JP3530567B2 - Method for producing resistant starch - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing resistant starch.

[0002]

2. Description of the Related Art In recent years, excessive intake of calories has become a problem due to obesity, and many low-calorie foods have been developed. Moreover, conventionally, the fiber contained in food has been regarded as unnecessary because it is not digested in the digestive tract, but recently, it has been noted that it is effective for maintaining health and preventing diseases. As the ones that contain a lot of this dietary fiber, there are grain hulls and bran, and there are also processed ones, but these are insoluble in water, and when used in food, they give a rough texture and impair the texture. Or Also,
Although water-soluble dietary fibers include natural gums and the like, their high viscosity makes it difficult to use them in large amounts in foods.

On the other hand, taking starch as an example, starch and processed products of starch such as α-starch, roasted dextrin, derivatives, glucose, starch syrup and multi-dextrin are used as food materials in large amounts in various processed foods. Has been done. However, most of these processed starch products contain 5% of indigestible ingredients.
(W / w) or less. Although only a few roasted dextrins are known as indigestible starches, the proportion of indigestible components in roasted dextrins is 30% (w /
w) No more. Recently, there has been reported a method for producing indigestible dextrin by using this roasted dextrin as a starting material to increase the indigestible component by an enzymatic reaction (Japanese Patent Laid-Open No. 5-148301). Specifically, about a few percent (3 to 10) of an aqueous acid solution having a concentration of about 1% is added to the raw starch.
%) Is added, and the mixture is roasted at 150 to 200 ° C. for 10 to 120 minutes to obtain roasted dextrin, and then α-amylase and glucoamylase are allowed to act on the activated carbon for decolorization and purification through an ion exchange resin. However, in this method, it is necessary to lengthen the heating time in order to improve the indigestible component ratio, but as the roasting progresses, the coloring progresses and the astringent taste increases, giving a unique heating odor. Come on. In addition, roasting at a high temperature requires a refining operation such as decolorization, so the roasting temperature is 15
It will be limited to about 0 ° C. to 200 ° C., and further treatment of enzymes such as amylase treatment and α-glucosidase treatment will improve the indigestible component.
Therefore, there is a problem in the manufacturing process that a large amount of enzyme chemicals are required and a decoloring operation is also required.

It is also known that the physical properties of starch are changed by wet heat treatment of starch. Changes in the physical properties of starch due to heat-moisture treatment include changes in equilibrium water content,
Changes in X-ray diffraction pattern, changes in swelling property of starch granules, increase in gelatinization start temperature, etc. are known. Furthermore, 3.5 times water was added to high amylose corn starch, and the temperature was kept at 134 ° C for 7 hours.
It is known that a resistant starch that is not decomposed by α-amylase is produced by performing heat treatment for 0 minutes twice (starch science 40, No. 3, p. 285-290, 1993). However, in this method, no acid treatment is performed, so that the starch is less likely to be decomposed and the relative humidity in the autoclave is 10
There is a problem that the wet heat treatment at 134 ° C. for 70 minutes under the condition of 0% is required twice, and the content rate is low at about 28% (w / w).

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to easily and easily produce an indigestible starch having less coloring and heating odor and less monosaccharide and oligosaccharide contents by heat-moisture treatment at a lower temperature and a shorter time than before. It is to provide a method which can be obtained in high yield.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have introduced a moist heat treatment with a low water content in a starch hydrolysis process using an acid catalyst. As a result, they have found that resistant starch can be efficiently produced, and completed the present invention.

That is, the present invention is characterized in that the acid-treated starch is used as a raw material, and the wet heat treatment is carried out at 130 ° C. to 140 ° C. while maintaining the moisture content thereof at 3 to 7% (w / w). It is a method for producing resistant starch.

In the present invention, the resistant starch is defined as a dietary fiber which is a food component which is resistant to and digestible.
It means an indigestible component produced from starch as a raw material.

The starch which can be used in the present invention includes grain starch such as corn starch, potato starch, rice starch and wheat starch. Corn starch is preferable because of its low price and easiness of reaction. The starch used in the present invention has a water content of about 10% (w / w).

The acid treatment in the present invention is 0.03 to 0.1% (w / w), preferably 0.0 to the above starch.
It is carried out by equilibrium adsorption of 5 to 0.07% (w / w) of an inorganic acid such as hydrochloric acid, sulfuric acid or nitric acid, preferably hydrochloric acid, on starch for 10 to 30 minutes at room temperature. 0.1% (w /
w) Addition of more than this causes side reaction (Maillard reaction), caramelization and intense coloring, and 0.03%
When the concentration is lower than (w / w), the yield of resistant starch becomes poor. When acid treatment is not carried out, most of the starch binding patterns after heat-moisture treatment are digestive α-1 → 4 bonds.
The acid treatment is essential for the production of resistant starch.

Next, the acid-adsorbed starch is separated by filtration, dried by air drying and vacuum drying, and the water content thereof is 3 to 7% (w / w).
w). The low water content as described above means that the presence of water contained in the starch used as a raw material promotes the production of glucose or reducing sugars associated with the decomposition of starch by the heat-moisture treatment, and at the same time, the reaction of producing indigestible starch. This is because the amount of monosaccharides and oligosaccharides is reduced and the content of resistant starch is increased by lowering the water content in order to inhibit the amount and lead to higher molecular weight.

After that, the dried acid-adsorbed starch is packed in a heat-resistant Teflon tetra-pack, and then deaerated to prevent the tetra-pack from exploding and sealed. In this case, the container is not limited to this as long as it is heat resistant and pressure resistant and can be hermetically sealed, and degassing is not necessary when using the heat resistant pressure resistant container. After sealing, in a constant temperature incubator, 130 ℃ ~ 14
30 minutes at 0 ° C, 30 to 60 minutes, preferably about 135 ° C
Wet heat treatment for a minute.

Starch that has been subjected to the moist heat treatment dissolves in water,
Adjust. Any ordinary alkali can be used to adjust the pH, but sodium carbonate is preferably used. After adjusting the pH to 5-5.5, preferably pH 5.2 with an aqueous sodium carbonate solution, the water-insoluble fraction is removed by centrifugation. Repeat this procedure for water-insoluble fraction 2-3
Repeat repeatedly to collect the supernatant and concentrate under reduced pressure. The concentrated supernatant is poured into alcohol with stirring, the alcohol-insoluble fraction is separated by centrifugation, and the supernatant is removed.
As the alcohol, any alcohol such as ethanol and methanol can be used, and acetone may be used. The separated precipitate is washed several times with alcohol and dehydrated repeatedly, then the alcohol is removed and air-dried. The powder obtained by the above operation is defined as indigestible starch-containing dextrin. By this alcohol treatment, a part of the coloring substance and the low molecular weight sugar is removed. In addition, a method of assimilating the low-molecular-weight sugar into baker's yeast can also be used for removing the low-molecular-weight sugar. Thus, a dextrin containing an indigestible starch having an average molecular weight of about 2000 and an indigestible starch content of about 60% (w / w) can be obtained with high efficiency.

[0014]

EXAMPLES The present invention will be specifically described below with reference to Examples and Experimental Examples, but the scope of the present invention is not limited by these. The measuring methods used in the examples and the experimental examples will be described below as reference examples.

Reference Example (1) Measurement of Indigestible Starch Content Measurement of the indigestible starch content was carried out by the Prosky-AOAC method (J. Assoc. Off. Anal. .
Chem., 71, 1017-1023, 1988). Accurately weigh 1 g of sample, and add 0.06 M phosphate buffer (pH 6.0) 5
0 ml was added, the pH was adjusted to 6.0 with 1N-NaOH, 0.1 ml of Termamyl (α-amylase manufactured by Novo Co.) was added, and the mixture was reacted at 90 ° C. for 60 minutes. After cooling, 1N-N
The pH is adjusted to 7.5 with aOH, 5.0 mg of protease (Sigma) is added, and the mixture is reacted at 90 ° C. for 60 minutes. Then, 5.0 ml of 1 M acetate buffer (pH 4.5) was added, cooled, adjusted to pH 4.5 with 0.5 M phosphate buffer, 0.1 ml of amyloglucosidase (Sigma) was added, and the temperature was 60 ° C. React for 60 minutes. After this, 60 ℃
Ethanol (99.5% (v / v)) was added, left for 1 hour or more, dehydrated twice with 30 ml ethanol, washed twice with 10 ml acetone, dried under reduced pressure, weighed, and indigestible The amount of natural starch.

(2) Measurement of average molecular weight Dissolve a sample in water and use a sample solution prepared to a concentration of 1000 ppm (W / W), and perform measurement by high performance liquid chromatography under the following conditions. Column: Tosoh G3000PWXL 30 cm Temperature: 40 ° C. Eluent: Water flow rate: 1 ml / min. Detector: RI Standard sample: oligosaccharide α-1,4mix [M. P. vinegar shop (MW 2000)] Maltopentaose Maltotriose

(3) Method for examining glycoside bond mode The glycoside bond mode is determined by the following methylation method [R. Gonda e
t al., Chem. Pham. Bull., 38 (10), 2771-2774 (199
[0)], and after hydrolysis, each glycosidic bond is quantified by gas chromatography to investigate.

A methylated and dehydrated sample (10 mg) was placed in a test tube with a screw for 1 m.
Add 1 liter of dehydrated DMSO and dissolve. To this is added 100 mg of NaOH and immediately 0.5 ml of methyl iodide. After replacement with nitrogen gas, the mixture was reacted with stirring with a stirrer for 1 to 2 hours, and 5 ml of water was added. To this, 5 ml of chloroform was added and shaken well, and the chloroform layer was transferred to an Erlenmeyer flask. The same operation is repeated 5 times, 25 ml of distilled water is added to the chloroform layer taken in the Erlenmeyer flask, and after shaking, the operation of collecting the chloroform layer is repeated 3 times. Next, it is dried under reduced pressure by an evaporator.

Confirmation of Complete Methylation After dissolving the sample with 1 to 2 ml of chloroform, IR is measured with chloroform as a control to confirm that there is no hydroxyl group.

Separation Sephadex LH-20 (Pharmacia) is used to separate the sugar fraction. Solvent is chloroform: methanol =
The sample is dissolved in 1 ml of solvent using 2: 1 and separated.
After confirming the sugar fraction by the phenol-sulfuric acid method, it is collected and dried under reduced pressure.

To the hydrolyzed methylated product, 1 to 2 ml of 90% (w / v) formic acid is added to perform nitrogen gas replacement, and the mixture is reacted at 100 ° C. for 3 to 8 hours and dried under reduced pressure. 1-2M trifluoroacetic acid 1-2
Add ml, replace with nitrogen gas and seal. The mixture is reacted at 100 ° C. for 3 to 10 hours and dried until trifluoroacetic acid is completely removed.

The reduced hydrolyzate is dissolved in 1 to 2 ml of 50% (v / v) or less of ethanol, 5 to 10 times the amount of sodium borohydride of the sample is added, and the mixture is left at room temperature for 2 to 4 hours. Amberlite CG-120 [H ⁺ ] (manufactured by Organo Corporation) is suspended in distilled water and added little by little to a sample. Add a sufficient amount and let stand for 10 minutes or more. After filtration, the residue is washed with 50% ethanol, further 99.5% (v / v) ethanol, and then dried under reduced pressure. After drying under reduced pressure, the precipitated boric acid crystals are dissolved in 5 to 10 ml of methanol and dried under reduced pressure. This operation is repeated twice.

To the acetylated sample, 0.3 ml of pyridine is added and dissolved, and then 0.3 ml of acetic anhydride is added. 95-100 on oil bath
The mixture is reacted at 90 ° C. for 90 to 120 minutes, and cooled after the reaction. Add 1 ml of toluene, concentrate under reduced pressure at 40 ° C. or lower, and dry to dryness.

The dissolved sample is dissolved in 0.5 ml of chloroform and analyzed by gas chromatography.

Conditions for gas chromatography [TIC] Mode: MF-EI [Pos.] Carrier gas: He 1.14 cm ³ / min Capillary column: 0.25 mm, 3m, HiCap-CBP10 (GL Science) 120 scan / min

Example 1 Commercially available corn starch 500
g was treated with 1 L of 0.05% (w / w) dilute hydrochloric acid aqueous solution for 10 minutes, filtered through filter paper, and air dried. It was dried under reduced pressure at room temperature to a water content of 5% (w / w). This acid-adsorbed starch was packed in a heat-resistant Teflon tetra pack and degassed.
The wet heat treatment was carried out at a temperature of 30 minutes in a constant temperature incubator. After the moist heat treatment, a 35% (w / w) aqueous solution was prepared to adjust the pH to 5.2, and then the water-insoluble fraction was removed by centrifugation. This operation was repeated twice for the water-insoluble fraction, and the supernatant was collected and concentrated under reduced pressure. The concentrated supernatant was poured into ethanol while stirring, and the ethanol-insoluble fraction was separated by centrifugation to remove the supernatant. The separated precipitate is
After repeating washing with ethanol several times and dehydration, ethanol was removed and air-dried to obtain dextrin containing indigestible starch. Indigestible starch was quantified according to the dietary fiber quantification method (Prosky-AOAC method), and the content was 64% (w / w)
And 202 g of resistant starch was obtained. As is clear from this result, the content of the indigestible component in the dextrin containing the indigestible starch produced by the present invention is high, and therefore it can be said that it is extremely indigestible. The average molecular weight was 2000, and the content of monosaccharides and oligosaccharides having a polymerization degree of 2 to 9 was 6.9%.

Example 2 200 ml of 100 g of rice starch
Was treated with a 0.05% (w / w) dilute hydrochloric acid aqueous solution for 10 minutes, filtered through filter paper, and air dried. Water content of 5% at room temperature
It was dried under reduced pressure to (w / w). The acid-adsorbed starch was packed in a pressure-resistant glass container and subjected to wet heat treatment at 140 ° C. for 30 minutes in a constant-temperature incubator. After the moist heat treatment, a 35% (w / w) aqueous solution was prepared to adjust the pH to 5.2, and then the water-insoluble fraction was removed by centrifugation. This operation was repeated twice for the water-insoluble fraction, and the supernatant was collected and concentrated under reduced pressure. The concentrated supernatant was poured into ethanol while stirring, and the ethanol-insoluble fraction was separated by centrifugation to remove the supernatant. The separated precipitate was repeatedly washed with ethanol and dehydrated several times, then ethanol was removed and air-dried to obtain dextrin containing indigestible starch. Dietary Fiber Assay (Pros
As a result of quantifying the resistant starch according to the ky-AOAC method), the content was 60% (w / w), and 48 g of resistant starch was obtained.

[Experimental Example 1] Relationship between moist heat temperature and indigestible starch production rate (method) The acid content of the acid-adsorbed starch treated with corn starch as the raw material in the same manner as in Example 1 was 7% ( w / w), 125, 130, 13
Wet heat treatment was performed at temperatures of 5, 140, and 145 ° C. for 30 minutes. Then, it was recovered by ethanol treatment and the content of resistant starch was measured by the Prosky-AOAC method. (Results) As shown in FIG. 1, in the range of 130 to 140 ° C., the production rate of the indigestible component was 30% or more, but 145
The production rate remarkably decreased at ℃ and 125 ℃.

[Experimental Example 2] Relationship between water content and indigestible starch production rate (method) Regarding acid-adsorbed starch treated with acid from corn starch in the same manner as in Example 1, the water content was 3, While maintaining at 5, 7, 10, 15% (w / w),
The wet heat treatment was performed at 135 ° C. for 30 minutes. Then, it was recovered by ethanol treatment and the content of resistant starch was adjusted to Prosky-A.
It was measured by the OAC method. (Result) As shown in FIG. 2, the water content is 7% (w / w)
In the range below, the production rate of resistant starch was 30% or more, but it was observed that the production rate tended to decrease as the water content rate increased.

[Experimental Example 3] Examination of glycoside binding mode of produced indigestible starch (method) Acid-adsorbed starch treated with acid in the same manner as in Example 1 and non-adsorbed acid not treated with acid for comparison Using starch as a sample, the acid-adsorbed starch was subjected to wet heat treatment at 135 ° C. for 30 minutes, and the acid-unadsorbed starch was subjected to wet heat treatment at 135 ° C. for 3 hours while maintaining the water content at 5% (w / w). After wet heat treatment, it was recovered by ethanol treatment to obtain indigestible starch. The binding mode of each indigestible starch was measured by subjecting the sample to methylation, hydrolysis and reduction, and acetylation, followed by GLS-M.
It investigated by the S method. (Results) In the acid-adsorbed starch, the formation of α-1 → 6 bond and a slight amount of α-1 → 2 bond was observed. On the other hand, in the acid-unadsorbed starch, most of the α-1 → 4 bonds were observed, and other bonds were hardly observed (Fig. 3). Also, Prosky-AOA
The indigestible starch content measured by the C method was 4% (w /
w).

[0031]

EFFECTS OF THE INVENTION According to the method for producing indigestible starch of the present invention, the indigestion with less coloring and heating odor and less content of monosaccharides and oligosaccharides can be achieved by wet heat treatment at a lower temperature and a shorter time than before. Starch can be easily obtained in high yield. Moreover, since the resistant starch produced by the method of the present invention is extremely resistant to digestion and has low calories, it is used as a low-calorie food material for people who need to restrict intake of calories and carbohydrates, and It can be used by being added to and mixed with many foods such as soft drinks, ice creams, breads, dressings, candies and fish paste products.

[Brief description of drawings]

FIG. 1 shows the relationship between moist heat temperature and production rate of resistant starch.

FIG. 2 shows the relationship between the water content rate and the indigestible starch production rate.

[Fig. 3] Fig. 3 shows changes in the glycoside binding mode of acid-adsorbed starch and acid-unadsorbed starch.

Continuation of front page (56) References JP-A-5-148301 (JP, A) JP-A-3-84001 (JP, A) JP-A-4-130102 (JP, A) Tsuneo Kobayashi, pancreas of heat-treated starch Degradability by α-amylase and formation of resistant starch by heat-moisture treatment, Starch Science, 1993, Vol. 40, No. 3, 285-290 (58) Fields investigated (Int. Cl. ⁷ , DB name) C08B 30/00-30/20 JISST file (JOIS)

Claims (2)

(57) [Claims] 1. A starch obtained by acid treatment is used as a raw material, and the moisture content thereof is maintained at 3 to 7% (w / w) while maintaining the temperature at 130.degree.
A method for producing indigestible starch, which comprises performing a heat-moisture treatment at 140 ° C. 2. The acid treatment is performed in the range of 0.03 to 0.
The method for producing indigestible starch according to claim 1, wherein 1% (w / w) of an inorganic acid is equilibrated and adsorbed on the starch.