JP3071412B2 - Retort sterilization method with F value control and retort sterilization apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an F value control system for producing packaged foods, infusions, and the like, and a retort sterilizer incorporating the same.

[0002]

2. Description of the Related Art In a conventional sterilization method, a temperature sensor is directly inserted into an article to be sterilized, and the temperature of the article is measured.
The value was calculated and the sterilization process was controlled so as to be within a predetermined F value. Usually, the planned sterilization conditions are determined by a retort tester. However, when applying this to a production machine, it is not possible to directly detect the product temperature and adjust the F value every time as in a test machine, so in most cases, a simple operation of holding for several minutes after the sterilization temperature is reached. Sterilization work is performed according to how to determine sterilization conditions.

[0003] In the case of such simple sterilization conditions, it is easy to select absolutely safe conditions without directly measuring the F value.
In all cases, sterilization was excessive and quality deterioration was inevitable.

[0004]

In the method of directly measuring the temperature of the product as described above, it is necessary to insert a temperature sensor for each batch, which is troublesome. The sensor insertion position must also be accurately set at a predetermined position so that the slowest temperature can be measured. This is a laborious and laborious operation even for a skilled person. If the F-number control is not set at a predetermined position, the F-number control with poor reproducibility results in negligible safety and lacks reliability.

[0005] When simple sterilization conditions are used, in actual operation, the control of the sterilization temperature controller is affected only by the change in the room temperature due to the seasonal change due to the heat radiation of the kettle.
Although slightly less than the setting, a deviation of about ± 0.5 ° C often occurs. Then, the higher the sterilization temperature is, the greater the effect of the substantial F value is, and in the worst case, the planned sterilization conditions may not be satisfied.

[0006] Furthermore, if a malfunction occurs on the utility such as a power failure, the sterilization conditions deviate from what degree of temperature and what number of minutes, making it impossible to evaluate the safety. Become. In this case, it is the worst condition in terms of quality.
As mentioned above, the error near the sterilization temperature is ± 0.5 ° C.
Even if it is within the range, the F value becomes a size that cannot be ignored, and therefore, the production site operates under the modified planned sterilization condition in which the planned sterilization condition of the test machine is multiplied by a certain safety factor. For example,
In sterilization at 120 ° C. with an F value of 4, the F value is 6-7 (50
It is a reality that it is about 75% increase).

The object of the present invention is to know the time-dependent change of the product temperature in a non-contact manner in real time and accurately, to control the F value to avoid heat sterilization exceeding the planned sterilization conditions, to shorten the sterilization time, The present invention provides a retort sterilizing method with F-value control and a sterilizing apparatus capable of reducing the burden on the user and improving the safety of food by increasing the accuracy. In addition, pots, packaging materials,
Provided is a retort sterilization method and a sterilization apparatus with F-value control that can control the tank temperature of contents and utilities to near a limit temperature, greatly reduce the heat sterilization time, and improve the quality.

First, the product temperature is simulated from the bath temperature using the individual heat transfer coefficient (α) determined by the product temperature monitoring system.
The F value control is carried out in a non-contact manner so that the change in product temperature with time can be known in real time and accurately, and the F value can be calculated simultaneously and the extension or shortening of the sterilization time can be instantaneously determined. Avoid heat sterilization beyond the planned sterilization conditions. As a result, an object of the present invention is to provide a retort sterilization method with F-value control and a sterilization apparatus capable of reducing the work load and shortening the sterilization time.

[0009] Further, the tank temperature resip to be controlled is obtained in advance by inputting the target product temperature resipe into a formula obtained by reversing the sequential calculation formula of the product temperature monitoring system, and the sterilization process is controlled by a programmed temperature to perform the sterilization. F that greatly reduces the time
An object of the present invention is to provide a retort sterilization method and a sterilization apparatus with value control.

[0010]

In order to achieve the above object, in the first invention, there is provided a retort sterilizer in which a product temperature monitoring system is incorporated in a control unit. The product temperature monitor system referred to here is based on a signal from a retort tester loaded with packaged food or infusion, etc., and measures the measured tank temperature (tw) (temperature of the heat transfer medium of packaged food, etc.) and the measured product temperature (tp) ( Means for accumulating each data of (packed food etc. internal temperature), and after the sterilization process, from the accumulated data, the heating side heat transfer coefficient (αH) and cooling side individual heat transfer coefficient (αC) of the packaged food or infusion solution etc. Is calculated using the individual heat transfer coefficients (αH) and (αC), and a simulated product temperature (tpc) is calculated .
Means for drawing a product temperature curve and displaying the data on the data curve of the measured bath temperature (tw) and the measured product temperature (tp). In this retort sterilizer, the heating-side individual heat transfer coefficient (αH) of a packaged food or infusion solution determined in advance by a retort tester
And the cooling-side individual heat transfer coefficient (αC), the measured tank temperature (tw) from the retort sterilizer in real time is used.
Means for calculating the simulated product temperature (tpc) and calculating the F value (Fc) is provided, and when the control F value (Fs) is reached in the sterilization process, the sterilization process is terminated and the process shifts to the cooling process. This is a retort sterilization method with value control.

[0011]In the second invention, the product temperature monitoring system
Simulated product temperature (t) using the individual heat transfer coefficient (α).
pc) as a means to draw a simulated temperature curve
Then, the following basic formula (sequential calculation formula-MAA formula) was used.
A retort sterilization method with F value control was adopted. Basic formula (Sequential calculation formula-MAA formula): tpn = tpn-1 + Δtpn (1) Δtpn = α × Δtwn + (1−α) × Δtpn-1 (2) Code explanation: tpn: current product temperature (° C)  tpn-1: previous product temperature in sequential calculation (° C)  Δtpn: Change in product temperature that contributed to reaching the current product temperature (° C)  Δtpn-1: Change in product temperature that contributed to reaching the previous product temperature (° C)  α: Individual heat transfer coefficient per specified time (dimensionless number)  twn: Current bath temperature (° C)  Δtwn: Change in bath temperature that contributed to reaching the current bath temperature (° C)

In the third invention, the measured tank temperature (tw) is based on a signal from a retort tester loaded with packaged food or infusion.
Means for accumulating data of (heat transfer medium temperature of packaged food, etc.) and measured product temperature (tp) (inner temperature of packaged food, etc.), and heating of packaged food or infusion solution from the accumulated data after the sterilization process. Means for calculating the side heat exchanger (αH) and the cooling-side individual heat transfer coefficient (αC), and the individual heat transfer coefficient (αH) and (α
Calculate the simulated product temperature (tpc) using C) and, Simi
Draw a temperature curve of the measured product, and measure the measured bath temperature (tw) and the measured product temperature.
(tp) data displayed on the data curve of (tp).
Product temperature monitoring system for packaged foods or infusions as control unit
Use the installed retort sterilizer. In this retort sterilizer, the heating-side individual heat transfer coefficient (αH) and the cooling-side individual heat transfer coefficient (αC) of the packaged food or infusion solution, etc., which are determined in advance by a retort tester, are used. simulator in real time corresponding to the measured bath temperature (tw)
Means for calculating the F value (Fc) by calculating the product temperature (tpc), and the F value which is set so that when the control F value (Fs) is reached in the sterilization process, the sterilization process is terminated and the cooling process is started. A retort sterilizer with a retort sterilizer with a built-in controllable retort sterilizer was installed in the control unit .

(Action) In the first invention, the delay time (δ), the individual heat transfer coefficient (α) (the individual heat transfer coefficient (αH) on the heating side and the individual using heat coefficient (αC)), from the bath temperature data material temperature of (tpc) in real time
It simulates and also calculates the F value (Fc). When the control F value (Fs) is reached in the sterilization process, the sterilization process is terminated and the process is shifted to the cooling process, so that a non-destructive operation can be performed so that there is no excessive sterilization treatment.

In the second invention,Product temperature monitoring system
Simulated product temperature (t) using the individual heat transfer coefficient (α).
pc) as a means to draw a simulated temperature curve
Then, using the following basic formula (a sequential calculation formula-the formula of MAA)
Was. Basic formula (MAA formula): tpn = tpn-1 + Δtpn (1) Δtpn = α × Δtwn + (1−α) × Δtpn-1 (2) here,  tpn: current product temperature (° C)  tpn-1: previous product temperature in sequential calculation (° C)  Δtpn: Change in product temperature that contributed to reaching the current product temperature (° C)  Δtpn-1: Change in product temperature that contributed to reaching the previous product temperature (° C)  α: Individual heat transfer coefficient per specified time (dimensionless number)  twn: Current bath temperature (° C)  Δtwn: Change in bath temperature that contributed to reaching the current bath temperature (° C)

According to the third aspect of the invention, a retort sterilizer with an F value control incorporating the above F value control can be provided irrespective of a hot water type, a steam type, a spray type or any other heating method.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The main points of the product temperature monitoring system are as follows. (1) Configuration of Basic Formula First, an equation representing the time-dependent change characteristic of the measured product temperature (tp) as the internal temperature of the packaged food or the infusion in the sterilization process is obtained.

In the retort, generally, the temperature simulation of FIG.
As seen in configuration model diagram, any bath temperature (tw)
The temperature of six different foods (tpA, tpB, tpC, tp
D, tpE, tpF), the characteristics of the change with time all draw an S-shaped curve on the heating side and draw an inverted S-shaped curve on the contrary on the cooling side. Here, the heating side refers to a section of temperature rise and sterilization. In short, a curve (curve) that indicates a delay in temperature rise at the start of heat transfer and that approaches asymptotically the bath temperature (tw) of the sterilization temperature at the end of heat transfer.
It is. Although this curve is similar to the hysteresis curve, it is difficult to express it as a single functional expression because there is no symmetry in the vertical and horizontal directions as in the hysteresis curve.

After trial and error, it has been found that the following successive calculation formula can best represent the material temperature curve currently being obtained. Basic formula (sequential calculation formula-MAA formula): tpn = tpn-1 + Δtpn (1) Δtpn = α × Δtwn + (1-α) × Δtpn-1 (2) Operation method: FIG. Is a model diagram of a sequential calculation graph of FIG.

Tp ₀ : temperature of product at the start of sterilization (° C.)... To be measured tw ₀ : bath temperature at the start of sterilization (° C.) Here, tw ₀ = tp ₀ . (3) θ1, θ2, θ3,... Θn-2, θn-1, θn: predetermined fixed time intervals (sampling cycle (θn = n × θ)) tw1, tw2, tw3,. twn-2, twn-1, twn: Actual measured tank temperature (C) taken at each sampling cycle tp1, tp2, tp3, ... tpn-2, tpn-1, tpn: Taken at each sampling cycle Actual measured temperature (° C.) Here, Δtwn = twn−twn−1 is shown.

Further, Δtpn-1 = tpn-1-tpn-2 is shown. α: Individual heat transfer coefficient (dimensionless number per predetermined time interval) Here, 1 to 30 seconds is practical. Heat transfer characteristics of individual heat transfer coefficient α: As shown in FIG. 1, the larger the α value, the higher the heat conductivity, and the smaller the α value, the lower the heat conductivity.

When the equation is expanded from the change diagram of the temperature distribution in a very short time in FIG. 3, the heat transfer characteristic becomes clearer. Development of Equation for Obtaining α: The flow of minute heat (qn) in minute time (θ) can be expressed by the following two methods. From the equation of heat conduction, qn = − (k / Te) × A × (tp n−1−twn) × θ (4) From the heat balance, qn = V × ρ × cp × (tp n −tp n-1) (5) It can be considered that the calorific values qn of the equations (4) and (5) are approximately equal. Next, the equation is expanded as follows.

V × ρ × cp × (tp n−tp n−1) = − (k / Te) × A × (tp n−1−twn) × θ (tp n−tpn−1) = ((( k / Te) × A × θ) / (V × ρ × cp)) × (twn−tp n-1) tpn = (((k / Te) × A × θ) / (V × ρ × cp)) X (twn−tp n−1) + tp n−1 ((k / Te) × A × θ) / (V × ρ × cp)) = α, (6) tp n = α × twn + (1−α) × tp n−1 As can be seen from FIG. 1, since the product temperature tpn shows a non-linear characteristic, it cannot be operated as it is. Then, in order to obtain linearity that enables sequential calculation, this is differentiated. As a result, the above basic formula (2) is obtained.

Δtpn = α × Δtwn + (1−α) × Δtpn−1 (2) From the above equation, the product temperature change can be sequentially calculated only from the bath temperature change. Therefore, the basic formula (1) simulated high product temperature curve of as shown in FIG. 1 accuracy by operating the sucrose
Become possible . tpn = tpn-1 + .DELTA.tpn (1) The shape characteristics of equation (6) will be further arranged.

Since T e = V / A, (7) α = (k × θ) / (Te ² × ρ × cp) (8) where k: heat of the packaged food conductivity (kcal / mh ℃) ρ: density of the packaged food (kg / m ³⁾ cp: specific heat of the packaged food (kcal / kg ℃) a: heat transfer surface area of the packaged food (m ²⁾ V: volume of the packaged food (m ³ ) twn: current bath temperature (° C) Δtwn: change in bath temperature contributing to reach the current bath temperature (° C) tpn: current product temperature (specified by the slowest temperature) (° C) Δtpn : Change in product temperature that contributed to reaching the current product temperature (° C) tp n-1: Previous product temperature in sequential calculation (° C) Δtp n-1: Product temperature that contributed to the previous product temperature in sequential calculation Change (° C) Te: Equivalent thickness of packaged food (m) θ: Sampling cycle (h) α: Individual heat transfer coefficient per specified time interval (dimensionless number) (2) Configuration of product temperature monitor (α value monitor) Measured tank temperature during the sterilization process of the target packaged food (tw) The actual product temperature
(tp) Take the data.

The F value is calculated from the actually measured tp data. (F value) Next, each initial value is determined. Calculate the Te of the packaged food from equation (7). ... (input manually) For the physical properties of food, substitute the physical properties of water at 25 ° C for the time being. (K) / (ρ × cp) = (0.522) / (997.1 × 0.9989) = 5.241 × 10 ^-4 (Input each property value manually) From the above, the initial value α ₀ of the individual heat transfer coefficient is Decided.

.. (Automatically calculated) tw ₀ (= tp ₀ ) is determined according to the equation (3). ... (Automatically input.) The counting of the elapsed time (θn) starts when the temperature in the chamber becomes uniform. For example, in the case of the hot water type, after the hot water is injected (or after the cooling water is injected), the counting is started from the time when the circulation pump is turned on.

After the temperature of the actually measured tank (twn) starts to rise, the delay time (δ) for forming a predetermined temperature gradient is required until the latest measured temperature (tpn) of the slowest speed starts to rise. ) Exists, so that this is also read automatically. The above basic formula
In (1) and (2), the initial values α ₀ and tw ₀ and the measured tank temperature (twn)
Simulate corresponding temperature data (tpc) by inserting data
Calculate . In this case, simulator delay time ([delta]) min as measured bath temperature (twn) data by shifting the material temperature data (tpc)
Calculation . Simultaneous with product temperature simulation
F value is also advance by calculating the. (Fc value) The measured F
The α value is basically determined by comparing the value with the calculated Fc value and converging to a certain precision. In this case, it is performed automatically using a general convergence method.

First, the heating-side individual heat transfer coefficient (αH) is calculated by comparing the F value and the Fc value at the end of heating.
The value is determined so as to converge to an accuracy within -0.1% compared to the F value. The reason for setting the negative range within -0.1% is due to consideration of the safety side.

Next, as the initial value of the cooling-side individual heat transfer coefficient (αC), αH determined immediately before is used. Then, a simulation calculation from the start to the end of the cooling is performed. in this case,
Convergence calculation is performed based on the net increase in the F value during the cooling step. Also in this case, usually, the accuracy is converged to within -0.1%.

If αC does not converge, the process returns to the initial delay time (δ), corrects it, and starts over. When the heating-side individual heat transfer coefficient (αH) and the cooling-side individual heat transfer coefficient (αC) are both determined with an accuracy of within -0.1% of the F value deviation, the final F value at the end of the sterilization process is also- Accuracy within 0.1% is obtained. (3) Configuration of Retort Testing Machine As temperature data during the sterilization process, one bath temperature tw and one or a plurality of product temperature tp data are transmitted to the product temperature monitor at predetermined regular intervals.

In this case, tw needs to accurately indicate the ambient temperature of the outer surface of the packaged food. In addition, temperature uniformity must be ensured in the bath. For the temperature detection sensor, a highly accurate thermistor or a resistance temperature detector is used. It should be noted that among the plurality of product temperature data, the one exhibiting the lowest F value is adopted as data, thereby enhancing safety.

Further, the temperature monitor may be incorporated in the control panel of the testing machine. (4) Configuration of the present invention As shown in the above product temperature monitoring system, each of the retort sterilization products has a specific delay time (δ) and individual heat transfer coefficient (α) (strictly speaking, αH on the heating side. ΑC) on the cooling side can be determined. From the data accumulation of these δ and α values, in the temperature range of retort sterilization (20 ° C to 135 ° C), even if the bath temperature (tw) is slightly changed, the δ and α values hardly change and remain constant. It is known. Furthermore, the δ and α values depend only on the physical properties of the contents, including the shape of the product and the packaging material, and it has been confirmed that the sterilization method may be a hot water method, a steam method, or any other method. . The present invention
This is a retort sterilization system that uses δ and α values that can be handled at a constant value.

Planned F value (F value finally required: F
t) is expressed by the sum of the control F value (F value for controlling the sterilization step to stop and shift to the cooling step: Fs) and the cooling F value (F value generated during cooling: Fr). The Ft value is usually determined by the person in charge of development and quality control using a retort tester and an F value monitor (or temperature monitor). F
The initial value of the s value is obtained by subtracting the initial value of Fr, which was previously obtained by idling, from the Ft value. In the case of dry operation, the cooling speed is fast because Fr
Since the value is low, it is a safe side in terms of sterilization. In the normal case, the absolute value of the Fr value is originally small,
The error is negligible because it accounts for a small percentage of the t value. Therefore, the first batch is somewhat sterilized on the safe side, but there is no problem. In addition, from the second batch, data of one batch is fed back to improve accuracy.

Sterilization is performed at a predetermined tank temperature (tw),
So the F calculated from the simulated product temperature (tpc)
When the value (Fc) reaches the control F value (Fs), the sterilization step is ended and the process shifts to the cooling step. When program temperature control of the sterilization process is performed for the purpose of greatly shortening the sterilization time, first, the basic equation (MAA equation) is reversely developed,
Draw an ideal arbitrary temperature resipe and simulate the corresponding tank temperature resipe . Next, simulate
The stored tank temperature resipe data is input to the sequencer in advance, and the entire sterilization process is controlled according to the program.

Basic formula (sequential calculation formula-MAA formula): tpn = tpn-1 + Δtpn (1) Δtpn = α × Δtwn + (1-α) × Δtpn-1 (2) Reverse expansion Expression: twn = twn-1 + Δtwn (9) Δtwn = (1 / α) × Δtpn − ((1−α) / α) × Δtpn−1 (10) where tpn: current Item temperature (° C) tpn-1: Previous item temperature in sequential calculation (° C) Δtpn: Item temperature change (° C) that contributed to reach current item temperature Δtpn-1: Contributed to reach previous item temperature Temperature change (° C) α: Individual heat transfer coefficient per predetermined time (dimensionless number) twn: Current tank temperature (° C) Δtwn-1: Previous tank temperature in sequential calculation (° C) Δtwn: Current tank Temperature change of tank that contributes to reaching temperature (° C.) Here, tw ₀ = tp ₀ is set. (11) Putting the determined δ and α into consideration, (9) (10) By operating the equation (11), it is possible to simulate the tank temperature resipe for an arbitrary product temperature resipe.

Basically, it is possible to simulate and draw the bath temperature resipe for any product temperature resipe, but the design conditions and utility conditions of the sterilization pot, the heat resistance of the packaging material, and the heat resistance of the food Because of these restrictions, it is necessary to select the optimal tank temperature recipe in consideration of all of them.

[0037]

[Example] Food type: Pudding in 70cc aluminum container (Te = 7mm) Sterilization method: Hot water method (static), aeration treatment method Sampling cycle: 15 sec F value calculation formula: Σ ((15/60 ) x1E + ((1.8 x tpn + 32-250) / 18)) Formula for calculating F value error (%): ((MAA F value-actual F value) / actual F value) x 100 (Test machine setting data ) Sterilization temperature 120 ℃ Sterilization temperature maintenance time 20 min (Result data of product temperature monitor in test machine) Initial product temperature tp ₀ = 43.7-46.1 ℃ (average 44.9 ℃) Delay time δ = 45-15 sec (average 30 sec) Heating-side individual heat transfer coefficient αH = 0.0486 to 0.0525 (average 0.0506) Cooling-side individual heat transfer coefficient αC = 0.0759 to 0.0763 (average 0.0761) Calculation final F value Fc = 9.2 to 10.3 (average 9.75) Actual measurement final F value F = 9.2 110.3 (average 9.75) (Determining planned sterilization conditions for production machines) Planned sterilization temperature 120 ° C Planned sterilization conditions Ft = 7 (Product temperature used for production machines) Setting data) of the initial product temperature tp ₀ = 45 ° C. or higher to apply the delay time [delta] = 30 sec heating side individual heat transfer coefficient .alpha.H = 0.0506 cooling side individual heat transfer coefficient αC = 0.0761 (F value control with retort production machine results in Nita Data) (See Fig. 4) Initial temperature tp ₀ = 45.2 ° C Calculation cooling F value Fr = 0.62 Calculation control F value Fs = 7-0.62 = 6.38 or more Sterilization temperature maintenance time 17.5 min Calculation final F value Fc = 7.10 Actual measurement final F Value F = 7.59 (Result data when steam pressure drop occurs in the above retort production machine) (See Fig. 5) Steam pressure drop point: 2 minutes after cam-up Steam pressure return point: 3 minutes after drop Return time to temperature: 2 minutes after steam pressure return Initial product temperature tp ₀ = 45.2 ° C Calculation cooling F value Fr = 0.62 Calculation control F value Fs = 7-0.62 = 6.38 or more Sterilization temperature maintenance time 19.5 min Calculation final F value Fc = 7.24 Final measured F value F = 7.67 Result data retort production machine the sterilization process was programmed temperature control) (see FIG. 6) products arbitrarily set the temperature temperature curve and the cooling curve of the temperature, in advance to determine the bath temperature curve to be controlled.

Initial product temperature tp ₀ = 45.2 ° C. Calculation cooling F value Fr = 0.62 Calculation control F value Fs = 7−0.62 = 6.38 or more Sterilization temperature maintenance time 13.5 min Calculation final F value Fc = 7.25 Actual measurement final F value F = 7.47 The results of the F value control of the three cases are all within + 10% of the planned sterilization conditions, and the F value control is operating effectively. Moreover, the actually measured final F value is larger than the calculated F value, and there is no problem in safety, and the initial purpose is sufficiently satisfied.

Although the present sample was conventionally processed under the sterilization conditions of 120 ° C. × 20 min, the use of the F value control of the present invention enables processing at about 120 ° C. × 17.5 min. became. The sterilization time is reduced by about 12.5%. Even when the steam pressure drops, the product temperature simulation is continuously performed and the F value control is performed, so that processing can be performed without any problem in most cases. With this F-number control, the sterilization time was extended by 2 minutes for the steam pressure drop of 3 minutes after the cam-up.

In the case where the program temperature control of the bath temperature is incorporated, the sterilization temperature time can be shortened by 32.5%, which sufficiently satisfies the purpose of greatly reducing the time. in this case,
While the tank temperature (tw) passed through the temperature range of 130 ° C for an instant during the temperature rise, there was no problem with the pot, packaging material and food. It can be said that this is planned overshoot control.

[0041]

According to the F value control system of the present invention, overheating in sterilization can be prevented. Furthermore, by incorporating a programmed temperature control system, the sterilization time can be significantly reduced. As the retort sterilizer, a steam type, a hot water type, and a spray (shower) type can be used.

By incorporating the product temperature monitor system into the retort sterilizer, a highly accurate simulated product temperature (tpc) can be obtained in real time from the measured tank temperature (tw) in a non-contact manner, and the calculation of the F value (Fc) can also be performed. Since the operation is performed, the work load is small, and the secure and safe F
Value control is possible. Reverse development is performed using the sequential calculation formula (MAA formula) of the product temperature monitor system, and a tank temperature recipe to be controlled corresponding to the product temperature recipe for the purpose of time reduction, etc. is prepared in advance and input to the retort sterilizer. By controlling the program temperature, the sterilization time can be significantly reduced.

A retort sterilization method with F-value control and sterilization that can prevent unnecessary quality deterioration of packaged foods, etc. by approaching the planned sterilization conditions and significantly shortening the sterilization time as described above. Equipment could be provided.

[Brief description of the drawings]

FIG. 1 is a simulation model of product temperature

FIG. 2 is a model diagram of a sequential calculation graph

FIG. 3 is a diagram showing a change in temperature distribution in a minute time.

FIG. 4 is a graph showing the results of a retort production machine with F-value control.

FIG. 5 is a graph showing a result when a steam pressure drop occurs.

FIG. 6 is a graph showing a result of a retort production machine when a program temperature control is performed.

[Explanation of symbols]

 tw Tank temperature tp Material temperature tpcSimulated temperature  α Individual heat transfer coefficient αH Heating-side individual heat transfer coefficient αC Cooling-side individual heat transfer coefficient MAA formula Basic formula (sequential calculation formula) tpA Infusion bag 100cc tpB Chicken soup 200g Pouch tpC Gala extract No.2 can tpD Chinese style soup 1kg Pouch tpE Curry sauce 1kg Pouch tpF Sesame tofu injection

Claims (3)

(57) [Claims] 1. Based on a signal from a retort testing machine loaded with packaged food or infusion, etc., the measured tank temperature (tw) (temperature of the heat transfer medium of the packaged food, etc.) and the measured product temperature (tp) (packaged food, etc.) Means for accumulating each data of internal temperature), and after completion of the sterilization step, the individual heat transfer coefficient of the packaged food or the infusion from the accumulated data.
means for calculating (α), means for displaying the calculation result,
Simulated product temperature (tp) using the individual heat transfer coefficient (α)
c) means for calculating a simulated product temperature curve, and calculating the simulated product temperature curve from the measured bath temperature (tw) and the measured product temperature.
(tp) means for displaying on the data curve, and a retort sterilizer incorporating a temperature monitoring system for packaged foods or infusions, etc., in the control unit, comprising: a packaged food or a packaged food determined in advance by a retort tester. The individual heat transfer coefficient (αH) and the individual heat transfer coefficient (α
C) and the measured tank temperature from the retort sterilizer
A means for calculating the simulated product temperature (tpc) in real time for (tw) and calculating the F value (Fc) is provided, and when the control F value (Fs) is reached in the sterilization process, the sterilization process ends and cooling is performed. A retort sterilization method with F-value control, characterized by shifting to a process. (2)Individual heat transfer in product temperature monitoring system
Calculate the simulated product temperature (tpc) using the coefficient (α),
The following basic formula is used to draw the simulated temperature curve.
2. The F according to claim 1, wherein (a sequential calculation formula-MAA formula) is used.
Retort sterilization method with value control. Basic formula (Sequential calculation formula-MAA formula): tpn = tpn-1 + Δtpn (1) Δtpn = α × Δtwn + (1−α) × Δtpn-1 (2) Code explanation: tpn: current product temperature (° C)  tpn-1: previous product temperature in sequential calculation (° C)  Δtpn: Change in product temperature that contributed to reaching the current product temperature (° C) Δtpn-1: Change in product temperature that contributed to reaching the previous product temperature (° C)  α: Individual heat transfer coefficient per specified time (dimensionless number)  twn: Current bath temperature (° C)  Δtwn: Change in bath temperature that contributed to reaching the current bath temperature (° C) 3. Based on a signal from a retort tester loaded with packaged food or infusion, etc., the measured tank temperature (tw) (temperature of the heat transfer medium of the packaged food, etc.) and the measured product temperature (tp) (packaged food, etc.) Means for accumulating each data of internal temperature), and after completion of the sterilization step, the individual heat transfer coefficient of the packaged food or the infusion from the accumulated data.
means for calculating (α), means for displaying the calculation result,
Simulated product temperature (tp) using the individual heat transfer coefficient (α)
c) means for calculating a simulated product temperature curve, and calculating the simulated product temperature curve from the measured bath temperature (tw) and the measured product temperature.
(tp) means for displaying on the data curve, and a retort sterilizer incorporating a temperature monitoring system for packaged foods or infusions in the control unit, comprising a packaged food or infusion determined in advance by a retort tester. Heating-side individual heat transfer coefficient (αH) and cooling-side individual heat transfer coefficient (αH
C) and the measured tank temperature from the retort sterilizer
means for calculating the simulated product temperature (tpc) in real time for (tw) and calculating the F value (Fc);
(Fs), when the sterilization process is completed, the retort sterilization control means with F value control that shifts to the cooling process is incorporated in the control unit, and is characterized by a hot water type, a steam type, and a spray type. And other retort sterilizers.