阅读说明：本技术 一种淀粉及其制品α-化程度的检测方法 (Method for detecting alpha-conversion degree of starch and product thereof ) 是由 王洪江 桂军强 王章丽 向俊宪 于 2020-06-19 设计创作，主要内容包括：本发明公开了一种淀粉及其制品α-化程度的检测方法,包括：(1)将至少两种已知α-化程度的淀粉产品分别配制成浓度相同的分散液,所述分散液的质量分数为0.4％～4％；(2)取同等质量的分散液样品,以相同条件固液分离后测定沉淀体积；(3)α-化程度与沉淀体积满足如下线性方程式：A＝aV+b,A为α-化程度,V为沉淀体积,a、b为参数；将测定的至少两组沉淀体积及对应的α-化程度与上述线性方程式结合,计算参数a和b,得到线性方程；(4)取待测淀粉产品,按照步骤(1)和(2)的条件处理后,测定沉淀体积Vx,将Vx代入上述线性方程中,即得该待测淀粉产品的α-化程度。本发明能迅速测得淀粉及其制品的α-化程度,准确率高,用时短,成本低。(The invention discloses a method for detecting alpha-conversion degree of starch and a product thereof, which comprises the following steps: (1) preparing at least two starch products with known alpha-degree into dispersion liquids with the same concentration respectively, wherein the mass fraction of the dispersion liquids is 0.4-4%; (2) taking a dispersion liquid sample with the same mass, carrying out solid-liquid separation under the same condition, and then determining the volume of the precipitate; (3) the degree of α -methylation and the precipitation volume satisfy the following linear equation: a is aV + b, a is the degree of α -formation, V is the precipitation volume, a, b are parameters; combining the measured at least two groups of precipitation volumes and the corresponding alpha-degree with the linear equation, and calculating parameters a and b to obtain a linear equation; (4) and (3) taking the starch product to be detected, processing according to the conditions in the steps (1) and (2), determining the deposition volume Vx, and substituting the Vx into the linear equation to obtain the alpha-degree of the starch product to be detected. The invention can rapidly measure the alpha-degree of the starch and the products thereof, and has the advantages of high accuracy, short time and low cost.)

1. A method for detecting the alpha-conversion degree of starch and products thereof is characterized by comprising the following steps:

(1) preparing at least two kinds of starch or starch products with known alpha-degree into dispersion liquid with the same concentration respectively, wherein the mass fraction of the dispersion liquid is 0.4-4%;

(2) taking dispersion liquid samples with the same mass, carrying out solid-liquid separation under the same conditions, and then respectively measuring the precipitation volume in each sample;

(3) determining a linear relationship between the degree of alpha-gelatinization and the sedimentation volume of the starch or starch preparation: the degree of α -methylation and the precipitation volume satisfy the following linear equation: a ═ aV + b, where a is the degree of α -alkylation, V is the precipitation volume, and a, b are parameters; combining at least two groups of precipitation volume data and corresponding alpha-degree determined in the step (2) with the linear equation, and calculating parameters a and b to obtain the linear equation;

(4) determining the alpha-conversion degree of the starch or starch product to be detected: and (3) taking the starch or starch product to be detected, processing according to the conditions in the steps (1) and (2), determining the deposition volume Vx, and substituting the Vx into the linear equation obtained in the step (3) to obtain the alpha-degree of the starch or starch product to be detected.

2. The method for detecting the degree of α -gelatinization of starch or starch products according to claim 1, wherein in step (2), the solid-liquid separation method comprises: centrifuging for 3-10 min under 3000-6000 r/min.

3. The method for detecting the degree of α -gelatinization of starch or starch products according to claim 1, wherein in step (1), two kinds of starch or starch products with known degrees of α -gelatinization are used.

4. The method for detecting the degree of α -gelatinization of starch or a product thereof according to claim 1, wherein in step (1), a raw starch or a raw starch product having a degree of α -gelatinization of 0 and a fully cooked starch or a fully cooked starch product having a degree of α -gelatinization of 100% are used.

5. The method for detecting the alpha-conversion degree of the starch or the starch product as claimed in claim 4, wherein the calculation formula of the alpha-conversion degree of the starch or the starch product to be detected is as follows:

Ax＝(Vx-V0)/(V100-V0)×100％

ax: determining the degree of alpha-formation of the starch or starch product

Vx: the corresponding precipitation volume of the starch or starch product to be detected;

v0: a sediment volume corresponding to raw starch or raw starch product with an alpha-degree of 0;

v100: the degree of alphatization is 100% of the sediment volume corresponding to a fully cooked starch or a fully cooked starch preparation.

6. The method for detecting the degree of α -gelatinization of starch or starch products according to claim 4, wherein said fully cooked starch or fully cooked starch product dispersion having a degree of α -gelatinization of 100% is prepared by: preparing starch suspension with the mass fraction of 2-8% by using raw starch, heating the starch suspension in a water bath until the starch suspension is completely alpha-shaped to obtain starch paste, and preparing the starch paste into solution with the mass fraction of 20-50%, wherein the solution is the fully cooked starch or the dispersion liquid of the fully cooked starch product.

Technical Field

The invention relates to a method for detecting alpha-conversion degree of starch and a product thereof.

Background

Raw starch molecules are closely arranged by intermolecular hydrogen bonding to form bundle-like micelles, the gaps between the raw starch molecules are small, water molecules are difficult to permeate into the raw starch molecules, and the raw starch with the micelle structure is called beta-starch. After the beta-starch is heated in water, the starch granules absorb water and expand, the volume is increased, the starch granules break, and the process of becoming a viscous colloid solution is called alpha-gelatinization.

When the starch is heated for alpha-melting, the physical change of the processes of water absorption swelling-re-swelling-infinite swelling-dissolving is presented. The alpha-swelling of the starch is a key typical characteristic of alpha-gelatinization of the starch, and the alpha-swelling rate of the starch refers to the percentage of the swelling volume of the alpha-gelatinized starch in the swelling volume of the full alpha-gelatinized starch, so that the alpha-gelatinization degree of the starch can be represented, and the alpha-gelatinization effect of the starch is reflected.

Disclosure of Invention

In order to solve the defects and shortcomings in the prior art, the invention aims to provide a method for detecting the alpha-conversion degree of starch and products thereof, which is simple to operate, low in cost and short in time consumption.

In order to realize the purpose, the technical scheme adopted by the invention is as follows:

a method for detecting the alpha-conversion degree of starch and products thereof comprises the following steps:

(1) preparing at least two kinds of starch or starch products with known alpha-degree into dispersion liquid with the same concentration respectively, wherein the mass fraction of the dispersion liquid is 0.4-4%;

(2) taking dispersion liquid samples with the same mass, carrying out solid-liquid separation under the same conditions, and then respectively measuring the precipitation volume in each sample;

(3) determining a linear relationship between the degree of alpha-gelatinization and the sedimentation volume of the starch or starch preparation: the degree of α -methylation and the precipitation volume satisfy the following linear equation: a ═ aV + b, where a is the degree of α -alkylation, V is the precipitation volume, and a, b are parameters; combining at least two groups of precipitation volume data and corresponding alpha-degree determined in the step (2) with the linear equation, and calculating parameters a and b to obtain the linear equation;

(4) determining the alpha-conversion degree of the starch or starch product to be detected: and (3) taking the starch or starch product to be detected, processing according to the conditions in the steps (1) and (2), determining the deposition volume Vx, and substituting the Vx into the linear equation obtained in the step (3) to obtain the alpha-degree of the starch or starch product to be detected.

The inventor finds that under certain concentration conditions, the alpha-conversion degree of the starch and the products thereof has a linear relation with the precipitation volume. Therefore, the linear equation A is fitted to aV + b according to more than two types of starch with known alpha-conversion degrees, so that the alpha-conversion degrees of the starch to be measured and the products thereof can be calculated according to the precipitation volume.

Controlling the mass fraction of the dispersion to be 0.4-4% is the applicable concentration of the detection method of the present invention, and the alpha-conversion degree and the precipitation volume of the starch and the products thereof are in a linear relationship in the range, and beyond the range, the detection method of the present invention cannot be applied.

Preferably, in the step (2), the solid-liquid separation method is as follows: centrifuging for 3-10 min under 3000-6000 r/min. In the invention, the solid-liquid separation condition has larger influence on the accuracy of the measurement of the precipitation volume, and the purpose of accurate measurement can be achieved by carrying out solid-liquid separation under the condition provided by the invention.

Preferably, in step (1), two starches or starch preparations of known degree of α -gelatinization are used. More preferably, in the step (1), raw starch (or raw starch product) having an α -gelatinization degree of 0 and fully cooked starch (or fully cooked starch product) having an α -gelatinization degree of 100% are used. In this case, the calculation formula of the degree of α -formation of the starch or starch product to be measured is as follows:

Ax＝(Vx-V0)/(V100-V0)×100％

ax: determining the degree of alpha-formation of the starch or starch product

Vx: the corresponding precipitation volume of the starch or starch product to be detected;

v0: a sediment volume corresponding to raw starch (or raw starch product) with an alpha-degree of 0;

v100: the degree of alphatization is the sediment volume corresponding to 100% of fully cooked starch (or fully cooked starch preparation).

In the step (1), the dispersion is prepared by a conventional method, and can be prepared in one step or step by step.

Preferably, the dispersion of the fully cooked starch (or fully cooked starch product) having the degree of α -gelatinization of 100% is prepared by: preparing starch suspension with the mass fraction of 2-8% by using raw starch, heating the starch suspension in a water bath until the starch suspension is completely alpha-shaped to obtain starch paste, and preparing the starch paste into solution with the mass fraction of 20-50%, wherein the solution is the dispersion liquid of the fully cooked starch (or fully cooked starch products).

Compared with the prior art, the invention has the beneficial effects that: the detection method can rapidly detect the alpha-degree of the starch and the products thereof, has high accuracy, simple operation flow, low requirement on the operation skill of personnel, convenient practical production and application, low requirement on equipment, short detection time, no need of using chemical reagents in the whole detection process, environmental protection and low detection cost, and can be used for on-line detection and judgment.

Detailed Description

To better illustrate the objects, aspects and advantages of the present invention, the present invention is further illustrated by the following examples. It is apparent that the following examples are only a part of the embodiments of the present invention, and not all of them. It should be understood that the embodiments of the present invention are only for illustrating the technical effects of the present invention, and are not intended to limit the scope of the present invention.

The invention provides a method for detecting alpha-conversion degree of starch and a product thereof, which comprises the following steps:

(1) determination of the sediment volume in dispersions of fully cooked starch samples

Preparing starch suspension with the mass fraction of X1(X1 is 2-8%), putting the starch suspension into a container with a proper size, heating the starch suspension to 90-100 ℃ in a boiling water bath while stirring, and then preserving the heat for 0min, 10min, 30min, 50min, 70min, 90min, 110min and the like. And preparing the starch paste with the corresponding heat preservation time into a dispersion liquid with the mass fraction of X2 (20-50% of X2) to ensure the consistency of the concentration. And (3) taking the dispersion liquid with the same mass in a graduated centrifuge tube with a proper size, centrifuging the dispersion liquid for the same time T (3-10 min) under the condition of the same centrifugal rotating speed R (3000-6000R/min), reading the sediment volume in the centrifuge tube, measuring each sample in parallel twice, and taking the average value as the centrifugal sediment volume of a single sample. The sample with the largest centrifugal sediment volume and tending to be stable is taken as the all alpha-gelatinized starch dispersion, and the sediment volume is recorded as V100.

(2) Determination of the sediment volume in a raw starch dispersion

Preparing raw starch dispersion liquid with the mass fraction of X1 multiplied by X2, putting the raw starch dispersion liquid with the same mass as that in the step (1) into a graduated centrifuge tube with a proper size, centrifuging under the same centrifugation condition as that in the step (1), reading the precipitation volume in the centrifuge tube, performing parallel measurement twice, and taking the average value as the precipitation volume of the raw starch dispersion liquid and marking as V0.

(3) Determination of degree of alpha-formation of sample to be tested

Preparing a sample dispersion liquid according to the method in the step (1), determining the centrifugal precipitation volume in the sample dispersion liquid, recording the centrifugal precipitation volume as Vx, and calculating the alpha-conversion degree Ax of the sample to be detected:

Ax＝(Vx-V0)/(V100-V0)×100％。