JP2544386B2 - Heat treatment method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heat treatment method for food. More specifically, the present invention is a high-speed transfer using a Coanda spiral flow, drying, puffing,
The present invention relates to a heat treatment method for foods which is highly efficient in sterilization and the like.

(Background Art) Conventionally, high-pressure heated air or superheated steam is used for processing materials such as soy sauce, miso, and brewed foods such as sake, manufacturing snack foods, drying vegetables and noodles, and sterilizing food powders. The method used is known.

However, many of these conventional heat treatment methods are batch systems or semi-batch systems, and even if they are continuous systems, the processing speed is slow, and food adheres to and remains on the processing equipment. There was a problem due to the above, and the quality of the collected food after processing was not uniform.

Therefore, there has been a strong demand for realization of a new heat treatment method which is a continuous method, is highly efficient, has no process troubles, and enables food processing of excellent quality.

On the other hand, a technique relating to the production and use of the Coanda spiral flow has been proposed by the inventor of the present invention as being useful for transportation of fluid, drying, separation, transportation of powder or fibrous material, opening, etc. There is.

The Coanda spiral flow is completely different from the laminar flow or turbulent flow known as the conventional fluid motion concept, and is different from the turbulent flow even under the motion condition of the fluid belonging to the turbulent flow region. It was discovered by the inventor of. Its generation has also already been proposed by the inventor.

That is, the inventor of the present invention adds a vector in the pipe radial direction to a fluid vector in the pipe direction to swirl the fluid, and a dynamic boundary layer is formed in the vicinity of the inner wall of the pipe based on the swirling flow. I found the fact that it travels at high speed in the pipeline direction while drawing a spiral. In such a Coanda spiral flow, the fluid travels at high speed,
Moreover, even if solid particles are present due to the presence of the dynamic boundary layer, they do not collide with the inner wall of the pipe as in the case of turbulent flow. Therefore, the state of the fluid is uniformly maintained in the process of spiral motion of the fluid, and local alteration due to collision and contact with the inner wall is also suppressed.

Such excellent properties are extremely useful as a chemical or physical unit process, or a system thereof, including transportation of fluids such as particles, slurries and fibrous substances.

The inventor of the present invention has described the generation of Coanda spiral flow having such excellent advantages, for example,
An apparatus as shown in FIG. 3 has already been proposed.

In the example shown in FIG. 3, the Coanda spiral flow generator (a) is connected to the pipe (a), and the cylinder (c) connected to the pipe (a) is directed in the opposite direction. The diameter is gradually increasing. A pressurized fluid, for example, a compressed flow of gas, air, or liquid is fed into the cylindrical tube (c) laterally through the introduction tube (d). To feed the pressurized fluid in the direction of the pipe (a), an annular slit (e) is provided. Further, a wall surface (f) that is smoothly curved is formed from the slit (e) toward the conduit (a).

On the side opposite to the curved wall surface (f), a bent wall surface (g) bent at a right angle or an acute angle is provided. The slit (e) allows the interval to be freely adjusted. Furthermore, a distribution chamber (h) for uniformly supplying the pressurized fluid to the slit (e) is provided.

The end face opposite to the pipe (a) is an inlet (q), and a fluid can be introduced from this inlet (q).

In the Coanda spiral flow generation device having such a structure, the motion vector of the pressurized fluid from the slit (e) and the motion vector of the fluid from the inlet (d) are combined to generate a spiral motion (c). At that time, at the outlet of the slit (e), the pressurized fluid moves by drawing the streamline of the arrow α by the Coanda effect, and forms a dynamic boundary layer near the inner wall surface of the conduit. Also, a large negative pressure region is generated on the side of the slit (e) on the inlet (k) side to promote the inflow of the fluid from the inlet (k).

The inventor of the present invention eliminates the drawbacks of the conventional batch system or the continuous system by turbulent flow transfer by using the Coanda spiral flow generated by the above-described generation device for heat treatment of food, and has an extremely high efficiency. The present invention has been completed by finding that heat treatment such as drying, puffing, and sterilization of high quality food can be performed.

(Object of the Invention) The present invention has been made in view of the circumstances as described above, and is capable of improving the drawbacks of the conventional method and obtaining a heat-treated food product of high efficiency and high quality. It is an object of the present invention to provide a heat treatment method for foods using.

DISCLOSURE OF THE INVENTION In order to achieve the above object, the food heat treatment method of the present invention transfers by a Coanda spiral flow,
It is characterized in that it is heat-treated with the heated air and / or steam sent in.

The heat treatment targeted by this method includes, for example, the following. That is, soy sauce, miso, brewed foods such as liquor, soybean, rice and other raw material powder short-time steaming treatment,
Examples include puffing treatment, drying treatment of vegetable powder and granules, drying treatment of noodles, gelatinization of starch, puffing for snack food production, drying of meat food, puffing and sterilization treatment of powdered food.

The method of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows an example of the method of the present invention. According to this example, the pipe (2) is connected to the Coanda spiral flow generator (1). Further, pressurized air is fed into the Coanda spiral flow generator (1) from the annular slit (3) after being pressurized by the compressor (4). Further, the food powder is introduced from the food powder supply (5).

As the Coanda spiral flow generator (1), for example, the one shown in FIG. 3 is used. Of course, it is not limited to the one shown in FIG. To date, various shapes and structures proposed by the inventor of this invention have been used.

At the outlet of the pipe (2), separators (6) and (7) for separating air and powder are provided. The separators (6) and (7) may be single or may be multi-stage. In addition, the separator (6) (7)
The air separation pipes (8) and (9) and the food powder granule collection pipe (10) are provided in the.

The apparatus for such heat treatment may be provided with a steam supply device (11) for inserting steam together with air.

The pressurized air sent from the annular slit (3) or the pressurized air mixed with steam has a pressure of, for example, 1 to 10
It can be changed over a wide range of kg / cm ² . The mixing ratio of the food powder particles can be up to about 2 to 6, for example. The pipe length can be up to several tens to 200 m, and the pipe diameter can be set appropriately.

The temperature of the pressurized air and steam can be selected according to the food to be treated, and can be as high as 100 to 300 ° C.

The transfer speed of the pipeline (2) is, for example, from about 20 m / sec to 13
High speeds of up to 0 m / sec are possible. Of course, 2
It can be set to 0 m / sec or less.

 FIG. 2 shows another example.

In the case of this example, a feed tank (5) for food raw material granules is provided in the middle of the pipeline (2), and a single separator (12) for separating air from food granules is provided. And then
A collection tube (13) for the food powder and an air separation tube (14) are provided. The separated air is supplied to, for example, a steam supplier (11).
May be circulated through. The heating energy of the air can be reduced by circulating the hot air.

In the case of the method and apparatus shown in these examples, the heat treatment of food can be performed at an extremely high speed for a short time. Moreover, the contact between the food particles and the pipeline is significantly suppressed, and the wear of the pipeline and the adhesion of the food particles are also suppressed.

Next, the method of the present invention will be described in more detail with reference to examples.

Example 1 A stainless pipe having a diameter of 30 mm and a length of 30 m was connected to the Coanda spiral flow generator shown in FIG. 3 to obtain 3 kg / cm.
^At a pressure of ² , superheated steam at 130 ° C. was fed into the generator, the chopped spinach was introduced into the Coanda spiral flow generator, and dried while being transferred into a pipe.

Dried spinach pieces with excellent color and scent were obtained.

Example 2 Using the same apparatus as in Example 1, at a pressure of ² kg / cm ² ,
Wheat flour was dried and sterilized by feeding superheated steam at 50 ° C. Wheat flour with a water content of 12.8% was dried to a water content of 6.8%, and the number of viable bacteria was sterilized to a level of 20 cells / g or less. Moreover, coliforms were not detected.

Example 3 Using the same apparatus as in Example 1, 180 at a pressure of 3 kg / cm ² .
Air at a temperature of ° C was introduced to sterilize the black pepper powder. It was sterilized by circulating it through a 30 m pipe three times.

The general viable cell count was reduced to less than 300 cells / g. No coliforms were detected.

Example 4 Using the same apparatus as in Example 1, at a pressure of 5 kg / cm ² , 2
The air of 00 ℃ was sent in to gelatinize the rice flour. The alpha processing was realized with excellent quality.

(Effects of the Invention) According to the present invention, as described in detail above, the heat treatment of the powdery or granular material of the food is realized with high efficiency.

Treatments such as drying, expansion and sterilization are continuously realized.
Moreover, there is no trouble caused by the adhesion of the object to be processed to the device.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of the method of the present invention.
FIG. 2 is a configuration diagram showing another example. FIG. 3 is a sectional view showing an example of a Coanda spiral flow generation device. 1 …… Coanda spiral flow generator 2 …… Pipe 3 …… annular slit 4 …… Compressor 5 …… Food powder supply tank 6,7 …… Separator 8,9 …… Air separation tube 10 …… Recovery pipe 11 …… Steam supply device 12 …… Separator 13 …… Recovery pipe 14 …… Air separation pipe

Claims (2)

(57) [Claims] 1. Transferring by a Coanda spiral flow,
A heat treatment method for foods, which comprises heat-treating with the heated air and / or steam introduced. 2. The heat treatment method for food according to claim 1, wherein the steam is superheated steam.