JPH0425784B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for continuously producing rice cake-like foods of good quality, such as good texture and excellent storage stability. (Prior Art) Mochi, a traditional food from ancient times, is manufactured by washing and soaking polished glutinous rice in water, steaming it, and then crushing, kneading, and shaping it. These processes are common not only in the traditional pounding process but also in the production of products that are distributed in large quantities on the market in the form of packaged rice cakes, cut rice cakes, and the like. In other words, in the latter case, mixers and single-screw steamers have been introduced to the process of crushing and kneading steamed glutinous rice, making mass production possible; combination, making continuous production virtually impossible. This is mainly due to the characteristics of the raw materials being handled.
In other words, this is due to the extremely sticky nature of steamed rice and rice cakes, and in addition to the increase in the number of personnel required due to multi-stage batch processing, there is economic loss due to the fact that much of the raw material is lost due to adhesion to containers etc. during each process. There was a lot of damage. (Object of the Invention) The object of the present invention is to perform a series of steps including steaming, crushing, kneading, and molding of polished glutinous rice using a single device, a twin-screw extruder, in the production of mochi using glutinous rice as a raw material. The purpose of the present invention is to provide a means for continuously producing rice cakes of excellent quality. (Structure of the Invention) The present invention provides the interior of the twin-screw extruder in which glutinous rice is continuously fed into a two-screw extruder, and the temperature gradient is adjusted such that the central barrel is at a high temperature and the tip barrel is at a low temperature. This is a continuous manufacturing method for rice cake-like foods, which involves heating, pressurizing, crushing, and kneading, and extruding these through a die. As glutinous rice, we use glutinous rice that has been soaked in water in advance, and if necessary, it is continuously fed into a twin-screw extruder together with water and auxiliary materials, and heated inside the twin-screw extruder.
It can be crushed and kneaded, extruded from a die, and molded immediately if necessary. The present invention will be explained in more detail below. The two-screw extruder used in the present invention is composed of two screws, a feeder, a barrel, a die, a screw drive device, etc., and is also equipped with a device that heats the entire barrel portion or a portion thereof. , equipped with a heating temperature control device for the heated area, etc. Depending on the type of equipment, each barrel is divided into several parts (for example four). In addition, the screw has a trapezoidal shape, a paddle shape,
There are ball-shaped and other shapes, and you can select an appropriate combination depending on the application.In particular, by making the screw part located at the outlet tip a pin-type screw, the crushing and shearing force can be increased. . Such a twin-screw extruder has the ability to process each process such as mixing, compression, kneading, crushing, shearing, heating, sterilization, molding and cooling in a single unit, and the mochi according to the present invention can also be used. , any type of equipment may be used to manufacture the equipment as long as it has such functions; for example, the 2EXT-60 type extruder manufactured by Kobe Steel, Ltd. is preferably used. . In producing a rice cake-like food according to the present invention, first, a fixed amount of glutinous rice is continuously fed into a two-screw extruder, along with water if necessary. The glutinous rice used can be selected from brown rice, 7-minute pounded rice, polished rice, etc. depending on the purpose. These glutinous rice may be used for producing mochi-like food according to the method of the present invention immediately after washing with water, but it is especially preferable to use rice that has been soaked in water after washing, since a product with excellent spreadability and good texture can be obtained. It's advantageous. The immersion time may be, for example, 5 to 24 hours. When adding water together with glutinous rice, the amount of water supplied will be adjusted depending on the moisture content of glutinous rice, the presence or absence of a water soaking process, the soaking time, etc., but it is assumed that the added water is evenly absorbed and retained by glutinous rice. It is best to adjust the moisture content of glutinous rice to be around 40 to 50%. Further, auxiliary materials such as seasonings such as sugar and salt, fats and oils, food coloring enzymes, enzymes, and starch may also be added as appropriate. The glutinous rice, water, and auxiliary materials supplied quantitatively in this way are transferred to the tip die by two screws inside the twin-screw extruder while being pressurized. The glutinous rice is steamed and gelatinized by the heat generated by pressurized kneading, and is further crushed and kneaded to form a rice cake-like mixture. Heating conditions should be adjusted depending on the amount of glutinous rice, whether or not water is supplied and the amount, combination of barrels and screws, etc., but for example, using glutinous rice that has been soaked in water for 20 hours and a twin-screw extruder consisting of four barrels. When processing, the barrel internal temperature is set to a high temperature such as the first barrel 60 to 80℃, the second barrel 110 to 130℃, the third barrel 130 to 150℃, and the fourth barrel 60 to 120℃. By adjusting the temperature gradient of the tip barrel to a low temperature, it is possible to keep the temperature of the product extruded from the tip die at 70℃ or higher and 100℃ or lower, ensuring sufficient gelatinization and eliminating unnecessary Excessive puffing is suppressed and rice cakes of good quality can be obtained. Furthermore, by adding a degassing step to the manufacturing process, a product with a dense structure can be obtained. (Example) Hereinafter, the present invention will be explained in more detail with reference to Examples. Example 1 Polished glutinous rice soaked in water for 20 hours after washing (moisture content of polished glutinous rice: 14.6%, moisture content of polished glutinous rice soaked in water for 20 hours: 43.1%) was continuously fed using a two-shaft system at a feeding rate of 75 kg/h. It was supplied to an extruder (Model 2EXT-60, manufactured by Kobe Steel, Ltd.). The screw configuration of this two-shaft extruder is a trapezoidal screw with a pitch of 50 mm, a trapezoidal screw with a pitch of 50 mm, and a trapezoidal screw with a pitch of 50 mm.
mm and 35 mm ball-shaped screws, 25 mm pitch trapezoid screws, 30 mm pitch paddle type screws, and 25 mm pitch trapezoid screws, each 120 mm in length, and the temperatures of the four barrels are 70°C, 120°C, 150°C, and
The temperature was set at 100℃. Under these conditions, the glutinous rice was sequentially heated, steamed, crushed, kneaded and sterilized in each barrel of the twin-screw extruder, and then extruded through a die with a 5 mm x 40 mm flat hole. Example 2 After washing with water, polished glutinous rice soaked in water for 20 hours and water were continuously fed into a twin-screw extruder (Model 2EXT-60 manufactured by Kobe Steel, Ltd.) at a feeding rate of 75 kg/h and 5/h, respectively. supplied. This two-screw extruder has pitches in order from the feed side.
Equipped with a 50mm ball-shaped screw 360mm, a 25mm pitch screw 120mm, and a 30mm pitch paddle-shaped screw 120mm.
The internal temperature of the four barrels surrounding this is set to 70
℃, the second barrel was set at 120℃, the third barrel was set at 150℃, and the fourth barrel was set at 100℃. Under this condition,
The glutinous rice is heated, steamed, crushed, kneaded, and sterilized in each barrel of the twin-screw extruder.
This was extruded through a die with a flat hole of 5 mm x 40 mm to produce a rice cake according to the present invention. The obtained rice cake had a smooth texture with excellent extensibility, and was no inferior to that made by pounding with a regular pestle. Example 3 Washed polished glutinous rice with water, 50 each
A twin-screw extruder (Kobe Steel, Ltd. 2EXT) is used continuously at a feeding rate of Kg/h and 24/h.
−60). The screw configuration of the twin-shaft extruder is, in order from the feed side, a trapezoidal screw with a pitch of 50mm, a ball screw with a pitch of 50mm and 35mm, a trapezoidal screw with a pitch of 25mm, and a trapezoidal screw with a pitch of 25mm.
A 30mm paddle type screw and a trapezoidal screw with a pitch of 25mm are each 120mm, and the temperature of the 4 barrels is different from each other.
Set at 75, 125, 150 and 100℃, die is Example 1
The same one was used. The rice cake thus obtained was a good product with a fine texture and no residual rice grains. Example 4 Polished glutinous rice soaked in water for 20 hours after washing, refined sugar and water were mixed at 35Kg/h, 50Kg/h and 15Kg/h, respectively.
The mixture was continuously fed to a two-screw extruder (Model 2EXT-60, manufactured by Kobe Steel, Ltd.) at a feed rate of 1 h. The final part of the screw configuration of this two-shaft extruder was replaced with the paddle type screw with a pitch of 30 mm in Example 2, and a pin screw with the same pitch was replaced with a pin screw of 120 mm.
The operation was carried out in the same manner as in Example 2 except that mm was used.
Obtained Gyuhi's product (Umugimochi). This product was of good quality with excellent transparency and spreadability. (Effects of the present invention) Comparative test In order to examine the quality of mochi produced by the method of the present invention, the mochi prepared in Example 2 was manufactured using a home mochi making machine (“Mochitsuko” manufactured by Toshiba Corporation). Comparative tests were conducted using baked rice cakes as a control and sensory tests. The results are shown below.

[Table] 〓 Very good ○ Good As is clear from the above results, the rice cake made by the method of the present invention spreads easily when baked, has extremely high puffiness, and has a smooth and good texture. The rice cakes were rated as well as or even better than the mochi made using a commercial mochi pounder. Comparative test of bactericidal effect In order to investigate the bactericidal effect of the mochi produced by the method of the present invention, the mochi prepared in Example 1 and the mochi produced using the home mochi making machine ("Mochitsuko") were tested. The initial number of viable bacteria was measured immediately after production based on the bacterial testing method according to the Food Sanitation Inspection Guidelines. In addition, measurements were also performed on the raw material glutinous rice. (Initial number of viable bacteria/g) Mochi produced according to the present invention <10 Mochi made using a home-use mochi making machine 2.3×10 ² Polished glutinous rice 6.4×10 ³ Polished glutinous rice soaked in water for 20 hours after washing with water 2.1×10 ⁵ In addition, 30 When we conducted a storage experiment at ℃, we found that the mochi made with a home-use mochi making machine spoiled after two weeks, while the mochi produced using the method of the present invention showed an increase in fungi after the fourth week. . As described above, according to the method of the present invention, there is no need to go through the complicated steps of conventional manufacturing methods.
A single twin-screw extruder can be used to continuously produce high-quality mochi-like foods. Because the rice cake-like food obtained by the method of the present invention is all performed inside a twin-screw extruder, contamination by microorganisms during the process, which was a concern with the conventional method, was avoided. '', it can be packaged in a sterilized state and has particularly excellent preservability. In addition, the properties of the resulting mochi-like food can be adjusted by changing the combination of screws and dies, feed amount, screw rotation speed, temperature, pressure, and other processing conditions. It is possible to produce various types of foods. Further, as shown in the example of gyuhi in Example 4, it is also possible to add auxiliary materials such as sugar, other seasonings, fats and oils, and food colorings, thereby making it possible to increase the variety of products. Conventionally, steaming, crushing, and kneading required a lot of time, but with the method of the present invention, these steps can be completed in a short time, for example, several tens of seconds (30 to 40 seconds). Now I can do it. Therefore the number
According to the method of the present invention, industrial production of rice cakes in units of 100 kg can be completed in a fraction of the time compared to conventional methods, and production efficiency can be significantly improved.

Claims (1)

[Scope of Claims] 1. Glue rice is continuously fed into a two-screw extruder and heated and processed inside the two-screw extruder, which is adjusted to a temperature gradient in which the central barrel is at a high temperature and the tip barrel is at a low temperature. A method for continuous production of a mochi-like food characterized by pressing, crushing, kneading, and extruding through a die. 2. The method for continuously producing a mochi-like food according to claim 1, using glutinous rice soaked in water in advance as the glutinous rice. 3. The continuous method for producing a mochi-like food according to claim 1 or 2, in which unground brown rice, 7-minute pounded rice, or polished rice is used as the glutinous rice. 4. A method for continuously producing a mochi-like food according to claims 1 to 3, wherein glutinous rice is put into a twin-screw extruder together with water. 5. A method for continuous production of a mochi-like food according to claims 1 to 4, wherein glutinous rice is charged into a twin-screw extruder together with auxiliary materials. 6. A method for continuously producing a rice cake-like food according to claims 1 to 5, which comprises extruding and molding from a die.