JP2020066703A - Method for producing indigestible starch - Google Patents

Abstract

To provide a method for producing indigestible starch composed of phosphoric acid-crosslinked starch with a high content of resistant starch.SOLUTION: A method for producing indigestible starch includes adding sodium trimetaphosphate to slurry containing raw material starch, wherein the slurry contains sodium salt that has the action of suppressing swelling of calcium salt and starch, and the amount of the added sodium trimetaphosphate is 10 pts.mass or more and 14 pts.mass or less relative to the 100 pts.mass of the raw material starch.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing resistant starch.

Indigestible starch is amylase resistant and has various physiological actions such as improvement of insulin responsiveness, improvement of intestinal function, and improvement of symptoms relating to blood fat, like dietary fiber.
Among phosphoric acid-crosslinked starches, those having a high degree of phosphoric acid crosslinkage suppress swelling (gelatinization) and are less susceptible to the action of amylase. Patent Document 1 and Non-Patent Document 1 describe production of indigestible starch by phosphorylation of raw starch. Patent Document 1 discloses an example in which a phosphoric acid crosslinking reaction of starch with sodium trimetaphosphate is carried out in the presence of sodium sulfate. Further, Patent Document 2 discloses that a phosphoric acid crosslinking reaction of starch with sodium trimetaphosphate is carried out in the presence of a calcium salt.

Japanese Patent Publication No. 2002-503959 Japanese Patent No. 4532603

Starch 2013, 65, 947-953

  An object of the present invention is to provide a method for producing a resistant starch comprising a phosphate-crosslinked starch having a high resistant starch content.

In order to solve the above problems, the present inventor has conducted diligent studies, and in the phosphoric acid crosslinking reaction with sodium trimetaphosphate in the presence of a calcium salt, a specific sodium salt is further added to describe in Patent Document 2. On the contrary, it was found that even if the added amount of sodium trimetaphosphate exceeds 1%, the degree of crosslinking suitable for the amount of reagent can be obtained. The present inventors have made further studies based on these findings and completed the present invention.
Specifically, the present invention provides the following [1] to [11].

[1] A method for producing a resistant starch, comprising:
Comprising adding sodium trimetaphosphate to the slurry containing the raw starch,
The slurry contains a calcium salt and a sodium salt having an action of suppressing swelling of starch,
The method for producing an indigestible starch, wherein the addition amount of the sodium trimetaphosphate is 100 parts by mass or more and 14 parts by mass or less relative to 100 parts by mass of the raw material starch.
[2] The method for producing indigestible starch according to [1], wherein the amount of sodium trimetaphosphate added is 11 parts by mass or more and 13 parts by mass or less based on 100 parts by mass of the raw material starch.
[3] The method for producing indigestible starch according to [1] or [2], wherein the calcium salt is calcium chloride.
[4] The method for producing indigestible starch according to any one of [1] to [3], wherein the sodium salt is sodium chloride or sodium sulfate.
[5] The method for producing indigestible starch according to [4], wherein the sodium salt is sodium chloride.
[6] The addition amount of the calcium salt to 100 parts by mass of the raw material starch is 0.1 parts by mass or more and less than 0.5 parts by mass, and the addition amount of the sodium salt is 100 parts by mass to 100 parts by mass of the starting starch. The method for producing indigestible starch according to any one of [1] to [5], which is 5 parts by mass or more and 3.0 parts by mass or less.
[7] The resistant starch content according to any one of [1] to [6], wherein the raw material starch has a resistant starch content of 20% or less according to the resistant starch measurement method of AOAC official method 2002.02. Production method.
[8] The method for producing indigestible starch according to any one of [1] to [7], wherein the raw material starch has an amylose content of less than 40% by mass.
[9] The method for producing an indigestible starch according to any one of [1] to [8], wherein the raw material starch is waxy starch or pea starch.
[10] The method for producing a resistant starch according to any one of [1] to [9], wherein the pH of the slurry is adjusted to 10 to 13 before addition of the sodium trimetaphosphate.
[11] The method for producing indigestible starch according to any one of [1] to [10], wherein the slurry is stirred for more than 3 hours after the sodium trimetaphosphate is added.

  According to the present invention, a method for producing resistant starch is provided. According to the production method of the present invention, it is possible to obtain a resistant starch composed of a phosphate-crosslinked starch having a high resistant starch content by a simple method.

RVA viscosity graph of the starch (1) obtained by the production method of the present invention using waxy corn starch as the raw starch, and RVA of the starch (Y1) obtained by the production method in which neither calcium salt nor sodium chloride was added to the slurry. It is a figure which shows a viscosity graph. RVA viscosity graph of raw starch (Waxy corn starch) (X), and starch (1, 2) obtained by the production method of the present invention from the above-mentioned raw starch, and starch obtained by a production method in which sodium chloride was not added ( It is a figure which shows the RVA viscosity graph of the starch (Y2) obtained by the manufacturing method which reduced the addition amount of Y2) and trimetaphosphoric acid. An RVA viscosity graph of the starch (1) obtained by the production method of the present invention in which pea starch was used as a raw material starch and calcium chloride and sodium chloride were added, and a production method in which neither calcium salt nor sodium chloride was added to the slurry It is a figure which shows the RVA viscosity graph of the obtained starch (Y1).

  Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be made based on typical embodiments or specific examples, but the present invention is not limited to such embodiments.

<Method for producing indigestible starch>
The method for producing a resistant starch according to the present invention includes reacting a starting starch with sodium trimetaphosphate to cause a phosphoric acid crosslinking reaction. Specifically, the method for producing a resistant starch of the present invention includes adding sodium trimetaphosphate to the raw starch slurry to cause the raw starch to undergo a phosphoric acid crosslinking reaction.

(Raw starch)
The raw material starch in the production method of the present invention is not particularly limited.
As the raw material starch, the starch isolated and purified from the plant may be used as it is, or the starch isolated and purified from the plant may be further subjected to a chemical treatment (for example, an acid treatment described below). It is preferable to use the starch isolated and purified from the plant as it is, from the viewpoint that the yield is good and that it does not affect the molecular weight of the resistant starch produced. Further, the raw material starch may or may not already have phosphoric acid crosslinks, but it is preferable not to have it. That is, the raw material starch is preferably starch that has not been subjected to phosphoric acid crosslinking treatment. The phosphorus content of the raw material starch is preferably 0.15% or less, more preferably 0.09% or less, and further preferably 0.03% or less. In the present specification, the phosphorus content is measured as described in the examples of the present specification in accordance with “Acetylated Phosphoric Acid Crosslinked Starch Purity Test (3)” on page 383 of Food Additives No. 9th Edition. Means a value.

According to the production method of the present invention, it is possible to obtain a resistant starch having a high resistant starch content even if the raw starch has a low resistant starch content. For example, the raw starch may have a resistant starch content of 20% or less.
“Resistant starch content” is an index showing the degree of indigestion of starch. In the present specification, the "resistant starch content" means the resistant starch content measured by the resistant starch measuring method of AOAC official method 2002.02. The resistant starch measurement method of AOAC official method 2002.02 is a method of performing digestion under conditions more in accordance with digestion in vivo as compared with the resistant starch measurement method based on the Prosky method. It is known that the measurement method has a high correlation with the result.

  Generally, starch with a high amylose content has a high resistant starch content. According to the production method of the present invention, a resistant starch having a high resistant starch content can be obtained even when the raw material starch is not a high amylose starch (a starch having a high amylose content). For example, the amylose content of the raw material starch may be less than 50% by mass, less than 40% by mass, or less than 35% by mass. In the present specification, the amylose content means the amylose content measured by the “method using an amylose precipitant” described in Starch Handbook (edited by Jiro Jiro, Asakura Shoten), page 50. According to the description of this document, the amylose content is 26 to 28% by mass for corn starch, 20 to 21% by mass for tapioca starch, and 34.5% by mass for pea starch.

  Specific examples of the raw material starch include corn starch, pea starch, rice starch, wheat starch, potato starch, tapioca starch, mung bean starch, and the like. Of these, corn starch, pea starch (Pea Starch), or potato starch is preferably used. Waxy cornstarch is preferred as the corn starch. Pea starch is a byproduct of protein extraction from peas and is preferred because it is cheaper to obtain than other starch species. In addition, pea starch has a whiter color of starch itself than other starch species, has almost no peculiar odor like the grain odor of corn starch, and has the advantage of not impairing the color and flavor of food when used in food. There is.

Although the molecular weight of the raw material starch is not particularly limited, the indigestible starch with a large molecular weight (phosphate cross-linked starch) is less susceptible to fermentation by intestinal bacteria after ingestion than the smaller one, so that It is preferable that the molecular weight is high. Specifically, the raw material starch may have a weight average molecular weight (Mw) of 5.0 × 10 ³ or more, and preferably 8.0 × 10 ³ or more. The upper limit of the molecular weight (weight average molecular weight) of the raw material starch is not particularly limited, but may be 1.0 × 10 ⁸ or less. The weight average molecular weight (Mw) is a value measured by GPC (gel permeation chromatography).

As the raw material starch, hydrolyzed starch obtained by acid-treating starch derived from various raw materials, which is a chemically modified starch, by a known method can also be used. In this case, the weight average molecular weight (Mw) of the raw starch after acid treatment is preferably 1.0 × 10 ⁴ or less. By using acid-treated raw starch, soluble components contained in the raw starch can be removed, so that the amount of sodium trimetaphosphate added can be reduced. Therefore, the phosphorus content of the obtained phosphoric acid-crosslinked starch can be further reduced.

(slurry)
In the present specification, “slurry” means either or both of a slurry containing a raw material starch and a reaction liquid containing starch and sodium trimetaphosphate during a reaction. In the present specification, the term "starch" may be used to include both the raw material starch and the produced resistant starch.
The slurry containing the raw material starch can be obtained by dissolving or suspending the raw material starch in water.
The starch concentration of the raw material starch slurry at the start of the phosphoric acid crosslinking reaction is not particularly limited, but is preferably the highest concentration within the range where the raw material starch slurry can be stirred. In the production method of the present invention, it is preferable to prepare a raw material starch slurry having the highest concentration within a stirrable range depending on the reaction system used and the performance of the stirrer. For example, the starch concentration of the raw material starch slurry at the start of the phosphoric acid crosslinking reaction may be 20% by mass or more, preferably 25% by mass or more, and more preferably 30% by mass or more. The starch concentration of the raw material starch slurry at the start of the phosphoric acid crosslinking reaction may be 50% by mass or less, and preferably 45% by mass or less. The starch concentration of the raw material starch slurry at the start of the phosphoric acid crosslinking reaction may be, for example, more than 20% by mass and 45% by mass or less.

  In the production method of the present invention, sodium trimetaphosphate may be further added during the progress of the phosphoric acid crosslinking reaction, or an alkaline solution or the like may be added for pH adjustment. Therefore, the starch concentration of the starch slurry may decrease during the progress of the phosphoric acid crosslinking reaction. When the raw material starch concentration of the starch slurry at the start of the phosphoric acid crosslinking reaction is 30% by mass or more, the starch concentration of the starch slurry at the end of the phosphoric acid crosslinking reaction is preferably 15% by mass or more, and 16% by mass or more. It is more preferable that the amount is 17% by mass or more, and it is further preferable that the amount is 17% by mass or more. By suppressing the decrease in the starch concentration of the starch slurry within the above range, it is possible to prevent a decrease in phosphoric acid crosslinking reaction efficiency and obtain a starch having a higher resistant starch content. Here, the end of the phosphoric acid crosslinking reaction means the time when all the sodium trimetaphosphate and the alkaline solution are added, and typically, the reaction liquid at the end of the phosphoric acid crosslinking reaction is a slurry after the phosphoric acid crosslinking reaction. Any starch slurry immediately before the addition of the acidic solution for neutralization may be used.

(Calcium salt and sodium salt having an action of suppressing swelling of starch)
In the production method of the present invention, the slurry containing the raw material starch contains, in addition to the raw material starch and water, a calcium salt and a sodium salt having an action of suppressing swelling of the starch.
Examples of calcium salts include calcium chloride, calcium hydroxide, calcium lactate and the like. Among the calcium salts, calcium chloride is preferred. The amount of calcium salt added to the slurry is preferably 0.1 parts by mass or more and less than 0.5 parts by mass, and 0.15 parts by mass or more and 0.4 parts by mass or less, relative to 100 parts by mass of the raw material starch. Is more preferable.

  The sodium salt having an action of suppressing the swelling of starch has an increased viscosity at the time of temperature increase when the starch slurry to which it is added is compared with the starch slurry to which it is not added, when the viscosity characteristics are analyzed by the Rapid Visco Analyzer (RVA). If it is small, it should be. The sodium salt having an action of suppressing swelling of starch can suppress gelatinization of starch.

  Examples of the sodium salt having an action of suppressing the swelling of starch include sodium chloride and sodium sulfate, and sodium chloride is preferable. The amount of sodium salt having an action of suppressing the swelling of starch to the raw material starch slurry is preferably 0.2 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the starting starch, and 0.5 It is more preferable that the amount is not less than 3.0 parts by mass and not more than 3.0 parts by mass.

  The amount of sodium salt added to the slurry is 0.1 parts by mass or more and less than 0.5 parts by mass with respect to 100 parts by mass of the raw material starch, and the sodium salt has an action of suppressing the swelling of the starch into the raw material starch slurry. The addition amount is preferably 0.5 parts by mass or more and 3.0 parts by mass or less with respect to 100 parts by mass of the raw material starch.

(Sodium trimetaphosphate)
In the production method of the present invention, sodium trimetaphosphate is used as the phosphoric acid crosslinking agent. Sodium trimetaphosphate acts on the hydroxyl groups of sugar chains present in starch to phosphorylate and crosslink the starch. By using sodium trimetaphosphate as the phosphoric acid crosslinking agent, the resistant starch can be produced by an inexpensive and safe method.

  In the production method of the present invention, the phosphoric acid crosslinking reaction using sodium trimetaphosphate is preferably performed under conditions of pH 10 to 13. The phosphoric acid crosslinking reaction of the present invention is more preferably carried out under the conditions of pH 11 to 12, more preferably about pH 11. In the present specification, to carry out the reaction under a predetermined pH condition means to bring the reaction solution of the phosphoric acid crosslinking reaction (the reaction solution containing starch and sodium trimetaphosphate during the reaction) to the above predetermined pH. . In order to maintain the condition of pH 10 to 13, an alkaline solution may be sequentially added during the reaction.

  The amount of sodium trimetaphosphate added is preferably 10 parts by mass or more, and more preferably 11 parts by mass or more, relative to 100 parts by mass (dry mass) of the raw material starch. By using 10 parts by mass or more of sodium trimetaphosphate, a resistant starch having a high phosphoric acid cross-linking degree and a high resistant starch content can be obtained.

  On the other hand, the amount of sodium trimetaphosphate added is preferably 14 parts by mass or less, and more preferably 13 parts by mass or less, relative to 100 parts by mass (dry mass) of the raw material starch. Phosphoric acid-crosslinked starch, which is a food additive, must have a phosphorus content that conforms to food additive specifications. In addition, with the increasing use of processed foods, there are now many opportunities to ingest various phosphates used as food additives. As a result, excessive intake of phosphate has become a problem, and resistant starch with low phosphorus content is desired. By adjusting the amount of sodium trimetaphosphate added to 14 parts by mass or less, preferably 13 parts by mass or less, with respect to 100 parts by mass (dry mass) of the raw material starch, a phosphoric acid-crosslinked starch having a phosphorus content according to the food additive standard is obtained. The indigestible starch consisting of

  Particularly, the addition amount of sodium trimetaphosphate is preferably 11 parts by mass or more and 13 parts by mass or less with respect to 100 parts by mass (dry mass) of the raw material starch.

  Sodium trimetaphosphate is usually added as it is to the starch slurry in powder form. Further, sodium trimetaphosphate may be added to the starch slurry at once or sequentially. In the case of sequential addition, it is preferable that the total addition mass of sodium trimetaphosphate be within the above-mentioned addition total mass range. Sodium trimetaphosphate is preferably added to the starch slurry all at once.

(Phosphoric acid crosslinking reaction)
The phosphoric acid crosslinking reaction is initiated by the addition of sodium trimetaphosphate. The raw starch slurry is preferably adjusted to pH 10 to 13 before adding sodium trimetaphosphate. The pH may be adjusted to 10 to 13 by adding an alkaline solution. After adjusting the pH to 10 to 13, it is preferable to further provide a step of stirring with the starch slurry only for 10 minutes to 1 hour, preferably about 30 minutes.

The starch slurry is preferably stirred during the phosphoric acid crosslinking reaction. This is for maintaining a uniform component concentration and pH throughout the starch slurry in the container.
The temperature of the starch slurry during the phosphoric acid crosslinking reaction may be 20 ° C to 70 ° C, preferably 30 ° C to 50 ° C, more preferably about 40 ° C.

(Alkaline solution)
In order to adjust the pH of the slurry, it is preferable to appropriately add an alkaline solution to the slurry. Examples of the alkaline solution include an aqueous solution of an alkali metal hydroxide, an aqueous solution of an alkaline earth metal hydroxide, an aqueous solution of an alkali metal carbonate, and an aqueous NaOH solution (sodium hydroxide solution) or an aqueous KOH solution ( An aqueous solution of potassium hydroxide) is preferred, and an aqueous solution of NaOH is more preferred.

  The concentration of the alkaline solution to be added may be, for example, in the range of 1% by mass to 20% by mass when an NaOH aqueous solution is used as the alkaline solution. The concentration of the alkaline solution is preferably as high as possible within the range where the starch does not gelatinize, depending on the starch concentration of the starch slurry. The range in which the starch does not gelatinize can be confirmed, for example, by confirming that the starch in the starch slurry has a crystal structure. The presence or absence of a crystal structure can be confirmed using, for example, a polarization microscope. In a polarization microscope, a specific birefringence called a polarization cross is observed when it has a crystalline structure (not gelatinized).

(Post-reaction treatment)
After the reaction, the reaction solution is adjusted to near neutrality (pH 4 to 7, preferably pH 6). The adjustment may be performed with a hydrochloric acid solution (HCl). The time from the start of sodium trimetaphosphate addition to HCl addition varies depending on conditions such as the reaction temperature, but is usually 10 minutes to 24 hours, preferably 1 hour to 6 hours, and more preferably more than 3 hours and 5 hours or less. .

  After the completion of the reaction, water is added to the starch slurry adjusted to pH 4 to 7, washed and dehydrated, and then dried to obtain a dry resistant starch.

<Indigestible starch>
In the production method of the present invention, for example, the resistant starch content according to the resistant starch measuring method of AOAC official method 2002.02 is preferably 30% or more, more preferably 33% or more, still more preferably 35% or more. It can be used to produce digestible starch. Further, according to the production method of the present invention, the phosphorus content of the phosphoric acid-crosslinked starch obtained is preferably 0.54% or less, more preferably 0.52% or less, still more preferably 0.49% or less, still more preferably 0. It can be suppressed to 0.46% or less.

Since the resistant starch obtained by the production method of the present invention has a high resistant starch content, it can be used as a material for functional foods that improve the quality of life and improve or prevent diseases like dietary fiber. . For example, the phosphate cross-linked starch obtained by the production method of the present invention can be expected to improve insulin responsiveness, improve intestinal function, and improve symptoms related to blood fat. The phosphoric acid cross-linked starch obtained by the production method of the present invention can be used, for example, by substituting a part or all of starch for foods and the like containing starch as a component.
Further, the production method of the present invention makes it possible to obtain resistant starch having a low phosphorus content. Such resistant starch can be used as a food additive.

  According to a preferred embodiment of the present invention, the phosphate-crosslinked starch obtained by the production method of the present invention is a pea-derived indigestible starch. Pea starch, which is the raw material, has a whiter starch color than other starch species, has almost no peculiar odor like the grain odor of corn starch, and does not impair the color and flavor of food when used in food. Because of the advantages, the peas-derived phosphate-crosslinked starch has almost no peculiar odor. Therefore, the peas-derived phosphate cross-linked starch is particularly used for noodles represented by udon, pasta, etc., where flavor and color are important; baked confectionery such as bread, cheese, cake; Japanese confectionery such as dango; yogurt, etc. By applying it to dairy products, etc., physiological effects peculiar to resistant starch can be expected.

  The features of the present invention will be described more specifically below with reference to Examples and Comparative Examples. Materials, usage amounts, ratios, processing contents, processing procedures, and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be limitedly interpreted by the following specific examples.

In the examples, the description "%" indicates "mass%".
In the examples, the measurement of the resistant starch content (RS content) was carried out by a reagent kit (AOAC method 2002.02) manufactured by Megazyme.
In addition, in the examples, the phosphorus content was measured according to the following procedure in accordance with “Acetylated Phosphoric Acid Crosslinked Starch Purity Test (3)” on page 383 of Food Additives Standards Edition 9th Edition.

1. About 10 g of sample starch (M (g) in dry mass) is precisely weighed into a crucible, and 10 ml of zinc acetate test solution is added.
2. The crucible is heated on a hot plate to evaporate the contents to dryness and further heated to carbonize the sample starch.
3. The crucible is then placed in an electric furnace (550 ° C.) and heated for 1-2 hours until there is no carbide.
4. Remove the crucible from the electric furnace, cool to room temperature, add about 15 mL of distilled water to the crucible, wash the vessel wall of the crucible with a nitric acid solution (diluted concentrated nitric acid 3 times), heat on a hot plate and boil.
5. After cooling, the contents of the crucible are transferred to a 200 mL volumetric flask and the volume is raised.
6. Accurately measure this solution (VmL) in a test tube, and add distilled water (WmL) to make a total of 3.5 mL. Next, 0.5 mL of nitric acid solution and 0.5 mL of vanadic acid test solution are added and stirred.
Add 0.5 mL of ammonium molybdate test solution for processed starch to the test tube of 7.6 every 30 seconds of each sample, stir well to develop color, and use this as the test solution.
8.7. After 10 minutes from the addition of the ammonium molybdate reagent solution, the absorbance is measured with a spectrophotometer (460 nm).
9. Take 0 mL, 0.5 mL, 1.0 mL, and 1.5 mL of the monopotassium phosphate standard solution (P = 50 ppm) in each test tube, and add distilled water to each test tube so that the total amount becomes 3.5 mL.
10. Sample Same as starch sample 6. The following operations are performed to measure the absorbance, and a calibration curve for the phosphorus concentration and the absorbance is obtained.
11. The phosphorus concentration in the test solution is obtained from the calibration curve, and the phosphorus content in starch is calculated from the following formula.
Phosphorus content (%) = phosphorus concentration in test solution (mg / mL) x 100 test solution V (mL) x sample starch dry mass M (g)

<Production of resistant starch>
Pea Starch (manufactured by PURIS) or waxy corn starch (manufactured by Japan Food Processing Co., Ltd., water content 14.57%) was used as a raw material starch, and was manufactured by the following procedure.
In a 1 L beaker, 200 g of dry mass of raw material starch was dissolved in distilled water. Pea Starch was made to have a raw material starch concentration of 30% by mass, and waxy corn starch was made to have a raw material starch concentration of 40% by mass. The obtained slurry was placed in a constant temperature water bath and kept at 40 ° C., and 2 g of sodium chloride (1.0% by mass relative to the mass of the raw material starch) and 0.4 g of calcium chloride dihydrate (0 relative to the mass of the raw material starch). 0.2% by weight) was added. The pH of the slurry was adjusted to 11.5 by adding 3% NaOH. After reaching pH 11.5, the mixture was stirred for 30 minutes as it was. The slurry was maintained at 40 ± 1 ° C. and pH 11.5 ± 0.3 during the reaction. Sodium trimetaphosphate (Yoneyama Chemical Industry Co., Ltd.) was added to the slurry so that the addition rate was as shown in Table 1 with respect to the mass of the raw material starch, and the reaction was started while stirring at 400 rpm. Four hours after the start of the reaction, the pH was adjusted to 6.0 ± 0.1 with 7% HCl. After centrifugally diluting and washing with 400 g of water using a centrifugal dehydrator, displacement washing with 400 g of water was performed and dehydration was performed. It was dried in a 70 ° C tray dryer.

Each of the obtained indigestible starches was analyzed using a Rapid Visco Analyzer (RVA) (Newport Scientific RVA4500) to obtain an RVA viscosity graph. The results are shown in FIGS.
Table 1 shows the RS content, phosphorus content, and RVA peak value of each obtained indigestible starch.

  From the results shown in Table 1, calcium chloride and calcium chloride were added in an example in which sodium trimetaphosphate was added in the range of 10 parts by mass or more and 14 parts by mass or less relative to 100 parts by mass of the raw material starch, and a higher RS content was obtained. It can be seen that the resistant starch which is possessed is obtained.

Claims (11)

A method for producing a resistant starch, comprising:
Comprising adding sodium trimetaphosphate to the slurry containing the raw starch,
The slurry contains a calcium salt and a sodium salt having an action of suppressing swelling of starch,
The method for producing the indigestible starch, wherein the addition amount of the sodium trimetaphosphate is 100 parts by mass or more and 14 parts by mass or less based on 100 parts by mass of the raw material starch. The method for producing indigestible starch according to claim 1, wherein the amount of the sodium trimetaphosphate added is 100 parts by mass or more and 11 parts by mass or more and 13 parts by mass or less based on 100 parts by mass of the raw material starch. The method for producing a resistant starch according to claim 1, wherein the calcium salt is calcium chloride. The method for producing a resistant starch according to any one of claims 1 to 3, wherein the sodium salt is sodium chloride or sodium sulfate. The method for producing a resistant starch according to claim 4, wherein the sodium salt is sodium chloride. The amount of the calcium salt added to 100 parts by mass of the raw material starch is 0.1 parts by mass or more and less than 0.5 parts by mass, and the amount of the sodium salt added to 100 parts by mass of the raw material starch is 0.5 parts by mass. It is above 3.0 parts by mass, and the method for producing resistant starch according to any one of claims 1 to 5. The method for producing a resistant starch according to any one of claims 1 to 6, wherein the raw starch has a resistant starch content of 20% or less according to the resistant starch measurement method of AOAC Official Method 2002.02. The method for producing indigestible starch according to claim 1, wherein the raw starch has an amylose content of less than 40% by mass. The method for producing an indigestible starch according to any one of claims 1 to 8, wherein the raw material starch is waxy starch or pea starch. The method for producing indigestible starch according to any one of claims 1 to 9, wherein the slurry is adjusted to have a pH of 10 to 13 before addition of the sodium trimetaphosphate. The method for producing a resistant starch according to any one of claims 1 to 10, wherein the slurry is stirred for more than 3 hours after the addition of the sodium trimetaphosphate.