3) and (4) obtaining a pyrodextrin crude product after the pyrolysis reaction is finished, and refining the pyrodextrin crude product to obtain a resistant dextrin product. The addition amount of the acid is 0.02-0.2% of the mass of the starch.

Chinese patent document CN109081874A discloses a preparation method of resistant dextrin, which comprises the following steps: reacting the corn starch subjected to acidification, dispersion, heating and sieving in sequence under the conditions of preset concentration, pH value, temperature, rotating speed and catalysis to prepare dextrin; the invention adopts corn starch as raw material, carries out acid heat treatment on the starch under the condition of high temperature, and then carries out enzymolysis reaction by using complex enzyme (high temperature resistant alpha amylase and transglucosidase) to prepare the resistant dextrin.

However, the technology disclosed in the above documents still has the disadvantages that the thermal reaction of starch is not uniform in the process of charring, the starch is easy to carbonize, and the product quality is seriously influenced.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a method for preparing resistant dextrin by using microwaves.

The technical scheme of the invention is as follows:

a method for preparing resistant dextrin by using microwaves comprises the following steps:

(1) adding an acid solution with the mass of 8-15% of that of the corn starch into the corn starch, and uniformly stirring to obtain a starch acid treatment sample;

(2) adding CaCl accounting for 0.2-0.8% of the mass of the sample into the starch acid treatment sample prepared in the step (1)₂Magnetically stirring for 15-25 min, and performing microwave heating treatment to obtain a resistant dextrin crude product;

(3) and (3) dissolving the resistant dextrin crude product obtained in the step (2) in water to prepare a solution with the mass concentration of 20-40%, adjusting the pH value of the solution to 5.5-6.5, performing enzymolysis by alpha-high temperature resistant amylase and composite saccharifying enzyme, then performing decolorization, ion exchange and nanofiltration, and finally performing spray drying to obtain the resistant dextrin.

According to the invention, the water content of the corn starch in the step (1) is preferably 12-14%.

According to the invention, the mass fraction of the acid solution in the step (1) is preferably 1-2%, and the acid is hydrochloric acid.

According to the present invention, the microwave heating process in step (2) is preferably carried out using a NJL07-3 type microwave oven for experiment.

According to the invention, the microwave heating treatment parameters in the step (2) are: the processing power is 200-600 w, and the heating time is 5-10 min.

According to the invention, the addition amount of the alpha-high temperature resistant amylase in the step (3) is preferably 1-2L per ton of corn starch.

According to the invention, the composite saccharifying enzyme in the step (3) is preferably a mixture of glucoamylase and pullulanase, and the addition amount of the composite saccharifying enzyme is 0.5-1L per ton of corn starch.

According to the invention, the reaction conditions of the alpha-high temperature resistant amylase in the step (3) are preferably 90-100 ℃, the enzyme reaction is carried out for 30-50 min, and the pH value is 5.8-6.0; the reaction conditions of the composite saccharifying enzyme are 55-60 ℃, the enzyme reaction lasts for 36-48 h, and the pH value is 4.2-4.5.

According to the invention, the decolorization in the step (3) adopts granular carbon to decolorize at 75-80 ℃, the feeding speed is 0.3-0.6 BV/h, and the feed liquid concentration is 30-50%.

According to the invention, the ion exchange conditions in the step (3) are preferably that the feeding temperature is 30-50 ℃, the conductance of the discharged material liquid is less than 100 mu s/cm, the light transmittance T440nm is more than 95%, and the pH value is 4.0-6.0.

According to the invention, the nanofiltration in the step (3) is preferably performed by a nanofiltration membrane with the molecular weight cutoff of 150-250, and the sugar concentration of the feed is 2-8%.

Preferably according to the present invention, the spray drying conditions in step (3) are: the inlet air temperature is 120-150 ℃, and the feeding concentration is 30-50%.

Technical characteristics and beneficial effects of the invention

1. The resistant dextrin is prepared by adopting a microwave method, enzyme cutting sites can be influenced to a great extent by using microwave heating, the sensitivity of the starch to enzyme is improved, the property of the starch is greatly changed, the starch after microwave heating treatment has burst holes, the burst holes provide effective channels for the enzyme to enter the starch from the outside, the enzymolysis rate is improved, and the resistant dextrin which is more uniform, higher in resistant content and better in anti-digestion performance is obtained. Meanwhile, the microwave has the advantages of short heating time and high heat energy utilization rate, and the microwave also has the radiation function, so that the product is uniformly heated, and the content of the product is improved.

2. The invention adopts the granular carbon to replace the traditional powdered activated carbon to decolorize the resistant dextrin product, and overcomes the defects that the powdered activated carbon can only be used once, the residual materials in the decolorized waste carbon cannot be recovered, the material loss is large, the yield is reduced, the labor intensity is high and the like. The decoloring method reduces energy consumption in the production process, thereby saving production cost.

Detailed Description

The technical solution of the present invention is further described with reference to the following examples, but the scope of the present invention is not limited thereto.

Enzyme reagent sources:

the alpha-high temperature resistant amylase is purchased from Novoxil and has the enzyme activity of 20000U/mL.

The compound saccharifying enzyme is purchased from Novoxin, and the total enzyme activity is 20000U/mL.

The raw material sources are as follows:

the corn starch is from the starch sugar company of the middle grain of Shandong Leling, and the water content is 12-14%