JPH07107963A - Prevention of excessive temperature rise in koji maker - Google Patents

Abstract

PURPOSE:To prevent quality deterioration of KOJI by avoiding the excessive temperature rise of KOJI during its production. CONSTITUTION:In the follow-up control of the body temperature a2 of KOJI in comparison with the target values A, the culture mixture is stirred to effect dissipation of heat to realize the follow-up, when the body temperature a2 wanders the higher value than the target but not follows even in the case where the indicated room temperature is lowered to a certain limit L and continued for a certain time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing excessive temperature rise in koji making.

[0002]

2. Description of the Prior Art Among the kojis for brewing sake, miso, soy sauce, etc., as a device and a method for obtaining a high-quality koji called "breakthrough spirit" for the brewing of high-quality sake, there has been disclosed in A technique as disclosed in Japanese Patent Laid-Open No. 5-7486 has been proposed. As shown in FIG. 1, this apparatus stores culture medium (steamed rice) in a large number of box-shaped wooden containers 2 and stacks the containers in two or more rows in an environment-controlled koji making room 1. It is a device that makes the overall koji-making conditions uniform by moving up and down and moving (circulating) between rows, and it is used to perform work such as intermediary work, finishing work, and koji-making after placing the culture medium on each container 2. The koji making operation is completed by controlling the product temperature of the culture medium corresponding to these work steps.

In the above product temperature control, the product temperature of the culture medium is detected by a product temperature sensor 9 installed in the container 2, and the air conditioner 5 is controlled so that the product temperature changes with time according to the target product temperature A shown in FIG. In addition to automatically controlling the room temperature according to a program, the room humidity is also detected, and the humidity is controlled by the humidifier and dehumidifier (air conditioner 5) so as to follow the set humidity.

[0004]

However, during actual temperature control, the temperature rise characteristic in the initial stage may be good and the temperature may rise sharply with respect to the set temperature depending on the type and characteristics of the koji. In such a case, even if the room temperature is continuously lowered to the lower limit position, the target set product temperature cannot be followed, and there is a concern that the excessive temperature rise may adversely affect the quality of koji. In addition, if the indicated room temperature is lowered below a certain limit against the above-mentioned excessive temperature rise, on the contrary, there is a possibility that the room temperature is lowered and the activity of the bacteria is impaired, resulting in deterioration of quality.

[0005]

The method of the present invention for solving the above-mentioned problems is achieved by controlling the room temperature of the culture medium in the environmental chamber 1 so that the product temperature of the culture medium is a preset target product. In the method of controlling the temperature according to the temperature and stirring the culture medium according to the process of koji making, the control instruction room temperature a ₁ changes the predetermined limit value L of the instruction room temperature a ₁ for a predetermined time t _s. Also, when the actually measured product temperature a ₂ is equal to or higher than the target product temperature A and does not follow the target product temperature A and approaches, the culture medium is forcibly and automatically agitated.

[0006]

[Operation] After the start of koji making, by controlling the room temperature according to whether the quality of the culture medium is higher or lower than the target temperature while measuring the temperature of the culture medium, the product temperature is controlled to follow the target temperature, but the room temperature is continuously maintained. If the temperature of the culture medium continues to rise even after the temperature has dropped to the specified value, the culture medium is automatically agitated to radiate heat and correct the product temperature to approach the target product temperature, preventing quality deterioration due to excessive temperature rise. To be done.

[0007]

FIG. 1 shows an outline of an apparatus used for carrying out the present invention. A koji making apparatus housed in a koji making room 1 whose environment is controlled by a controller 8 (host computer) is a koji lid (container). 2, a placing device 3 for placing a culture medium such as steamed rice in which a koji mold has been placed, and a large number of the placed containers 2 are loaded and stacked, and in the stacked state, each container 2 is placed under temperature, humidity and CO ₂ A circulation mechanism 4 that raises and lowers and transfers and circulates (transfers or rotates) in order to evenly give the koji-making conditions such as the concentration, and the filling shape is changed on the circulation mechanism 4 if necessary, and the production in each koji lid 2 is performed. And a stirring device 6 for making the koji conditions uniform. The koji lid 2 is a rectangular wooden box and has a structure capable of maintaining the ventilation of the inside and the outside in a stacked state.

As shown in FIG. 1, the koji making chamber 1 forms an environment chamber for accommodating the koji making chamber device, and the outside air is purified by an air conditioner 5 installed outside the room to control the temperature and temperature through the daft 7. It has a function to adjust humidity, air volume, and oxygen concentration, carbon dioxide concentration, etc. if necessary. The koji making room 1 is connected to an external host computer 8 to measure and control the internal environment as described above, a thermometer 9, a hygrometer 11, carbon dioxide (CO ₂ ).
A densitometer 12 for sampling and measuring, and a container 2 in a circulation mechanism 4 to be described later are provided with a temperature detector (sensor) 26 for sampling and measuring the product temperature of the moving container 2 and the culture medium inside the container 2. Has been.

A slave computer 13 such as a sequencer is connected between the host computer 8 and the respective operating parts of the arranging device 3, the circulation mechanism 4 and the stirring device 6 to control the operation of each part. The host computer 8 is provided with a display device 14 such as a display screen, a storage unit 18 such as a hard disk 16 and a floppy disk 17, and the air conditioner 5 is connected to the host computer 8 online (RS-232C) to be controlled. It has become.

Below the arranging device 3, a carry-in line 22 composed of a belt conveyor for placing the koji lid 2 on standby is installed in the left-right direction. The koji lid 2 has a hopper 2
From the lower end of 1, steamed rice planted with a predetermined amount of koji mold is discharged and dropped, and the steamed rice has an initial shape of a mountain shape.
The koji lid 2 after the coating is sequentially fed into the circulation mechanism 4 on the left side in FIG.

The circulation mechanism 4 accommodates the left half of the carry-in line 22 in the lower part, and an upper transfer line 23 composed of a conveyor or the like parallel to the carry-in line 22 is provided in the upper part thereof. In between, the ascending line 24a and the descending line 24b in the state where a large number of koji lids 2 are stacked in two rows are supported, and the koji lid 2 is shown by the operation of the ascending line 24a, the descending line 24b, the carry-in line 22 and the transfer line 23. As described above, the container 2 is transshipped in the clockwise direction, for example, by sequentially feeding and rotating one stage at a time every 5 minutes for circulation.

The stirring device 6 is provided downward on the circulation mechanism 4, a rotating stirring unit is inserted into the koji lid 2 so as to be able to move up and down, and the internal stirrer is raised as needed during the rotation operation of the koji lid 2. Stir the steamed rice or change the filling shape. These agitation and change of the filling shape are mainly made by steaming rice according to the timing and purpose of the work such as middle work, sushi work, and malted rice that are traditionally performed when making sake koji. It is performed for the purpose of homogenizing the whole body, allowing it to cool, evaporating, and controlling the growth of koji in the next step.

In the present embodiment, in the koji making room 1, as shown in FIG. 2, computer control is carried out in accordance with a program preset so that the product temperature follows the set product temperature A,
While controlling the humidity to follow the set humidity, the agitation is performed between the control start after preheating of the koji making room 1 and the koji-making, in particular, before the koji-making which is the work in the final stage, Agitation of the steamed rice in the containers 2 is started, for example, about 40 minutes before the scheduled time, and agitation of all the containers 2 is completed about 5 minutes before the malted rice.

A temperature detector 26 comprising a rod-shaped platinum temperature sensor (thermocouple) for detecting the product temperature is provided in the container 2 along the inner surface of the bottom plate so as to penetrate the container side plate. 26 is an elevating line 24a for sample measurement,
One is provided in each of 24b, and the product temperature is constantly detected during the ascending / descending of the ascending line 24a and the descending line 24b, and the detection information is provided to the host computer 8. The mechanism and method for measuring the article temperature during the movement of the containers on the elevating lines 24a and 24b are the same as those disclosed in JP-A-5-7486.
An outlet is connected to the plug on the side of the container so that it can be connected and disconnected freely, and it follows up and down, but its detailed description is omitted.

Since the ideal koji-made koji is obtained by adjusting environmental conditions such as temperature and humidity in the koji-making process over time, the ideal temperature, which is one of the environmental conditions, is generally empirical. You can ask. Therefore, in this embodiment, an ideal set product temperature from the start of environmental control during koji making to the start of koji (about 24 hours) is provided in advance, and the measured product temperature a measured by the temperature detector 26 is set for this. _The air conditioner 5 controls the instruction room temperature a ₁ to be measured by the thermometer 9 so that ₂ follows the set product temperature. Prior to the above-mentioned product temperature follow-up control, the koji making chamber 1 and the koji lid 2 need to be preheated to a predetermined value in advance in order to make the product temperature at the start of control more accurately follow the target temperature A. After preheating and assembling, the product temperature control for koji making is started.

In the above product temperature control, depending on the type of koji,
For example, in the case of koji where the momentum of koji mold is active, such as total sterilization,
Immediately after the start of the koji making control, the temperature rising characteristic is strong, and the product temperature a ₂ continues to rapidly increase as indicated by (a) and (b) in FIG. On the other hand, the instruction room temperature a ₁ continues to be lowered to prevent the product temperature a ₂ from excessively rising, but a predetermined limit value (predetermined value) for the instruction room temperature a ₁ not to excessively suppress the activity of Aspergillus oryzae. state lowered to L: also passed (Note specified room temperature a ₁ is the predetermined value L is set so as not to descend below) the preset predetermined time t _s should be noted the material temperature a ₂ (i) There may be a case where the rising state (state in which the transition above the target temperature A ₂ at least the target temperature A ₂ continues) cannot be suppressed. The predetermined value L is a lower limit value of activity suppression of koji mold in the koji making process or a value close thereto.

In this embodiment, when the room temperature control alone cannot suppress the excessive temperature rise of the product as described above, the stirring device 6 is operated in accordance with the rotation operation of the container 2 in the circulation mechanism 4. Then, the culture medium in the container 2 is stirred for a necessary time to radiate heat from the culture medium, and the room temperature a ₂
Is forcibly reduced to follow the target product temperature A as shown in FIG.

The forcible product temperature lowering control by the stirring device 6 is automatically performed by setting conditions in advance in the control program. When the product temperature can follow the target product temperature A by the above stirring, the normal follow-up control is automatically performed.

Further, the forced heat radiation is set to be performed before the middle job during the koji making work. In addition to this stirring, whether or not it is necessary to further stir the middle job is determined artificially or automatically by a computer. It is decided arbitrarily.
And, at least, we try not to perform forced heat dissipation due to unplanned agitation after the middle job. As a result, damage to the koji caused by agitation at the growth stage after the middle job is prevented.

[0020]

As described above, the method of the present invention can prevent quality deterioration due to excessive increase in the product temperature of the culture medium during koji making, and set a prescribed value of the indicated room temperature to be extremely low. Therefore, problems such as uneven generation of Aspergillus and deterioration of quality due to the extreme temperature difference between the surface and the inside due to excessive cooling of the culture medium are prevented.

[Brief description of drawings]

FIG. 1 is an overall explanatory diagram showing an example of an apparatus used in the method of the present invention.

FIG. 2 is a graph showing the relationship between the curve of the set product temperature and the set humidity for controlling the product temperature of koji making according to the present invention and the koji making operation.

[Explanation of symbols]

1 Koji making room (environmental room) A Set product temperature a ₁ Instructed room temperature a ₂ Measured room temperature L Predetermined limit value (predetermined value)

Claims (1)

[Claims] 1. By controlling the room temperature of the culture medium in the environment room (1), the temperature of the culture medium is controlled so as to follow a preset target temperature, and the temperature of the culture medium is adjusted according to the koji making process. in method in which stirring the culture medium, an instruction of the control room (a ₁₎ is an instruction room temperature predetermined limit values (a _{1) (L)} a predetermined time (t _s) also remained measured product temperature (a ₂₎ Is a value higher than the target temperature (A) and does not follow the target temperature (A) and approaches the target temperature (A).