JP4083208B2 - Production method of instant noodles - Google Patents

Description

  The present invention relates to a method for producing instant noodles in which noodles are gelatinized and then dried at a low temperature, and a bactericidal treatment method for the instant noodles.

  Instant noodles have a low moisture content and are excellent in preservability. In cooking, hot noodles can be poured and allowed to stand for a few minutes, or can be restored and eaten only by boiling for about 1 to 3 minutes. However, general instant noodles have a texture and appearance different from those of raw noodles or dried noodles boiled in order to dry the once-gelatinized noodle strings at a higher temperature. In other words, instant fried noodles have a very porous structure of noodle strings due to swelling when dried by frying, and thus have a texture that does not have a frustrating texture. In addition, in the case of hot-air dried instant noodles, which are general non-fried noodles, the texture is as if a film is stretched on the surface of the noodle strings due to the drying treatment with hot air. Therefore, in any case, the surface of the noodle strings is rough due to heat at the time of drying, and the texture is not as smooth and textured as boiled raw noodles.

  Therefore, as a method for bringing such instant noodles closer to the texture of noodles to be eaten by boiling raw noodles, there is a technique for drying α-noodle strings at a low temperature. Other methods for drying instant noodles at low temperatures include freeze-dried noodle technology that freezes noodle strings and then sublimates and dries moisture in the frozen state. There is a technique for drying and a technique for drying noodle strings at a low temperature from ice temperature without freezing (hereinafter, these instant noodles dried at a low temperature are called “low temperature dry instant noodles”, and the drying temperature does not exceed 60 ° C. Drying is referred to as “low-temperature drying.” However, as low-temperature drying instant noodles, it is not necessary that the temperature in the drying process is completely 60 ° C. or lower, and if the main drying temperature is 60 ° C. or lower, for example, the drying finishing stage Only noodles that are treated for a short time at 60 ° C. or higher are also included in the low-temperature dry instant noodles of the present invention).

  Among the above, as the freeze-drying technique, there are many other techniques as described in Patent Document 1 below, and as the technique for drying while thawing after freezing, Patent Document 2, Patent Document 3, Patent Document 4 and the technique without freezing. As a technique for drying at a low temperature, there are Patent Document 5, Patent Document 6, Patent Document 7, and the like. However, the present inventors have analyzed the number of viable bacteria in low-temperature dried instant noodle products that have been dried at a low temperature as described above, and found that there are very many viable bacteria.

  The number of viable bacteria may vary depending on the washing process and flavoring process in the instant noodle production process, or depending on the cooling time after pregelatinization and the sanitary condition of the factory. In comparison, in the case of these low-temperature dried instant noodles, there were cases in which they were many on the order of 10 2 to 4 4. Instant noodles have a low moisture content in the final product, so there is almost no increase in the number of bacteria during storage, especially when instant noodles that have been dried at low temperatures are stored using the usual storage method. There is no problem. However, the fact that the number of bacteria is large means that the probability of contamination with pathogenic bacteria such as food poisoning bacteria increases, and when this is stored under high humidity, there are local areas with high water content. There is also a risk of corruption.

  The instant noodles that are dried at a low temperature in this way have a large number of bacteria, which is considered to be due to the fact that the final drying process is performed at a low temperature. In general, in the case of instant noodles that are dried at a low temperature, the noodle strings are sufficiently α to improve the return of the noodles to hot water, and the water content after α conversion is increased. In general, cooling with cold water and washing with water are performed for the purpose of removing the surface of the noodle strings and tightening the noodle strings. Moreover, in order to suppress the binding between the noodle strings, the noodle strings may be brought into contact with a liquid containing a loosening improver (often mixed with a seasoning liquid). These solutions (including the seasoning liquid and the cooling liquid) are easy for bacteria to grow, and the noodle strings that have adsorbed this liquid are not exposed to high heat in the subsequent drying process, so the bacteria are not killed. That is, in the case of fried noodles and hot-air dried noodles, the drying process is performed at a high temperature, so that a considerable amount of bacteria can be killed by the drying treatment at this high temperature, but in the case of low-temperature dried instant noodles, the drying temperature is low. In addition, since the time required for drying is long, the bacteria do not die, and in some cases, they may grow during the drying process, or may be contaminated by falling bacteria during the drying process.

  Therefore, the present inventors tried to put instant noodles commercialized by low temperature drying into a constant temperature dryer at 85 ° C. for 30 minutes, but the viable cell count was hardly changed. Moreover, although the drying process at 85 ° C. was introduced every 30 minutes at various stages in the middle of the low temperature drying process to confirm the change in the number of viable bacteria, it was about 30 minutes regardless of which stage was introduced in the low temperature drying process. However, the number of viable bacteria could not be reduced so much, and the texture of low temperature dry noodles tended to be lost.

  In contrast, when the final product of instant noodles dried at low temperature was steamed (heated with steam), the number of viable bacteria could be significantly reduced even when the heating time was short. However, when this treatment is carried out while the moisture content of the noodle strings is high, that is, it is introduced in the early to mid-stage of the low temperature drying treatment, the effect of reducing the number of viable bacteria is weak. The texture was lost and the flavor was degraded. Furthermore, it is not preferable that the steaming process is performed in the initial to middle stage of the low-temperature drying process because the number of bacteria may increase due to adhesion of falling bacteria during the subsequent drying process.

  In light of the above examination results, the present inventors have cooked noodle strings to reduce the number of bacteria in the noodle strings, and in order to maintain the noodle quality and flavor of the low-temperature dried instant noodles, It is preferable that the moisture content of the noodle strings is not more than a specific numerical value, and if the drying is proceeded to reach the specific moisture content, ) The drying treatment is not necessarily carried out at a low temperature, and it has been found out that the quality of noodles by the low-temperature drying treatment can be maintained, and so on.

  In addition, there are many techniques for sterilizing or sterilizing bacteria in noodles, such as a technique for surface treatment with ethanol or organic acid, a technique for adding a bacteriostatic agent such as protamine or glycine, or a technique for microwave irradiation. However, all are technologies for wet noodles containing a lot of moisture, such as raw noodles, boiled noodles, and raw type LL noodles. As in the present invention, instant noodles in a dry state, especially low-temperature dry instant noodles, are produced by low-temperature drying. As far as the present inventor is aware, there is no prior art regarding a technique for reducing the number of viable bacteria in the noodle strings while taking advantage of the merit.

JP 54-35228 JP 1-153055 JP-A-1-225454 JP-A-3-280850 JP-A 64-85061 JP-A-1-137946 JP 2001-252037

  The present invention is a low-temperature instant noodle that is dried at a low temperature after pre-gelatinizing the noodle strings. Advantages of drying at a low temperature, that is, different from fried noodles or hot-air dried noodles, smooth and textured when raw noodles are boiled back It is an object of the present invention to provide a method for suppressing the number of viable bacteria in noodle strings while maintaining a certain texture, and a method for producing instant noodles using the same.

  As means for solving the above-mentioned problems, the following instant noodle manufacturing method can be proposed. That is, a step of α-treating noodle strings, a step of drying the α-treated noodle wires at a low temperature of 60 ° C. or less to make the moisture content 20% or less, and a noodle strand having a moisture content of 20% or less by low-temperature drying Including a step of steaming, a step of low-temperature drying and steaming of the noodle strings that are subjected to secondary drying (60 ° C. or lower or 60 ° C. or higher), and a moisture content of the noodle strings of 12% or less. This is a method for producing instant noodles. According to this method, the number of viable bacteria in the product noodle strings can be suppressed while maintaining the quality and flavor of noodles obtained by low temperature drying. In addition, the steaming as used in the field of this invention means heating with steam, and means the steaming process using 100 degreeC or the saturated steam more than the temperature close to it, or 100 degreeC or more superheated steam. The final moisture content of the noodle strings (the moisture content of the product) is set to 12% or less in order to impart storage stability as instant noodles, and if it exceeds 12%, generation of mold, deterioration of flavor, etc. May cause problems.

  Moreover, in the said manufacturing method, a secondary drying process can be 60 degreeC or more, Preferably it is 60-100 degreeC, and the moisture content of a noodle string can be 12% or less. This is based on the finding that when the moisture content of the noodle strings has already reached 20% or less by low temperature drying, the noodle quality by low temperature drying can be sufficiently maintained even if the subsequent drying temperature is increased to 60 ° C. or higher. By adopting such a secondary drying method, the drying time of the noodle strings can be shortened.

  The instant noodle manufacturing method of the present invention that solves the above problems is preferably a step of α-treating the noodle strings, and drying the α-treated noodle strings at a low temperature of 60 ° C. or less, preferably having a moisture content of 12% or less. Of instant noodles including each step of a step of 10% or less, a step of steaming a noodle string having a moisture content of 12% or less, preferably 10% or less by low-temperature drying so that the moisture content does not exceed 12%. It is a manufacturing method. In this way, when the moisture content is reduced to 12% or less by low-temperature drying and the moisture content of the noodle strings is kept to 12% or less by the steaming treatment, a secondary drying treatment is necessarily required as in the production method described above. Without commercialization, it is possible to commercialize. The reason why the ultimate moisture content by low-temperature drying is preferably 10% or less is that the moisture content may increase by about 0 to 2% during the steaming treatment.

  In the present invention, after the step of drying at a low temperature to reduce the water content to 12% or less, the moisture content reaches 20% or less at 60 ° C. or lower, and then the drying temperature is increased to 60 ° C. or higher. It is good also as a process made into 12% or less. This is because, after the moisture content is reduced to about 20%, the temperature is raised to 60 ° C. or higher and drying has little effect on the noodle quality.

  Moreover, as another means for solving the above problems, the following method for producing instant noodles can be proposed. That is, a step of α-treating noodle strings, a step of drying the α-treated noodle wires at a low temperature of 60 ° C. or less to make the moisture content 20% or less, and a noodle strand having a moisture content of 20% or less by low-temperature drying This is a method for producing instant noodles, which includes each step of steaming with a superheated steam to make the moisture content of the noodle strings 12% or less. This is a steaming process using superheated steam. By using superheated steam at 100 ° C. or higher, drying can be carried out simultaneously while applying steam. In this case, the secondary drying process is omitted. Is also possible. Even in the case of this method, the viable count of noodle strings can be suppressed while maintaining the noodle quality by low temperature drying.

  Moreover, the present invention is a method in which the noodle strings are heated with steam for a relatively short period of time, preferably 10 seconds to 3 minutes, particularly preferably 15 seconds to 2 minutes, in the method for producing instant noodles. By virtue of such a short-time treatment, the number of viable bacteria on the noodle strings can be reduced to 1/100 to 1/10000 or less as compared with the case where the steaming treatment is not performed.

  Further, the present invention provides the instant noodles manufacturing method described above, wherein the noodle strings subjected to the gelatinization treatment are processed at a temperature of 60 ° C. or less after the step of gelatinizing the noodle strings and before the step of drying at a low temperature of 60 ° C. or less. It is a manufacturing method of the instant noodles which further includes the process made to contact this solution. The contact process of the pregelatinized noodle strings to this solution is a process of cooling the noodle strings before drying at a low temperature, or applying a taste improver or a loosening improver to the noodle strings, and immersing the noodle strings in the solution. Or it is the process of spraying a solution on a noodle string. In this step, when the temperature of the solution is 60 ° C. or less, the number of viable bacteria in the noodle strings often increases remarkably, and therefore the production method of the present invention is applied to such a 60 ° C. for the pregelatinized noodle strings. It is particularly preferred when employed in low-temperature dried instant noodles having a step of contacting the following solutions.

  In the instant noodle production method described above, the present invention is preferably such that the drying treatment at a low temperature of 60 ° C. or lower freezes the gelatinized noodle strings once, and thaws the frozen noodle strings. This is a drying process. In this way, the noodle strings are once frozen after being frozen, and the frozen noodles are dried at 60 ° C. or lower while being thawed (different from freeze-drying that is dried while frozen), thereby providing a smoother and more dense feeling. High-quality noodles that seem to be low-temperature dry noodles can be produced stably.

  According to the present invention, a characteristic of low-temperature dry instant noodles, there is a feeling of cooking as if boiled raw noodles while being instant noodles, the noodle quality is also high in density, smooth, and good in taste Authentic noodles can be obtained. In addition, compared to conventional general instant noodles, there is no unnatural wave, and the noodles can be made much better than hot air dry noodles, which are general non-fried instant noodles. And while maintaining the noodle quality and advantages of such low-temperature dried instant noodles, the number of viable bacteria in the noodle strings of the low-temperature dried instant noodles can be suppressed to the same level or lower than that of fried noodles and hot-air dried noodles.

  In particular, in the present invention, the steaming treatment is performed after reducing the moisture content of the noodle strings by drying at a low temperature of 60 ° C. or lower, so that the bactericidal effect is remarkable even if the cooking time is very short. The effect is exerted, and the influence of heating by steam on the noodle quality can be minimized to almost eliminated.

Hereinafter, the present invention will be described in detail according to the manufacturing process of instant noodles.
As the noodle raw material used in the present invention, wheat flour is the main raw material, and starch, buckwheat flour, various flours and the like can be used. Further, as an auxiliary material, egg white and various thickeners commonly used in instant noodles, gluten, salt, citrus, pigments and the like can be added. These may be added together with the main raw material in powder form, or may be added by dissolving or suspending in kneading water.

  In the present invention, in accordance with a conventional method for producing instant noodles, the above main raw materials, auxiliary raw materials and kneading water are well kneaded to prepare a noodle dough, which is rolled and cut out or extruded by an extruder or the like to produce raw noodles Get a line. In steps such as kneading, noodle band making, and extrusion, kneading, extruding, and the like can be performed under reduced pressure or under vacuum in order to improve the texture by densifying the noodle strings.

  Next, the obtained raw noodle strings are α-ized. Since the noodles of the present invention are dried at a low temperature of 60 ° C. or lower, it is preferable to α-α by a method that increases the water content. This is because when the moisture content is the same as that of ordinary fried noodles or hot-air dried instant noodles, the noodles have a bad texture when returned to hot water, and the texture and stickiness of freshly boiled raw noodles are obtained. This is because there are problems such as difficulty. Specifically, it is preferable to increase the water content to 60% or more, and preferably 65 to 75%. As a method for converting to α, it is preferable to boil, and to boil it sufficiently in boiling water. Is preferred. Generally, in the case of instant fried noodles and hot-air dried instant noodles, it is α-ized by steaming, but the moisture content in steaming is usually in the order of 30%, so when steaming it is combined with boiled or polyhydrated Alternatively, it is preferable to carry out a treatment in which hot water is sufficiently contained in the noodle strings before or after steaming or in the middle of steaming. A moisture content of 65% is a situation where the raw noodles with a cutting blade of No. 20 are treated with boil for about 3 minutes, and when eaten as it is, it is in a state of being overboiled. In addition, although the process of alpha-grading raw noodle strings was described above, it is not necessarily limited to raw noodle strings, and dry noodles or instant noodles may be boiled back to alpha.

  It is desirable to cool the gelatinized noodles once. Generally, it is washed with water and cooled with water for the purpose of preventing the binding of the noodle strings and tightening the noodle strings. In addition, the noodle strings are preferably immersed in a solution (seasoning liquid) containing salt, sodium glutamate, a loosening improver (lecithin or water-soluble hemicellulose), etc., for the purpose of improving the flavor of the noodle strings and the unraveling during eating. Or spray these solutions onto the noodle strings. Usually, in the case of instant noodles that are dried at a low temperature, it is desirable that the moisture content is high and, as described above, it is desirable to boil them to a fully gelatinized state, so that binding between noodle strings tends to occur. Therefore, in the case of low-temperature dried instant noodles, it is particularly preferable to attach a liquid containing a loosening improver to the noodle strings.

  In low-temperature dried instant noodles, the influence of the final product on the number of viable bacteria is greatly affected by this washing and flavoring solution. Therefore, it is preferable to use those solutions having a small number of viable bacteria. However, for water washing, a method of showering tap water on the noodle strings can also be adopted, but when using a seasoning liquid (including a liquid containing only a loosening agent), a method of immersing the noodle strings in the solution is used, In general, the immersion liquid is always replenished in small amounts. Alternatively, a spraying method can be employed, but even in this case, the solution is usually a circulation replenishment method. Therefore, when using a seasoning liquid, the number of bacteria in a liquid will increase gradually.

  According to the knowledge of the present inventors, if the temperature of the seasoning liquid is always 60 ° C. or higher, the number of viable bacteria in the liquid can be greatly reduced, but if it is 60 ° C. or higher, the cooling effect cannot be obtained. In addition, there are many cases where nurmi appears on the surface of the noodle strings or the change in flavor. Therefore, in the case of instant noodles to be dried at low temperature, it is desirable to obtain a preferable noodle quality in which the seasoning liquid is not 60 ° C. or higher. It is particularly effective to use the method of the present invention. In addition, it is possible to add antibacterial agents such as alcohol and protamine to the seasoning liquid (including liquids containing only the loosening agent) and cooling water. The flavor and texture are often affected.

  The noodle strings are then frozen and dried, or dried at low temperature without freezing. As a method of once freezing and drying, there are a freeze-drying method of drying in a vacuum state while maintaining a frozen state, Japanese Patent Application Laid-Open No. 1-153055 (Patent Document 2), which is once frozen and then dried at a low temperature while thawing. There is a method such as Kaihei 3-280850 (Patent Document 4). As methods for drying at low temperature without freezing, JP-A 64-85061 (Patent Document 5), JP-A-1-137946 (Patent Document 6), JP-A 2001-252037 (Patent Document 7). ) And the like.

  In the freeze-drying method, the noodle mass that has been frozen in a tray or the like is placed in the tray or removed from the tray, and dried by reducing the pressure with a vacuum pump in a freeze-dryer. Although various drying temperatures are possible depending on the situation, a method of drying at a temperature (shelf temperature) of about 30 to 60 ° C. for about 10 to 30 hours is generally recommended.

  In the method of drying the frozen noodle mass while thawing, the noodle mass frozen in a tray or the like is dried while being put in the tray or removed from the tray by applying cold air under atmospheric pressure. As for the drying temperature, the method of JP-A-1-53055 (Patent Document 2) is dried at about 15-18 ° C. in the wet state by the method of JP-A-3-280850 (Patent Document 4) under the ice temperature. However, since these methods require a very long time for drying, the quality of low-temperature dry noodles can be imparted also by the following method developed by the present inventors. In other words, the pregelatinized noodles are completely frozen and dried at first at a temperature of 50 ° C. or less while thawing until the moisture content of the noodle strings falls below the moisture content before freezing (because the noodles are frozen, The water content is once increased), and after 60 ° C. or lower, the moisture content reaches 20% or lower, and then dried at 60 ° C. or lower or 60 ° C. or higher. The method of freezing and then drying at a low temperature while thawing is superior in terms of quality stability when mass-produced, etc., than drying at a low temperature without freezing.

  The method of drying without freezing is preferably a method such as JP-A-1-137946 (Patent Document 6) that slowly drys while maintaining a temperature state close to the ice temperature, but JP-A-2001-252037 (Patent Document 7). As described above, a certain level of quality can be obtained by drying at 35 ° C. or lower. Even in the case of drying at a low temperature without freezing in this way, after reducing the water content to about 20%, increasing the temperature to 60 ° C. or higher and drying it has little effect on the noodle quality.

  In the present invention, when the moisture content is 12% or less (preferably 10% or less) and dried to a state where there is no problem in storage stability as instant noodles by the above-described low temperature drying method, What is necessary is just to perform a steaming process so that a water content may not become 12% or more. However, if the moisture content reaches 20% or less in the drying process at a low temperature, the noodle quality dried by the low temperature drying process is not used for a long time. Has little effect. Further, when the moisture content reaches 20% or less, the noodle quality obtained by the low temperature drying treatment can be maintained even if the drying treatment is performed at 60 ° C. or more.

  In addition, even when the moisture content of the noodle strings is set to 12% or less by a drying process by low-temperature drying, the surface of the noodle strings after the treatment is particularly cooked using normal saturated steam (normal pressure of 100 ° C. or less). Since it often becomes wet, it is preferable to perform a secondary drying treatment to remove excess water adhering to the surface of the noodle strings. On the other hand, when the steaming process uses superheated steam (saturated steam heated to 100 ° C or higher under normal pressure, which has the effect of drying the noodle strings because of its high temperature), depending on the temperature and steam volume, Since the moisture content of the wire can be reduced, the secondary drying step may be unnecessary even if the moisture content of the noodle strings after low temperature drying is in the range of 12 to 20%.

The steaming condition of the present invention is preferably a steam flow rate of about 100 to 800 kg / m ³ / hr in a steam warehouse, and the time is considerably short, that is, about 10 seconds to 5 minutes, preferably 10 seconds to About 3 minutes, particularly preferably about 15 seconds to 2 minutes is preferable. If it is 10 seconds or less, the antibacterial effect may not be sufficient, and if it is performed for 5 minutes or more, or if it is performed for 3 minutes or more when the steam flow rate is high, the quality of noodles may be lost. In addition, when steaming is performed using superheated steam, when it is expected that the drying of the noodle strings is further promoted by this, the temperature near the center of the superheated steam steam chamber (the temperature at which the noodle strings touch) is 125 to 180 ° C. It is good to be about.

  Low temperature dry instant noodles manufactured in this way and dried to a moisture content of 12% or less are prepared by pouring hot water at the time of eating and leaving for about 3 to 5 minutes, or cooking for about 1 to 3 minutes. It becomes noodles with high convenience that can be eaten just by themselves. The product can be used in cup noodles or bag noodles, and can be applied to Chinese noodles such as ramen, Japanese noodles such as udon and soba, and spaghetti.

  The present invention will be specifically described below based on examples, but the present invention should not be construed as being limited based on the disclosure of these experimental examples and examples.

[Experiment 1] (Changes in the number of bacteria by low-temperature drying method)
First, the transition of the number of viable noodle strings in the drying process of the low temperature drying method was examined by the following method.
50 g of starch was mixed with 950 g of wheat flour, 10 g of kansui (sodium carbonate + potassium carbonate), 1 g of sodium polyphosphate and 350 ml of kneading water dissolved in 1 g of gardenia pigment were added and kneaded with a mixer for 15 minutes to prepare a noodle dough. . This was rolled to a thickness of 1.1 mm with a rolling mill, cut out with a square blade No. 20 to obtain noodle strings, and cut into a serving of 110 g. Boil this with sufficient boiling water for 3 minutes until it has been boiled for 3 minutes, wash thoroughly with about 20 ° C tap water, cool the noodle strings, drain, and then immerse in the following seasoning liquid for 30 seconds Then, the liquid was drained and put into a cylindrical tray having a diameter of 145 mm and a height of 50 mm. The noodle weight at this time was 250 g, and the noodle string moisture was 72%. This was put in a freezer at −35 ° C. and rapidly frozen to be completely frozen for 30 minutes to obtain a sample before drying.

The frozen noodle mass sample was dried at a drying chamber temperature of 40 ° C. and humidity of about 20 g / m ^{3 at a} wind speed of 3 m / s for 2.5 hours, followed by a drying chamber temperature of 50 ° C. and humidity of about 20 g / m ^{3 at a} wind speed of 3 m / s The noodle strings were dried to about 10% by performing a low temperature drying treatment for 1 hour. Further, as a final drying, the temperature was raised to 70 ° C., and the drying was further performed for 30 minutes at a humidity of about 20 g / m ^{3 and a} wind speed of 3 m / s, so that the final moisture content was about 8%. The water content of the noodles was calculated by comparing the weight at the time of measurement with the dry weight of all raw materials.

  The seasoning solution was a solution containing 1% sodium chloride, 0.3% sodium glutamate, and 1% water-soluble hemicellulose (a loosening improver), which was used for the seasoning of the noodle strings continuously for 8 hours at the manufacturing plant (immersion) A method of constantly replenishing the amount adsorbed to the noodle strings by the method of 1) was used, which was left standing at room temperature for another 20 hours. The temperature of the seasoning liquid is about 20 ° C. The number of bacteria in the seasoning liquid, the frozen noodle mass before drying, the number of viable bacteria in each noodle string after drying at 40 ° C., after drying at 50 ° C., and after drying at 70 ° C. were measured.

  The inspection method of the viable cell count (general viable cell count) was based on the following method. That is, 10 g (10 ml) of a sample was aseptically weighed in a sterile petri dish, 90 ml of sterilized physiological saline was added, the sample was sufficiently dispersed and suspended in a liquid with a stomacher, and then diluted serially to an appropriate magnification. . Dispense and mix 20 ml of standard agar medium with 1 ml of this diluted solution, and incubate at 35 ° C. for 48 hours, count the number of colonies that appeared on the plate, determine the average of the two plates, and dilute The number of viable bacteria per 1 g (1 ml) of the sample was determined by multiplying by the magnification. The method for measuring the number of viable bacteria was similarly carried out in other examples.

As a result, the number of general viable bacteria in the seasoning liquid is 3.4 × 10 ⁴ / ml,
The general viable count of frozen noodles before drying is 3.2 × 10 ⁴ / g,
5.9 × 10 ⁴ / g (water content 24%) after drying at 40 ° C.
1.5 × 10 ⁴ / g (water content 9%) after drying at 50 ° C.,
After drying at 70 ° C., it was 1.7 × 10 ⁴ / g (water content 8%).
From this result, it was understood that the viable count of noodle strings could hardly be reduced by the low temperature drying method, and it was understood that the antibacterial effect could not be expected even if the finish drying was performed at a certain high temperature.

[Example 1]
The seasoning liquid prepared on another day was diluted 10 times in the same manner as the seasoning liquid used in Experimental Example 1, and a frozen sample before drying was prepared in the same manner as in Experimental Example 1 using this. . The number of viable bacteria in the seasoning liquid was 3.0 × 10 ³ / ml. The drying process is the same as in Experimental Example 1, and when low-temperature drying at 50 ° C. is completed (water content: about 9%), steaming with saturated steam or superheated steam is performed under the conditions shown in Table 1 below, followed by steaming and drying. The secondary (re) drying treatment was performed for 30 minutes at a temperature of 70 ° C. and a humidity of about 20 g / m ^{3 and a} wind speed of 3 m / s.

After the drying treatment, the number of fungi on the noodle strings was measured, and at the same time, 450 ml of hot water was poured and allowed to stand for 4 minutes for restoration, and the taste was evaluated by 5 panelists. In addition, as a comparative example, what was dried at 70 ° C. for 30 minutes as it was after the low-temperature drying at 50 ° C. without performing the steaming treatment after the low-temperature drying was compared as a control. Steaming conditions were carried out at saturated steam (normal pressure) at a steam flow rate of 200 or 400 kg / m ³ / hr, in the case of superheated steam at a steam flow rate of 700 kg / m ³ / hr, and at an actual measured temperature of 146 ° C. in the center of the steamhouse. The final noodle strings had a water content of about 8 to 10%.

The results are shown in Table 1, and the number of viable bacteria was suppressed in all the steamed treatments (saturated steam 400 kg / m ³ / hr x 30 seconds is due to contamination at the time of bacterial inspection based on previous and subsequent data. Seem). In addition, the texture of the noodles was slightly saturated with hot air-dried instant noodles at a saturated steam of 400 kg / m ³ / hr × 60 seconds. The texture with texture was maintained.

Of the above examples, those steamed with saturated steam 200 kg / m ³ / hr (normal pressure) for 30 seconds and those steamed with superheated steam 700 kg / m ³ / hr for 30 seconds (water content after drying at 50 ° C. 9 %), Which was left in the room without re-drying after cooking, was prepared at the same time. After standing, the weight was measured and the water content was measured. As a result, 10% was cooked with saturated steam and 9% was using superheated steam. In both cases, like the above-mentioned secondary (re) drying treatment, hot water was poured and left to eat for 4 minutes. As a result, the noodles had a smooth and textured texture like low-temperature dry instant noodles.

[Example 2]
A sample in a frozen state before drying was prepared in the same manner as in Experimental Example 1 using the seasoning liquid prepared on another day as in Experimental Example 1. The number of bacteria in the seasoning liquid was 1.0 × 10 ⁵ / ml. This frozen sample was dried for 2.5 hours at 40 ° C. and humidity of about 20 g / m ^{3 at a} wind speed of 3 m / s (water content 24%), and then at 50 ° C. and humidity of about 20 g / m ^{3 at a} wind speed of 3 m / s for 15 minutes. 20 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, and the same low temperature drying as in Experimental Example 1, 60 minutes.

After drying at low temperature, the noodle mass was measured to calculate the moisture content, and immediately steamed in saturated steam (normal pressure) for 30 minutes under steaming conditions of 200 kg / m ³ / hr. Further, the water content of the product obtained by measuring the weight was calculated by raising the drying temperature to 70 ° C. until the water content was considered to be 10% or less as a secondary (re-) drying treatment. The number of viable bacteria in the noodle strings after the drying treatment was measured, and the taste was evaluated with five panelists as in Example 1 for sensory evaluation. In addition, as a comparative example, the low-temperature drying at 50 ° C. was performed for 60 minutes, and the samples that were not steamed were compared as controls.

  The results are shown in Table 2. The low-temperature drying treatment was performed while drying at a low temperature until the water content was about 20% or less gave a smooth and textured texture like low-temperature drying noodles. Therefore, when the moisture content was only dried to about 25%, a texture similar to low-temperature dried instant noodles could not be obtained. In addition, when the steaming is performed, the sterilization effect is higher when the water content is lowered in advance. Especially, the steaming is most effective when the water content is reduced to about 15% or less by drying at low temperature. Was thought to increase.

Claims (5)

A method for producing instant noodles,
A process of α-treating the noodle strings,
a step of drying the pregelatinized noodle strings at a low temperature of 60 ° C. or less so that the water content is 12% or less;
A method for producing instant noodles comprising each step of steaming a noodle string having a water content of 12% or less by low-temperature drying so that the water content does not become 12% or more.   The step of drying at a low temperature to reduce the water content to 12% or less is a step of raising the drying temperature to 60 ° C. or higher and reducing the water content to 12% or less after the water content reaches 20% or less at 60 ° C. or less. The method for producing instant noodles according to claim 1.   The method for producing instant noodles according to claim 1 or 2, wherein the steaming process is a process of heating the noodle strings with steam for 10 seconds to 3 minutes.   After the step of α-treating the noodle strings, further comprising the step of contacting the α-treated noodle strings with a solution of 60 ° C. or lower before drying the α-treated noodle wires at a low temperature of 60 ° C. or lower. The manufacturing method of the instant noodles in any one of Claim 1 to 3.   The instant drying according to any one of claims 1 to 4, wherein the drying process at a low temperature of 60 ° C or lower is a drying process in which the gelatinized noodle strings are once frozen and the frozen noodle strings are thawed. A method for producing noodles.