JP5599650B2 - Efficient production method of wet heat-treated starch using superheated steam - Google Patents

Description

  The present invention relates to an efficient method for producing a wet heat-treated starch in which the swelling of starch particles is suppressed when the aqueous dispersion is heated, the starch particles are less likely to disintegrate, and the heat resistance and acid resistance of the paste liquid are excellent.

  Conventionally, chemically synthesized starch has been used in order to impart heat resistance, heat resistance, mechanical resistance and stability to processed food when it is manufactured.

  On the other hand, unlike chemically treated starch, wet heat-treated starch is known as a starch physically treated using only water and heat.

  Wet heat-treated starch is obtained by heating starch particles containing moisture that does not gelatinize when heated in the presence of appropriate moisture, with little scientific change such as depolymerization, It is recognized as a highly safe food (see Non-Patent Documents 1 and 2).

Recently, the properties of wet heat-treated starch have been studied and used in various foods.
For example, there are retort food, custard cream, food for microwave oven, and the like.

  The method for producing the wet heat-treated starch is that when the potato starch or corn starch is heated at 95-100 ° C. under a relative humidity of 100%, the wet heat-treated starch is produced by L. Reported by Sair. According to this report, starch is spread in a thin layer of about 2 cm thickness, placed in a pressure vessel with a relative humidity of 100%, and heated at 95-100 ° C. for about 16 hours. Attempts have been made to humidify the starch and adjust the water content to 18-27% and place it in a sealed container and heat it in an air oven.

  However, none of these could be industrially produced in large quantities by a research method. Recently, a so-called reduced pressure heating method has been developed and industrially heat-treated starch has been industrially produced. This method is a system in which starch is put in a container in a first stage, sealed and decompressed, saturated steam is introduced into the container in a second stage, and humidified and heated. (Patent Document 1)

However, this method is costly on the apparatus and is difficult to operate, so that the wet heat-treated starch is expensive. For this reason, the characteristics are good and the use is not widespread even though the safety is high.
Recently, there has been a strong demand in the market for a heat-treated starch having excellent safety and useful properties to be supplied at a lower cost.

Patent No. 2996707

Toshiro Fukui, “Starch Science Experimental Method”, Asakura Shoten, 1979, pages 242-245 Yoshiki Kurahashi, “Encyclopedia of Starch Science”, Asakura Shoten, 2003, 417-421

  The main object of the present invention is to provide a wet heat-treated starch that is cheaper, can be produced in large quantities, and is superior in quality to conventional ones.

  The present inventor has intensively studied to obtain a method for producing a heat-treated starch that is cheaper, can be mass-produced, and is excellent in quality.

  As a result, by using superheated steam having a superheat degree of 1 to 30 ° C., it is found that the apparatus is cheaper, can be produced in large quantities, and can be produced in high quality wet heat-treated starch, Furthermore, earnest examination was repeated and it came to complete this invention.

  That is, the present invention relates to the following efficient method for producing wet heat-treated starch.

  Item 1: An air and superheated steam discharge line and a pressurized superheated steam input line are attached, a heating device is provided in the surrounding area to heat the inner wall, and a pressure-resistant sealing can be performed against the internal pressure provided with a device for mixing starch. Using a container, the temperature of the superheated steam that introduces the temperature of the inner wall in advance is increased based on the temperature and the degree of superheat, and while adding starch and mixing, open the discharge valve of air and superheated steam, An efficient method for producing wet heat-treated starch, which comprises introducing superheated steam at 30 ° C., exhausting the air inside, closing the valve of the discharge line, and heating the starch for a predetermined time.

  The temperature of the superheated steam to be introduced is 101 to 180 ° C, preferably 102 to 150 ° C, more preferably 103 to 140 ° C. When the temperature of the superheated steam is higher than 180 ° C., the flavor is deteriorated, and when it is lower than 101 ° C., the swelling suppressing effect cannot be obtained.

  The heating time is 1 to 180 minutes, preferably 2 to 150 minutes, more preferably 2 to 140 minutes. If the heating time is longer than 180 minutes, the flavor is poor, and if it is shorter than 1 minute, the swelling suppressing effect cannot be obtained.

According to the method of the present invention, it is possible to produce high-quality wet heat-treated starch in a larger amount and in a shorter time with a less expensive apparatus.

Further, the method of the present invention can obtain a wet-heat-treated starch having desired physical properties by controlling the temperature, time and superheat degree at which the starch is treated.

Hereinafter, the present invention will be described in more detail.
The function of wet heat treatment on starch is as follows.
It is known that the gelatinization start temperature increases, the heat resistance increases, the acid resistance increases, the mechanical shear force increases, the content of resistant starch increases, the resistance to a microwave oven increases, and the like.

Superheated steam is steam that has been heated above its boiling point, and is steam that does not condense even if the temperature drops somewhat.
Water vapor at a temperature higher than the saturated water vapor temperature corresponding to the pressure is called superheated water vapor.
Originally, superheated steam is used in ovens and the like, and is used for baking and drying foods.
The degree of superheat is important for using this in the production of wet heat-treated starch.

The degree of superheat refers to the difference between the temperature of superheated steam and the temperature of saturated steam (boiling point).
That is, the difference between the temperature of superheated steam and the temperature of saturated steam at the same pressure.

  As a result of investigating the production method of wet heat-treated starch suitable for mass production at low cost, and as a result of investigating whether superheated steam is better than saturated steam, it is suitable for use. When superheated steam, which is commonly used, was used, the heat resistance deteriorated. This was because the temperature of the superheated steam used was as high as 350 ° C. at normal pressure.

Therefore, the present inventor has conducted intensive research on the idea of superheat.
As a result, when the degree of superheat exceeds 30 ° C, the starch becomes dry and heated, causing thermal decomposition, and unlike the properties of wet heat-treated starch, it becomes difficult to suppress swelling of the particles, and heat resistance and acid resistance are lost. It became easier to dissolve in water.

  When the degree of superheating is lower than 1 ° C., condensation tends to occur, and starch gelatinization occurs during heating.

That is, when the degree of superheat is in the range of 1 to 30 ° C., it can be made in a shorter time than a wet heat-treated starch made using saturated steam, and can be excellent in heat resistance, acid resistance and mechanical resistance.
Preferably it is 2-25 degreeC, More preferably, it is 3-20 degreeC.

Another important point constituting the present invention is the apparatus.
That is, in order to maintain the degree of superheat, a pressure vessel that can withstand the internal pressure is required, and the temperature of the inner wall is set based on the temperature of the superheated steam to be introduced and the degree of superheat. In order to stabilize the control, the temperature should be about the same as the superheated steam introduced.

Also, the starch used as a raw material must have a high product temperature in order to prevent dew condensation when superheated steam is introduced.
And in order to mix raw material starch uniformly, a stirrer is required.

  The starch used in the present invention includes starches such as tapioca starch, potato starch, sweet potato starch, corn starch, sago starch and rice starch, and also includes flour such as rice flour, wheat flour and corn flour containing a large amount of starch.

The present invention will be described below with reference to experimental examples and examples.
In the following experimental examples, the following were used as raw materials.
Corn starch potato starch wheat starch
Evaluation Wet heat-treated starch was made using superheated steam with different superheat degrees, and the effect was compared.

(1) Creation of wet heat-treated starch using superheated steam A heating device is attached to the surroundings to mix the superheated steam introduction line, air and superheated steam discharge line, raw material inlet, raw material outlet, and starch introduced into the interior. Use a pressure-resistant airtight container with an internal pressure stirrer, and set the temperature of the inner wall of the airtight container to the same temperature as the superheated steam to be introduced. Of different superheated steam.

  Open the exhaust valve for air and superheated steam, exhaust the internal air sufficiently, close the exhaust line, pressurize and heat at constant temperature for a certain time, close the superheated steam introduction line after heating, After opening the valve of the steam discharge line, the treated starch was taken out of the container and cooled, and then pulverized to examine its physical properties.

  The physical properties of the starch thus obtained were examined by the following method.

1) The state when the wet heat treatment was completed and the container was taken out was examined visually.
Evaluation criteria A: Very uniform and in good condition
○: Uniform and in good condition
Δ: Slightly uniform
X: non-uniform and lumpy 2) Viscosity change by Brabender amylograph was examined.

The viscosity characteristics by Brabender amylograph were as follows. That is, a total amount of 450 g starch emulsion suspension is prepared. Perform at a concentration (anhydride equivalent) suitable for each starch. Then it was amylographed. The temperature was raised from 50 ° C. at a rate of 1.5 ° C. per minute, kept at the same temperature for 30 minutes after heating at 95 ° C., that is, 30 minutes, and then cooled at a rate of 1.5 ° C. per minute for 30 minutes. The viscosity was read. As a result, viscosity rising start temperature (gelatinization start temperature) and maximum viscosity reaching temperature, viscosity at that time, 95 ° C reaching viscosity, viscosity after heating at 95 ° C for 30 minutes, and viscosity when cooled to 50 ° C, respectively It was measured.

  As a result, starch particles remain, and those having a low maximum viscosity at the time of temperature rise are recognized as being well suppressed. When the swelling of starch is well suppressed, the heat resistance, acid resistance and viscosity stability of the paste liquid increase. Also, the texture is less pastey, so-called adhesion is reduced, and the texture becomes short.

From the amylograph, the suppression of swelling and disintegration of starch particles was evaluated according to the following criteria.
A: Very suppressed
○: Suppressed
Δ: Slightly suppressed
×: Not suppressed

3) Microscopic observation of the paste after measurement of the Brabender amylograph was performed.
The state of starch particles was observed.
Evaluation Criteria A: Swelling of starch particles is suppressed and not disintegrated.
○: Most starch particles remain without being disintegrated.
Δ: Most starch particles are disintegrated, but some remain.
X: Starch particles are disintegrated.

4) A paste solution was prepared and subjected to a heat resistance test.
An aqueous dispersion of starch prepared at a constant concentration, although different depending on the raw material starch, was heated at 95 ° C. and then cooled to 40 ° C., and the viscosity was measured with a B-type viscometer. This was heated under pressure in an autoclave at 120 ° C. for 20 minutes, cooled to 40 ° C., and the viscosity was measured.

Those having no decrease in viscosity before and after heating of the autoclave were evaluated as having heat resistance.
The heat resistance was evaluated according to the following criteria.
A: Extremely heat-resistant O: Heat-resistant Δ: Slightly heat-resistant ×: No heat resistance Experimental Example 1 Test results when corn starch was used as a raw material starch are shown below.

実験例２原料として馬鈴薯澱粉を用いた場合の試験結果を次に示す

Experimental Example 2 Test results when potato starch is used as a raw material are shown below.

実験例３原料として小麦澱粉を用いた場合の試験結果を次に示す

Experimental Example 3 The test results when wheat starch is used as a raw material are shown below.

As is clear from Tables 1, 2, and 3, as a result of performing the test by changing the degree of superheat using corn starch, potato starch, and wheat starch, when the degree of superheat is 1 to 30 ° C., it is effective in suppressing starch swelling. It was found that it had excellent heat resistance.

Industrial applicability

By the method of the present invention, it becomes possible to supply moist heat-treated starch that is cheaper and has better quality, that is, heat resistance, acid resistance, and mechanical resistance, so that a safe food with excellent flavor and texture can be produced. Become.
Specifically, it is frequently used for custard cream, soup, sauce, retort food, dressing and soft yogurt, which are excellent in flavor, texture and viscosity stability.

Claims (3)

A discharge line for air and superheated steam and a line for introducing pressurized superheated steam are provided, a heating device is provided in the surrounding area to heat the inner wall, and a container that can withstand pressure is sealed to the internal pressure with a device for mixing starch. The temperature of the superheated steam that introduces the temperature of the inner wall in advance is increased based on the temperature and the degree of superheat, and the starch and the superheated steam discharge valve are opened while mixing the starch and mixing, Efficient production of heat-moisture treated starch characterized by introducing superheated steam at a temperature of 102 to 150 ° C. and discharging the internal air, then closing the valve of the discharge line and heating the starch for 1 to 180 minutes while stirring the starch. Law. The efficient manufacturing method of the wet heat processing starch of Claim 1 whose superheat degree of superheated steam is 2-25 degreeC. The efficient manufacturing method of the wet heat processing starch of Claim 1 or 2 whose temperature of superheated steam is 103-140 degreeC.