CN108354166A - A kind of high dietary-fiber cornstarch gel and preparation method thereof - Google Patents

Abstract

A kind of high dietary-fiber cornstarch gel and preparation method thereof, belongs to product depth processing technique field.The high dietary-fiber cornstarch gel, raw material include cornstarch, dietary fiber and water；Wherein, the mass percent of each component is that the percentage of cornstarch and dietary fiber gross mass is 5~20wt.%, and surplus is water, in mass ratio, cornstarch：Dietary fiber=(1~20):(0.5~4).The preparation method, including：Raw material is weighed according to composition of raw materials；Cornstarch and water are mixed, stirred evenly, cornstarch gel is formed；Dietary fiber is added to be gelatinized, gelatinization point is 70~80 DEG C, obtains high dietary-fiber cornstarch gel.The gel is while ensureing cornstarch characteristic, the also effect of increased dietary fiber.Meanwhile influence is produced on corn starch pasting and rheological properties, the optimization for the processing characteristics of high dietary-fiber cornstarch class product provides theoretical foundation.

Description

A kind of high dietary fiber cornstarch gel and preparation method thereof

technical field

The invention relates to the technical field of food deep processing, in particular to a high dietary fiber cornstarch gel and a preparation method thereof.

Background technique

Starch is the main component of cereal foods and the main source of energy for the human body. Starch has attracted widespread attention due to its biodegradability, low cost, and wider practicability. Starch products have been widely used in food, paper, textile, plastics, cosmetics, adhesives and pharmaceuticals and other fields. In order to meet different requirements, different modification techniques, such as physical, chemical and enzymatic methods, have been used to enhance or weaken some of its characteristics or improve its specific properties. Corn starch has a wide range of functions, such as waxy corn starch can be used in sugar, brewing, food, adhesive production and other applications.

Dietary fiber is a general term for fiber compounds, the main components of which are cellulose, lignin and hemicellulose, as well as pectin, gum and pectin analogues. Dietary fiber is mainly divided into soluble dietary fiber and insoluble dietary fiber according to water solubility. Insoluble dietary fiber is mainly cellulose, which is the most abundant renewable biomass resource in nature. It is a linear high molecular polymer formed by connecting glucose structural units through β-1,4 glycosidic bonds. Soluble dietary fiber is mainly polydextrose (polydextrose), which is a D-glucose polymer formed by vacuum polycondensation after mixing glucose, sorbitol and citric acid as raw materials in a specific proportion and heating it into a molten mixture. Polydextrose is a random polycondensation product of D-glucose, mainly composed of 1,6-glycosidic bonds, with an average molecular weight of about 3200, a limiting molecular weight of less than 22000, and an average degree of polymerization of 20.

Because dietary fiber can promote cardiovascular and cerebrovascular health, prevent diabetes, prevent overweight, and improve the human immune system, it has received more and more attention. However, because its own characteristics will affect the processing performance and sensory quality of the food itself, dietary fiber The reasonable application has become the focus of attention.

Contents of the invention

The purpose of this invention is to provide a kind of high dietary fiber cornstarch gel and preparation method thereof, this product is to obtain water-soluble dietary fiber cornstarch gel or water-insoluble dietary fiber by adding different types of dietary fiber to cornstarch Corn starch gel, through the analysis of its gelatinization and rheological properties, proves that high dietary fiber corn starch gel is a non-Newtonian fluid, which is of great significance in food production and transportation.

A kind of high dietary fiber cornstarch gel of the present invention, raw material comprises cornstarch, dietary fiber and water; Wherein, the mass percentage of each component is, the percentage of the total mass of cornstarch and dietary fiber is 5～20wt.%. The amount is water, and by mass ratio, cornstarch: dietary fiber=(1～20):(0.5～4).

Wherein, the dietary fiber is one of cellulose or polydextrose.

Wherein, the dietary fiber is one of cellulose or polydextrose.

Preferably, in the high dietary fiber cornstarch gel, the mass ratio is cornstarch: dietary fiber = 20: (1-4), especially, the mass ratio is cornstarch: dietary fiber = 10:1.

A kind of preparation method of high dietary fiber cornstarch gel of the present invention, comprises the following steps:

(1) Weigh raw materials according to the formula of high dietary fiber cornstarch gel;

(2) mix cornstarch and water, stir evenly, form cornstarch gel;

(3) Adding dietary fiber to the corn starch gel for gelatinization, the gelatinization temperature is 70-80° C. to obtain high dietary fiber corn starch gel.

In the step (3), the preferred gelatinization process is: keep at 50°C for 1min, raise to 90°C at 12.2°C/min, keep for 2.5min, cool down to 50°C at 11.8°C/min, Keep for 2min.

A kind of high dietary fiber cornstarch gel of the present invention and preparation method thereof, compared with prior art, its beneficial effect is:

Provides a high dietary fiber cornstarch gel. This gel not only guarantees the characteristics of cornstarch, but also increases the dietary fiber to enhance the product's role in promoting cardiovascular and cerebrovascular health, preventing diabetes, preventing overweight, and improving the human immune system. role. At the same time, the addition of dietary fiber has an effect on the gelatinization and rheological properties of corn starch, which provides a theoretical basis for the optimization of the processing properties of high dietary fiber corn starch products.

After adding cellulose, the viscosity of corn starch increased, the retrogradation value increased, and the stability decreased. Adding polydextrose will improve the stability of the gel system. Static rheological tests showed that the cornstarch gel after adding cellulose and polydextrose was a non-Newtonian fluid with shear thinning. The hysteresis loop of corn starch gel after cellulose added tended to increase, and polydextrose had little effect on the thixotropy of corn starch. Polydextrose will increase the Newtonian fluid behavior of the starch gel system. Dynamic rheological tests show that the cornstarch gel after the addition of cellulose and polydextrose is a weak gel, and the addition of cellulose will increase the elasticity of the gel system. The addition of a small amount of polydextrose will increase the gel strength of the starch gel, and with the increase of the addition amount, it will decrease the strength of the starch gel. The shear structure recovery test shows that when the addition amount is 10%, a relatively stable structure is produced inside the gel system.

Description of drawings

Fig. 1 is the variation curve of the apparent viscosity of the cornstarch gel system with different contents of cellulose of the present invention along with the shear rate;

Fig. 2 is the variation curve of the apparent viscosity of the polydextrose cornstarch gel system with different contents of the present invention along with the shear rate;

Fig. 3 is the variation curve of cornstarch gel shear stress with shear rate under different cellulose addition amounts of the present invention.

Fig. 4 is the variation curve of cornstarch gel shear stress with shear rate under different polydextrose additions of the present invention;

Fig. 5 is the frequency scanning figure of cornstarch gel under different cellulose additions of the present invention;

Fig. 6 is the frequency scanning figure of cornstarch gel under different polydextrose addition amounts of the present invention;

Fig. 7 is the test figure of the recovery force of the cornstarch gel shear structure under different cellulose additions of the present invention;

Fig. 8 is the test chart of the shear structure recovery force of corn starch gel under different polydextrose addition amounts of the present invention;

In the figure, CS, corn starch; C, cellulose; P, polydextrose.

Detailed ways

The present invention will be described in further detail below in conjunction with embodiment.

In the following examples, unless otherwise specified, the raw materials and equipment are commercially available.

Example 1

A kind of high dietary fiber cornstarch gel, raw material comprises cornstarch, cellulose and water; Wherein, the mass percentage of each component is, the percentage of the total mass of cornstarch and cellulose is 10wt.%, and the balance is water, according to Mass ratio, corn starch: cellulose = 20:1.

A preparation method for high dietary fiber cornstarch gel, comprising the following steps:

(1) Weigh raw materials according to the formula of high dietary fiber cornstarch gel;

(2) mix cornstarch and water, stir evenly, form cornstarch gel;

(3) Add cellulose to the corn starch gel for gelatinization, the gelatinization temperature is 77.90°C, and obtain high dietary fiber corn starch gel.

The research on gelatinization and rheological properties of the prepared high dietary fiber cornstarch gel comprises the following steps:

Step 1. Study of Gel Pasting

The high dietary fiber corn starch added with cellulose was used as the experimental sample, and the rapid viscosity analyzer was used for testing. The test conditions were: keep at 50°C for 1min, raise to 90°C at 12.2°C/min, keep for 2.5min, and hold at 11.8°C/min. The temperature was lowered to 50°C for 1 minute, and kept at 50°C for 2 minutes to obtain its gelatinization characteristics; the RVA characteristic values of the corn starch and cellulose mixed gel system are shown in Table 1.

Step 2. Study of rheological properties

(1) Take fully gelatinized high dietary fiber cornstarch and put it on the test platform of the rheometer, select a flat mold with a diameter of 25mm and a static shear test program for testing, and during the test, the rheometer should be scraped off. There is excess high dietary fiber cornstarch on the platform, and paraffin oil is added around the rheometer test platform to prevent moisture volatilization of high dietary fiber cornstarch:

The static shear test procedure is: in the first 150s, the shear rate (γ) increases from 0 to 300s ^-1 , and in the last 150s, the shear rate (γ) decreases from 300 to 0s ^-1 to test the high dietary fiber During the process of corn starch gel, the change of its shear stress (τ);

Perform fitting analysis on the rheological model, specifically: perform model fitting analysis on the hysteresis loop formed by the uplink and downlink, the specific formula is:

τ=τ ₀ +Kγ ⁿ (1)

In the formula: τ—shear stress, Pa; τ ₀ —yield stress, Pa; K—consistency coefficient, Pa sn; γ—shear rate, s ^-1 ; n—flow characteristic index, dimensionless, indicating that the liquid deviates from degree of Newtonian fluid.

(2) Dynamic rheological properties test

Take fully gelatinized high dietary fiber cornstarch on the test platform of the rheometer, select a flat mold with a diameter of 25mm and test the dynamic rheological properties, set the temperature of the rheometer at 25°C, set the strain at 1%, and perform frequency Scanning, the frequency scanning range is 0.1 ~ 100r/s, and the changes of storage modulus (G') and loss modulus (G″) are measured;

(3) Shear structure recovery force test

Take fully gelatinized high dietary fiber cornstarch and place it on the test platform of the rheometer, select a flat mold with a diameter of 25mm, and keep the temperature constant at 25°C;

The test program consists of three stages: low-speed shear, high-speed shear, and low-speed shear;

Measure the change of apparent viscosity (η) of the sample during shearing for 120s, 60s, and 180s at shear rates of 1s ^-1 , 300s ^-1 , and 1s ^-1 respectively;

The shear structural recovery force was recorded as the ratio of the apparent viscosity in the first 30 s of the third stage to the apparent viscosity in the first stage.

In the above-mentioned research method of gelatinization and rheological properties of high dietary fiber cornstarch gel, each research test was repeated 3 times, and the difference between the average values was analyzed using SPSS 22.0 software (p<0.05).

Example 2

A kind of high dietary fiber cornstarch gel, raw material comprises cornstarch, cellulose and water; Wherein, the mass percentage of each component is, the percentage of the total mass of cornstarch and cellulose is 10wt.%, and the balance is water, according to Mass ratio, corn starch: cellulose = 10:1.

A preparation method for high dietary fiber cornstarch gel, comprising the following steps:

(1) Weigh raw materials according to the formula of high dietary fiber cornstarch gel;

(2) mix cornstarch and water, stir evenly, form cornstarch gel;

(3) Add cellulose to corn starch gel for gelatinization, the gelatinization temperature is 78.08°C, and obtain high dietary fiber corn starch gel.

The research on pasting and rheological properties of the prepared high dietary fiber cornstarch gel is the same as in Example 1.

Example 3

A kind of high dietary fiber cornstarch gel, raw material comprises cornstarch, cellulose and water; Wherein, the mass percentage of each component is, the percentage of the total mass of cornstarch and cellulose is 10wt.%, and the balance is water, according to Mass ratio, corn starch: cellulose = 5:1.

A preparation method for high dietary fiber cornstarch gel, comprising the following steps:

(1) Weigh raw materials according to the formula of high dietary fiber cornstarch gel;

(2) mix cornstarch and water, stir evenly, form cornstarch gel;

(3) Add cellulose to the corn starch gel for gelatinization, the gelatinization temperature is 77.31°C, and obtain high dietary fiber corn starch gel.

The research on pasting and rheological properties of the prepared high dietary fiber cornstarch gel is the same as in Example 1.

Analyze the RVA eigenvalues of cornstarch gel with different contents of cellulose, and obtain the following table:

Table 1 RVA eigenvalues of corn starch and cellulose mixed gel system

After adding different amounts of cellulose, the peak viscosity, minimum viscosity, final viscosity, disintegration value and retrogradation value of corn starch increased. This is because cellulose is easy to absorb water, and the inter-chain and intra-chain hydrogen bonds of cellulose molecules are relatively small, and most of the hydroxyl groups form hydrogen bonds with surrounding water molecules.

During the gelatinization process, the contact between starch molecules and water will be affected, and the water-absorbing swelling of starch granules will be hindered to a certain extent, resulting in an increase in viscosity. With the increase of cellulose addition, the structure density of starch gel was not high during the aging process, and the strength was low, so the stability was poor, which was manifested by the increase of retrogradation value.

Table 2 Characteristic values of rheological parameters of starch gel under different cellulose additions

It can be seen from Table 2 that after adding cellulose, the flow characteristic index first increases and then decreases, indicating that the degree of shear thinning first decreases and then increases. It shows that the addition of a small amount of cellulose can interact with starch molecules to generate intermolecular interaction force. With the increase of cellulose addition, more cellulose exists as a filler, thus leading to the enhancement of shear thinning.

The research and test results of Examples 1 to 3 were analyzed, and the curves of the apparent viscosity of the cornstarch gel system with different contents of cellulose along with the shear rate are shown in Figure 1; The change curve of shear rate is shown in Figure 3, and the frequency scan of corn starch gel under different cellulose additions is shown in Figure 5. See Figure 7 for the test chart of the shear structure resilience of corn starch gel under different cellulose additions.

From Figure 1, it can be seen that when the shear rate increases from 0s ^-1 to 50s ^-1 , the apparent viscosity decreases rapidly with the increase of the shear rate, and the apparent viscosity decreases when the shear rate reaches 50s ^-1 The trend is gradually flattening, indicating that corn starch gel has a shear thinning phenomenon under the action of shear stress. Shear thinning indicates that starch gel is a non-Newtonian fluid, which is of great significance in food production and transportation.

From Figure 3, it can be seen that when the amount of cellulose added gradually increases, the hysteresis area of the starch gel system tends to increase. The larger the hysteresis area, the more damage the structure of the starch gel system receives during the shearing process. big.

It shows that with the increasing amount of cellulose added, the formation of starch gel structure may be affected to a certain extent. When the starch gel system is damaged by shearing, it is difficult to return to the original state.

Example 4

A kind of high dietary fiber cornstarch gel, raw material comprises cornstarch, polydextrose and water; Wherein, the mass percentage of each component is, the percentage of the total mass of cornstarch and polydextrose is 10wt.%, and the balance is water, according to Mass ratio, corn starch: polydextrose = 10:1.

A preparation method for high dietary fiber cornstarch gel, comprising the following steps:

(1) Weigh raw materials according to the formula of high dietary fiber cornstarch gel;

(2) mix cornstarch and water, stir evenly, form cornstarch gel;

(3) Add polydextrose to the corn starch gel for gelatinization, the gelatinization temperature is 78.72°C, and obtain high dietary fiber corn starch gel.

The research on pasting and rheological properties of the prepared high dietary fiber cornstarch gel is the same as in Example 1.

Example 5

A kind of high dietary fiber cornstarch gel, raw material comprises cornstarch, polydextrose and water; Wherein, the mass percentage of each component is, the percentage of the total mass of cornstarch and polydextrose is 10wt.%, and the balance is water, according to Mass ratio, corn starch: polydextrose = 10:1.

A preparation method for high dietary fiber cornstarch gel, comprising the following steps:

(1) Weigh raw materials according to the formula of high dietary fiber cornstarch gel;

(2) mix cornstarch and water, stir evenly, form cornstarch gel;

(3) Add polydextrose to the corn starch gel for gelatinization, the gelatinization temperature is 78.81°C, and obtain high dietary fiber corn starch gel.

The research on pasting and rheological properties of the prepared high dietary fiber cornstarch gel is the same as in Example 1.

Example 6

A kind of high dietary fiber cornstarch gel, raw material comprises cornstarch, polydextrose and water; Wherein, the mass percentage of each component is, the percentage of the total mass of cornstarch and polydextrose is 10wt.%, and the balance is water, according to Mass ratio, corn starch: polydextrose = 10:1.

A preparation method for high dietary fiber cornstarch gel, comprising the following steps:

(1) Weigh raw materials according to the formula of high dietary fiber cornstarch gel;

(2) mix cornstarch and water, stir evenly, form cornstarch gel;

(3) Add polydextrose to corn starch gel for gelatinization, the gelatinization temperature is 79.13°C, and obtain high dietary fiber corn starch gel.

The research on pasting and rheological properties of the prepared high dietary fiber cornstarch gel is the same as in Example 1.

The RVA eigenvalues of polydextrose cornstarch gel with different contents were analyzed, and the following table was obtained:

Table 3 RVA characteristic value of corn starch and polydextrose mixed gel system

After adding different amounts of polydextrose, the peak viscosity, minimum viscosity and final viscosity of corn starch remained unchanged, the disintegration value and retrogradation value decreased, and the gelatinization temperature increased. The decrease of retrogradation value shows that the addition of polydextrose can promote the formation of intermolecular force with starch molecules, making the whole gel system more stable.

The research and test results of Examples 4 to 6 were analyzed, and the curves of the apparent viscosity of the cornstarch gel system with different contents of polydextrose with the shear rate are shown in Fig. 2; The change curve of shear rate is shown in Figure 4, and the frequency scan of corn starch gel under different polydextrose additions is shown in Figure 6. See Figure 8 for the test chart of the shear structure resilience of corn starch gel under different polydextrose additions.

From Figure 2, it can be seen that when the shear rate increases from 0s ^-1 to 50s ^-1 , the apparent viscosity decreases rapidly with the increase of the shear rate, and the apparent viscosity decreases when the shear rate reaches 50s ^-1 The trend is gradually flattening, indicating that corn starch gel has a shear thinning phenomenon under the action of shear stress. Shear thinning indicates that starch gel is a non-Newtonian fluid, which is of great significance in food production and transportation.

From Figure 4, it can be seen that when polydextrose is added, the hysteresis loop of the rheological curve of each added amount does not change significantly. Has little effect.

Table 4 Characteristic values of starch gel rheological parameters under different polydextrose additions

It can be seen from Table 4 that the flow characteristic index of cornstarch gel added with polydextrose tends to increase, indicating that with the increasing amount of polydextrose added, the degree of shear thinning decreases. With the addition of polydextrose, the starch macromolecules in the gel system aggregate and intertwine to form a network structure, which makes the gel system have a yield stress, and there is an interaction force with the starch molecules, resulting in a dense network structure. Decrease, so that the yield stress that the starch gel system needs to overcome becomes smaller, and the consistency coefficient decreases.

comparative example

A kind of cornstarch gel, comprises cornstarch and water, and the percentage of cornstarch mass is 10wt.%;

The gelatinization and rheological properties of the prepared high dietary fiber cornstarch gel are studied, step 1 is the same as in Example 1.

It can be seen from Figure 5 and Figure 6 that after the frequency scanning of the gel formed by cellulose, polydextrose and corn starch, the storage modulus of the gel system is significantly greater than the loss modulus, both of which are within the frequency scanning range Crossover did not occur, indicating that the starch gel after addition of cellulose and polydextrose was a weak gel.

The greater the amount of cellulose added, the greater the storage modulus and loss modulus, indicating that with the increasing amount of cellulose added, the interaction between starch molecules and cellulose molecules is strengthened to form a gel with a firm network structure. The elasticity of the gel system increases.

With the increasing amount of polydextrose, the storage modulus and loss modulus showed a trend of increasing first and then decreasing, indicating that adding a small amount of polydextrose would increase the gel strength of starch gel, while polydextrose When the added amount is too high, the strength of starch gel will be reduced.

It can be seen from Fig. 5 and Fig. 6 that in the gel system formed by cellulose or polydextrose and starch, the storage modulus and loss modulus both increase with the increase of the angular frequency, and the storage modulus The value is much larger than the loss modulus, so the loss angle is less than 1, showing a typical weak gel rheological dynamic system.

It can be seen from Figure 7 and Figure 8 that the viscosity of the cellulose cornstarch gel system and the polydextrose cornstarch gel system in the third stage of low-speed shearing is less than that in the first stage of low-speed shearing, indicating that starch gelation during the shearing process The internal structure of the system is damaged and the ability to recover is weakened.

It is calculated that when the corn starch content is 5% cellulose, the shear structure recovery force of the corn starch gel system is 0.60%, and when the corn starch content is 10% cellulose, the shear structure recovery of the corn starch gel system The force is 0.73%, when the content of corn starch is 20% cellulose, the shear structure recovery force of corn starch gel system is 0.61%, when the content of corn starch is 5% polydextrose, the shear structure recovery force of corn starch gel system is 0.61%. The structural resilience is 0.64%. When the content of cornstarch is 10% polydextrose, the shear structural resilience of the cornstarch gel system is 0.70%. When the content of cornstarch is 20% polydextrose, the The shear structural recovery force is 0.50%. For corn starch without dietary fiber, the shear structural recovery of the corn starch gel system is 0.66%. Explain that in the test, the internal structure of the gel of corn starch gel can not recover quickly under high-speed shearing, and when the addition of cellulose and polydextrose is at 10%, the recovery ability is higher than that of the original starch gel, indicating that in When the addition amount was 10%, a more stable new structure was generated inside the shear-induced system.

Claims (7)

1. a kind of high dietary-fiber cornstarch gel, which is characterized in that the high dietary-fiber cornstarch gel raw material includes Cornstarch, dietary fiber and water；Wherein, the mass percent of each component is, cornstarch and dietary fiber gross mass Percentage is 5~20wt.%, and surplus is water, in mass ratio, cornstarch：Dietary fiber=(1~20):(0.5~4).

2. high dietary-fiber cornstarch gel as described in claim 1, which is characterized in that the dietary fiber is fiber One kind in element or polydextrose.

3. high dietary-fiber cornstarch gel as described in claim 1, which is characterized in that the dietary fiber is fiber One kind in element or polydextrose.

4. high dietary-fiber cornstarch gel as described in claim 1, which is characterized in that the high dietary-fiber corn In starch gel, in mass ratio, cornstarch：Dietary fiber=20：(1~4).

5. high dietary-fiber cornstarch gel as described in claim 1, which is characterized in that the high dietary-fiber corn In starch gel, in mass ratio, cornstarch：Dietary fiber=10：1.

6. the preparation method of the high dietary-fiber cornstarch gel described in any one of Claims 1 to 5, feature exist In including the following steps：

(1) raw material is weighed according to the formula of high dietary-fiber cornstarch gel；

(2) cornstarch and water are mixed, is stirred evenly, form cornstarch gel；

(3) dietary fiber is added into cornstarch gel to be gelatinized, gelatinization point is 70~80 DEG C, obtains high dietary-fiber Cornstarch gel.

7. the preparation method of high dietary-fiber cornstarch gel as claimed in claim 6, which is characterized in that the step (3) in, specific gelatinization process is：1min is kept at 50 DEG C, 90 DEG C is raised to 12.2 DEG C/min, 2.5min is kept, with 11.8 DEG C/min cools to 50 DEG C, keep 2min at 50 DEG C.