JPS6332433B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The method of the present invention mainly relates to a pressurizing method in steam retort sterilization for heating and sterilizing foods.

Conventional configurations and their problems In the case of steam-type retort sterilization methods, conventionally pressurized air was directly injected into the processing tank, or when steam was introduced, air was introduced into the piping to mix the steam and air. The method used was to introduce heated air (The Theory and Practice of Retort Foods, written by Ushio Shimizu and Rio Yokoyama, published by Koshobo Co., Ltd. on May 1, 1970,
P.73-76 reference).

However, with this method, temperature uniformity within the processing tank cannot be achieved, and when pressurized air is injected into the tank, mixing is not performed smoothly due to the difference in specific gravity between the steam and air. There were problems such as difficulty in controlling the temperature and pressure inside.

Purpose of the Invention The present invention solves the above-mentioned problems of the conventional method, and provides a two-tank system including a processing tank and a preheating tank, as well as a steam retort sterilizer that can easily control the temperature and pressure inside the processing tank. The purpose of this paper is to provide a pressure method.

Structure of the Invention In order to achieve the above-mentioned object, the present invention is a steam retort sterilization method in which a product is loaded into a processing tank and heated with steam, in which a preheating tank as a pressure vessel is provided in addition to the processing tank, allowing communication between the two. The inside of the preheating tank is preheated with steam in advance, a predetermined amount of pressurized air is injected into the preheating tank, and after preheating, this pressurized air is supplied as pressurized air to the processing tank. This method is used to pressurize steam retort sterilization.

Therefore, during the heating process in the processing tank, it has become possible to inject into the processing tank pressurized air at a uniform temperature that has been preheated and pressurized in a separate preheating tank as a pressurizing process. Pressure and heating can be easily adjusted in the preheating tank, and uniform pressurization and heating can be achieved by injecting this into the processing tank.

DESCRIPTION OF EMBODIMENTS Hereinafter, drawings shown as embodiments will be described.

Reference numeral 1 denotes a processing tank, which serves as a retort into which the object 2 to be heated and sterilized, such as food, is placed and processed. 3 is a preheating tank, which is communicated with the processing tank 1 through an injection pipe 4. The upper end of the injection pipe 4 is arranged in the preheating tank 3 so as to open at the upper end. S indicates steam, A indicates air, D indicates drain, and HA indicates preheated pressurized air.

Figure 1 shows the process of steam retort sterilization.
A shows the degassing process, B shows the temperature raising process, C shows the heating process, and D shows the cooling process. In the treatment tank 1, steam S is injected while degassing is performed as a degassing process (a), and a temperature raising process (b) is started. Next, the product enters a heating process (c), where it is sterilized by heating for a certain period of time, and after being cooled in a cooling process (d), the product is taken out.

In the present invention, a separate preheating tank 3 is provided in addition to the processing tank 1, and the two can communicate with each other through a connecting pipe. The preheating tank 3 is filled with steam in advance and heated to a predetermined temperature, and pressurized air is fed into the preheating tank 3 to obtain pressurized air.

In the processing tank 1, before starting the heating process, the preheating tank 3
The pressurized air prepared in step 1 was injected into the processing tank via the connecting pipe 4.

With the above configuration, during the heating process in the processing tank, air for pressure adjustment enters the processing tank through the connecting pipe, making it easy to adjust the pressure. In addition, since the connecting pipe was installed in the preheating tank so that it opened near the top end, only the air warmed in the preheating tank was selectively injected into the processing tank, ensuring uniform pressure and heating temperature. Now I can get it.

When the pressure in the processing tank decreases during the heating process, air from the preheating tank enters the processing tank and is pressurized, so that a uniform pressurized state is always obtained. Also, when the temperature of the preheating tank drops, steam is injected to heat it, making uniform pressure and heating possible.

What is shown in Fig. 2 is the result of measuring the temperature in the processing tank at four points and calculating the F value by a computer from the temperature at each point.When compared with the conventional example shown in Fig. 3, It is clear that the F value due to the pressurization method of the present invention is extremely uniform. That is, in FIGS. 2 and 3, the calculated values shift from right to left, where A indicates the temperature inside the processing tank and B indicates the F value.

In the method of the present invention shown in FIG. 2, the temperature inside the tank is set at 120°C, showing a state with no variation, but in the conventional example shown in FIG.
℃ temperature difference, and when using the method of the present invention regarding the F value, a constant F value can be obtained from the sensors placed in four locations on the product placed in the processing tank, as shown in Figure 2 B.
A graph showing the values was obtained.

In this example, the F value is calculated at a heating temperature of 120℃,
Z value = 18°F, sterilization temperature = 250°F.

As shown in FIG. 3B, in the conventional example, the F values from the sensors inserted at four locations on the product in the processing tank vary.

Effects of the Invention As described above, when the method of the present invention is used, uniform pressure treatment in the processing tank is facilitated in steam retort sterilization, and breakage of the bags can be prevented even when the food is in the form of a pouch. Also, there is no temperature variation,
Uniform heating can be achieved. Therefore, there is no need to set a high temperature in consideration of the safety factor based on the F value, making it possible to sterilize in a short time and improve food quality.
Moreover, the effects are excellent, such as the fact that temperature and pressure can be easily controlled using pressurized air that is regulated in a preheating tank provided separately from the processing tank.

[Brief explanation of drawings]

FIG. 1 is a process diagram of steam retort sterilization, together with the process of the preheating tank used in the method of the present invention.
FIGS. 2 and 3 are computer plots of heating temperature and F value. 1... Processing tank, 2... Product, 3... Preheating tank, 4
...Connection piping, S...Steam, A...Air, HA...
...pressurized air.

Claims (1)

[Scope of Claims] 1. In a steam retort sterilization method in which a product is loaded into a processing tank and heated with steam, a preheating tank as a pressure vessel is provided in addition to the processing tank so that the two can communicate with each other, and the preheating tank The inside of the processing tank is preheated in advance with steam, a predetermined amount of pressurized air is injected into the preheating tank, and after preheating, this pressurized air is supplied to the processing tank as pressurized air. Pressure method for steam retort sterilization. 2. The steam according to claim 1, wherein when pressurized air prepared in advance in the preheating tank is injected into the processing tank, the steam is communicated with the processing tank via a connecting pipe opened near the upper end of the preheating tank. Pressure method in retort sterilization.