JP5452370B2 - Method for producing sterilized grain - Google Patents

Description

  The present invention relates to a method for producing a sterilized cereal grain, in which, despite being sterilized (sterilized), there is no deterioration in quality, and when milled, a flour having good suitability for secondary processing is obtained.

  Cereals are eaten as a staple food in many areas. If the food is contaminated with bacterial microorganisms, there are problems in food hygiene and also in the quality of the food. As a method of sterilizing food, sterilization by heating is generally performed, but in order to sufficiently sterilize (sterilize) microorganisms, it is necessary to treat the food at a high temperature for a long time. There is a problem that the flavor of food is impaired and the quality of the protein and starch is deteriorated by heat denaturation.

In order to solve the above-described problems in heat sterilization, a method has been proposed in which food powder is accelerated by ultrasonic waves to collide with a rigid body, and the food powder is sterilized by the collision energy (see Patent Document 1). . Moreover, the method of making flour contact with ozone gas and disinfecting flour by the disinfection power of ozone gas is proposed (refer patent document 2).
However, with the sterilization methods described in these patent documents, it is difficult to spread ultrasonic waves and ozone gas to all powders, and it is costly to sterilize flour that is consumed in large quantities as a staple food. There was a problem of being high.

On the other hand, as an improved method of heat sterilization, microorganisms that adhere to the granular material, such as rice powder and green tea powder, are immediately released in a low-pressure space following a short heating and pressurizing treatment There has been proposed a sterilization method that shortens the heating time by sterilizing the water in the water rapidly (see Patent Document 3). According to this sterilization method, it is said that the quality deterioration of the granular material by heating is reduced and a sufficient sterilization effect is obtained.
However, even with this sterilization method, it is difficult to completely prevent the quality of the flour from being deteriorated, and the suitability for secondary processing may be significantly reduced particularly when applied to wheat flour.

Japanese Unexamined Patent Publication No. 2009-22 JP 2002-10767 A International Publication No. 2009/145198 Pamphlet

In view of the above situation, the present inventors have various sterilization methods for the purpose of providing a method for sterilizing flour, in which a sufficient sterilizing effect is obtained, and there is no deterioration in quality, and a flour having good suitability for secondary processing is obtained. Repeated examination.
As a result, the present inventors used the grain seeds without crushing them, using the grains as they are, and by pressing the grains under pressure under specific conditions and then rapidly reducing the pressure, General viable bacteria, molds, yeasts, coliforms, etc. of grains can be killed by the effect of boiling under reduced pressure due to sudden pressure reduction from the pressurized heating state, and the grains are not subjected to the heat treatment. It was found that a flour having a quality equivalent to that of cereal grains, good quality, and good suitability for secondary processing can be obtained.

This invention is made | formed based on the said knowledge, and provides the manufacturing method of the sterilized grain grain characterized by having the process of following (1) and (2).
(1) Step of adding 0 to 10% by mass of cereal grains to cereal grains and then heating under pressure for 0.001 to 60 seconds under conditions of a temperature of 100 to 180 ° C. and a pressure of 0.01 to 0.7 MPa ( 2) A step of rapidly depressurizing the grain that has been pressurized and heated in the step (1) within 0.00001 to 10 seconds.

  According to the method for producing sterilized cereal grains of the present invention, when sterilization (sterilization) is sufficiently performed and sterilization (sterilization) is performed, there is no deterioration in quality and milling is performed. Thus, it is possible to produce a sterilized cereal grain from which a flour having good quality and good secondary processing suitability can be obtained.

Grain grains used in the present invention are not particularly limited, and examples thereof include rice, corn, wheat (wheat, barley, oat, rye, pearl barley, etc.), gramineous plants such as milo, millet, and millet, Examples include seeds of legumes such as soybeans, red beans, peanuts, peas, and kidney beans, and wheat seeds (wheat grains) are particularly preferable.
These seeds need to be used in the form of grains without being pulverized. When pulverized seeds are used, deterioration in quality is inevitable. In particular, when wheat is milled and used in the form of wheat flour, the suitability for secondary processing may be significantly reduced.
As long as it is in the form of grains, it may be one with the outer skin attached or may be one with the outer skin peeled, but the one with the outer skin attached is preferable because there is no deterioration in quality.

It is preferable to add water to the grain before the grain is heated under pressure. Addition to the grain is not always necessary from the viewpoint of sterilization, but it is preferable to add water to the grain from the viewpoint of sterilization without causing deterioration of the quality of the grain.
In addition, when the grain is used with the hull attached, the hull is hard and fragile. Therefore, when the treatment according to the present invention is performed without adding water to the grain, the hull is crushed and becomes fine, and it is difficult to separate the hull. It becomes. By adding water to the grain, the outer skin absorbs water and becomes tough, making it difficult to break. Moreover, the grain grain thus hydrolyzed also has the advantage that the tempering step can be omitted when milling after the pressure heating treatment in the step (1) and the pressure reduction treatment in the step (2) of the present invention. is there.

0.1-10 mass% is preferable with respect to the mass of a grain, and, as for the amount of water to a grain, 1-5 mass% is more preferable.
If the amount of water added to the cereal grains is too large, the water content of the powder increases after milling the sterilized cereal grains of the present invention, resulting in “dama”, and the number of molds, yeasts and general viable bacteria tends to grow.

The pressure heating of the cereal grains is performed at a temperature of 100 to 180 ° C, preferably 110 to 160 ° C, more preferably 120 to 150 ° C and a pressure of 0.01 to 0.7 MPa, preferably 0.05 to 0.5 MPa, more preferably. Is carried out under conditions of 0.1 to 0.4 MPa.
If the heating temperature is too low, the sterilizing effect of molds, yeasts and general viable counts is deteriorated, and if it is too high, the grain is denatured and the secondary processing suitability of the grain food is significantly lowered.
Pressurization pressure and temperature are closely related. If the pressurization pressure is too low, the heating temperature will be low, so the bactericidal effect of mold, yeast and general viable count will be worse, and the pressurization pressure will be too high. When the grain is denatured, the suitability for the secondary processing of the grain food is significantly reduced.

The heating method may be any method that can heat the grain within the above heating temperature. For example, as a heating source, fire (including direct fire or via oil, ceramics or metal), electricity, infrared, Examples thereof include a method using heat of chemical reaction such as gas, steam, hot air, electromagnetic wave, high frequency, microwave, induction current, frictional heat, or oxidation reaction heat.
Specifically, for example, the grain may be heated using a heater, a stove, an induction heater (IH), a microwave oven, a steam cooker, a roaster, a steamer, or the like as a heating device.

As a method of pressurization, a method in which a pressure medium is filled in a container containing grain grains can be mentioned. The pressure medium may be gas, liquid, or solid.
Specifically, for example, an autoclave, a hydraulic device, a pump, a plunger pump, or the like may be used as a pressurizing device.

The pressure heating of the grain is performed by appropriately combining the heating method (heating device) and the pressing method (pressing device).
The pressure heating time is 0.001 to 60 seconds, preferably 0.01 to 5 seconds, more preferably 0.2 to 2 seconds.
If the pressure heating time is less than 0.001 seconds, the sterilization effect of mold, yeast and general viable count will deteriorate due to insufficient pressure heating. Due to denaturation, the grain food is not suitable for secondary processing.

As a method of rapidly depressurizing the grain that has been pressurized and heated as described above, a container for performing the pressurized heating is provided with a lid, a die, a nozzle, and the like, from which the atmosphere flows into the container or the container The method of releasing the grain of the inside into air | atmosphere etc. is mentioned. At that time, it is possible to adjust the time required to depressurize the grain by adjusting the diameter and depth of the lid, dice and nozzle, but the bactericidal effect is not affected by the time required for depressurization. It is important to reduce the pressure instantaneously so that boiling occurs sufficiently.
The time required to rapidly depressurize the grain is 0.00001 to 10 seconds. Within this range, it may be appropriately selected according to the depressurization method. For example, in the method of flowing the air into the container, the time is 0.00001 to 10 seconds, preferably 0.5 to 5 seconds, more preferably 0.1 to 1 second. Further, in the method of releasing the grain in the container into the atmosphere, it is 0.00001 to 0.1 seconds, preferably 0.0001 to 0.08 seconds, more preferably 0.001 to 0.05 seconds. .

  After the decompression, it is preferable to cool the grain. Examples of the cooling method include water cooling and air cooling, and it is preferable to quickly cool to 40 ° C. or less with chiller water, a cooling fan, a cyclone or the like.

As an apparatus suitable for carrying out the method for producing sterilized cereal grains of the present invention, the following sterilization apparatus described in International Publication No. 2009/145198 (Patent Document 3) can be exemplified.
A raw material supply unit, a heat condensable gas supply unit, a joint formed by connecting the raw material supply unit and the heat condensable gas supply unit, a heated airflow pipe connected downstream of the joint, and the heating A decompression unit disposed downstream of the airflow tube, a cooling airflow tube connected to the decompression unit in the middle thereof, a cooling unit connected to the upstream of the cooling airflow tube, and sending a non-aggregating gas into the cooling airflow tube, A powder sterilizer comprising a powder separator connected downstream of the cooling airflow tube.
This sterilization apparatus is commercially available as a powder sterilization apparatus Sonic Stera (trade name, manufactured by Fujiwara Techno Art Co., Ltd.), and the pressure heating treatment in the step (1) and the pressure reduction treatment in the step (2) of the present invention. Can be performed continuously, which is preferable.
Moreover, as a said apparatus, the "4 food pressure sterilization apparatus (brand name)" by Shinwa Machine Co., Ltd. can also be used. This apparatus is also preferable because the step (1) and the step (2) of the present invention can be performed continuously.

  Examples of the present invention and comparative examples are given below, but the present invention is not limited by the following examples.

Examples 1-4
Using a “4 edible pressure sterilizer (trade name)” manufactured by Shinwa Kikai Co., Ltd., pressurizing and heating wheat grains (US-made hooft waist) with the outer skin attached under the conditions shown in Table 1. A reduced-pressure treatment was performed to produce sterilized wheat grains. The wheat grains were added with 3% by mass before being heated under pressure. The resulting sterilized wheat grains were milled with a test mill manufactured by Wenger in Germany, sponge cake and tempura were produced by a conventional method, and the number of general viable bacteria and fungi / yeast and the suitability for secondary processing were evaluated. Table 1 shows the results.

The evaluation criteria for the suitability for secondary processing in Table 1 are as follows.
Sponge cake ○ Good cake volume, inner layer, texture and taste.
△ Slightly good cake volume, inner layer, texture and taste.
X The cake volume, inner layer, texture, and taste are poor.
Tempura ○ Appearance (fried color, flower bloom), texture (sakumi), good taste.
△ Appearance (fried color, flower bloom), texture (sakumi), taste slightly good.
× Appearance (fried color, flower bloom), texture (sakumi), bad taste.

Comparative Examples 1-4
Using “4 edible pressure sterilizer (trade name)” manufactured by Shinwa Machine Co., Ltd., the wheat flour (Nisshin Flour Flour) is subjected to pressure heat treatment and pressure reduction treatment under the same conditions as in Examples 1-4. Each sterilized flour was produced. Bacteria inspection was carried out on the resulting sterilized wheat flour. Table 2 shows the results (general viable bacteria and mold / yeast bacterial count).
Moreover, sponge cake and tempura were manufactured using the obtained sterilized wheat flour in the same manner as in Examples 1 to 4, and the suitability for secondary processing was evaluated according to the same evaluation criteria as in Examples 1 to 4. Table 2 shows the results.

  As is clear from the results of the fungus inspection and the evaluation results of the secondary processing suitability shown in Tables 1 and 2, in Examples 1 to 4 in which the wheat grains were processed as they were without being pulverized, they were sufficiently used as food. Despite being sterilized (sterilized) and sterilized (sterilized), there is no deterioration in quality, and when milled, the quality equivalent to that of untreated wheat grains (control) and Whereas flour having secondary processing suitability is obtained, in Comparative Examples 1 to 4 in which flour is processed, a sufficient bactericidal effect is exhibited, but the quality of the flour due to heating is unavoidable, and secondary processing is performed. The aptitude decreases.

Examples 5-7
Using a powder sterilizer Sonic Stera (trade name, manufactured by Fujiwara Techno Art Co., Ltd.), the wheat grains (US-made hoofite waist) with the outer shell attached under pressure and heat treatment and reduced pressure under the conditions shown in Table 3 Treatment was performed to produce sterilized wheat grains. The wheat grains were added with 3% by mass before being heated under pressure. The resulting sterilized wheat grains were milled with a test mill manufactured by Wenger in Germany, sponge cake and tempura were produced by a conventional method, and the number of general viable bacteria and fungi / yeast and the suitability for secondary processing were evaluated. The evaluation criteria for the suitability for secondary processing are the same as in Examples 1-4. Table 3 shows the results.

Comparative Examples 5-7
Using a powder sterilizer Sonic Stera (trade name, manufactured by Fujiwara Techno Art Co., Ltd.), the wheat flour (Nisshin Flour Flour) is subjected to pressure heat treatment and reduced pressure treatment under the same conditions as in Examples 5 to 7, and reduced. Each fungal flour was produced. Bacteria inspection was carried out on the resulting sterilized wheat flour. Table 4 shows the results (general viable bacteria and mold / yeast bacterial count).
Moreover, sponge cake and tempura were manufactured using the obtained sterilized wheat flour in the same manner as in Examples 1 to 4, and the suitability for secondary processing was evaluated according to the same evaluation criteria as in Examples 1 to 4. Table 4 shows the results.

  As is clear from the results of the bacterial tests and the evaluation results of the secondary processing suitability shown in Table 3 and Table 4, also in Examples 5 to 7 and Comparative Examples 5 to 7, Examples 1 to 4 and Comparative Examples 1 to 4 were used. Similar results were obtained.

Claims (2)

Possess the following steps (1) and (2), a manufacturing method of sterilization cereal grains, wherein the following cereal grains are wheat grains.
(1) Before pressurizing and heating the grain, 0.1 to 10% by mass with respect to the grain, then 0.001 to 60 under conditions of a temperature of 100 to 180 ° C. and a pressure of 0.01 to 0.7 MPa. Step of pressurizing and heating for 2 seconds (2) Step of rapidly depressurizing the grain that has been pressurized and heated in Step (1) within 0.00001 to 10 seconds Furthermore, the manufacturing method of the sterilized cereal grain of Claim 1 which has the process of cooling the grain grain which passed through the said (2) process by the water cooling method or the air cooling method.