JPS61280244A - Production of starch for processing - Google Patents

Abstract

PURPOSE:To obtain simply a starch for processing suitable for foods, cosmetics, etc., having high gelatinization degree and high swelling degree and a small number of live molds, without causing deterioration of quality, by heating a starch with superheated steam under a specific condition. CONSTITUTION:A starch (corn starch, African millet starch, etc. adjusted preferably to 18-30W/W water content) is heat-treated with superheated steam at <=9kg/cm<2> gauge pressure, preferably at 0.5-3.0kg/cm<2> at 105-350 deg.C, preferably at 120-250 deg.C for <=5min, preferably for 3sec-2min, to give the aimed starch for processing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing starch for processing, and particularly to a method for producing starch for processing, in which starch is treated with superheated steam at a predetermined pressure and temperature.

[Problem that the invention seeks to solve]

Conventionally, pregelatinized starch has been known as a type of starch for processing, and its manufacturing method involves adding water to starch to make an emulsion, heating it to gelatinize it, and then spreading it out into a film on the surface of a drum dryer, etc. A method is known in which the starch emulsion is then heated, dried, scraped, and pulverized, but this method requires a huge amount of time to gelatinize (gelatinize) a starch emulsion with a high water content and dehydrate and dry it. Recently, starch emulsions of 10 to 40% (solid content) have been processed under pressure to produce approximately 120% starch. A method of heating at °C and then spray drying (Japanese Patent Publication No. 47-10014), and a method of extruding a starch emulsion with low water content using an extruder under high temperature and high pressure conditions, and then drying and powdering it. (Japanese Patent Publication No. 50-18642, Japanese Patent Publication No. 58-2218.3)
However, these methods also have the same drawbacks as the above-mentioned methods because the gelatinization treatment and the drying and/or pulverization treatment are performed separately.

On the other hand, a method of directly treating starch with heated air and a method of directly treating starch with saturated steam have been studied, but each method has problems and drawbacks, and it is difficult to say that these methods are fully satisfactory.

That is, the method of treating starch with heated air has the advantage of being able to perform gelatinization and drying of starch at the same time, but on the other hand, heated air has poor thermal conductivity, so it can process starch uniformly in a short period of time. It is difficult to raise the temperature of the product, and it tends to become locally hot and burnt, and it also tends to cause browning due to air oxidation in a short period of time.

In addition, in the method of treating starch with saturated steam, when starch comes into contact with saturated steam, the steam condenses and adheres to the starch, and a part of the starch gelatinizes. It has the disadvantage that it is difficult to obtain uniformly pregelatinized starch due to lumps, adhesion to the inner wall surface of the device, or localized increase in water content.

[Means for solving problems]

Therefore, in order to develop a method for producing starch for processing without the above-mentioned drawbacks and problems, the present inventors conducted various studies and found that starch was processed at a gauge pressure of 9 kg/ca or less and at a temperature of 1.
It was found that the above object was achieved by heat treatment within 5 minutes in the presence of superheated steam at 05 to 350''C, and based on this knowledge, the present invention was completed.

That is, the present invention is a method for producing starch for processing, which is characterized in that starch is heat-treated within 5 minutes at a gauge pressure of 9 kg/ca or less and a temperature of 105 to 350°C in the presence of superheated steam.

[For production]

The present invention will be explained in detail below.

First, the starches used in the present invention include barley,
Starch separated from barley such as wheat and oats; corn (
EE Shu IS), starch separated from cereals such as sorghum, millet, millet, millet, takaliang, milo, etc., and starch separated from potatoes such as potatoes, horse mackerel, and challah mackerel (tapioca).

These may be used alone or in combination.

Further, these starches may be used after adjusting the moisture content by adding water as appropriate.

Next, to practice the invention, the starch was prepared at a gauge pressure of 9 kg.
/ cA or less, preferably 0.5 to 3.0 kg/cJ
r, temperature 105-350°C1 preferably 120-25
Within 5 minutes, preferably 3 minutes in the presence of heated steam at 0 °C
Heat for seconds to 2 minutes. The above-mentioned temperature and time are inversely proportional to each other, and it is preferable to shorten the time when the temperature is high, and to lengthen the time when the temperature is low.

In the present invention, it is extremely important to use superheated steam as a heating medium for starch; other heating media, such as heated air and saturated steam, each have their own problems and drawbacks as described above, and the present invention Unfavorable (%.

On the other hand, when using superheated steam, it is possible to prevent quality deterioration such as starch browning due to oxidation, scorching, partial excess moisture in starch, partial gelatinization, starch clumping, and uneven gelatinization. The temperature of starch can be raised in a short time while making it possible to easily obtain processing starch suitable for food, cosmetics, medicine, agricultural chemicals, and other industrial uses.

Next, the heating conditions for the superheated steam used in the present invention are as described above, but if the conditions exceed a gauge pressure of 9kq/cTls and a temperature of 350°C, starch will develop a burnt odor and may become discolored (browning). ) and charring will become significant, which is not preferable.

On the other hand, if the temperature is less than 105°C, the physical properties of the product starch for processing cannot be sufficiently changed, making it difficult to obtain the desired starch for processing, which is not preferable.

On the other hand, the heating condition is a gauge pressure of 9 ky/cr1
When the temperature is within 105 to 350'C, a suitable starch for processing without the above-mentioned disadvantages can be obtained.

Note that the pressure, temperature, and time employed in the present invention are preferably changed as appropriate depending on the water content of the starch at the time of starting or the use of the starch for processing.

That is, the water content is 3 to 35 (W/W, )% (hereinafter % is W).
/W) starch is used as raw material, and the degree of gelatinization and /
Or, in order to obtain processing starch with a high degree of swelling, the starch is put into a batch-type or continuous-type pressure heating device, heated under pressure in the presence of superheated steam, and then instantaneously heated under lower pressure, e.g. It may be discharged under atmospheric pressure and subjected to swelling treatment.

Examples of devices for carrying out the above-mentioned puffing treatment include, for example, Japanese Patent Publication No. 46-34747 r "Method and Apparatus for Manufacturing Puffed Foods Using Air Stream Heating Method", Japanese Patent Publication No. 55-33622 r Continuous Steaming and Heating Apparatus", Japanese Patent Publication No. 55-33622 r Continuous Steaming and Heating Apparatus" 26180r Heat sterilization method for powder and granular materials" and the apparatus described in JP-A-57-8
2686r "Method and Apparatus for Heat Treatment of Powder and Grain Materials".

On the other hand, starch with a low moisture content of 2 to 14% was treated without the above-mentioned swelling treatment (i.e., by heat treatment with superheated steam under atmospheric pressure or heat treatment with superheated steam under pressure). (After that, the pressure is gradually decompressed)
, there is a limit to increasing the degree of gelatinization. In such a case, in order to further increase the degree of gelatinization, the heating conditions must be made harsher. However, if it is too harsh, it will cause quality deterioration such as coloring and burning of the product.

However, in such cases, if water is added uniformly to the raw material starch by sprinkling water or spraying water to adjust the moisture content to 18-30% after the first heat treatment,
Even in the heat treatment without the above-mentioned swelling treatment, it is possible to easily obtain processing starch having the desired degree of gelatinization.

As a method for obtaining processing starch with a high degree of gelatinization by the above-mentioned heat treatment without swelling treatment, for example, the starch can be heated using a batch type, high-speed stirring type heating device as described in JP-A-57-82686. The starch is then heated under pressure in the presence of superheated steam, and then the pressure is gradually decompressed to take out the treated starch. , heat under pressure, but at that time, only the pressure conditions are set to a particularly low value, the eel is heated at a temperature sufficient for gelatinization for a predetermined period of time, and then the pressure is instantly decompressed to a lower pressure. It will be done.

In this way, by appropriately changing the pressure, temperature, and time, it is possible to create products with various properties such as degree of gelatinization, degree of swelling, and gel strength, and which have a very small number of viable bacteria and are excellent for processing. starch can be obtained.

The processed starch obtained by the present invention has excellent water solubility and dissolution stability, so it can be used as a thickening agent for sauces, gravies, etc., and since it is processed under high temperature and high pressure conditions, it is also bacterially clean. It can be used in place of conventional starch (or processed starch) in various foods for which the use of conventional starch or processed starch is known, such as rice crackers and snack foods. It has excellent effects on improving the structure and texture of Western confectionery and bread, improving deterioration (preventing aging), improving flavor, and preserving flavor immediately after production. Furthermore, when applied to foods such as croquettes and batters for frying that require high viscosity (adhesiveness) during the processing process (for example, deep-frying process), it provides excellent moldability. In addition, when used in processed meat products such as ham, sausage, and hamburger steak, and processed seafood products such as kamaboko and chikuwa, it has excellent binding retention effect, gel reinforcement effect, syneresis prevention effect when kept at low temperature, and anti-aging effect during storage. When used in heated foods such as retort processed foods, it has a good gel strength retention effect. According to the present invention, processing starches having various degrees of gelatinization and digestibility can be obtained, among which starches with a good degree of gelatinization and digestibility are used for livestock
Suitable for use as fish feed and fishing bait. Further, finely pulverized products have excellent water retention properties, and are therefore suitably used as base materials, powder materials, and tablets for cosmetics, pharmaceuticals, and agricultural chemicals.

Furthermore, for other industrial purposes, it can be suitably used as an adsorption base material or carrier for Class 4 fragrances, and as an inner layer filler for soundproofing and moistureproofing materials.

[Effects of the present invention]

(1) According to the present invention, starch or modified starch can be used as a substitute for starch or powder (or modified starch) in various foods, cosmetics, pharmaceuticals, agricultural chemicals, and other industrial products for which the use of starch or modified starch is known. When added to a product, a superior processing starch can be obtained that can improve several important properties desired in the product.

(2) According to the present invention, starch is gelatinized and dried at the same time, processing starch can be produced from raw starch all at once with good productivity, and labor, time, and production costs can be significantly reduced.

(3) Browning of starch due to oxidation, charring, partial moisture content of starch, partial gelatinization, lumping of starch, uneven gelatinization, etc.
Starch for processing can be obtained in a short time with the deterioration of quality being prevented as much as possible.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 (Production of starch for processing by swelling corn starch) Corn starch (moisture 10%) was continuously heated in a continuous pressure heating device using an air flow heating method (device described in Japanese Patent Publication No. 46-34747). The heat treatment conditions shown in Table 1 below were introduced into the trowel, and the heat treatment was carried out to obtain the appearance and characteristics as shown in Table 1. Processing starch having a gelatinization degree (according to Keiji Kainuma et al. [Starch Science J 28, 235 (1981)]) was obtained.

From the results in Table 1, it can be seen that Category 2 (comparative example) using saturated steam has the drawbacks of being sticky as a whole, resulting in partial lumps, a low degree of gelatinization, and slightly low digestibility.

In addition, in Category 3 (comparative example) using heated air, the overall color becomes light brown and has a considerable burnt odor, but in Category 1 of the present invention, which uses superheated steam, the resulting processed starch is completely It is found that the product is smooth and has no lumps, is white and has no strange odor, has a very high degree of gelatinization, and has good digestibility.

Example 2 (Production method for processing starch using cornstarch with different moisture content as raw material) Cornstarch (moisture content 10%) was placed in a closed container equipped with a stirrer, and water was sprayed to obtain various moisture contents as shown in Table 2. Corn starch was obtained and placed in a high-speed stirring type heating device (device described in JP-A-57-82686) filled with superheated steam, at a gauge pressure of 2.5 kg/crl and a temperature of 2.
After heating under pressure at 20°C for 40 seconds, the pressure was gradually released.
Various heat-treated corn starches were obtained.

The digestibility of the various processed cornstarch obtained and its relationship with the degree of gelatinization were investigated, and the following results were obtained.

However, the criteria for determining the degree of gelatinization of treated starch in Table 2 are as follows.

Degree of gelatinization is 29 or less: - 〃 30-59: ± 〃 60-89: + 〃 90 or more: ++ From the results in Table 2, the moisture content of cornstarch is 18-
It can be seen that when the content is 30 (W/W)%, a very preferable pregelatinized cornstarch with a high degree of gelatinization and no formation of cohesive lumps can be obtained. It can also be seen that very good results can be obtained in terms of digestibility.

Example 3 (Production method for processing starch using cornstarch as raw material) Raw material cornstarch, which had been adjusted to have a water content of 20 (W/W)% by adding water, was placed in a closed cylindrical container filled with superheated steam. The material is introduced into a high-speed stirring type heating device that stirs and disperses the raw material by rotating rotatable blades at high speed with a small gap on the inner periphery, and the gauge pressure is 2.5 kg/c.
T! , heated under pressure for 40 seconds in the presence of superheated steam at a temperature of 220°C, and then gradually depressurized, taken out, and unexpanded α
Cornstarch with a degree of oxidation of 82% was obtained.

Example 4 Potatoes (moisture 12%) were placed in a sealed container equipped with a stirrer and water was sprayed to obtain potato starch with a water content of 25%, which was then introduced into a high-speed stirring type heating device filled with superheated steam. ,
Gauge pressure 2, 5 kg/crl, temperature 220″C
After heating under pressure for 40 seconds, the pressure was gradually released and taken out to obtain pregelatinized potato starch.

Example 5 (Production method of processing starch by expanding corn starch) Corn starch (moisture 10%) was continuously heated in a continuous pressure heating device using an air flow heating method (device described in Japanese Patent Publication No. 46-34747). Introduced, gauge pressure 3.5 kg
/ ctl and heated under pressure for 7 seconds in the presence of superheated steam at a temperature of 220°C, and then instantaneously and continuously released to atmospheric pressure to obtain processing cornstarch with a high degree of gelatinization.

Claims (3)

[Claims] (1) Starch at a gauge pressure of 9 kg/cm^2 or less and a temperature of 10
A method for producing starch for processing, which comprises heat-treating the starch for less than 5 minutes in the presence of superheated steam at 5 to 350°C. (2) Claim 1, characterized in that the starch is starch whose moisture content is adjusted to 18 to 30 (W/W)%.
Method for producing starch for processing as described in Section 1. (3) Processing starch according to claim 1 or 2, wherein the starch is one or more selected from the group consisting of corn starch, sorghum starch, millet starch, potato starch, sweet potato starch, and tapioca. manufacturing method.