JP3670104B2 - Method for producing sterilized food - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a variety of sterilized foods.
[0002]
[Prior art]
Today, food preferences are required to be diverse, and the content of the same food type is varied.
[0003]
In such foods, countermeasures against microorganisms, particularly microorganisms that cause harm to humans, such as food poisoning bacteria and spoilage bacteria, are very important, but in recent years, with the development of food processing technology, technology to sterilize foods in a sterile state has been developed. Many such sterilized foods have been established. These sterilized foods are convenient because they can be stored for a long time as they are, and because they can be eaten immediately by simple processing such as opening or immediately warming slightly. A very useful food form.
[0004]
As a form having the same effect, there is a food that can be stored for a long period of time by suppressing the growth of microorganisms by processing the food and then storing it at a frozen or refrigerated temperature. However, in order to store and distribute these foods in a low temperature range, large-scale equipment and a great deal of energy are required to cool or maintain the foods to that temperature. On the other hand, the sterilized food can be stored in a normal temperature range, and the sterilized food is very useful in terms of equipment and energy consumption.
[0005]
Such sterilization treatment is currently performed mainly by heating food. However, excessive heat treatment in sterilization has various effects on foods, and in some cases changes its original properties, causing a significant decrease in palatability. That is, flavor deterioration such as heating odor, change in color tone such as browning, change in viscosity and texture, and the like. Therefore, various sterilization methods have been developed in order to perform the heat treatment required for sterilization in as short a time as possible and to minimize the deterioration of food due to heating.
[0006]
For example, there are a steam injection method (steam infusion method) as a direct heating method, a plate type sterilization, a tubular type sterilization, a surface scraping type sterilization as an indirect heating method, and an electric heating sterilization as other methods.
[0007]
[Problems to be solved by the invention]
However, each of these sterilization methods is suitable for continuously producing a large variety of foods as described below, but is suitable for continuously producing many kinds of foods. Absent.
[0008]
That is, all of these methods are methods of filling and packaging after sterilization, and sterilization to filling must be performed aseptically in a continuous sealed in-line. In order to maintain such a sterile condition, it is necessary to prevent contamination of microorganisms from the outside, such as by providing a steam blocking part at the boundary between the outside and the inline. There is a drawback of large scale and large financial burden. In addition, there is a risk in terms of work due to the presence of high temperature parts in the process.
[0009]
In addition, in-line sterilization work is always required when starting production or once restarting after interruption by washing or the like, and there is a disadvantage that efficiency is deteriorated due to energy consumption and time loss. In order to increase the operation efficiency, it is necessary to maintain aseptic conditions as much as possible and continuously manufacture the products. However, when foods of different varieties are continuously produced by these methods, a portion where both types of foods are mixed is produced while the varieties are changed, and most of them are lost. For this reason, it is difficult to switch frequently. In addition, when continuously producing foods with different shades in color and flavor, it is necessary to manufacture from a thin one in order to reduce the loss as much as possible, and there is no flexibility in manufacturing.
[0010]
Thus, when manufactured using the above conventional sterilization treatment method, it is suitable for mass production of small varieties of sterilized foods, but various diverse varieties of sterilized foods can be produced on the same line. However, it is not suitable for continuous or simultaneous production, and is very difficult.
[0011]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for sterilizing foods in a short time and easily and continuously producing a variety of sterilized foods. is there.
[0012]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, a method for producing a sterilized food according to claim 1 is characterized in that a food is filled in a container by a non-aseptic filling process having a plurality of filling series, and in an electric field having a frequency of 1 MHz to several GHz. The food in the container is sterilized by dielectric heating.
[0013]
According to the method described above, the food is subjected to a processing step such as preparation as necessary, and then filled into a container by a non-aseptic filling step having a plurality of filling series. The food filled in the container is heat sterilized by dielectric heating using an electromagnetic wave having a frequency of 1 MHz to several GHz for each container.
[0014]
Therefore, the food is filled in the container by a non-aseptic filling process and sterilized after filling and packaging. Since the filling process is non-aseptic, it is much simpler than the aseptic filling equipment, and there is no need to maintain sterility or re-sterilization when switching to other varieties. The loss of energy and time is reduced. In addition, since sterilization is performed after filling and packaging, even if foods of different varieties are manufactured continuously or simultaneously, there is no fear that both types of foods are mixed in the sterilization process. Therefore, a variety of foods can be sterilized continuously or simultaneously to produce a variety of sterilized foods in a short time and easily.
[0015]
In addition, unlike the above-described conventional method of heating and sterilizing from the outside, heat is generated from the inside of the food, so there is less danger due to the high temperature part during the sterilization process.
[0016]
In addition to the above-described configuration, the present invention fills a sterilized portion with foods having different compositions for each filling series, which are filled in containers of approximately the same shape and have substantially the same dielectric constant , and then, A plurality of foods obtained from a plurality of filling lines are sterilized by heating at a time by one heating.
In addition to the above-described configuration, the sterilized food manufacturing method is configured to fill a plurality of types of the above-mentioned foods into the substantially same shape of the container and to perform the dielectric heating continuously or simultaneously on the food. You can also
[0017]
By the above method, a plurality of kinds of foods are filled in a container having substantially the same shape, and sterilized continuously or simultaneously by dielectric heating.
[0018]
Since the shape of the container is almost constant, when the foods that are the contents in the container are compared with each other, if there is no extreme difference in the composition or amount of the ingredients, the container and the food are included. There is no significant difference in the dielectric constant of the object to be heated.
[0019]
The sterilization process is sterilized by dielectric heating using electromagnetic waves having a frequency of 1 MHz to several GHz. In such sterilization by dielectric heating, the magnitude of the sterilization effect is affected by the dielectric constant of the object to be heated. However, as described above, there is no significant difference in the dielectric constant of the object to be heated even if the food in the container is changed, so that dissimilar foods can be sufficiently sterilized continuously or simultaneously with the dielectric heating conditions kept almost constant. can do.
[0020]
Therefore, the labor and time for changing the heating conditions each time the product type is changed are greatly reduced. Therefore, a wide variety of sterilized foods can be easily produced in a short time.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
One embodiment of the present invention will be described with reference to FIGS. 1 to 3 as follows.
[0022]
The food in the present invention includes all widely general foods, and does not particularly limit the properties and composition thereof. That is, the food may be in any form such as liquid, semi-fluid, solid, powder, etc., and there is no restriction on physical properties such as viscoelasticity, and in the composition, the water content is high or low, sugar content, salt concentration Also, there is no particular limitation on the shape such as the presence of a discontinuous phase or solid-liquid mixing. However, foods that are sterilized consecutively or simultaneously must not change significantly in content. This is because if the dielectric constant changes greatly, the sterilization process must be adjusted to the optimum setting according to the individual food.
[0023]
The filling process is performed by a non-sterile filling apparatus having a plurality of filling lines. The plurality of filling series may be a single device having a plurality of filling portions or a plurality of devices having a single filling portion.
[0024]
In order to sterilize after filling, the filling device may be a non-sterile device and does not particularly limit the filling method.
[0025]
About the material of the container with which it fills, what is necessary is just to have heat resistance which has electromagnetic wave permeability and can endure a sterilization process. Generally, CP (cellulose propionate), PP (polypropylene), nylon, PET (polyethylene terephthalate), or a composite material thereof is suitable.
[0026]
There is no particular limitation on the shape of the container. It may be an irregular shape such as a pillow-type package (pillow-like container) or a shaped fixed container. However, it is desirable that a plurality of types of foods to be sterilized continuously or simultaneously are filled in containers of the same shape.
[0027]
That is, as shown in FIG. 1, when various kinds of foods are filled in the same shape container, if there is no extreme change in the contents, these various kinds of foods are sterilized continuously or simultaneously in parallel. It is possible.
[0028]
As shown in the figure, in the non-aseptic filling step 11, there are a filling line 21, a filling line 22, and a filling line 23. In the filling line 21, the food A is filled in the container 31 by the filling device 24. In the filling line 22, the container B is similarly filled with the food B by the filling device 25. In the filling line 23, the container C is similarly filled with the food C by the filling device 26.
[0029]
Each container 31 filled with each food is transferred to the sterilization step 12 by a belt conveyor or the like, and sequentially fed into the sterilization unit 13 to be sterilized. In this sterilization process 12, as shown in the figure, the food contained in each container 31 is not uniform, when food A is contained, when food B is contained, when food C is contained There is. However, since one type of container 31 is used in common, it is possible to increase substantially the same sterilization effect under a certain heating condition regardless of the order in which the containers 31 are sent to the sterilization unit 13. For this reason, as shown in the figure, it is possible to send these foods to the sterilization unit 13 in an arbitrary order regardless of the type of food, and to sterilize various foods simultaneously in parallel. Moreover, it is also possible to send to the sterilization part 13 in order of the kind of food, and to sterilize various foods continuously including the time of change of a kind.
[0030]
On the other hand, as shown in FIG. 2, a case where various kinds of foods are filled in containers having different shapes will be considered. In the non-aseptic filling step 14, there are a filling line 21, a filling line 22, and a filling line 23. In the filling line 21, the food A is filled in the container 31, but in the filling line 22, the food B is filled in a container 32 having a shape different from that of the container 31. In the filling line 23, the food C is filled in a container 33 having a shape different from that of the container 31 and the container 32.
[0031]
Each container 31, 32, 33 filled with each food is transferred to the sterilization step 15 by a belt conveyor or the like, and sequentially fed into the sterilization unit 13 to be sterilized. Here, all the rows of containers A are sent to the sterilizing unit 13 before the containers B and C, and are continuously sterilized under the sterilizing conditions for the containers A. After that, all the rows of the containers B are sent to the sterilizing unit 13 before the containers C, and are continuously sterilized under the sterilizing conditions for the containers B. After that, the row of containers C is fed into the sterilizing unit 13 and continuously sterilized under the sterilizing conditions for the containers C.
[0032]
In this way, when the shape of the container is changed in the middle, there is a possibility that the conditions at the time of sterilization may be appropriately adjusted to optimum conditions according to the individual containers (31, 32, 33). . In that case, it becomes difficult to sterilize various foods simultaneously in parallel under substantially constant sterilization conditions as shown in FIG. Therefore, in this case, as shown in FIG. 2, it is necessary to sterilize the same kind of food continuously to some extent, and to change the sterilization conditions each time the shape of the container changes.
[0033]
However, if the sterilization conditions are not changed even if the container shapes are different, it is possible to sterilize various foods in parallel as shown in FIG.
[0034]
In the above example, foods of different varieties are sterilized one by one, but as another example, as shown in FIG. 3, a plurality of foods of the same or different varieties filled in the same container 31 are It can also be configured such that it is simultaneously fed to the sterilizing unit 13 and then these foods are heat sterilized one by one at a time by one heating.
[0035]
It is also possible to prepare a plurality of sterilization units 13 and heat and sterilize foods of the same or different varieties in parallel with the plurality of sterilization units 13.
[0036]
In the present invention, the frequency of the electromagnetic wave used for sterilization is 1 MHz to several GHz effective as dielectric heating. At a frequency lower than this, the food previously filled in the container is not heated by dielectric heating. Moreover, it is practically difficult at a frequency larger than this.
[0037]
The sterilization temperature may be set to an optimum temperature according to the content and composition of the object, but a temperature of 120 ° C. to 180 ° C. is effective and preferable for sterilization of food. When the temperature is too low, it takes a long time to sterilize the food, and when the temperature is too high, the food is burnt, which causes adverse effects due to heating.
[0038]
The time required to reach the sterilization temperature is preferably as short as possible in order to reduce the influence of heating on the food, and is preferably in the range of 10 to 90 seconds. If it is too short, it becomes difficult to control the sterilization temperature. On the other hand, if the length is too long, the food is adversely affected by heating.
[0039]
After reaching the sterilization temperature, the food is maintained at this temperature for a holding time (sterilization time) for sterilizing the food as necessary. The holding time is appropriately set according to the sterilization temperature, the content composition of the heating object, the size, and the like, but a holding time of 0 to 180 seconds is preferable. If it is too long, the food will be adversely affected by heating, and the sterilization efficiency will be reduced.
[0040]
Generally, the sterilization time M at an arbitrary temperature T _i is calculated by the following equation.
M = F × 10 ^{(Tr-Ti) / z}
In this equation, F is a required F value, T _r is a reference temperature, T _i is an arbitrary temperature, and z is a parameter indicating the heat resistance of the microorganism. The reference temperature T _r , z value and F value are set according to the properties of the individual food. For example, in a food having a neutral pH, the reference temperature is 121.1 ° C., z = 10 ° C., F value Is usually at least 4 minutes. The sterilization temperature is maintained only during the sterilization time M.
[0041]
As for cooling, in order to minimize the effects of heating on food, it is necessary to perform immediately after the sterilization treatment, but if the time and cooling temperature are set according to the degree of influence on the heat of each food Good. The cooling method is not particularly limited, but in general, the cooled liquid or gas is brought into contact with the periphery of the food and cooled by its heat conduction. A mechanism for cooling the inside of the sterilizing apparatus may be attached, or a method of cooling after taking out food from the sterilizing apparatus may be used.
[0042]
The cooled food is further packaged as necessary, and stored and distributed as it is at room temperature. However, due to the characteristics of the food, if necessary, it is refrigerated at a refrigerated temperature.
[0043]
【Example】
The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.
The outline of the apparatus used in this example is as follows.
As shown in FIG. 4, the sterilizer 1 includes a vacuum tube type high frequency oscillator 2 having a frequency of 13.56 MHz and an output of 7 kW, and passes through a tuning circuit 3 including a capacitor having a variable capacitance and a coil having a variable impedance. , Connected to the heating unit 4.
[0044]
The heating unit 4 includes two upper and lower electrode plates, that is, an upper electrode plate 5a and a lower electrode plate 5b, and a shell 6 formed of an insulator. The high frequency oscillator 2 is connected to the upper electrode plate 5a through the tuning circuit 3, and the lower electrode plate 5b is grounded. A press cylinder 7 is connected to the upper electrode plate 5a and can be pressed toward the lower electrode plate 5b. The shell 6 is located between the upper electrode plate 5a and the lower electrode plate 5b, and there is a space for arranging a sample to be heated at the center.
[0045]
Heating is performed by the following method. In all the following examples, the same method was used. That is, a sample was prepared by using 200 g of food material, filling the pillow-shaped container formed of two layers of CP and nylon with the food material, and hermetically packaging by heat sealing. This sample is placed at the center of the shell 6, the upper electrode plate 5 a is lowered by the press cylinder 7, the space at the center of the shell 6 is sealed, and then the high frequency is oscillated by the high frequency oscillator 2 to heat the sample. did. At this time, the high-frequency output from the upper electrode plate 5a was adjusted to 1.82 kW, and the heat treatment was performed with the same settings in the following examples. All the samples were heated to a predetermined temperature after heating was started, and at that time, high-frequency oscillation was stopped and the temperature was maintained for about 1 minute. Subsequently, the process was shifted to cooling so that the sample temperature was 30 ° C. or lower.
[0046]
[Example 1]
10 parts by weight of sugar, 16 parts by weight of starch syrup, 6 parts by weight of coconut oil, 4 parts by weight of skim milk powder, 0.5 parts by weight of glycerin fatty acid ester and 0.05 parts by weight of carrageenan are sequentially added to water while heating and stirring. Was 100. The mixture was heated to 70 ° C. and completely dissolved, and then homogenized with a homogenizer to obtain an ice cream mix. This was filled and packaged in a container as described above to prepare a sample, which was heat sterilized using the above apparatus and conditions.
[0047]
[Example 2]
8 parts by weight of sugar, 9 parts by weight of starch syrup, 4 parts by weight of coconut oil, 8 parts by weight of skim milk powder, 0.5 parts by weight of glycerin fatty acid ester and 0.05 parts by weight of carrageenan are sequentially added to water while heating and stirring. Was 100. The mixture was heated to 70 ° C. and completely dissolved, and then homogenized with a homogenizer to obtain a shake mix. This was filled and packaged in a container as described above to prepare a sample, which was heat sterilized using the above apparatus and conditions.
[0048]
Example 3
Coconut oil 23 parts by weight, skim milk powder 6 parts by weight, casein sodium 3 parts by weight, glycerin fatty acid ester 0.7 parts by weight, sugar ester 0.5 parts by weight, carrageenan 0.05 parts by weight in water while heating and stirring Sequentially added, the total was 100. The mixture was heated to 70 ° C. and completely dissolved, and then homogenized with a homogenizer to obtain a coffee cream. This was filled and packaged in a container as described above to prepare a sample, which was heat sterilized using the above apparatus and conditions.
[0049]
Example 4
18 parts by weight of sugar, 25 parts by weight of coconut oil, 7 parts by weight of skim milk powder, 2 parts by weight of sodium caseinate, and 0.5 parts by weight of glycerin fatty acid ester were sequentially added to water while heating and stirring to make 100 as a whole. The mixture was heated to 70 ° C. and completely dissolved, and then homogenized with a homogenizer to obtain a whipped cream mix. This was filled and packaged in a container as described above to prepare a sample, which was heat sterilized using the above apparatus and conditions.
[0050]
Example 5
Two containers are prepared, one container containing 100 g of the ice cream mix obtained in Example 1, and the other container containing 100 g of the coffee cream obtained in Example 3 above. Samples were filled and packaged as described above. And these two containers were heat-sterilized simultaneously with the said apparatus and conditions.
[0051]
In Examples 1-5, each sample showed the same temperature rising tendency, and reached 130 degreeC in 1 minute 30 seconds. When the fungus test was performed on each sample, no bacteria were detected. Further, there was no problem in color tone and flavor.
[0052]
As a result, like the food materials mentioned in these examples, different varieties of foods are filled in the same container, and this is sent to the above apparatus in an arbitrary order, all continuously under the same heating conditions. Alternatively, it can be seen that a large amount of sterilized food products with good quality such as flavor can be easily produced in a short time by heat sterilization in parallel.
[0053]
【The invention's effect】
As described above, the method for producing a sterilized food according to claim 1 fills a container with a food by a non-aseptic filling process having a plurality of filling series, and performs dielectric heating in an electric field having a frequency of 1 MHz to several GHz. To sterilize the food in the container.
[0054]
Therefore, there is an effect that a variety of foods can be sterilized continuously or simultaneously to produce a variety of sterilized foods in a short time and easily.
[0055]
Production method of the present sterilized food, in addition to the arrangement as described above, constituting the plural kinds of the food substantially charged to the container having the same shape, so as to perform successively or simultaneously the dielectric heating with respect to the food You can also
[0056]
Therefore, in addition to the effect by the structure of Claim 1, there exists an effect that many types of sterilized foodstuffs can be manufactured further in a short time and easily.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a sterilization process in one configuration example of a sterilizer according to the present invention.
FIG. 2 is an explanatory view showing a sterilization process in another configuration example of the sterilization apparatus according to the present invention.
FIG. 3 is an explanatory view showing a sterilization process in still another configuration example of the sterilization apparatus according to the present invention.
FIG. 4 is an explanatory view showing a configuration example of a sterilizer according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sterilization apparatus 2 High frequency oscillator 3 Tuning circuit 4 Heating part 5a Upper electrode plate 5b Lower electrode plate 6 Shell 7 Press cylinder 11 Non-aseptic filling process 12 Sterilization process 13 Sterilization part 14 Non-aseptic filling process 15 Sterilization process 21, 22 , 23 Filling series 24, 25, 26 Fillers 31, 32, 33 Containers

Claims (1)

A non-aseptic filling process with a plurality of filling lines fills containers of approximately the same shape with foods of different compositions for each filling line to make the dielectric constant substantially the same , and simultaneously feeds it to the sterilization unit,
A method for producing a sterilized food, characterized in that a plurality of foods obtained from a plurality of filling series are heat-sterilized simultaneously by one heating by dielectric heating in an electric field having a frequency of 1 MHz to several GHz.

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