JPH0288601A - Production of alpha-starch and apparatus therefor - Google Patents

Abstract

PURPOSE:To obtain alpha-starch with saved energy in a simple apparatus without using an additive and heating operation by continuously compressing raw starch grains containing a specific amount of moisture at ordinary temperature and continuously compressing alpha-starch with generated heat following the compaction. CONSTITUTION:A raw starch granular material (D) containing 5-40wt.% moisture are fed to a raw material hopper 9 and a screw 10 provided in the hopper 9 is rotated with a motor 11 mounted on the hopper 9 to push the raw starch material (D) into a prepressurizing chamber 2. The resultant densified raw starch material (D) is subsequently passed between a pair of cylindrical rolls (1A) and (1B) provided under the prepressurizing chamber 2 to apply a pressure thereto with a hydraulic cylinder 4. The raw starch material (D) is continuously compressed at ordinary temperature, pregelatinized with generated heat following the compaction and then continuously squeezed out to afford the objective alpha-starch.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for gelatinizing starch and an apparatus therefor. The present invention provides an apparatus for pregelatinizing starch raw materials.

[Prior art] The conventional method for producing pregelatinized starch mainly involves making raw starch granules into an aqueous slurry, spreading this thinly on a drum dryer and heating it.
In many cases, starch was pregelatinized to form a thin film of dried pregelatinized starch. There are also cases where crosstalk and heating are performed using an extruder, or heating and humidification are performed by passing superheated steam into the tank container. However, there are quite a few proposals that aim to improve quality by specifying detailed processing conditions based on this premise.

For example, starch granules are heated at a temperature that swells but does not break and then aged (Japanese Patent Application Laid-Open No. 114300/1982), and water slurry is heated to a swelling temperature and then rapidly cooled at a specific rate (Japanese Patent Publication No. 114300/1983). 30202), the specific gelatinization start temperature is at least 1 at least 50'C or higher.
Items that are heated at temperatures below 0°C
600), and one in which raw starch granules are suspended in an aqueous alcohol solution to form a slurry, which is then gelatinized by heating under pressure (Japanese Unexamined Patent Publication No. 63-49054).

[Problems to be Solved by the Invention] All the known techniques cited above are based on the heating means of raw starch granules in the form of a slurry containing at least 40% by weight of water, and this premise is This is an improvement in processing technology based on the current situation.

Requiring a heating means for equipment is a burden on equipment costs; 2. increase in work management items; 1. increase in quality variation factors; complicating maintenance inspections; 2. considerations for the work environment; cumulative increase in energy costs. This creates a load on equipment operation. Since the energy cost assumes a moisture content of at least 40%, and generally 100 to 300%, the cost required for dry pieces is an extremely important factor.

The object of the present invention is to provide a new method for producing pregelatinized starch in which the heating means, which has not been suspected by anyone in the field of production, is removed from the apparatus, and an apparatus for carrying out this method.

[Means for solving the problem] The method for producing pregelatinized starch according to the present invention includes a method for producing pregelatinized starch containing 5 to 40% by weight.
The process involves continuously squeezing raw starch granules containing moisture at room temperature, and continuously squeezing out the gelatinized starch due to the heat generated during compaction. The above-mentioned problem was solved by controlling the gelatinization ratio of the starch to be squeezed out.

In addition, the equipment used in this method includes a raw material supply hopper and a compression roll consisting of a pair of cylindrical rolls provided at the bottom of the hopper that rotate in parallel to each other in opposite directions. A vertical screw is installed vertically,
A pre-pressure chamber is formed by the side wall at the lowest part of the hopper and the lower end of the screw pestle,
The pair of cylindrical rolls installed directly below the preload chamber can be moved telescopically in the distance between their axes, and the screw punch, the preload chamber, and the pair of cylindrical rolls can be moved reciprocally with respect to the hopper in this device. There is also disclosed a horizontal compression roll arranged at right angles while maintaining the same positional relationship.

[Function] When explaining the present invention in detail, the following 5 to 40% by weight
The raw starch granules containing water will be referred to as 1 starch raw material.

It is a well-known principle that when a substance is compacted by mechanical pressure, the compacted substance generates heat in order to suppress the molecular movement of the substance, and as the pressure increases, the calorific value of the substance also increases. be.

On the other hand, it is a well-known principle that starch raw materials undergo gelatinization by heating, and that if the starch raw material has a high moisture content, it will be gelatinized at a low heating temperature, and if the starch raw material has a low moisture content, it will gelatinize at a high heating temperature.

The present invention has been made focusing on the above two principles, so that when the starch raw material passes under pressure between a pair of cylindrical rolls, it becomes compacted, the temperature of the starch raw material rises within a short time, and the starch becomes α
It is based on the action of changing.

In other words, the starch raw material is supplied from the upper part of the hopper, and is forced to move inside the hopper by the spiral surface of the screw punch that rotates through the center of the hopper and is subjected to pressure, and this pressure is rapidly increased. Reaching the preload chamber, the forced feeding and compression action quickly induces heat generation due to intermolecular friction, and the compaction action reaches its maximum due to the rotation of the rolls that are caught between the cylindrical rolls directly below, causing a heat generation effect. It is also at its peak at this time.

As a result, the starch raw material reaches the temperature necessary for alteration, gelatinizes at a rate corresponding to the calorific value, and is discharged from between the rolls. Since the heat generation effect can be freely controlled by the compaction effect, the heat generation effect can be controlled to a desired state by varying the rotational speed of the screw punch or changing the gap between both rolls in order to adjust the compaction effect.

[Example] Hereinafter, Example (1) of the present invention will be described based on FIG. 1.

Cylindrical rolls IA, 1B are connected to shafts 3A, 3B, shaft 3
A is pivotally fixed to the fork 6, and the shaft 3B is pivotally supported to the bracket 7. The fork 6 is connected to the rod 5 of the hydraulic cylinder 4. The bracket 7 and the hydraulic cylinder 4 are fixed to the support 8. The hydraulic pressure is transmitted to the rod 5, fork 6, and shaft 3A of the hydraulic cylinder 4, and the cylindrical roll 1A moves and comes into pressure contact with the fixed cylindrical roll 1B. Therefore, by controlling the hydraulic pressure, a pair of cylindrical rolls 1A and 1B are
It is possible to control the pressing force between the two.

A pre-pressure chamber 2 is installed on the upper part of the cylindrical rolls IA and 1B, and the upper part of the pre-pressure chamber 2 is connected to a hopper 9. Hopper 9 and preload chamber 2
A screw 10 as an example of a screw punch is provided on the center line of the screw 10, and the lower end of the screw 10 is fitted into the preload chamber 2 and has a spiral blade in the direction of sending the starch raw material 20 downward.
The upper end of the hopper 9 is connected to a hopper 11 attached to the upper part of the hopper 9.

When the rotation of the screw 10 is increased to feed a large amount of starch raw material, the amount that is not discharged by the cylindrical rolls IA and 1B accumulates in the preload chamber 2, reducing the voids in the starch material and increasing the bulk density. It is elaborated.

A feed port 13 for starch raw material is provided in the upper part of the hopper 9, and the starch raw material is inputted and supplied from here. The starch raw material put into the hopper 9 is fed into the pre-pressure chamber 2 by the rotation of the screw 10 and densified, and then passed between the cylindrical rolls 1A and IB whose pressurizing force is controlled by the hydraulic cylinder 4. The starch α-gelatin which has changed to a predetermined degree of gelatinization while gradually generating heat during compaction is continuously discharged.

Next, Example (2) of the present invention will be explained based on FIG.

The cylindrical rolls 12A, 12B are coupled with shafts 32A, 32B, the shaft 32A is pivotally supported on the fork 6B, and the shaft 32s is pivotally supported on the bracket 7B. Fork 6B is hydraulic cylinder 4
It is connected to the rod 5B of B.

Bracket 7B and hydraulic cylinder 4B are fixed to support 8A.

The hydraulic pressure is transmitted to the rod 5B of the hydraulic cylinder 4B, the lever 6B, and the shaft 32A, and the cylindrical roll 12A moves and presses against the fixed cylindrical roll 12B. This is similar to FIG. 1 of Example (1). That is, the embodiment (2) of the present invention has a pair of cylindrical ports IA,
18. 12A and 12B are provided to pressurize the starch raw material in two stages, and when compared with Example (1), it is possible to lengthen the pressurization time of the starch raw material. Therefore, it becomes possible to lengthen the heat generation retention time of the starch raw material, and the control range of the degree of gelatinization of starch is expanded.

The above two embodiments have been explained, but in both embodiments, the starch raw material flows in a straight line from above to below, whereas the prepressure chamber 1 has a cylindrical roll placed horizontally and flows perpendicular to the hopper. This also constitutes a preferred embodiment after coordinate transformation. (Fig. 3) [Effects of the invention] As described above, this invention is based on the addition of conventional chemical substances.

This is a method for gelatinizing starch that does not require heating means.

Therefore, the conventional procurement of chemical substances, addition of chemical substances, superheated steam generator, heater, and heating process can be omitted, resulting in a great effect in saving resources and energy.

What is noteworthy is the effect of being able to arbitrarily vary the ratio of pregelatinized starch from the same starch raw material depending on the purpose. By controlling the density of the starch raw material in the pre-pressure chamber) and by controlling the hydraulic pressure of the cylinder, that is, by controlling the compaction between the cylindrical rolls), three types of α-starch with different degrees of gelatinization were obtained from the same starch raw material. I confirmed that I got it.

(Margin below) Table 1 is a front sectional view of Example (2) of the present application, and Example (3) of the present application.
Front sectional view.

IA, 1B...Cylindrical roll 2...
...Pre-pressure chamber 9 ...Hopper 10 ...Screw (screw) 12A, 123 ...Cylindrical roll Fig. 3 is a different type of instant food. As a result, various degrees of gelatinization are required for this important raw material, alpha starch.

Therefore, the starch gelatinization device of the present invention can control the degree of starch gelatinization with simple operations and can continuously produce controlled alpha-starch, so it is highly effective in producing alpha-starch from small to large quantities. It is something that demonstrates the.

[Brief explanation of the drawing]

Claims (4)

[Claims] (1) It is characterized by continuously squeezing raw starch granules containing 5 to 40% by weight of water at room temperature, and continuously squeezing out the starch that has been gelatinized by the heat generated during compaction. A method for producing pregelatinized starch. (2) The method for producing pregelatinized starch according to claim 1, characterized in that the pregelatinization ratio of the starch to be expressed is arbitrarily adjusted by controlling the pressing force used for squeezing. (3) A compression roll consisting of a raw material supply hopper and a pair of cylindrical rolls provided at the bottom of the hopper that are parallel to each other and rotate in opposite directions. A preload chamber is formed by the lowermost side wall and the lower end of the screw rod, and the pair of cylindrical rolls mounted directly below the preload chamber are movable telescopically in the distance between their axes. Equipment used in the method. (4) In claim 3, the screw rod, the prepressure chamber, and the pair of cylindrical rolls are arranged in series with respect to the hopper while maintaining the same mutual positional relationship to form a horizontal type. Equipment used in the method.