KR101974436B1 - Method of preparing resistant starch nano particle - Google Patents

Abstract

Embodiments of the present invention include a method for producing starch nanoparticles by acid treatment of starch to decompose into starch nanoparticles; Cross-linking the pre-starch nanoparticles; Dispersing the crosslinked pre-starch nanoparticles; And a step of lyophilizing the dispersed pre-starch nanoparticles, thereby providing a method for producing resistive starch nanoparticles having homogeneous particle size and excellent dispersion stability, excellent compatibility with liquid food, and high dietary fiber content do.

Description

METHOD OF PREPARING RESISTANT STARCH NANO PARTICLE [0002]

The present invention relates to a method for producing resistive starch nanoparticles.

Resistant starch (RS) is a starch or starch hydrolyzate which is not digested and absorbed in the small intestine of a human body but is fermented by probiotics in the large intestine to produce short chain fatty acids. Resistant starch is fermented by intestinal microorganisms in the large intestine to increase the production of short chain fatty acids such as acetic acid, propionic acid, butyric acid, etc., and is effective in inhibiting colorectal cancer and has physiological activity almost similar to dietary fiber, It is said to be excellent for its effectiveness.

These resistant starches can be divided into five types according to their shape. They can be classified into five types, such as RS1, which is physically difficult to access digestive enzymes such as grains or seeds, bananas, potatoes and high amylose corn starch, RS2, which is starch particles that are difficult to digest by digestive enzymes, RS3 which is formed by starch aging, RS4 which shows resistance to digestive enzymes by chemical modification, and RS5 by amylose and lipid complex. Among them, RS4-type resistant starch has been developed relatively recently, and it is known that all commercially available starch such as corn starch, wheat starch, etc., which are lower in price than RS2 or RS3 type resistant starch prepared from expensive raw materials such as high amylose corn starch The starch can be manufactured, the content of the resistant starch can be relatively increased, the water absorption is difficult, and the physiological functionality is expected to increase.

However, such resistant starch is not well soluble in water, and its particle size is on the micrometer level, and it is difficult to apply because it is precipitated and separated without dissolving or dispersing in liquid foods. Korean Patent Publication No. 10-2007-0083589 discloses an enzyme-resistant starch and a production method thereof, but fails to provide an alternative to the above-mentioned problem.

Korean Patent Publication No. 10-2007-0083589

An object of the present invention is to provide a method for producing resistive starch nanoparticles having improved mechanical and physical properties.

1. Acid treatment of starch to decompose into starch nanoparticles; Cross-linking the pre-starch nanoparticles; Dispersing the crosslinked pre-starch nanoparticles; And lyophilizing the dispersed pre-starch nanoparticles.

2. The method of producing resistive starch nanoparticles as described in 1 above, wherein the dispersion is performed by ultrasonication of the cross-linked pre-starch nanoparticles.

3. The method of claim 2, wherein the ultrasonic treatment is performed for 15 to 60 minutes.

4. The method of producing resistive starch nanoparticles according to item 1 above, wherein acid-treating the starch comprises hydrolyzing the starch by reacting with the acid.

5. The method of claim 4, wherein acid treating the starch further comprises neutralizing the hydrolyzed starch with a base.

6. The method of producing resistive starch nanoparticles according to 4 above, wherein the acid comprises at least one selected from the group consisting of hydrochloric acid, sulfuric acid, carbonic acid, citric acid, acetic acid and lactic acid.

7. The method for producing resistive starch nanoparticles as described in 1 above, wherein the cross-linking is performed by adding a cross-linking agent and a base to the pre-starch nanoparticles.

8. The method for producing resistive starch nanoparticles according to 7 above, further comprising neutralizing the bridged pre-starch nanoparticles by adding an acid thereto.

9. The method of claim 7, wherein the cross-linking agent comprises at least one selected from the group consisting of sodium trimetaphosphate and sodium tripolyphosphate.

10. The starch according to 1 above, wherein the starch is at least one selected from the group consisting of glutinous rice starch, waxy corn starch, wheat starch, rice starch, corn starch, tapioca starch, sweet potato starch, Gt;

11. The method of claim 1, wherein the size of the resistive starch nanoparticles is adjusted to 20 to 300 nm.

The method for producing resistive starch nanoparticles according to embodiments of the present invention can produce a resistive starch nanoparticle having a homogeneous particle size, excellent dispersion stability, and high dietary fiber content by performing cross-linking treatment on the starch nanoparticles.

In addition, the method for producing resistive starch nanoparticles according to embodiments of the present invention can produce resistive starch nanoparticles having high dispersion stability and nanoscale resistance through, for example, ultrasonic treatment and freeze-drying treatment, And is excellent in compatibility with liquid foods.

Therefore, the above-mentioned resistive starch nanoparticles can be incorporated into the liquid food composition with high dispersibility, and thus it is possible to provide a liquid food composition excellent in suppression of colon cancer, prevention of constipation, and lowering of blood sugar.

Fig. 1 shows SEM observation results of the particles produced by the manufacturing methods of Examples and Comparative Examples.
Fig. 2 shows the size and distribution of the particles produced by the manufacturing methods of Examples and Comparative Examples.
Fig. 3 shows X-ray diffraction patterns of the particles prepared by the manufacturing method of Examples and Comparative Examples. Fig.
Fig. 4 shows a zeta potential measurement graph of the particles produced by the manufacturing methods of Examples and Comparative Examples.
Fig. 5 illustrates the dispersion stability of the particles produced by the manufacturing methods of Examples and Comparative Examples.

Embodiments of the present invention are directed to a method for preparing starch nanoparticles comprising dissolving starch nanoparticles by acid treatment of starch, crosslinking the pre-starch nanoparticles, dispersing the crosslinked pre-starch nanoparticles, The present invention also provides a method for producing a resistant starch nanoparticle having homogeneous particle size, excellent dispersion stability, excellent compatibility with liquid foods, and high dietary fiber content, including a step of lyophilizing particles.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to examples.

According to the method for producing the resistant starch nanoparticles of the embodiments, the starch is first acid-treated to form or decompose the pre-starch nanoparticles. For example, the starch may be obtained through acid treatment to nanostructured levels of pre-starch nanoparticles or pre-starch blocklet nanoparticles.

According to the embodiments, the method for producing resistive starch nanoparticles can produce pre-starch nanoparticles or resistive starch nanoparticles of nano-size (about 10 ^-7 to 10 ^-9 m) Surface area and excellent dispersion stability. Resistant starch is generally insoluble in liquids such as water. However, according to the embodiments, the resistive starch nanoparticles are dispersed or miscible in a liquid food composition as the particle size is included in the colloid particle size, It is possible to prepare a liquid food having an increased dietary fiber content.

Resistant starch nanoparticles are not digested in the small intestine but are fermented by intestinal microorganisms in the large intestine to increase the production of short chain fatty acids such as acetic acid, propionic acid, butyric acid and the like, and are effective for inhibiting colorectal cancer. It is active in preventing constipation and lowering blood sugar. It can also lower glycemic index and cholesterol levels and is useful for the human body.

The starch may be, for example, a grain powder, and may be selected from the group consisting of glutinous rice starch, waxy corn starch, wheat starch, rice starch, corn starch, tapioca starch, sweet potato starch, potato starch, But is not limited thereto.

In some embodiments, it is preferred to use starches having a small particle size so as to obtain starch nanoparticles of nanosized size with the starch, for example, the starch may comprise glutinous rice starch.

The starch may be obtained, for example, by immersing the grain in distilled water or an alkaline solution and separating the starch from the grain. Specifically, starch can be separated or obtained from cereals by repeating the steps of washing cereals, immersing them in distilled water and / or an alkali solution, pulverizing and / or sieving them, and centrifuging them. The sieving can be performed using, for example, a sieve of 100 to 300 mesh.

The starch may be acid treated to form pre-starch nanoparticles. In some embodiments, acid treatment of the starch may form nano-sized pre-starch nanoparticles by hydrolysis of the starch by reaction with an acid. In some embodiments, the acid treatment of the starch may be performed by reacting the starch with an acid to hydrolyze it in a blocklet state.

The acid may be, for example, hydrochloric acid, sulfuric acid, carbonic acid, citric acid, acetic acid, lactic acid, combinations of two or more thereof, and the like, preferably hydrochloric acid. have.

In some embodiments, there is no particular limitation on the time for performing the hydrolysis process through the acid, but the acid treatment can be performed preferably for 3 to 15 days, more preferably for 7 to 10 days. In the above range, the hydrolysis effect of the starch can be ensured.

In one embodiment, a centrifugation process may be performed after the acid hydrolysis process, and the acid treated starch may be centrifuged to obtain precipitated starch nanoparticles from the solution.

In some embodiments, acid treatment of the starch may comprise neutralizing the hydrolyzed starch or pre-starch nanoparticles with a base, whereby the acid-treated starch or pre-starch nanoparticles It can be neutralized to about pH 7. The base is not particularly limited, and examples thereof include sodium hydroxide, potassium hydroxide and the like. In one embodiment, after the base neutralization process, a cleaning process using distilled water may be involved.

In some embodiments, the lyophilization process may be performed after the acid hydrolysis and base neutralization processes and may be carried out by grinding and / or through a 100-300 mesh sieve in terms of readily obtaining starch nanoparticles. Sieve can be performed.

According to the manufacturing method of the resistive starch nanoparticles of the embodiments, the pre-starch nanoparticles are crosslinked. When the pre-starch nanoparticles are crosslinked and dispersed in a liquid phase, dispersion stability is improved, and intergranular agglomeration can be effectively prevented.

In some embodiments, cross-linking may be performed by adding a cross-linking agent to the pre-starch nanoparticles. The pre-starch nanoparticles can improve the dispersion stability of the resistant starch nanoparticles by cross-linking with the cross-linking agent, and prevent agglomeration between the particles at the time of dispersion.

In some embodiments, the amount of the cross-linking agent to be added is not particularly limited, and may be, for example, 5 to 12 parts by weight based on 100 parts by weight of the pre-starch nanoparticles.

In some embodiments, the cross-linking agent may contain up to 0.4 part by weight of phosphorus based on 100 parts by weight of the pre-starch nanoparticles.

The cross-linking agent is not particularly limited as long as it can crosslink the pre-starch nanoparticles, and may include, for example, sodium trimetaphosphate (STMP) and / or sodium tripolyphosphate (STPP) , And it is preferable to use sodium metaphosphate and sodium tripolyphosphate as a cross-linking agent, preferably in terms of dispersion stability and prevention of agglomeration.

In some embodiments, the crosslinking agent may be provided in the form of an aqueous solution of a crosslinking agent comprising 8 to 12% by weight of sodium metaphosphate and 0.01 to 1% by weight of sodium tripolyphosphate, The pre-starch nanoparticles can be crosslinked.

In some embodiments, 5-15 parts by weight of anhydrous sodium sulfate is added to 100 parts by weight of the pre-starch nanoparticles in order to prevent the pre-starch nanoparticles from becoming pregelatinized before adding the cross-linking agent Can be added.

In some embodiments, in view of facilitating the cross-linking reaction between the pre-starch nanoparticles, the cross-linking of the pre-starch nanoparticles may further include a base with the cross-linking agent, The crosslinking can be carried out at a pH of about 10 to 12, preferably at about pH 11 to 11.5. There are no particular restrictions on the base used, for example, sodium hydroxide, potassium hydroxide, and the like. In one embodiment, the method may further include neutralizing the pre-starch nanoparticles crosslinked through the cross-linking agent and the base by further adding an acid.

The method for preparing the resistant starch nanoparticles according to the embodiments may include dispersing the crosslinked pre-starch nanoparticles. For example, the dispersion can be performed by ultrasonication of the pre-starch nanoparticles.

The ultrasonic treatment can be performed in terms of reducing the particle size of the pre-starch nanoparticles or the resistant starch nanoparticles to improve dispersibility and prevent intergranular aggregation.

The ultrasonic treatment method is not particularly limited, and for example, the ultrasonic treatment may be performed for about 15 to 60 minutes. In the above range, the pre-starch nanoparticles may be included in the stable colloidal dispersion quality range. If the ultrasonic treatment time is less than about 15 minutes, agglomeration between nanoparticles may be formed to increase the particle size. If the ultrasonic treatment time exceeds about 60 minutes, further improvement of particle uniformity and dispersion stability may not be expected.

According to embodiments, the method for preparing the resistant starch nanoparticles may comprise lyophilizing the dispersed pre-starch nanoparticles to form the resistant starch nanoparticles. The lyophilization is carried out to further increase the dispersibility of the dispersed or ultrasonicated pre-starch nanoparticles and to minimize agglomeration between the resistant starch nanoparticles upon dispersion in the liquid phase. Also, the freeze-drying reduces the phenomenon of sticking to each other between the resistive starch nanoparticles, prevents an increase in particle size, and makes the particle shape uniform.

In some embodiments, the freeze-drying can be performed at about -90 to -40 占 폚 in terms of preventing particle size increase and further improving uniformity.

In some embodiments, the resistive starch nanoparticles may be made by the methods described above and made into nano-sized particles, for example, having a particle size of about 20 to 300 nm.

The resist starch nanoparticles according to the embodiments can produce nano-sized resistive starch nanoparticles or starch nanoparticles, and can prevent agglomeration between particles when mixed with a liquid food composition or the like, and are excellent in dispersibility. Therefore, the resistive starch nanoparticles prepared by the above-described production method are excellent in solubility in liquid composition and excellent in workability as a liquid food. Therefore, when the above-mentioned resistant starch nanoparticles are mixed to prepare a liquid food composition or the like, useful components such as dietary fiber can be easily delivered into a living body.

In addition, embodiments of the present invention provide resistance starch nanoparticles prepared by the above-described production method and liquid food compositions comprising the same.

The above-mentioned resistant starch nanoparticles are excellent in dispersibility when they are prepared by the above-mentioned method and are mixed with a liquid composition or the like and at the same time, they are excellent in dispersibility in a liquid composition and excellent in workability as a liquid food.

Further, in some embodiments, the resistive starch nanoparticles may have a particle size of 20 to 300 nm, so that the dispersibility-improving effect and the intergranular flocculation inhibition effect are excellent.

Accordingly, the liquid food composition containing the resistant starch nanoparticles can easily provide a variety of useful components such as dietary fiber in vivo, and it is possible to provide a liquid food composition containing the resistant starch nanoparticles, Excellent workability due to low impact.

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. It will be apparent to those skilled in the art that various changes and modifications can be made to the embodiments within the spirit and scope of the appended claims.

Examples and Comparative Examples

Example 1: Preparation of Resistant Starch Nanoparticles (AHW-10-SFD)

The glutinous rice was washed with running water, soaked at room temperature for 4 hours, and immersed in 0.2% NaOH solution for 1 hour. The immersed glutinous rice was pulverized with a mixer and sieved in a 100-mesh and 270-mesh sieve. Thereafter, the starch slurry was allowed to stand, and the solution in which the starch was precipitated was centrifuged at a speed of 3000 rpm for 30 minutes to obtain rice starch. The starch was neutralized with 1N HCl solution, washed with distilled water, dried at room temperature, pulverized, and passed through a 100-mesh sieve.

The glutinous rice starch (75 g) obtained in the above procedure was mixed with 2.2 N HCl solution (225 mL) and hydrolyzed at a rate of 100 rpm in a constant temperature water bath at 35 캜 for 10 days. Thereafter, centrifugation was performed at a speed of 8,000 rpm to obtain a dispersion of the dispersed starch nanoparticles except for the precipitate. The dispersion of the starch nanoparticles was neutralized with 1N NaOH solution. The dispersion of the starch nanoparticles was rapidly frozen at -80 ° C, dried with a freeze dryer (manufactured by IlshinBioBase), and then passed through a 270 mesh sieve.

10% by weight of anhydrous sodium sulfate, 11.98% by weight of sodium trimetaphosphate and 0.02% by weight of sodium tripolyphosphate based on the total weight of the starch nanoparticles were added to the starch nanoparticles obtained in the above procedure and stirred. Then, 1N NaOH solution was added until the pH of the starch mixture became 11.50 and cross-linked for 3 hours in a constant temperature water bath at 45 ° C. The mixture was then neutralized with 1N HCl solution and the crosslinked starch nanoparticles were precipitated. Thereafter, the precipitate was centrifuged at 8,000 rpm for 15 minutes to obtain cross-linked starch nanoparticles.

Then, the cross-linked starch nanoparticles were sonicated for 30 minutes at 700 W and 40 kHz using a sonicator (Power sonic 520, manufactured by Hewashin Technology), centrifuged and dried. Thereafter, the starch nanoparticles treated with a freeze dryer were rapidly frozen at -80 ° C, freeze-dried, and sieved with a 270 mesh sieve to obtain a resistant starch nanoparticle (AHW-10-SFD).

Comparative Example 1: Preparation of starch particles (NS)

The glutinous rice was washed with running water, soaked at room temperature for 4 hours, and immersed in 0.2% NaOH solution for 1 hour. The immersed glutinous rice was pulverized with a mixer and sieved in a 100-mesh and 270-mesh sieve. Thereafter, the starch slurry was allowed to stand, and the solution in which the starch was precipitated was centrifuged at a speed of 3000 rpm for 30 minutes to obtain rice starch. The starch was neutralized with 1N HCl solution, washed with distilled water, dried at room temperature, pulverized, and passed through a 100-mesh sieve to prepare starch particles (NS).

Comparative Example 2: Preparation of acid-treated starch nanoparticles (AHW-7)

The glutinous rice was washed with running water, soaked at room temperature for 4 hours, and immersed in 0.2% NaOH solution for 1 hour. The immersed glutinous rice was pulverized with a mixer and sieved in a 100-mesh and 270-mesh sieve. Thereafter, the starch slurry was allowed to stand, and the solution in which the starch was precipitated was centrifuged at a speed of 3000 rpm for 30 minutes to obtain a starch of glutinous rice. The starch was neutralized with 1N HCl solution, washed with distilled water, dried at room temperature, pulverized, and passed through a 100-mesh sieve.

The glutinous rice starch (75 g) obtained in the above procedure was mixed with 2.2 N HCl solution (225 mL) and hydrolyzed at a rate of 100 rpm in a constant temperature water bath at 35 캜 for 7 days. Thereafter, centrifugation was carried out at a speed of 8,000 rpm to remove the precipitate to obtain a nanoparticle dispersion. The starch nanoparticle dispersion was neutralized with 1N NaOH solution. The dispersion of the starch nanoparticles was rapidly frozen at -80 ° C, dried with a freeze dryer (manufactured by IlshinBioBase), and sieved into a 270-mesh sieve to obtain acid-treated starch nanoparticles (AHW-7).

Comparative Examples 3 to 5 (AHW-8 to AHW-10)

Comparative Examples 3 to 5 (AHW-8 to AHW-10) were prepared in the same manner as in Comparative Example 1, except that the hydrolysis periods were changed to 8, 9, and 10 days, respectively.

Comparative Example 6: Production of resistive starch nanoparticles (AHW-10-FD)

In Comparative Example 6, resistant starch nanoparticles (AHW-10-FD) were prepared in the same manner as in Example 1, except that the dispersing step and the ultrasonic treatment step were not performed.

Comparative Example 7: Preparation of resistive starch nanoparticles (AHW-10-SE)

In Comparative Example 7, 80% ethanol solution was prepared by adding ethanol to the cross-linked starch nanoparticles, followed by ultrasonic wave to keep the particle size at nano size when the particles were formed by dehydration. Resisted starch nanoparticles (AHW-10-SE) were prepared in the same manner as in Example 1 except for the remaining steps.

Experimental Example

1. Observation of particle shape

Particle morphology observation of Example 1 and Comparative Examples was carried out with a scanning electron microscope (SEM, JSM-7500F, JEOL), each resistive starch nanoparticle was placed on a stub for a sample and coated with gold under a condition of 20 kV for 100 seconds 5,000 times magnification. The results are shown in FIG.

1, the resistive starch nanoparticles (AHW-10-SFD) of Example 1 which had been subjected to the ultrasonic treatment and the freeze-drying process were found to have a significantly uniform and uniform size , And it can be seen that there are few aggregated particles and excellent dispersibility.

 However, SEM observation of the resistive starch nanoparticles (AHW-10-FD) of Comparative Example 6 in which lyophilization was performed alone showed that aggregation of the particles was somewhat observed and the dispersibility was poor. Further, in the resistive starch nanoparticles (AHW-10-SE) of Comparative Example 7, which was dried by ethanol dehydration, the aggregation of the particles was observed remarkably by SEM observation, and the particles were found to have irregular and minute uniform shapes.

Comparative Examples 2 (AHW-7), 3 (AHW-8), 4 (AHW-9) and Comparative Example 5 (AHW-10) in which only the acid- But the size of particles is not uniform, irregular, coagulation is found considerably, and dispersibility is poor. Comparative Example 1 (NS) in which no acid treatment hydrolysis was carried out showed that the particle size distribution was irregular and irregular, and that the particle size was much larger than that in Example 1 and that aggregation occurred very much.

2. Observation of particle size distribution

The particle size and distribution of the particles of Example 1 and Comparative Examples were measured using a Malvern Zetasizer Nano ZS (manufactured by Malvern Instruments Ltd.) at 0.01 wt% in distilled water. The results are shown in FIG.

Referring to FIG. 2, the particles of Example 1 had a particle size of 211.9 nm on average, a peak size of 255.0 nm, and a sharp normal distribution with one peak. Therefore, it is confirmed that the particles of Example 1 are prevented from agglomeration of particles through ultrasonic treatment and freeze-drying, so that they are small in size, uniform in size, and excellent in dispersion stability as compared with Comparative Examples.

The particles of Comparative Example 6 had an average size of 300.0 nm and the particle size of the peak point was 342.0 nm and the particle size was significantly different from that of Example 1 and the particles of Comparative Example 7 had an average of 459.7 nm And the particle size of the peak point is 396.1 nm. It can be seen that the particle size is significantly different from the particle of Example 1, and many peaks are found, so that the uniformity is poor and the aggregation occurs .

The particles of Comparative Example 1 have an average particle size of 3576.6 nm, which is excessively larger than that of Example 1, and the particles of Comparative Examples 2 to 5 have nanoscale particle sizes, but many peaks are found It can be seen that the particle size is not uniform and coagulation occurs.

3. X-ray diffraction measurement

The X-ray diffraction pattern of starch particles was analyzed using a 3D high resolution X-ray diffractometer (Empyrean, PANalytical Co.) to confirm the crystal structure of the starch particles. The device conditions were a target Cu-K alpha, a filter Ni, a voltage of 40 kV, a current of 30 mA, diffraction by diffraction at a diffraction angle (2?) = 40-5 °, and the results are shown in Fig.

The crystalline form of starch distinguishes A, B, C type and V type by amylose and lipid bond according to the diffraction pattern (Buleon. Colonna. Planchot. & Ba11., 1998). Referring to FIG. 3, the particles of Example 1 and Comparative Examples all showed an A-type crystalline pattern showing peaks at diffraction angles (2?) = 15. 17. 18. 23 °. As a result, it can be confirmed that the starch particles of Example 1 and Comparative Examples have a crystal structure similar to that of amylopectin.

In particular, the particles of Comparative Examples 2 to 5 subjected to the acid treatment hydrolysis had a crystal form similar to that of Comparative Example 1 in which no acid treatment was carried out, but had a diffraction angle (2?) Of 15. 23 But the peak of the diffraction angle (2?) = 15. 23 ° disappears in the particles of Example 1 in which ultrasonic treatment and freeze-drying were carried out. That is, it was found that the block lees prepared by acid treatment from the measurement of x-ray diffraction had crystal structure like amylopectin, and the resistive starch nanoparticles produced by cross-linking did not change the crystal structure.

4. Evaluation of dispersion stability of starch particles

(1) Zeta potential measurement

The zeta potential (?) Is a parameter for measuring the attraction force or repulsion between particles, and is a parameter capable of measuring the dispersion stability of the particles. The zeta potentials of Examples 1, 6 and 7 were measured using a Malvern Zetasizer Nano ZS (manufactured by Malvern Instruments Ltd.) with 0.01 wt% of the sample in distilled water. The results are shown in FIG. 4 .

The dispersion stability of the particles according to the value of zeta potential can be evaluated as follows (Bhattacharjee, 2016).

<Evaluation Criteria>

-10 <ζ <10: high instability

-20 <ζ ≤ -10 or 10 ≤ ζ <20: Low level of stability

-30 <ζ ≤ -20 or 20 ≤ ζ <30: Medium stability

-30 ≥ ζ or 30 ≤ ζ: high level of stability

4, the zeta potential value of Example 1 is -43.0 mV, the zeta potential value of Comparative Example 6 is -37.1 mV, and the zeta potential value of Comparative Example 7 is -35.4 mV. It was confirmed that the resistive starch nanoparticles of the largest example 1 had the highest dispersion stability.

(2) Observation of dispersion stability

The dispersion stability of the resistant starch nanoparticles was measured using Turbiscan AGS (Formulaction, L'Union) 0.3 g of the sample of Example 1, Comparative Example 6 and Comparative Example 7 was added to 30 mL of distilled water, and 1% aqueous solution And the dispersion stability was measured by measuring the degree of dispersion over 6 hours in 7 days.

The dispersion stability of the resistive starch nanoparticles of Examples and Comparative Examples is shown in Fig. Referring to FIG. 5, the transmittance of the dispersion containing the resistive starch nanoparticles of Comparative Example 6 and Comparative Example 7 tends to increase with the lapse of time. This is because the dispersion stability is decreased and the particles are deposited on the bottom of the solution, Is increased. However, the particles of Example 1 have a slower deposition rate than the comparative examples and have a stable dispersion form.

Claims (11)

Treating the starch with acid to decompose the starch nanoparticles;
Cross-linking the pre-starch nanoparticles;
Ultrasonically dispersing and dispersing the crosslinked pre-starch nanoparticles; And
And lyophilizing the dispersed pre-starch nanoparticles.
delete The method of claim 1, wherein the ultrasonic treatment is performed for 15 to 60 minutes.
The method according to claim 1, wherein acid treating the starch comprises hydrolyzing the starch by reaction with an acid.
5. The method of claim 4, wherein acid treating the starch further comprises neutralizing the hydrolyzed starch with a base.
5. The method according to claim 4, wherein the acid comprises at least one selected from the group consisting of hydrochloric acid, sulfuric acid, carbonic acid, citric acid, acetic acid and lactic acid.
The method according to claim 1, wherein the cross-linking is performed by adding a cross-linking agent and a base to the pre-starch nanoparticles.
8. The method according to claim 7, further comprising the step of adding an acid to the cross-linked pre-starch nanoparticles to neutralize the pre-starch nanoparticles.
8. The method of claim 7, wherein the cross-linking agent comprises at least one selected from the group consisting of sodium trimetaphosphate and sodium tripolyphosphate.
The method according to claim 1, wherein the starch comprises at least one selected from the group consisting of glutinous rice starch, waxy corn starch, wheat starch, rice starch, corn starch, tapioca starch, sweet potato starch and potato starch .
The method according to claim 1, wherein the size of the resistive starch nanoparticles is adjusted to 20 to 300 nm.

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