JP2780731B2 - Method and apparatus for adjusting acidity of immersion liquid in continuous acid immersion treatment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a food which is immersed in an acid solution as a pretreatment for adjusting the food to a low pH in order to preserve the food for a long time by pasteurization. In the continuous acid immersion treatment, a method for simply and reliably maintaining a suitable pH of the immersion liquid, and a continuous acid immersion treatment apparatus for performing the method, more specifically, the present invention, Conventionally, even in a low pH range where it has been difficult to accurately adjust the pH on the order of 0.1, the fluctuation of the pH of the immersion liquid in the immersion tank is simply and reliably kept within the set range on the order of 0.1. The present invention relates to a method for adjusting the acidity of an immersion liquid in an immersion tank of a continuous acid immersion treatment apparatus for food, which can be automatically controlled, and an apparatus for performing the method.

[0002]

2. Description of the Related Art In order to preserve food for a long period of time, it is general to apply some kind of heat sterilization treatment to the food at the stage of the final product. Conventionally, various methods for treating food with an organic acid or the like to lower its pH and performing pasteurization have been studied. Since the quality deterioration of the food accompanying the treatment is remarkable, and thus the high-temperature treatment is difficult, various methods for adjusting the noodles to a low pH and then pasteurizing the noodles have been studied.

[0003] Generally, for example, as a sterilization technique for long-term storage of noodles, a method of heat-sterilizing the noodles can be mentioned. In addition, the quality of the noodles was unavoidably deteriorated, for example, the noodle strings were easily cut. Therefore, to improve the quality of the noodles, lower the pH (acid),
A method of pasteurization (for example, at 85 ° C. for 30 minutes or more) is being studied.

By the way, as a method of adjusting the pH of noodles, for example, there is generally a method of immersing the noodles in a pH-adjusted acid solution in an immersion tank. In this case, a method is employed in which the noodles are heated in a boiling step after production, subjected to a cooling step of cooling with water in a cooling tank, and then subjected to an acid dipping treatment in a dipping tank. For this reason, the immersion liquid in the immersion tank is diluted by water that moves to the immersion tank together with the noodles from the cooling step, and as a result, the pH of the immersion liquid increases, so the pH of the immersion liquid is sometimes measured with a pH meter, It is necessary to replenish the acid solution and adjust the pH of the immersion liquid to a certain level.

[0005] However, the lower the pH of the immersion liquid, the more difficult it is to ensure the measurement accuracy by the measurement with a pH meter. , 0.1 on the order of 0.1 is very difficult. Therefore, conventionally, the pH in such a low pH region has
At present, adjustment of pH is manually performed depending on human experience and feeling, and therefore, pH adjustment is not always perfect, and defective products are generated at a ratio of one meal to thousands of meals. Was in a situation that was unavoidable.

In such a situation, as a method for adjusting the acidity of the impregnating liquid, for example, a method for adjusting the acidity of the impregnating liquid for a porous substrate (Japanese Patent Application Laid-Open No. 60-74263) has been proposed. Although this technology is to measure the titration acidity by an automatic titrator and automatically replenish an appropriate amount of the acid mother liquor with the obtained measured value, this technology is used when manufacturing porous plates such as alkaline storage batteries. The present invention relates to a method for adjusting the acidity of an impregnating liquid, and the immersion treatment is temporarily interrupted during measurement. On the other hand, in the method of the present invention, for the purpose of preserving food, the food is continuously sampled from an immersion tank in which an acid immersion treatment is being performed, titration acidity is measured, and an appropriate amount of an acid mother liquor is automatically and continuously replenished. It is not necessary to interrupt the immersion treatment.

Further, a food is immersed in an acidic immersion liquid and
As a method of adjusting H, for example, after making noodles into a desired shape, boiled and washed flour-based noodles contain (a) citric acid or lactic acid and (b) salt, and optionally (c) sodium glutamate. A method for producing instant-cookable flour-based noodles that can be circulated at room temperature, characterized by being immersed in an aqueous solution, then packed in a bag, and then sterilized by heating (Japanese Unexamined Patent Publication No.
4-85048) has been proposed. However, the gazette discloses the result of examining the relationship between the pH and the preservability of the noodles when an organic acid is used, and also performs heat sterilization such as hot water sterilization after the acid immersion treatment of the noodles. However, as for the replenishment method of the acid mother liquor, there is only a very general statement that the initial processing liquid concentration is always maintained by supplying at a constant rate, and the acidity of the immersion liquid should be adjusted by an automatic titrator or the like. Nothing is said about it.

[0008] Further, as a method for producing Japanese-style or Chinese noodles in a microwave oven container, steamed Japanese-style or Chinese noodles are immersed in an organic acid-containing solution to adjust the pH to 4.0 to 5.5, and then opened upward. After dispensing the Japanese style or Chinese noodles in a high-frequency permeable heat-resistant container having a portion, the air content is 100 to 2
The upper opening of the container is sealed with a heat-adhesive film so that the concentration becomes 50%, and 90 to 110% in a pressure and heat sterilizer.
℃, 15-60 at gauge pressure 0.2-2.0 kg / cm ³
Production of Japanese-style or Chinese noodles in a microwave oven characterized by heating for one minute (JP-A-2-200156)
Has been proposed. However, although the publication discloses that the pH is adjusted by immersion in an organic acid-containing solution, it does not mention at all how to replenish the acid mother liquor.

As described above, although various proposals have been made on acid immersion treatment techniques for foods, mainly noodles, etc., specific techniques for continuously maintaining an acid immersion liquid in a specific acidic state have been proposed. Almost no proposal has been made, and in such a situation, especially in a low pH range where the pH is low, the acid mother liquor is automatically supplied so that the stable pH condition can be continuously maintained. There was a strong demand in the art to develop a technique for adjusting acidity.

[0010]

In view of such circumstances, the present inventors have automatically adjusted the acidity of the immersion liquid to maintain a stable pH condition even in a low pH range. As a result of intensive studies with the aim of developing a technology that performs immersion, the titration acidity of the immersion liquid is measured by an automatic titrator, and the supply of the acid mother liquor is increased or decreased based on the measured value to automatically adjust the acidity of the immersion liquid. It has been found that the intended purpose can be achieved by adopting the control method, and the present invention has been completed.

An object of the present invention is to provide a continuous acid immersion treatment apparatus for foods for carrying out the method for adjusting the acidity of the immersion liquid.

Further, the present invention provides a method for adjusting the acidity of an immersion liquid in a continuous acid immersion treatment apparatus for foods, which can automatically control the fluctuation of the acidity of the immersion liquid in the immersion tank within a set range. It is intended for.

[0013]

The present invention for achieving the above object comprises the following technical means (1) to (6). (1) In the method for adjusting the acidity of an immersion liquid in an immersion tank of a continuous acid immersion treatment apparatus for food, the titration acidity of the immersion liquid is measured by an automatic titrator, and the acid mother liquor to the immersion tank is measured based on the measured value. A method for adjusting the acidity of an immersion liquid in an immersion tank of a continuous acid immersion treatment apparatus for food, wherein the acidity of the immersion liquid is automatically controlled by increasing or decreasing the supply amount of the immersion liquid.

(2) The minimum supply amount of the acid mother liquor is set, and the acid mother liquor is set in three or more stages based on the strength of the electric signal from the automatic titrator which changes according to the increase / decrease of the titration acidity of the immersion liquid. The acidity adjustment method of the immersion liquid according to (1), wherein the supply amount of the acid mother liquor is selected and the supply amount of the acid mother liquor is increased or decreased according to the supply amount.

(3) The method for adjusting the acidity of an immersion liquid according to the above (1), wherein the automatic titration apparatus samples and titrates the immersion liquid from an overflow tank.

(4) When the continuous acid immersion treatment apparatus for food is started or when the supply of food as an object to be immersed is interrupted, the absence of the object to be immersed in the immersion tank is detected by a detecting means such as a photoelectric tube. The acidity adjusting method of the immersion liquid according to the above (2), wherein the supply amount of the acid mother liquor is reduced to the minimum supply amount.

(5) An immersion tank for immersing the object to be immersed, an overflow tank for storing an immersion liquid overflowing from the immersion tank, and an automatic titrator for measuring the titration acidity of the immersion liquid are provided. The automatic titrator was installed so that it could be sampled from the overflow tank, and the supply amount of the acid mother liquor to the immersion tank was increased or decreased based on the measured value, so that the acidity of the immersion liquid was automatically controlled. Characteristic continuous acid immersion treatment equipment for food.

(6) The acid mother liquor is supplied to a circulating system in which the immersion liquid is circulated between the immersion tank and the overflow tank, and further, two or more selected from bubbling, showering, and counterflow. The continuous acid immersion treatment apparatus according to the above (5), further comprising means for supplying the immersion liquid to the immersion tank, which can be performed by combining the methods.

Next, the continuous acid immersion treatment apparatus of the present invention and the method for adjusting the acidity of the immersion liquid in the immersion tank of the treatment apparatus of the present invention will be described in detail using the case of boiled noodles as an example. The present invention is not a method of adding an organic acid or the like to the raw material flour at the time of so-called noodle-making in which water is added to the raw material flour to form a dough, and adjusting the acidity, but noodle-making and boiling, and then boiled noodles. The present invention relates to a method for adjusting the pH of boiled noodles by continuously immersing immersion in an acid solution, a method for adjusting the acidity of the immersion solution, and an apparatus for performing the method.

The acidity of the immersion liquid of the present invention is adjusted by transferring the boiled noodles after the boiling in the boiling step to a cooling tank for cooling, and then to an immersion tank for acid immersion. In, is carried out by automatically increasing or decreasing the supply amount of the acid mother liquor to be supplied into the immersion tank,
The acid mother liquor to be supplied may be a commonly used acid, and is not particularly limited. For example, an aqueous solution containing an organic acid such as gluconic acid, lactic acid, or citric acid is preferred. Then, after the boiling, the boiled noodles cooled in the cooling tank are immersed in an acidic aqueous solution adjusted to a liquid temperature of 40 ° C., preferably 20 to 30 ° C. for 10 to 60 seconds in a dipping tank, Thereafter, the boiled noodles are directly bagged and sealed without washing with water, and then subjected to low-temperature heat sterilization by heating means such as steam or hot water.

The present invention is suitably applied to the above-mentioned boiled noodles, but is not limited to the boiled noodles, and is mainly made of starches such as flour, buckwheat flour, rice flour, and prepared flour, which are kneaded by a conventional method. Udon, kishimen, hiramen, hiyamugi, somen, soba, soba, chinese noodles, yakisoba, champon, cold noodles, rice noodles, etc. molded into noodle strings by rolling, cutting, extruding, hand rolling, or hand-working etc. It is also applicable to noodle products of the type described above, and is not limited to such noodle products, and can be applied to all food products produced through a process of immersing in water and cooling after heating. It is equally applicable.

As described above, the method of the present invention can be suitably applied to boiled noodles among flour-based noodles. Here, the noodles can include all types of noodles.
Typically, it includes pasta such as udon (handmade udon, roll noodle udon, etc.), buckwheat containing flour, ramen, spaghetti and macaroni. After applying the method of the present invention to these, by pasteurization,
For example, boiled noodles can be distributed virtually safely at room temperature for as long as 6 months, without affecting the original taste of the boiled noodles and increasing the product cost significantly. There is no. In the method of the present invention, in the immersion treatment after boiling the noodles, the acidity of the immersion liquid can be easily and reliably adjusted. Therefore, contrary to the conventional wisdom, the pH of the boiled noodle product is set to 3.5. It has been found that the temperature can be reduced to a narrow range of about 4.3, and that an unexpected long-term normal temperature distribution can be achieved by the subsequent pasteurization.

[0023] The boiled noodles to be treated by the method of the present invention are produced as known to those skilled in the art. That is, water is added to a raw material for noodles such as flour and kneaded. In the case of udon or the like, the noodles are rolled and then cut into noodles to make noodles.
In the case of macaroni, spaghetti, etc., the kneaded dough is directly extruded under high pressure to form molded noodles. In this manner, the noodles having the desired shape are boiled and washed with water to obtain a so-called boiled noodle state.

Regarding the method for adjusting the acidity of the immersion liquid of the present invention,
FIG. 1 is a side view showing an outline of a main part of a continuous acid immersion treatment apparatus including a cooling tank, a first immersion tank, and a second immersion tank. Is a plan view of the same. In FIG. 1, the noodles transferred to the cooling tank through the boiling process are cooled in the cooling tank,
After being transferred to the first bath for immersion and subjected to the first acid solution immersion treatment, it is further transferred to the second bath for immersion, subjected to the second acid solution immersion treatment, and then transferred to the filling step. Then, they are appropriately bagged by a filling machine, and then transferred to a low-temperature heat sterilization step.

In the method and the continuous acid immersion treatment apparatus according to the present invention having such a constitution as a basic constitution, as shown in FIG. 3, an automatic titration apparatus D comprises a first immersion tank A and a second immersion treatment apparatus.
It is connected to an overflow tank (drop tank) C for storing the immersion liquid overflowing from the tank B, and is installed so as to sample from the overflow tank by the sampling pump c. In this case, the sampling from the overflow tank (drop tank) C can absorb variation with time if it is from the overflow tank, but if it is from the immersion tank, water adhering to the noodles in the cooling tank may be mixed. This is because variation may occur depending on the sampling location. Therefore, it is configured to overflow from the first immersion tank A and the second immersion tank B, and the overflow tank (drop tank)
It is preferable to measure the titratable acidity at C, but the present invention is not limited to such a configuration, and the design can be changed as appropriate. Also, the specific configuration of each component such as the immersion tank and the overflow tank (drop tank) can be appropriately changed in design.

Next, the immersion liquid sampled from the overflow tank (drop tank) C by the sampling pump c is measured for its titration acidity by an automatic titrator D, and the supply amount of the acid mother liquor is set based on the measured value. Then, the acidity of the immersion liquid is adjusted by operating the acid mother liquor injection pump f via the acid immersion line control panel E and supplying the required amount of acid mother liquor to the first immersion tank A and the second immersion tank B. Is done.
In supplying the acid mother liquor to the immersion tank, the immersion liquid is circulated between the immersion tank and the overflow tank (drop tank) C by the circulation pumps d and e so that the acid mother liquor is supplied to the circulation system. This is preferable because it mixes with the immersion liquid before being supplied to the immersion tank. Furthermore, in this case, the supply of the immersion liquid to the immersion tank is performed by supplying the immersion liquid by showering from the shower nozzles a and b at the upper part of the immersion tank and supplying the immersion liquid to the floating noodles. ,
In the immersion tank, a method of supplying the immersion liquid in such a manner that the blowing direction of the immersion liquid and the flow of the noodles are opposed to each other. The method is preferably carried out by means of an immersion liquid supply means which can be carried out by combining two or more methods selected from among methods of stirring and simultaneously replacing the immersion liquid in the noodles. Also, a plate heat exchanger j incorporated in the circulation system
For example, it is preferable to lower the temperature of the immersion liquid warmed by the noodles and to stabilize the adsorption of the acid on the noodles by keeping the temperature of the immersion liquid constant.

The method for setting the supply amount of the acid mother liquor is, for example, to set the supply amount of the acid mother liquor in advance to a minimum supply amount (lower limit value) and an upper limit value, a normal value, and a lower limit value.
The supply amount of the acid mother liquor set in three or more steps is selected based on the strength of the electric signal from the automatic titrator that fluctuates according to the increase or decrease in the measured titration acidity. A preferred method is to increase or decrease the supply amount of the acid mother liquor according to the supply amount. The setting of the supply amount of the acid mother liquor is, for example, as shown in Table 1, by setting the maximum supply amount of the acid mother liquor supply device (pump) to 10
When 0% is set, the normal value of the supply amount of the acid mother liquor is set to 20%,
Three or more levels are set so that the upper limit is 22% and the lower limit is 18%. Thus, the acidity of the immersion liquid can be adjusted in a very efficient manner by selecting the three or more levels of the acid mother liquor supply according to the titration acidity level of the immersion liquid.

[0028]

[Table 1]

Further, a detecting device F such as a photoelectric tube for detecting the presence or absence of noodles is installed at the entrance of the immersion tank, and when the continuous acid immersion treatment device is started or when the supply of the object to be immersed is interrupted. A preferable method is to detect the absence of the object to be immersed in the immersion tank by the detecting device F such as the photoelectric tube and reduce the supply amount of the acid mother liquor to the minimum supply amount. The specific configuration of the detection device F is not particularly limited, and an appropriate configuration can be used. By adopting such a method, when there is no object to be immersed in the immersion tank, for example, the pH increases due to water droplets adhering to an empty basket that has passed through the cooling tank. That is, the acidity of the immersion liquid in the immersion tank can be stabilized. The setting of the minimum supply amount in this case is, for example, as shown in Table 1,
It is possible to set a value equal to or less than the lower limit, for example, 8%. Such a normal value, upper limit value, lower limit value, and lower limit value of the supply amount of the acid mother liquor are exemplarily shown here, and it is needless to say that the present invention is not limited to the numerical values.

As described above, the present invention is based on the principle that the titration acidity of an immersion liquid is measured by an automatic titrator and the supply amount of an acid mother liquor is automatically increased or decreased based on the measured value. In addition, the supply amount of the acid mother liquor was previously set at three or more stages, and the three or more stages were set based on the strength of the electric signal from the automatic titrator, which changed according to the increase or decrease of the titration acidity of the immersion liquid. The supply amount of the acid mother liquor is selected, and the supply amount of the acid mother liquor is increased or decreased according to the supply amount. Furthermore, when the continuous acid immersion treatment apparatus is started or when the supply of the immersion object is interrupted, the absence of the immersion object in the immersion tank is detected by a detector such as a photoelectric tube, and the supply amount of the acid mother liquor is determined. The present invention is characterized in that the supply amount is reduced to the minimum supply amount, whereby the acidity of the immersion liquid in the immersion tank can be stabilized even during idle operation. The components of the continuous acid immersion treatment apparatus of the present invention, such as an automatic control system, may be designed using ordinary equipment, and the specific configuration is not particularly limited.

The cooling treatment in the cooling tank and the immersion treatment in the immersion tank may be performed by a conventional method, and are not particularly limited. For example, in the immersion step, for example, a plate heat exchanger is used. 10 noodles in an organic acid aqueous solution having a concentration of 0.2 to 20% cooled to a normal temperature to 40 ° C.
It is preferable that the noodles are immersed for up to 60 seconds so that the pH of the noodles becomes 3.5 to 4.3. In addition, "pH of noodles" referred to in this specification means that the noodles are finely cut into approximately 1 cm,
100 g of pure water is added to 10 g of the shredded noodles, and the mixture is pulverized for about 1 minute using a stomacher, a homogenizer or a juice mixer, and the pulverized product is transferred to a beaker for about 5 minutes.
PH of the supernatant liquid after being allowed to stand for
It was measured using an H meter.

In the method of the present invention, if necessary, for example, in the case of Chinese noodles that have undergone the above-described immersion step, 1 to 5% of the weight of the noodles may be immersed in fats and oils, sprayed by spraying or other appropriate means. Can be applied to the surface.

The noodles that have undergone the above-described processing are, for example, 18 servings per serving.
After being divided in an appropriate amount of about 0 g, the mixture is dispensed into a high-frequency permeable heat-resistant container, and this container is replaced with an inert gas such as nitrogen gas if necessary. It is sealed by welding a heat-adhesive film.

Next, the heat-resistant container enclosing the noodles is placed in a normal heat sterilization apparatus such as a hot water bath heating system or a steam blowing heating system, at 90 to 110 ° C. and a gauge pressure of 0 to 1.0 k.
g / cm ² for 15-60 minutes and heat sterilization. After the completion of the heat sterilization, cooling water or pressurized air is introduced into the apparatus, cooling is performed while maintaining the pressurized state, and the temperature of the contents is reduced to about 60 ° C. or lower, and then the container is set in the apparatus. And then allowed to cool to room temperature.

Although the certainty of sterilization is slightly lowered, if economical priority is given, heat treatment in a hot water tank or in a steam tunnel can be adopted. Also, after taking out from the device, press the container as soon as possible,
If the contents of the noodles are vibrated by performing a treatment such as shaking, the noodles are more easily loosened. Needless to say, the bagged or packaged noodle product according to the present invention can be made into a specific product form by separately attaching an appropriate seasoning, such as a soup for retort packaging, a sauce, etc. Absent.

Although the case of boiled noodles has been described above, the present invention is not limited to such a case, and is similarly applied to all kinds of foods manufactured through the same immersion process. It goes without saying that it is possible to do so. Note that, in FIGS. 1 to 3 described above, a continuous acid immersion apparatus having a plurality of immersion tanks of the first immersion tank A and the second immersion tank B has been described. However, the present invention is not limited to this. For example, those having a single immersion tank consisting of only the first immersion tank can be used as appropriate.

[0037]

EXAMPLES Next, the present invention will be described specifically with reference to examples, but the present invention is not limited to the examples. Example 1 Based on 100 parts by weight of flour, 32 parts by weight of water, 1 part by weight of sodium chloride and 0.3 part by weight of can flour were added and kneaded for 10 minutes. And rolling was performed to make the final noodle cloth thickness 1.5 mm, and raw Chinese noodles were cut out continuously with a 2G cutting edge angle device.

After steaming the noodles for 5 minutes, they were transferred to a cooling bath, washed with water in the cooling bath and cooled to obtain steamed noodles.
The steamed noodles are transferred to a immersion tank of a continuous acid immersion apparatus, and immersed in a 2.3% aqueous gluconic acid solution cooled to 20 ° C. for 30 seconds by a plate heat exchanger to adjust the pH of the noodles to a standard range (pH 3.0). 5 to 3.9). At the time of the immersion treatment, the acidity of the immersion liquid in the immersion tank was controlled using the acidity management system using the automatic titrator of the present invention, similar to FIGS.

That is, the sampling point of the automatic titrator was set at the center of the overflow tank (drop tank), and the supply amount of the acid mother liquor was set to 100% as shown in Table 1. The upper limit of the supply amount of acid mother liquor is 22%, the normal value is 20%, and the lower limit is 18%
The acidity of the immersion liquid in the immersion tank was automatically controlled by measuring the titration acidity of the sample, selecting and supplying the acid mother liquor supply amount based on the measured value, and increasing or decreasing the acid mother liquor supply amount. . At that time, the supply of the acid mother liquor is performed to a circulation system of the immersion liquid circulating between the immersion tank and the overflow tank, and further, the immersion liquid is showered from a shower nozzle at the upper part of the immersion tank. The immersion treatment was performed so that the noodles were supplied to the supplied noodles and the immersion liquid was supplied by bubbling from a bubble nozzle below the immersion tank.

In this case, the upper limit of the titratable acidity is set to 190,
In addition, as a result of controlling the supply amount of the acid mother liquor by setting the lower limit to 160, the acidity of the immersion liquid is continuously maintained within the specification range, and the product pH is continuously maintained within the specification range (pH 3.5).
To 3.9). The results (transition) of the measured titration acidity of the immersion liquid and the product pH over time are shown in FIGS. 4 and 5, respectively.

After the continuous acid dipping treatment of the noodles is completed as described above, salad oil equivalent to 3% by weight of the noodles is spray-applied, the steamed noodles are transferred to the filling step, and the major axis and minor axis of the upper opening are formed. Have an approximately elliptical shape with a bottom major axis and minor axis of about 12.5 and 7 cm, respectively, about 16 and 9.5 cm, and a depth of 3.5 cm and a capacity of 450 ml in a tray tray made of polypropylene of 180 g. And the upper opening of the container was sealed with a polypropylene film and sealed using a hermetic sealing device SH-31 manufactured by Shikoku Koki Co., Ltd.

Next, this was heated and sterilized with a hot water bath (a retort sterilizer manufactured by Hisaka Manufacturing Co., Ltd .: RC).
S-160 / 30GA), and the tank was filled with 90 ° C. hot water heated in advance in a hot water tank at the upper part of the apparatus, and the pressurized state with a gauge pressure of 0.5 kg / cm ^2. For 30 minutes. Thereafter, cooling water was introduced from the lower part of the sterilizing tank to gradually lower the water temperature in the tank to 60 ° C.
Hold for minutes. Thereafter, the apparatus was opened, the container was taken out, and allowed to cool to room temperature to obtain a product.

[0043]

As described in detail above, the present invention relates to a method and an apparatus for adjusting the acidity of an immersion liquid in an immersion tank in a continuous acid immersion treatment of food.
The titration acidity of the immersion liquid is measured by an automatic titrator, and the acidity of the immersion liquid is adjusted by increasing or decreasing the supply amount of the acid mother liquor based on the measured value. Even in the low pH range around pH 2, instead of relying on human experience and feeling as in the conventional method,
It is possible to replenish the acid mother liquor and adjust the acidity by an automated system based on accurate measurements from an automatic titrator.

Therefore, the fluctuation of the pH of the immersion liquid can be reliably controlled within a small set range even in a low pH range. Further, conventionally, it was considered that accurate adjustment of pH was difficult due to a range of error in a pH meter.
Even in the H range, the acidity can be accurately and reliably adjusted by automatic control on the order of 0.1. Furthermore,
Since the continuous acid immersion treatment apparatus of the present invention does not need to prepare a large amount of acid solution in advance, the equipment itself can be considerably smaller than the conventional apparatus, so that the apparatus can be made compact. can do.

[Brief description of the drawings]

FIG. 1 shows a cooling bath in a continuous acid immersion treatment apparatus of the present invention;
It is a side view which shows the outline of an immersion tank.

FIG. 2 shows a cooling bath in the continuous acid immersion treatment apparatus of the present invention;
It is a top view which shows the outline of an immersion tank.

FIG. 3 shows an outline of a continuous acid immersion treatment apparatus for carrying out the acidity adjusting method by the automatic titrator according to the present invention.

FIG. 4 shows the transition of the titration acidity of the immersion liquid when the supply amount of the acid mother liquor is automatically controlled according to the present invention.

FIG. 5 shows the transition of the product pH when the supply amount of the acid mother liquor is automatically controlled according to the present invention.

[Explanation of symbols]

 A First immersion tank B Second immersion tank C Overflow tank (drop tank) D Automatic titrator E Acid immersion line control panel F Detector a Shower nozzle b Shower nozzle c Sampling pump d Pump e Pump f Acid mother liquor injection pump g Servo Type constant flow pump h Bubble nozzle i Bubble nozzle j Plate heat exchanger

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) A23L 3/3454 A23L 1/16 A23L 1/162

Claims (6)

(57) [Claims] In a method for adjusting the acidity of an immersion liquid in an immersion tank of a continuous acid immersion treatment apparatus for food, the titration acidity of the immersion liquid is measured by an automatic titrator, and the acidity of the immersion liquid is measured based on the measured value. A method for adjusting the acidity of an immersion liquid in an immersion tank of a continuous acid immersion treatment apparatus for food, wherein the acidity of the immersion liquid is automatically controlled by increasing or decreasing the supply amount of an acid mother liquor. 2. A minimum supply amount of an acid mother liquor is set, and the acid mother liquor is set in three or more stages based on the strength of an electric signal from an automatic titrator that changes according to the increase or decrease of the titration acidity of the immersion liquid. 2. The method according to claim 1, wherein a supply amount is selected, and the supply amount of the acid mother liquor is increased or decreased according to the supply amount. 3. An automatic titrator for sampling and titrating an immersion liquid from an overflow tank.
The method for adjusting the acidity of the immersion liquid according to the description. 4. When starting the continuous acid immersion treatment apparatus for food or when the supply of food as an object to be immersed is interrupted.
3. The method for adjusting the acidity of an immersion liquid according to claim 2, wherein the absence of an object to be immersed in the immersion tank is detected by a detection means such as a photoelectric tube, and the supply amount of the acid mother liquor is reduced to the minimum supply amount. 5. An immersion tank for immersing an object to be immersed, an overflow tank for storing an immersion liquid overflowed from the immersion tank, and an automatic titrator for measuring the titration acidity of the immersion liquid, The automatic titrator is installed so that it can be sampled from the overflow tank, and the supply amount of the acid mother liquor to the immersion tank is increased or decreased based on the measured value, so that the acidity of the immersion liquid is automatically controlled. A continuous acid immersion treatment device for foods. 6. An acid mother liquor is supplied to a circulation system in which an immersion liquid is circulated between an immersion tank and an overflow tank, and further, at least two methods selected from bubbling, showering, and counterflow. 6. The continuous acid immersion treatment apparatus according to claim 5, further comprising a supply unit for supplying the immersion liquid to the immersion tank, which can be performed in combination with the above.