JPH09278802A - Production of aging-resistant starch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an aging-resistant starch having an excellent aging resistance, a high safety and an excellent taste by heat-treating a starch with fructose or a saccharide mainly comprising fructose in the presence of an acid under a dry condition. SOLUTION: 3 to 50 pts.wt. fructose or saccharide containing the same amount of fructose is added to 100 pts.wt. starch and 0.01 to 5 pts.-wt. acid, preferably an organic acid, is added to the obtained mixture. The resultant mixture is heat-treated at 60 to 200 deg.C for 10 min to 5 hr under a dry condition to obtain an aging-resistant starch. By this treatment, the intended aging-resistant starch having a desired viscosity either higher or lower than that of the starting starch can be obtained without reducing the mol. wt. of the starch. This starch is useful in the field of processed foodstuffs such as boiled pastes of marine products, raw or half-cooked foods, boiled and frozen noodles, Japanese-style and Western-style cakes, and boiled rice.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an aging-resistant starch, which is excellent not only in aging resistance but also in texture and safety and is required to have quality stability during production and storage. The present invention relates to a method for producing starch useful in the field, particularly in the field of processed foods requiring refrigeration, freezing, or microwave resistance.

[0002]

2. Description of the Related Art In recent years, along with the diversification of living environment such as the nuclear family and the increase of working women, the tendency toward instant home meals has increased, and the market for take-away foods such as side dishes has expanded rapidly. As a result, there is an increasing demand for cooked foods or foods with a simplified cooking process. Reflecting these trends, there is a strong demand for the development of starch suitable for the production of processed foods having refrigeration, freezing and microwave oven resistance. In order to meet these requirements, phosphoric acid crosslinked starch has been used as an aging resistant starch. But,
In addition to natural-oriented health food mood, ingesting a large amount of phosphate cross-linked starch causes calcium excretion from the body,
The danger to health is pointed out. Therefore, the demand for starch as a food material that contributes to the improvement of storage stability of processed foods and is friendly to human health is increasing not only in Japan but also in Western countries.

When processed foods are consumed within a few days after production, regardless of the type of starch used as a raw material,
There is almost no problem in terms of quality. However, after the processed food is manufactured, it is stored frozen at -25 ° C for 1 month or more,
In processed foods where the texture does not change and in particular water separation is not required, when ordinary starch is used, the starch ages and water separation occurs within a few days, so satisfy these requirements. I can't. On the other hand, if the phosphoric acid cross-linked starch is used, the processed food can withstand storage for several months, but there is a fear of unnatural texture and offensive odor and human health.

[0004]

Ordinary starch forms particles having a size of several microns to several tens of microns, and when its water suspension is heated, the particles absorb water as the temperature rises. Begins swelling. When heating is further continued, the particles disintegrate at around 90 ° C., and the starch molecules are dispersed in water to form a so-called glue solution. The starch molecules in the paste solution start to reassociate or recrystallize with cooling. As a result, the viscosity of the paste solution increases and eventually forms a gel. This phenomenon is called aging.

Aging of a low-concentration starch paste solution causes an increase in viscosity and precipitation of fine crystals. With a high-concentration paste solution, as aging progresses, the fluidity is completely lost and an elastic solid or brittle solid is formed. This phenomenon causes deterioration of food quality. The aging phenomenon usually occurs more easily at lower temperatures,
Especially, it is said that it is most likely to occur near 0 to 5 ° C. As described above, since the temperature at which bacterial growth is suppressed and the temperature at which aging is promoted coincide with each other, aging of starch has become an important issue to be solved in low temperature distribution and low temperature preservation foods.

As one of the methods for suppressing aging, conventionally, a method of introducing an acetic acid group, a phosphoric acid group, a hydroxyethyl group or the like into the hydroxyl group of glucose, which is a constituent unit of starch, has been adopted. Due to the presence of these substituents,
It tries to prevent the aging by hindering rearrangement of starch molecular chains in three dimensions. In the past, esterified starch (eg, acetic acid, stearic acid starch, etc.) and etherified starch (eg, hydroxyethylated, hydroxypropylated starch, etc.) have been manufactured to improve aging resistance. However, as a food additive, many substances that improve aging resistance are not allowed to be added to the food in an amount of 2% or more. Further, the aging resistance is not satisfactory except for the phosphate cross-linked starch.

As another method of suppressing the aging of starch, a method of heating and roasting starch is known (supervised by Jiro Nikuni, "Starch Science Handbook" p.496-500 (1982) Asakura Shoten). The roasted dextrin is obtained by heating starch in the presence or absence of an acid. The heat treatment conditions for British gum obtained by roasting without addition of acid are 135 to 220 ° C. and 10 to 20 hours. In addition, with white dextrin to which mineral acid is added, 8
3-8 hours at 0-120 ° C, 1 for yellow dextrin
It is 6 to 18 hours at 50 to 220 ° C.

In this reaction, when water is present and the temperature is low and the temperature is low, 1% of glucose constituting the main chain and branches of starch is converted into
The 4 and 1 → 6 glycosidic bonds are decomposed to lower the molecular weight, resulting in a decrease in viscosity and an increase in reduction value. On the other hand, 160
In the high temperature stage above ℃, the cold water solubility increases and the reduction value decreases. That is, the molecules broken at the initial stage undergo a transition / re-association to have a new highly branched structure. As the structure, glucose, which is a constituent of starch, is mainly composed of 1 → 4, 1 → 6 glycosidic bonds, and there are also trace amounts of 1 → 3, 1 → 2 glycosidic bonds. Such a high branching structure prevents starch recrystallization,
Prevent aging.

The viscosity of the roasted dextrin thus obtained is affected by lowering the molecular weight, and the 10% solution of British gum and yellow dextrin shows a low value of 10 cps or less at 27 ° C. On the contrary,
The viscosity of the raw corn starch is extremely higher than that of dextrin, and cannot be measured under the same measurement conditions because it exceeds the measurement range of the viscometer. Therefore, when a 5% solution with a reduced concentration is measured at 99 ° C, it shows 500 cps or more.
Thus, the viscosity of roasted dextrin is extremely low, and therefore it cannot be used in applications requiring ordinary viscosity as starch. Therefore, phosphoric acid crosslinked starch having excellent aging resistance cannot be substituted. Under such circumstances, the development of a starch that is health-friendly, has excellent aging resistance, has the same viscosity as that of the raw material starch, and is easy to industrially produce is awaited.

By the way, a reaction similar to the transfer / re-association that occurs in the process of producing dextrin converts starch into galactose,
It has long been known that these monosaccharides are incorporated into starch molecular chains when heated in the presence of an acid together with monosaccharides such as xylose (edited by Michinori Nakamura and Keiji Kainuma, “Starch-related Experimental method for carbohydrates "p.282-283 (1986) Academic Publishing Center). For example, waxy corn starch 26
g and D-xylose together with 1.2 ml of 2.4N hydrochloric acid,
Heating at 140 ° C. for 3 hours produces a starch with 0.19 xylose molecules bound per 100 glucose molecules. However, the obtained starch is soluble in cold water. That is, in the presence of excess hydrochloric acid, heat treatment under severe conditions of 140 ° C. for 3 hours causes a decomposition / transfer reaction similar to that of normal roasted dextrin, resulting in a sharp decrease in molecular weight, low molecular weight, and low molecular weight. Only viscous products can be obtained. By reducing the amount of the inorganic acid, it is possible to prevent the viscosity from decreasing, but the monosaccharide uptake reaction also decreases, and the aging resistance becomes significantly poor.

[0011]

In view of the above situation, the present inventors have conducted extensive studies on a method for improving the aging resistance of starch, and as a result, have determined that starch contains fructose or fructose as a main component. In the presence of the sugar to be used and the same acid as in the conventional roasting method, preferably an organic acid, heat treatment is performed at 60 to 200 ° C. for 10 minutes to 5 hours to suppress viscosity decrease and to efficiently convert the sugar into starch. I succeeded in combining them well. Thus, the inventors have found that a starch having excellent aging resistance (particularly resistance to refrigeration, freezing or microwave oven) can be efficiently obtained, and arrived at the present invention.

According to the present invention, starch is fructose or a sugar having fructose as a main component in the presence of an acid under dry conditions of 60 to 200.
The present invention relates to a method for producing an aging resistant starch, which comprises performing a heat treatment at 10 ° C. for 10 minutes to 5 hours.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The method of the present invention, which comprises heating starch with fructose in the presence of an acid, particularly a trace amount of an organic acid, has the following advantages. That is, all of the starch, fructose and acid used are substances widely recognized as natural products or foods or food additives, and the conditions for mixing these components and heating at a temperature of about 100 ° C. for several hours are: , It is a condition often used in normal food cooking process, and there is no concern about health. Moreover, this method only heats the mixed raw materials for a predetermined time while standing or mixing, and does not require other complicated operations. Furthermore, if the amount of acids such as fructose and organic acids is appropriately set, it is possible to use the whole product as it is without post-treatment after cooling,
Economical and efficient. The present invention will be described in detail below.

The type of starch used in the present invention is not limited, but examples thereof include starch such as corn, potato, sweet potato, tapioca, wheat and rice, and processed starch such as flour and esterified starch, etherified starch and cross-linked starch. Yes,
These 1 type (s) or 2 or more types are mentioned. In the present invention, in order to improve the aging resistance of starch, fructose or a sugar containing fructose as a main component is used. It has been known that fructose exhibits higher reactivity than other saccharides in a fructoside bond formation reaction in an aqueous solution. However, fructose, together with starch in the presence of acids, especially traces of organic acids, at 60 to 200 ° C. for 10 minutes to 5 hours, preferably 7
As a roasting condition at 0 to 150 ° C. for about 30 minutes to 3 hours, a relatively low temperature and a short heat treatment show unexpected reactivity, and the properties of starch are epoch-making. It has heretofore been completely unpredictable to give starches which have been modified and have a very high resistance to aging.

Glucose, galactose, xylose,
Even if a sugar such as sucrose was used and heat-treated under the same conditions, it was not possible to give starch having the same high aging resistance as that of fructose. Thus, the reactivity of sugars other than fructose was significantly inferior to that of fructose. Only by using fructose, in the presence of acid efficiently,
It was possible to obtain a starch having an economically desired viscosity and high aging resistance. The advantage of using fructose is that it is highly reactive so that the desired starch can be produced at low processing temperatures, short processing times with acids, especially with smaller amounts of organic acids. Therefore, a desired aging-resistant starch having a higher viscosity to a lower viscosity than the raw material starch can be obtained without lowering the molecular weight of the starch. Contrary to this, normal dextrin
When the roasting temperature is raised, the aging property is improved, but it has a drawback that the starch is decomposed and the viscosity is lowered. It is not clear what interaction between starch and fructose occurred, but it is possible that fructose formed a bond with glucose constituting starch and was incorporated into the starch molecule. Although the reaction mechanism is not clear, it is certain that the aging-resistant starch of the present invention can be efficiently produced only when fructose or a sugar having fructose as a main component is used.

Unlike the acetic acid, phosphoric acid, ethylene oxide, propylene oxide and the like that have been conventionally used for modifying starch, fructose has a very similar chemical structure and properties to glucose, and therefore has a natural texture. Can be given to. Furthermore, one of the great advantages is that the food itself is not a chemical such as acetic acid, phosphoric acid, ethylene oxide or propylene oxide. Moreover, the effect of improving the aging property of starch is extremely large as compared with these chemicals.

The fructose used in the present invention may be crystals, powder, syrup or solution. Further, other carbohydrates may be present as long as they are fructose-based carbohydrates. In this case, the reaction efficiency is slightly lowered, but it can be used. For example, the use of high fructose corn syrup (fructose content: 95%, other mainly glucose) is preferable from the viewpoint of economy.

The amount of fructose incorporated into starch by the method of the present invention is proportional to the amount added. In order to obtain the desired aging resistance, the amount of fructose is usually selected in the range of 3 to 50 parts by weight based on 100 parts by weight of starch. When the amount of fructose is less than 3 parts by weight, the starch after heat treatment has poor aging resistance, and when it exceeds 50 parts by weight, the amount of unreacted fructose increases and the product is sweetened. It is disadvantageous because it may require post-treatment such as cleaning.

Next, the acid is not particularly limited, and for example, inorganic acids such as hydrochloric acid, nitric acid and sulfuric acid and organic acids such as oxalic acid, acetic acid, succinic acid, citric acid, fumaric acid and malic acid can be used. However, considering the corrosion of the device and the side reaction of starch, the organic acid is preferable. In particular, organic acids such as acetic acid, succinic acid, citric acid, malic acid, adipic acid, gluconic acid, tartaric acid, lactic acid, fumaric acid, and ascorbic acid, which are legally recognized as food additives, are used for food applications. Recommended when used to modify starch.
The advantage of using an organic acid is that even when the amount of acid used is large, the rate of causing side reactions such as viscosity decrease is small,
In addition, when used in a small amount, the catalytic effect is sufficiently exhibited. The reason for this is not clear, but because the degree of acid dissociation of organic acids is low, the cleavage of starch molecules is suppressed, and further volatilization and
It is presumed that since it has a low transpiration property, it stays in the reaction system to the end and the catalytic action gradually continues.

The amount of acid in the reaction system is not particularly limited in the case of an organic acid, but if an excessive amount of organic acid is added to the reaction system, a large amount of alkali is required for neutralization after the reaction, while However, if the addition amount is small, the uptake amount of fructose decreases. Therefore, usually, it should be selected in the range of 0.01 to 5 parts by weight with respect to 100 parts by weight of starch. On the other hand, when an inorganic acid is used, it depends on the desired viscosity of the product and roasting conditions, but the amount used in the usual production of roasted dextrin (for example, 1% hydrochloric acid 1% to 100 parts by weight starch).
About 10 to 10 ml) is preferable.

Next, the selection of the temperature during the heat treatment depends on the acid amount of the catalyst, the fructose amount, the reaction time, etc., but it is usually 60 to 200 ° C., preferably 70 to 150 ° C.
It is. When the temperature is lower than 60 ° C, the reaction rate is slow, and it is inefficient as an industrial production method. When the temperature is 200 ° C or higher, the starch molecules are decomposed / transferred / re-associated, and the low molecular weight dextrin having a high branching degree is produced. Is generated. Further, the starch is colored, which is not preferable in terms of the appearance of the product.

The heat treatment time depends on other treatment conditions as in the selection of the treatment temperature, but it is preferable that the heat treatment time is short when the treatment temperature is high and long when the treatment temperature is low. Specifically, it is 10 minutes to 5 hours, preferably 30 minutes to 3 hours. When the treatment time is short, the reaction rate is low, and when the treatment time is too long, coloring and a decrease in viscosity occur. This heat treatment can be carried out by an ordinary method and is not particularly limited, but a dry method is preferable. That is, after adding and mixing fructose and acid to powdered starch, the water content is reduced to 3
A method in which the temperature is adjusted to 0% or less and then heat treatment is performed at a predetermined temperature for a predetermined time while standing or mixing is preferable.

The starch treated as described above may be washed with water or other solvent, filtered, and then dried to obtain a product, but preferably, the amount of fructose and the neutralization reaction do not require a washing step. It is desirable to select a reaction condition in which the treated starch is directly used as a product by using a trace amount of an organic acid that does not require

Foods that can be produced using the treated starch of the present invention include fish paste products such as fish ham, sausage and kamaboko, raw or semi-raw type products such as udon, buckwheat, spaghetti and macaroni, Boiled frozen noodles, bread, castella, cakes, Western sweets such as cookies, pastes such as flower paste, yokan,
Examples include Japanese sweets such as uiro, dumplings, and paste, rice cakes such as packing rice cakes, cut rice cakes, daifuku rice cakes, dumplings, spring rolls, white rice, red rice, rice cooked with rice, etc.

The method of the present invention can significantly improve the aging resistance of starch. For example cornstarch 10
The starch of the present invention obtained by treating 0 parts by weight of 20 parts by weight of fructose and 0.1 parts by weight of citric acid at 100 ° C. for 2 hours is 95
Even if it is stored for 1 month at a temperature of 4 ° C,
Gelation and its viscosity change did not occur, and no syneresis was observed. Furthermore, good aging resistance was also observed in the measurement of the change with time of the turbidity of the paste solution. On the other hand, the paste solution of the raw corn starch under the same conditions gelled immediately after gelatinization.

Regarding the amylogram viscosity of the starch obtained by the method of the present invention, a decrease in the gelatinization start temperature and a change in the maximum viscosity are generally recognized as compared with the starting starch. The lowering of the gelatinization start temperature is a result of the fact that the structure of the starch molecule in the starch particle is changed as a result of the incorporation of the fructose molecule into the starch molecular chain, and the starch molecule is easily swelled. Usually, the decrease in the gelatinization start temperature of the 7% -concentrated treated starch solution is in the range of several degrees Celsius to several tens of degrees Celsius. The maximum viscosity can be increased or decreased depending on the processing conditions selected. That is, when fructose is introduced while suppressing the cleavage of the molecular chain of starch, the viscosity increases as the amount of introduced fructose increases. On the other hand, when the amount of acid is increased and the hydrolysis reaction is promoted, the maximum viscosity decreases as the molecular weight decreases. Therefore, by appropriately adjusting the increase in the maximum viscosity due to the incorporation of fructose molecules into the starch and the decrease in the maximum viscosity due to the acid, the maximum viscosity of the treated starch is made several hundred BU higher than that of the raw starch, or It is possible to have a low viscosity that crawls on the baseline. Even when the viscosity is reduced to the level of roasted dextrin, the aging property can be improved under milder treatment conditions as compared with roasted dextrin, and the method of the present invention can be said to be an industrially excellent method.

[0027]

EXAMPLES Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. Reference Example 1 Amylograph Curve FIG. 1 is a curve showing the relationship between viscosity and temperature when a starch suspension is heated at a constant rate (1.5 ° C./min). The temperature at which the viscosity starts to rise sharply and the tangent to the curve forms an angle of 45 ° with the baseline is the gelatinization start temperature. The increased viscosity decreases through the maximum viscosity. Also,
The gelatinization start temperature is a temperature at which starch particles start to swell.
That is, a low gelatinization start temperature means swelling at a low temperature. The maximum viscosity is the viscosity when the swelling of the starch particles, which has started to swell, becomes maximum. Therefore, the higher the maximum viscosity of the starch, the greater the swelling of the particles. After undergoing maximum swelling (ie maximum viscosity), the starch particles disintegrate and form a paste solution. In the present invention, the amylograph curve was measured using a 7% suspension of starch, except where otherwise specified.

Reference Example 2 Method for Measuring Anti-Aging Effect A 2% suspension of sample starch was gelatinized by heating at 95 ° C. for 30 minutes with stirring, then cooled to room temperature, and the absorbance was measured using visible light of 500 nm. And the difference in absorbance measured after storage at 5 ° C. for 65 hours was taken as the aging degree, and the difference in absorbance of the raw starch paste solution was taken as 100%. For example, the initial absorbance of raw material corn starch is 0.654 and 1.014 after 65 hours.
The difference of 0.360 was expressed as 100%.

Reference Example 3 Corn Starch Amylograph Curve Corn starch has a gelatinization starting temperature of 80 ° C. and a maximum viscosity of 460.
It showed BU. The glue solution after the amylograph curve measurement was immediately gelled after cooling.

Reference Example 4 Amylograph curve of potato starch Since potato starch has a high viscosity, a 4% suspension was used. The gelatinization starting temperature was 64 ° C. and the maximum viscosity was 840 BU. The glue solution after the amylograph curve measurement was cooled and then thickened and gelled.

Example 1 Corn starch 200 g (dry matter), fructose 30 g (dry matter)
After adjusting the mixture of water and 0.4 g of citric acid to a water content of 20%, mix well with a crusher, spread on a vat, and put 1 in a hot air drier.
After heat treatment at 30 ° C for 1 hour, washing with water, filtration and drying,
210 g of treated starch was obtained. The gelatinization start temperature of this treated starch was 69 ° C, which was 11 ° C lower than that of corn starch. This is because the amount of fructose incorporated into the starch molecule is quite large,
This is probably because the internal structure of starch changed significantly. Also, the maximum viscosity is 660 BU, which is 2 more than cornstarch.
It rose by 00 BU. It is considered that this is because the increase in the maximum viscosity due to the incorporation of fructose into the starch molecule exceeded the decrease due to the hydrolysis reaction.

After the amylograph curve measurement, the paste solution was kept at 5 ° C for 3
After storage for 0 days, no gelation occurred, no water separation indicating aging was observed, and the paste solution showed a smooth feel. The aging rate viewed from the turbidity ratio was 3.6%. In addition, the structure of the treated starch and the structural change after the gelatinized paste solution was stored at 4 ° C. for 3 days were analyzed by X-ray diffraction (X-ray diffractometer RAD-1 manufactured by Rigaku Denki Co., Ltd.).
The results of examination in A) are shown in FIGS. 2 and 3. As is clear from FIG. 2, there is no change in X-ray diffraction between the untreated corn starch and the fructose-treated corn starch according to the present invention,
It was found that the original structure of starch was not changed by the fructose treatment. Further, as is clear from FIG. 3, when the untreated starch was stored at 4 ° C. for 3 days, the peak showing crystallinity was 2θ = 1.
It is around 7.5 ° and shows the B pattern, whereas the treated starch does not change from the A pattern immediately after gelatinization.
It was found that the starch does not crystallize or age even when subjected to low temperature treatment.

Example 2 210 g of treated starch was obtained by the same treatment as in Example 1 except that the treatment time was 2 hours and the amount of citric acid was 0.1 g. The gelatinization start temperature of this treated starch was 69 ° C, which was 11 ° C lower than that of corn starch. The maximum viscosity is 300B
U is 160 BU lower than cornstarch. Furthermore, even after the maximum viscosity was exhibited, the viscosity gradually increased with time and reached 600 BU after 30 minutes at 95 ° C. It is considered that the decrease in the maximum viscosity of the amylogram curve and the subsequent increase were caused in part by the crosslinking reaction for a long time due to high temperature heating. However, after storing the paste solution after the amylograph curve was stored at 5 ° C. for 30 days, no water separation indicating aging was observed, and the paste solution showed a smooth feel. Treated starches were obtained which gave good aging resistance despite changes in amylogram viscosity behavior. The aging rate was 5.0%.

Example 3 A mixture of 200 g of corn starch (dry matter), 20 g of high fructose (fructose 95%, 5% glucose) (dry matter) and 0.4 g of succinic acid was adjusted to a water content of 20% and mixed well with a grinder. Spread it in a wide vat and heat it in a hot air dryer at 80 ℃.
And heat treated for 3 hours. Then, after washing with water, filtration and drying were performed to obtain 204 g of treated starch. The gelatinization start temperature of this treated starch was 72 ° C, which was 8 ° C lower than that of corn starch.
Maximum viscosity is 570BU, 110B more than cornstarch
U rose. In addition, the paste solution after measuring the amylograph curve is 5
After storage at 30 ° C. for 30 days, no water separation indicating aging was observed and the paste solution showed a smooth feel. The aging rate was 7.2%.

Example 4 210 g of treated starch was obtained in the same manner as in Example 1 except that 3 ml of 0.2N hydrochloric acid was used and heat treatment was carried out for 1 hour. The gelatinization start temperature of the obtained treated starch was 70 ° C, which was 10 ° C lower than that of corn starch. The maximum viscosity was 600 BU, which was 140 BU higher than that of corn starch. After storing the paste solution after measuring the amylograph curve at 5 ° C. for 30 days, no water separation indicating aging was observed and the paste solution had a smooth feel. The aging rate was 4.5%.

Example 5 A mixture of 20 kg of potato starch (dry matter), 3 kg of fructose (dry matter) and 40 g of citric acid was adjusted to a water content of 15% and then stirred and mixed with a speed mixer. After heat treatment with a paddle dryer (manufactured by Nara Machinery) at 135 ° C. for 2 hours with stirring, the mixture was washed with water, filtered, and dried to obtain 22 kg of treated starch (dry matter). The gelatinization start temperature of this treated starch is 52 ° C,
The temperature was 12 ° C lower than that of potato starch. The maximum viscosity is 95
At 0BU, it was 110 BU higher than potato starch. After storing the paste solution after measuring the amylograph curve at 5 ° C. for 30 days, no water separation indicating aging was observed and the paste solution had a smooth feel.
The aging rate was 3.5%.

Comparative Example 1 200 g of corn starch (dry matter) and 30 g of fructose (dry matter)
The mixture was treated as in Example 1 without citric acid. The gelatinization start temperature of the treated starch was 80 ° C., which was not different from that of corn starch, but the maximum viscosity was 420 BU, which was 40 BU lower than that of corn starch. That is, the gelatinization start temperature is not different from that of the raw material cornstarch, indicating that the incorporation of fructose into the starch molecule is small. The maximum viscosity hardly increases due to the incorporation of fructose into the starch molecule, and the viscosity does not decrease due to the hydrolysis reaction of the starch molecule using citric acid as a catalyst, but as a result of some thermal decomposition reaction,
Although it was slightly lower, the result was almost the same as the raw corn starch. The glue solution after the amylogram measurement was gelated after cooling. The aging rate is 85.2%
Met.

Comparative Example 2 The same procedure as in Example 1 was carried out without adding 30 g of fructose to a mixture of 200 g of corn starch (dry matter) and 0.4 g of citric acid. The gelatinization start temperature of the obtained treated starch was 80 ° C, which was not different from that of corn starch, but the maximum viscosity was 110 BU.
It was 350 BU lower than that of corn starch. There was no increase due to the incorporation of fructose into the starch molecule, and the hydrolysis reaction of the starch molecule using citric acid as a catalyst occurred alone, resulting in a significant decrease in viscosity. The paste solution after the amylogram measurement was cooled and then gelled. The aging rate is 95.
It was 6%.

Comparative Example 3 200 g of corn starch (dry matter), 30 g of glucose
Example 1 using a mixture of (dry matter) and 0.4 g of citric acid
The same treatment was performed. Gelatinization start temperature of treated starch is 78 ℃
Then, it was only 2 ° C lower than cornstarch.
The maximum viscosity is 210 BU, which is 2 more than cornstarch.
It decreased by 50 BU. The gelatinization onset temperature was almost the same as that of the raw material cornstarch, indicating that glucose was not taken up into the starch molecule. Further, the decrease in maximum viscosity is due to the fact that there is almost no increase due to the incorporation of glucose into the starch molecule, and therefore the decrease in viscosity due to the hydrolysis reaction of the starch molecule using citric acid as a catalyst has a large effect. The paste solution after the amylogram measurement was stored at 5 ° C. for 30 days, then gelled and caused severe water separation. The aging rate was 52.2%.

Comparative Example 4 200 g of corn starch (dry matter), 30 g of sugar (dry matter)
And 0.4 g of citric acid were used and treated in the same manner as in Example 1. As a result, the gelatinization start temperature of the treated starch is 78 ° C.
Then, it was only 2 ° C lower than cornstarch.
Maximum viscosity is 153BU, 307BU more than cornstarch
Dropped. The gelatinization onset temperature was almost the same as that of the raw material corn starch, indicating that sugar was less incorporated into the starch molecule. In addition, the decrease in maximum viscosity hardly occurs due to the incorporation of sugar into the starch molecule,
This is because the decrease in viscosity due to the hydrolysis reaction of starch molecules with citric acid as a catalyst had a great effect. The paste solution after the amylogram measurement was stored at 5 ° C. for 30 days and then gelated, causing severe water separation. The aging rate was 55.6%.

Comparative Example 5 200 g corn starch (dry matter), 30 g xylose
Example 1 using a mixture of (dry matter) and citric acid 0.4 g
The same treatment was performed. The gelatinization start temperature of the obtained treated starch was 77 ° C, which was only 3 ° C lower than that of corn starch. Maximum viscosity is 220 BU, 2 more than cornstarch
It decreased by 40 BU. The gelatinization onset temperature was almost the same as that of the raw material corn starch, indicating that xylose was less incorporated into the starch molecule. The decrease in maximum viscosity is due to the fact that there is almost no increase due to the incorporation of xylose into the starch molecule, and therefore the decrease in viscosity due to the hydrolysis reaction of the starch molecule with citric acid as a catalyst has a large effect. The paste solution after the amylogram measurement was stored at 5 ° C. for 30 days and then gelated, causing severe water separation. The aging rate was 65.0%.

Comparative Example 6 200 g of corn starch (dry matter), 30 g of fructose (dry matter)
And a citric acid 0.4g mixture is used, and the treatment temperature is 50 ° C.
The same treatment as in Example 1 was carried out except that The gelatinization start temperature of the obtained treated starch was 79 ° C, which was only 1 ° C lower than that of corn starch. Maximum viscosity is 430B
At U, it was 60 BU lower than that of corn starch. That is, the gelatinization start temperature was almost the same as that of the raw material corn starch, indicating that the incorporation of fructose into the starch molecule was small. Further, the maximum viscosity hardly increases due to the incorporation of fructose into the starch molecule, and the viscosity does not decrease due to the hydrolysis reaction of the starch molecule using citric acid as a catalyst. The result is almost the same as the raw material corn starch.
The glue solution after the amylogram measurement was gelated after cooling. The aging rate was 100%. The results of the above Examples and Comparative Examples are summarized in Table 1.

[0043]

[Table 1]

Example 6 Production of Kashiwa Mochi After mixing 180 g of top fresh powder, 20 g of fructose-treated starch and 170 ml of water, kneading well, steaming for 20 minutes in a steamer under boiling and kneading for 5 minutes. The dough was soaked in water and cooled until it became cold, 20 g of starch starch was dissolved in 40 g of water, added to the dough, and kneaded. Each piece was divided into 20 g, rounded, and shaped to a height of 2 cm.
This was placed in a steamer and steamed on high heat for 8 minutes. Then, it was stored in a refrigerator (5 ° C.) for 2 days, and the aging degree was measured. The aging degree was evaluated by an increase in hardness by a rheometer and a sensory test. Further, instead of the treated starch according to the present invention, a non-added starch and a corn starch-added starch were prepared and their aging properties were compared. The results are shown in Table 2.

[0045]

[Table 2] Note) ○: No dryness, good taste and texture △: Slightly dry, but good texture ×: Dry and bad texture

As is apparent from the table, the addition of the treated starch made it harder to harden, suppressed aging, and retained the texture of Kashiwa-mochi for a long time.

Example 7 Preparation of Uiro After mixing 25 g of kudzu powder and 150 g of water and dissolving them well, 90 g of fresh new flour and 10 g of fructose-treated starch were added and mixed well. On the other hand, 100 g of white sucrose was mixed with 150 g of water, heated and completely dissolved, and then this honey was added to the above material and mixed, and the mixture was heated to about 50 ° C. on low heat. Then, the dough was poured into a sink, steamed in a steamer for 20 minutes, and then allowed to cool at room temperature. After this was refrigerated for 2 days (5 ° C.), the degree of aging was measured.
The aging degree was measured by an increase in hardness with a rheometer and a sensory test. Further, instead of the treated starch according to the present invention, a non-added starch and a corn starch-added starch were prepared and their aging properties were compared. The results are shown in Table 3.

[0048]

[Table 3] Note) ○: No dryness, good taste and texture △: Slightly dry, but good texture ×: Dry and bad texture

As is clear from the table, by adding the treated starch, it was difficult for the starch to harden, aging was suppressed, and the texture of uiro was maintained for a long time.

Example 8 Preparation of custard cream 100 g of whole egg, 20 g of starch and 100 g of white sucrose were thoroughly mixed, and then 500 g of milk was added to disperse and lining. The mixture was kneaded with heating at 90 ° C., and finally kneaded so that the weight became 80% of the initial weight. After cooling to 40 ° C with stirring in running water and allowing to cool at room temperature, -20 ° C
The sample was stored at the freezing temperature of 1 week and then naturally thawed at room temperature, and the aging degree was measured. The aging degree was evaluated by an increase in hardness by a rheometer and a sensory test. The results are shown in Table 4.

[0051]

[Table 4] Note) ○: Fine texture, good melting in the mouth ×: Coarse texture, rough texture, poor melting in the mouth

As is clear from the table, by adding the treated starch, the custard cream did not become hard even after freezing and thawing, the aging was suppressed, and it had a smooth texture similar to that before freezing.

[0053]

INDUSTRIAL APPLICABILITY The aging resistant starch of the present invention incorporates a fructose molecule into the starch molecule to prevent rearrangement of the starch molecule in the starch paste solution, thus suppressing aging. Moreover, unlike the processed starch that uses conventionally used chemicals, the aging-resistant starch of the present invention is highly safe for the human body and has an excellent taste, so that it is used as a raw material for processed foods. It is highly appreciated. In particular, this aging resistant starch is suitable for use in refrigeration, freezing and microwave ovens.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an amylograph curve.

FIG. 2 is an X-ray diffraction diagram of untreated cornstarch and fructose-treated cornstarch of the present invention.

FIG. 3 is an X-ray diffraction diagram showing the structural changes of untreated corn starch and fructose-treated corn starch of the present invention after storage at low temperature.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kuroki 2-27-11, Tennocho, Handa City, Aichi Prefecture Heights Part 203

Claims (4)

[Claims] 1. In the presence of an acid, starch is mixed with fructose or a sugar containing fructose as a main component at 60 to 200 ° C. under dry conditions.
A method for producing an aging-resistant starch, which comprises performing a heat treatment for 0 minutes to 5 hours. 2. The method according to claim 1, wherein the acid is an organic acid. 3. An aging-resistant starch produced by the method according to claim 1. 4. A method for preventing aging of a food containing starch, which comprises adding the aging-resistant starch according to claim 3.